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Comparison of Positional Therapy to CPAP in Patients with Positional Obstructive Sleep Apnea
Abstract
We hypothesized that positional therapy would be equivalent to continuous positive airway pressure (CPAP) at normalizing the apnea-hypopnea index (AHI) in patients with positional obstructive sleep apnea (OSA).
Thirty-eight patients (25 men, 49 +/- 12 years of age, body mass index 31 +/- 5 kg/m2) with positional OSA (nonsupine AHI <5 events/h) identified on a baseline polysomnogram were studied. Patients were randomly assigned to a night with a positional device (PD) and a night on CPAP (10 +/- 3 cm H2O).
Positional therapy was equivalent to CPAP at normalizing the AHI to less than 5 events per hour (92% and 97%, respectively [p = 0.16]). The AHI decreased from a median of 11 events per hour (interquartile range 9-15, range 6-26) to 2 (1-4, 0-8) and 0 events per hour (0-2, 0-7) with the PD and CPAP, respectively; the difference between treatments was significant (p < 0.001). The percentage of total sleep time in the supine position decreased from 40% (23%-67%, 7%-82%) to 0% (0%-0%, 0%-27%) with the PD (p < 0.001) but was unchanged with CPAP (51% [36%-69%, 0%-100%]). The lowest SaO2 increased with the PD and CPAP therapy, from 85% (83%-89%, 76%-93%) to 89% (86%-9%1, 78%-95%) and 89% (87%-91%, 81%-95%), respectively (p < 0.001). The total sleep time was unchanged with the PD, but decreased with CPAP, from 338 (303-374, 159-449) minutes to 334 (287-366, 194-397) and 319 (266-343, 170-386) minutes, respectively (p = 0.02). Sleep efficiency, spontaneous arousal index, and sleep architecture were unchanged with both therapies.
Positional therapy is equivalent to CPAP at normalizing the AHI in patients with positional OSA, with similar effects on sleep quality and nocturnal oxygenation.
... Summary of the evidence For PICOs 7 and 8, 1632 studies were originally identified, five of them for PICO 7, including 221 participants who were randomised to either positional therapy or CPAP (supplementary figures e7 and e12, supplementary tables e10 and e18) [78][79][80][81][82][83][84]. For the definition of positional OSA, all studies shared the criterion of the supine AHI to be at least twice as high as the nonsupine AHI. ...
... In one study (n=13), positional therapy consisted of a backpack with a soft ball inside [78]. A similar backpack-like device was used by PERMUT et al. [79] (n=38). Another study (n=20) applied the "tennis ball technique" (TBT) [81]. ...
... All but one study [79] did not exclude patients with severe OSA. However, considering the mean baseline AHI, these studies were in the range of moderate OSA (AHI 15-30 events·h −1 ). ...
Treatment of obstructive sleep apnoea (OSA) in adults is evolving, as new therapies have been explored and introduced in clinical practice, while other approaches have been refined or reconsidered. In this European Respiratory Society (ERS) guideline on non-continuous positive airway pressure (CPAP) therapies for OSA, we present recommendations determined by a systematic review of the literature. It is an update of the 2011 ERS statement on non-CPAP therapies, advanced into a clinical guideline. A multidisciplinary group of experts, including pulmonary, surgical, dentistry and ear–nose–throat specialists, methodologists and patient representatives considered the most relevant clinical questions (for both clinicians and patients) relating to the management of OSA. Eight key clinical questions were generated and a systematic review was conducted to identify published randomised clinical trials that answered these questions. We used the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach to assess the quality of the evidence and the strength of recommendations. The resulting guideline addresses gastric bypass surgery, custom-made dual-block mandibular advancement devices, hypoglossal nerve stimulation, myofunctional therapy, maxillo-mandibular osteotomy, carbonic anhydrase inhibitors and positional therapy. These recommendations can be used to benchmark quality of care for people with OSA across Europe and to improve outcomes.
... In 1984, Cartwright was the first to randomly define positional apnea as one in which the supine AHI is at least twice as high as the non-supine AHI. 19,20 Notably, the medical literature cites several modified versions of Cartwright's classification. [18][19][20] Regardless of the classification used, it has already been demonstrated that a significant number of patients experience a marked effect of position on desaturations, cyclic variations on heart rate, loud snoring, and apneas and hypopneas, as demonstrated in 2017 by Ravesloot et al. ...
... 19,20 Notably, the medical literature cites several modified versions of Cartwright's classification. [18][19][20] Regardless of the classification used, it has already been demonstrated that a significant number of patients experience a marked effect of position on desaturations, cyclic variations on heart rate, loud snoring, and apneas and hypopneas, as demonstrated in 2017 by Ravesloot et al. 21 The high prevalence of position-dependent obstructive sleep apnea (POSA) points to the importance of evaluating the impact on the diagnosis of a device that, in principle, would enable the patient to spend less time in the supine position. ...
Introduction The prevalence of moderate to severe sleep-disordered breathing is of 17% among men aged between 50 and 70-years, and of 9% among women in the same age group. In Brazil, obstructive sleep apnea (OSA) is also highly prevalent, and it is associated with metabolic and cardiovascular impacts, excessive daytime sleepiness, and increasing risk of traffic accidents. Laboratory-based polysomnography is the gold standard test for OSA diagnosis. However, its complexity has led to the search for alternatives to simplify the diagnosis, such as the out-of-center sleep test (OCST).
Objectives To discusses the minimum OCST recording time and the potential effects of the supine position on this parameter.
Data Synthesis We conducted a search on the PubMed, Web of Science, Scopus, and Embase databases to identify relevant studies on OCST recording time and a possible association with body position. We used a combination of terms, including Obstructive Sleep Apnea and Home Monitoring OR Home Care Services OR Portable Monitoring AND Supine OR Position OR Recording Time OR Positional Obstructive Sleep Apnea . The references of the selected articles were also reviewed to find other relevant studies. Through our approach, eighteen articles were retrieved and included in the present study.
Conclusion Since OCSTs are conducted in an unattended environment, with potential signal loss during the night, it is crucial to determine the minimum recording time to validate the test and assess how the time spent in the supine position affects this parameter. After reviewing the literature, this topic remains to be clarified, and additional studies should focus on that matter.
... This socalled positional OSA (POSA) is defined as a two-fold increase in AHI in supine compared to non-supine position and mostly with an AHI < 5 in non-supine position. [9][10][11] Using this definition, Mador et al. observed that POSA is widespread in patients with OSA and related to the severity of OSA: 49.5% in mild OSA, 19.4% in moderate OSA, and 6.5 % in severe OSA. 10 Positional therapy (PT) is defined as preventing patients from sleeping in the supine sleeping position. The traditional PT method is the 'tennis ball technique', which involves sewing a tennis ball into the back of a shirt worn during sleep, so that the discomfort from lying on the tennis ball will force the patient into a non-supine position. ...
... Positional therapies are simple and can be effective tools in positional obstructive sleep apnea treatment. [12][13][14][15]24 Permut et al. 9 demonstrated that the effects of position therapy were comparable to CPAP treatment, but more convenient to use. Positional therapy devices include chest or lumbar blinders, full-length cushions, a tennis ball attached to the back of nightwear, semirigid backpacks, and electric sensors that alert when people change position. ...
Objectives: Positional obstructive sleep apnea (POSA) is common and affects sleep quality. This study was to identify the efficacy of using a Thai traditional triangle cushion as a position device for therapy in POSA. Methods: This open-label, self-control, prospective intervention study enrolled adult patients with POSA. The 8-weeks positional advice was performed, followed by 8-weeks using a Thai triangle cushion. Study outcomes were to measure changes in Epworth sleepiness scale (ESS) scores and 36-Item Short Form Health Survey (SF-36) and problems/complaints during the study. Results: There were 10 patients enrolled in total, with a mean age of 55.8 years old (SD 11.3), with an average apnea-hypopnea index (AHI) of 26.1, a supine AHI of 35.3, a non-supine AHI of 8.6 and the average baseline ESS was 10 (SD3.5). The positional advice did not improve the ESS score from baseline [the mean difference in ESS score of +0.20 (95%CI-2.01 to 2.41, p-value 0.84)]. Using cushion intervention significantly reduced the ESS score from baseline [-3.6 (95%CI-5.00 to-2.20), p-value<0.001]. The period of using a cushion (intervention) also significantly reduced the ESS score when compared with the period of positional advice (control), with an ESS reduction of -3.8 (95%CI-6.47 to-1.13), p-value 0.011. The quality of life is improved only during the period of using a cushion. There were no complaints from the patients related to positional advice or using the intervention cushion. Conclusions: The Thai traditional triangle cushion, as a positional device in treating patients with positional obstructive sleep apnea, is effective and comfortable.
... Several strategies including positional therapy have been explored [2][3][4]. Traditional positional therapy refers to avoiding the supine position, improving OSA severity in 25 to 60% of patients [4,5]. However, this positional therapy may be discomfortable during sleep and poorly tolerated. ...
Purpose
Head rotation is an effective positional therapy for obstructive sleep apnea (OSA). However, not all OSA patients benefit from head rotation. This study aimed to explore the clinical phenotype of OSA patients who can benefit from head rotation.
Methods
We performed a retrospective review of 184 consecutive OSA patients who underwent polysomnography. Head rotation in supine position was determined by high-quality video recording. According to the changes in apnea–hypopnea index (AHI) after head rotation, OSA patients were divided into two groups: patients with response to head rotation(HR) and patients without response to head rotation(NHR). Demographic factors and overnight polysomnography were analyzed.
Results
Compared with NHR group, HR group showed significantly lower AHI (51.8 vs 31.5, p < 0.01), time spent with oxygen saturation below 90%(5.3% vs 0.51%, p < 0.01), and higher lowest oxygen saturation(80% vs 86%, p < 0.05). Logistic regression showed that AHI was an independent factor to predict the decrease of AHI in head rotation (OR 0.985, 95% CI 0.970–0.979, p < 0.05). Among mild to moderate group (AHI < 30/h), severe group (30/h ≤ AHI < 60/h), and extremely severe group (AHI ≥ 60/h), the percentage decrease of AHI in head rotation was 18.5%, 9.5%, and 2.6%, respectively. Surprisingly, the percentage decrease of AHI of 6 responders in mild to moderate group was more than 50%.
Conclusion
OSA patients who respond well to head rotation have less severe disease, and patients with mild to moderate OSA are more likely to improve and benefit from this position. Our research provides potential strategies and insights into the individual treatment of OSA patients.
... There is an increasing body of evidence to support PT as an effective strategy in treating OSA, especially mild to moderate OSA [12,15]. PT also effectively lowers AHI and reduces CPAP pressures, and it was found to be equivalent to CPAP in patients with POSA [16][17][18]. Furthermore, patients with POSA and e-POSA had a significantly lower likelihood of treatment adherence (PAP daily use ≥ 4 h) at 6 months and were at higher risk of PAP treatment withdrawal than those without POSA [19]. Heinzer et al. [10] reported in a large population-based study that POSA accounted for 75% of OSA subjects, while e-POSA was present in 36% of OSA subjects, recommending that a large proportion of OSA patients could be treated with PT and again underscoring the importance of establishing the diagnosis of POSA. ...
Purpose
Positional obstructive sleep apnoea (POSA) is of important clinical significance, as positional treatment can augment or obviate continuous positive airway pressure. This study aimed to determine the prevalence of POSA and its characteristics using different definitions.
Methods
We retrospectively examined a cohort of patients who underwent polysomnography (PSG) between 2013 and 2019 at two sleep centres. Demographic data and PSG data were collected from 624 patients with an apnoea–hypopnea index (AHI) ≥ 5. POSA was defined using different criteria as follows: (1) AHI of at least twice as high in the supine position as in the lateral position (Cartwright’ s definition). (2) A supine AHI ≥ 10 and a lateral AHI < 10 (Marklun’s definition). (3) AHI of at least twice as high in the supine position than in the lateral position, with the lateral AHI not exceeding 5 (Mador’s definition or Exclusive POSA; e-POSA). (4) AHI ≥ 15/h; a supine AHI ≥ twice that of the nonsupine AHI ≥ 20 min of sleep in the supine and nonsupine positions; and a nonsupine AHI < 15 (Bignold’s definition).
Results
The prevalence of POSA was 54% (Cartwright), 38.6% (Mador), 33.8% (Marklund) and 8.3% (Bignold). Multivariate regression analysis showed a body mass index (BMI) < 35 kg/m ² was the only significant predictor of POSA. Mador’s definition had the highest diagnostic yield (sensitivity 63%; specificity 100%; area under the receiver operating characteristic curve 90.2%).
Conclusion
POSA is common, but its prevalence depends on the definition used. Low BMI was identified as a significant predictor.
... As a result, OSA severity may vary significantly depending on a body position during sleep. In some patients, lateral sleep position can improve or even resolve OSA (Permut et al., 2010;de Vries et al., 2015;Barnes et al., 2017). However, the efficacy of positional treatment is inferior to CPAP therapy. ...
Obstructive sleep apnea (OSA) is a disease that results from loss of upper airway muscle tone leading to upper airway collapse during sleep in anatomically susceptible persons, leading to recurrent periods of hypoventilation, hypoxia, and arousals from sleep. Significant clinical consequences of the disorder cover a wide spectrum and include daytime hypersomnolence, neurocognitive dysfunction, cardiovascular disease, metabolic dysfunction, respiratory failure, and pulmonary hypertension. With escalating rates of obesity a major risk factor for OSA, the public health burden from OSA and its sequalae are expected to increase, as well. In this chapter, we review the mechanisms responsible for the development of OSA and associated neurocognitive and cardiometabolic comorbidities. Emphasis is placed on the neural control of the striated muscles that control the pharyngeal passages, especially regulation of hypoglossal motoneuron activity throughout the sleep/wake cycle, the neurocognitive complications of OSA, and the therapeutic options available to treat OSA including recent pharmacotherapeutic developments.
... With the strong association of OSA to cardiovascular disease, such as AF and HF, and with the high prevalence of POSA, patients who are unable to tolerate or unwilling to try CPAP should be considered for PT. In patients with POSA, PT has been shown to be as effective as CPAP in normalizing AHI, improving nocturnal oxygenation, and improving sleep quality [31]. However, despite the efficacy of PT, adherence over time has been generally poor [32]. ...
Purpose
Obstructive sleep apnea (OSA) is a common, potentially modifiable condition implicated in the pathogenesis of atrial fibrillation (AF). The presence and severity of OSA is largely sleep position–dependent, yet there is high variability in positional dependence among patients with OSA. We investigated the prevalence of positional OSA (POSA) and examined associated factors in patients with AF.
Methods
We recruited an equal number of patients with and without AF who underwent diagnostic polysomnography. Patients included had ≥ 120 min of total sleep time with 30 min of sleep in both supine and lateral positions. POSA was defined as an overall apnea hypopnea index (AHI) ≥ 5/h, supine AHI (sAHI) ≥ 5/h, and sAHI greater than twice the non-supine AHI. POSA prevalence was compared in patients with and without AF adjusting for age, sex, OSA severity, and heart failure.
Results
A total of patients (male: 56%, mean age 62 years) were included. POSA prevalence was similar between the two groups (46% vs. 39%; p = 0.33). Obesity and severe OSA (AHI ≥ 30/h) were associated with low likelihood of POSA (OR [CI] of 0.17 [0.09–0.32] and 0.28 [0.12–0.62]). In patients with AF, male sex was associated with a higher likelihood of POSA (OR [CI] of 3.16 [1.06–10.4]).
Conclusion
POSA is common, affecting more than half of patients with AF, but the prevalence was similar in those without AF. Obesity and more severe OSA are associated with lower odds of POSA. Positional therapy should be considered in patients with mild OSA and POSA.
... Patients had to sleep with a bulky mass strapped to their back to prevent them from sleeping in the supine position. This technique has been shown to be effective in reducing supine sleep time and occurrence of respiratory events but appeared to have a very low compliance rate (about 10%) when prescribed for long term use (Bignold et al. 2009;Permut et al. 2010). Shoulder, neck or back complaints that restrict certain sleeping positions form a contraindication for PT. ...
... A high continuous positive airway pressure setting may even cause central sleep apnoea in some patients due to elevated carbon dioxide excretion [31]. Furthermore, the individuals who demonstrated a high ∆Supine% in the hospital but low values at home may have positional OSA, and they may therefore be able to consider positional therapy as a treatment option [32]. ...
Obstructive sleep apnoea (OSA) is a global health concern, and polysomnography (PSG) is the gold standard for assessing OSA severity. However, the sleep parameters of home-based and in-laboratory PSG vary because of environmental factors, and the magnitude of these discrepancies remains unclear. We enrolled 125 Taiwanese patients who underwent PSG while wearing a single-lead electrocardiogram patch (RootiRx). After the PSG, all participants were instructed to continue wearing the RootiRx over three subsequent nights. Scores on OSA indices—namely, the apnoea–hypopnea index, chest effort index (CEI), cyclic variation of heart rate index (CVHRI), and combined CVHRI and CEI (Rx index), were determined. The patients were divided into three groups based on PSG-determined OSA severity. The variables (various severity groups and environmental measurements) were subjected to mean comparisons, and their correlations were examined by Pearson’s correlation coefficient. The hospital-based CVHRI, CEI, and Rx index differed significantly among the severity groups. All three groups exhibited a significantly lower percentage of supine sleep time in the home-based assessment, compared with the hospital-based assessment. The percentage of supine sleep time (∆Supine%) exhibited a significant but weak to moderate positive correlation with each of the OSA indices. A significant but weak-to-moderate correlation between the ∆Supine% and ∆Rx index was still observed among the patients with high sleep efficiency (≥80%), who could reduce the effect of short sleep duration, leading to underestimation of the patients’ OSA severity. The high supine percentage of sleep may cause OSA indices’ overestimation in the hospital-based examination. Sleep recording at home with patch-type wearable devices may aid in accurate OSA diagnosis.
... Recent studies have shown that changing to a lateral sleeping position can decrease the AHI for patients with positional sleep apnea [4]. This behavioral intervention is known as "positional therapy," and is an effective noninvasive and nonpharmaceutical treatment for those with positional sleep apnea [5]. ...
Background
Sleep apnea is a respiratory disorder characterized by frequent breathing cessation during sleep. Sleep apnea severity is determined by the apnea-hypopnea index (AHI), which is the hourly rate of respiratory events. In positional sleep apnea, the AHI is higher in the supine sleeping position than it is in other sleeping positions. Positional therapy is a behavioral strategy (eg, wearing an item to encourage sleeping toward the lateral position) to treat positional apnea. The gold standard of diagnosing sleep apnea and whether or not it is positional is polysomnography; however, this test is inconvenient, expensive, and has a long waiting list.
Objective
The objective of this study was to develop and evaluate a noncontact method to estimate sleep apnea severity and to distinguish positional versus nonpositional sleep apnea.
MethodsA noncontact deep-learning algorithm was developed to analyze infrared video of sleep for estimating AHI and to distinguish patients with positional vs nonpositional sleep apnea. Specifically, a 3D convolutional neural network (CNN) architecture was used to process movements extracted by optical flow to detect respiratory events. Positional sleep apnea patients were subsequently identified by combining the AHI information provided by the 3D-CNN model with the sleeping position (supine vs lateral) detected via a previously developed CNN model.
ResultsThe algorithm was validated on data of 41 participants, including 26 men and 15 women with a mean age of 53 (SD 13) years, BMI of 30 (SD 7), AHI of 27 (SD 31) events/hour, and sleep duration of 5 (SD 1) hours; 20 participants had positional sleep apnea, 15 participants had nonpositional sleep apnea, and the positional status could not be discriminated for the remaining 6 participants. AHI values estimated by the 3D-CNN model correlated strongly and significantly with the gold standard (Spearman correlation coefficient 0.79, P
... Positional device therapy is an effective management strategy that is increasingly recognized and utilized as an alternative treatment for POSA in adult populations [16e18]. A previous study in an adult population with mild to moderate OSA demonstrated equivalency to CPAP at normalizing the apneahypopnea index (<5 events/hour) [16]. However, there is no efficacy data on the use of positional devices for the management of OSA in children. ...
Background
There is a critical gap in identifying effective interventions for children with obstructive sleep apnea (OSA) who do not tolerate continuous positive airway pressure therapy. Positional OSA (POSA) is a common clinical phenotype whereby OSA occurs predominantly while sleeping in supine position. POSA may be amenable to treatment with a positional device, a belt worn around the chest with cushions on the back to prevent supine positioning, but no data exists in children. The primary aim of this study was to evaluate the efficacy of positional device therapy for the treatment of POSA in children.
Methods
In this observational study, children aged 4-18 years with POSA and an obstructive apnea-hypopnea index (OAHI) ≥ 5 events/hour on baseline polysomnography (PSG) underwent a second PSG to evaluate the efficacy of a positional device. The primary outcome was the change in OAHI.
Results
Ten children were included (8 male, median age 11.2 years, median body mass index z-score 1.6). Compared to the baseline PSG, PSG data obtained while using a positional device showed a reduced median (interquartile range) OAHI (15.2 [8.3-25.6] versus 6.7 [1.0-13.7] events/hour respectively; p=0.004) and percentage of total sleep time in supine position (54.4 [35.0-80.6]% versus 4.2 [1.1-25.2]% respectively; p=0.04). Despite observed improvements in the oxygen desaturation index, these results were not statistically significant.
Significance and Conclusions
In this novel pilot study, positional device therapy was effective for the treatment of POSA. Positional device therapy may potentially change clinical practice as a cost-efficient and non-invasive treatment option for POSA.
... 6 Positional therapy has proven to be effective in alleviating P-OSAHS. [7][8][9] The efficacy of P-OSAHS is limited as some patients continue to suffer greatly in the nonsupine position. ...
Background
Positional obstructive sleep apnea hypopnea syndrome (P-OSAHS) is a distinct OSAHS type. Whether velopharyngeal surgery is efficacious for patients with P-OSAHS remains unclear.
Aim/Objective
To investigate the efficacy and factors influencing velopharyngeal surgery for treatment of patients with P-OSAHS, defined as the apnea hypopnea index (AHI) in different body postures (supine AHI ≥2*nonsupine AHI).
Materials and Methods
A total of 44 patients with P-OSAHS who underwent velopharyngeal surgery were retrospectively studied. The clinical data of these patients, including polysomnography (PSG), physical examination, and surgical information, were collected for analysis. All patients underwent a PSG about 6 months after surgery to determine the treatment outcomes.
Results
The overall AHI of the 44 patients decreased from 40.2 ± 18.7 events/h to 18.5 ± 17.5 events/h after surgery ( P < .001). There were 29 responders (65.9%) according to the classical definition of surgical success. The percentage of sleep time with oxygen saturation below 90% (CT90) was the only predictive parameter for surgical success ( P = .014, odds ratio value = 0.894). There was no significant difference between the change in supine AHI (−55.9 ± 35.2%) and the change in nonsupine AHI (−43.4 ± 74.1%; P = .167), and these 2 parameters were significantly correlated ( r = 0.616, P < .001). Among the 38 patients with residual OSAHS (residual AHI ≥5), 28 had persistent P-OSAHS, and the percentage was as high as 82.4%.
Conclusions and Significance
Patients with P-OSAHS with a lower CT90 value are more likely to benefit from velopharyngeal surgery. Positional therapy could be indicated for most of the patients who are not cured by such surgery.
... The PrenaBelt is worn at the level of the waist and has two back pockets each containing two rigid, hollow, polyethylene balls held securely in place by a foam insert (figure 1.). The theoretical mechanism of the Prena-Belt is based on the tennis-ball technique of positional therapy [39][40][41] : when supine, the balls apply pressure points across the user's lower back, prompting her to reposition herself in a lateral position to maintain comfort. The sham-PrenaBelt was identical in appearance, materials and construction to the PrenaBelt, but had soft foam balls instead of firm plastic balls and did not have foam inserts. ...
Objective
To evaluate the effect, on birth weight and birth weight centile, of use of the PrenaBelt, a maternal positional therapy device, during sleep in the home setting throughout the third trimester of pregnancy.
Design
A double-blind, sham-controlled, randomised clinical trial.
Setting
Conducted from September 2015 to May 2016, at a single, tertiary-level centre in Accra, Ghana.
Participants
Two-hundred participants entered the study. One-hundred-eighty-one participants completed the study. Participants were women, 18 to 35 years of age, with low-risk, singleton, pregnancies in their third-trimester, with body mass index <35 kg/m ² at the first antenatal appointment for the index pregnancy and without known foetal abnormalities, pregnancy complications or medical conditions complicating sleep.
Interventions
Participants were randomised by computer-generated, one-to-one, simple randomisation to receive either the PrenaBelt or sham-PrenaBelt. Participants were instructed to wear their assigned device to sleep every night for the remainder of their pregnancy (approximately 12 weeks in total) and were provided a sleep diary to track their use. Allocation concealment was by unmarked, security-tinted, sealed envelopes. Participants and the outcomes assessor were blinded to allocation.
Primary and secondary outcome measures
The primary outcomes were birth weight and birth weight centile. Secondary outcomes included adherence to using the assigned device nightly, sleeping position, pregnancy outcomes and feedback from participants and maternity personnel.
Results
One-hundred-sixty-seven participants were included in the primary analysis. The adherence to using the assigned device nightly was 56%. The mean ±SD birth weight in the PrenaBelt group (n=83) was 3191g±483 and in the sham-PrenaBelt group (n=84) was 3081g±484 (difference 110 g, 95% CI −38 to 258, p=0.14). The median (IQR) customised birth weight centile in the PrenaBelt group was 43% (18 to 67) and in the sham-PrenaBelt group was 31% (14 to 58) (difference 7%, 95% CI −2 to 17, p=0.11).
Conclusions
The PrenaBelt did not have a statistically significant effect on birth weight or birth weight centile in comparison to the sham-PrenaBelt.
Trial registration number
NCT02379728 .
... Positional treatment, although still a subject of an ongoing debate regarding the method, feasibility criteria, long-term efficacy and compliance, can be an option in patients with this OSAS endotype. In clinical practice, it means that a positional treatment can be safely tried in this selected group of low SBQ score while awaiting PSG assessment 10,11 . ...
Polysomnography (PSG) is considered the gold standard in obstructive sleep apnea-hypopnea syndrome (OSAS) diagnostics, but its availability is still limited. Thus, it seems useful to assess patients pre-diagnostic risk for OSAS to prioritize the use of this examination. The purpose of this study was to assess positive (PPV) and negative (NPV) predictive values of the STOP BANG questionnaire (SBQ) in patients with presumptive diagnosis of OSAS. From a database of 1,171 (880 men) patients of a university based sleep center, 1,123 (847 men) met eligibility criteria and their SBQ scores were subject to the Bayesian analysis. The analysis of PPV and NPV was conducted at all values of SBQ for all subjects, but also separately for males and females, and for total sleep time (TS) and for sleep in the lateral position (LP). The probability of OSAS (AHI ≥ 5) and at least moderate OSAS (AHI ≥ 15) for TS was 0.766 and 0.516, while for LP the values were 0.432 and 0.289, respectively. Overall, due to low specificity, SBQ had low PPV for TS and LP. Negative test result (SBQ < 3) revealed NPV of 0.620 at AHI < 5 and 0.859 at AHI < 15 for TS, while in LP NPV values were 0.935 at AHI < 5 and 1.0 at AHI < 15, (n = 31), while SBQ < 4 generated NPV of 0.943 in LP (n = 105). SBQ did not change probabilities of OSAS to confirm or rebut diagnosis for TS. However, it is highly probable that SQB can rule out OSAS diagnosis at AHI ≥ 15 for LP.
... (REF) 3 Over time, various modifications have been introduced, including various parameters such as the overall AHI, AHI in the supine and nonsupine position, and time spent in various body positions. [6][7][8][9][10] Patients diagnosed with POSA (PP) benefit from avoiding the supine position, which can be achieved through positional therapy (PT). Various forms of PT exist, varying from the so-called tennis-ball technique to a new generation of PT: vibrotactile feedback devices. ...
Objective
To compare the effect of lateral head rotation to lateral head and trunk rotation on upper airway patency during drug‐induced sleep endoscopy (DISE) in nonpositional obstructive sleep apnea (OSA) patients (NPP) and positional OSA patients (PP).
Methods
Prospective cohort study.
Results
In total 92 patients were included. Seventy‐five patients were male (82%) with a mean age of 47.2 ± 11.3 years, a body mass index of 27.0 ± 3.3 kg/m², and a median apnea–hypopnea index of 16.7 per hour (8.7, 26,5). Of all patients, 75% were PP. Lateral head rotation and lateral head and trunk rotation findings are similar in NPP at each possible level of obstruction, with exception of the oropharynx but not in PP. In PP, lateral head rotation and both lateral head and trunk observations were different at every possible obstruction site.
Conclusion
The effect of lateral head rotation and lateral head and trunk rotation on upper airway patency during DISE is significantly different in PP. In NPP, similar results regarding the degree of upper airway obstruction were found at the level of the velum, tongue base, and epiglottis.
Level of Evidence
2B Laryngoscope, 2018
In the United States, 1%–4% of children have obstructive sleep apnea (OSA), while up to 40% have been reported to snore. OSA is more common in children with obesity, Black race, lower socioeconomic status, male sex, and craniofacial anomalies. Presenting symptoms may include poor school performance, issues with focus and concentration, behavioral issues, apneas, gasping, and daytime sleepiness. Definitive diagnosis remains the polysomnogram, and the primary treatment is typically adenotonsillectomy. When surgery is not a good option, medical therapy may include positive airway pressure, oral appliances, weight loss, medical treatment (like montelukast or nasal steroids), and positional therapy. Surgery may be considered for persistent OSA. Drug-induced sleep endoscopy or cine MRI is typically used to assess for sites of obstruction. Surgery based on site of obstruction typically focuses on the nose, palate, pharynx/tongue base, larynx, or craniofacial surgery.
Dental sleep appliances achieve a 50% response in around 65% of patients with obstructive sleep apnea and a complete response in 35–40%. This means that all practitioners will need to augment the effect of a dental sleep appliance at some stage. There are many ways in which adjunctive therapies can be used to augment both the objective and subjective outcomes of DSA therapy. This chapter discusses the use of multiple adjunct therapies including positional therapies, positive airway pressure therapies, therapies aimed at stabilizing or improving compromised anatomy in the upper airway, and therapies aimed at improving the subjective outcomes of sleep.KeywordsDental sleep applianceObstructive sleep apneaPositional obstructive sleep apneaCognitive behavioral therapy for insomniaCircadian rhythm disordersBright light therapyOral EPAPNasal EPAP
Background:
Evaluation and interpretation of the literature on obstructive sleep apnea is needed to consolidate and summarize key factors important for clinical management of the OSA adult patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA).
Methods:
Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidence-based review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus.
Results:
The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA and treatment on the multiple comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated.
Conclusion:
This review of the literature in OSA consolidates the available knowledge and identifies the limitations of the current evidence. This effort aims to highlight the basis of OSA evidence-based practice and identify future research needs. Knowledge gaps and opportunities for improvement include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy. This article is protected by copyright. All rights reserved.
Purpose
Head rotation is thought to have an effect on obstructive sleep apnea (OSA) severity. However, keeping the head rotated fully during sleep is difficult to maintain, and the effect of head rotation is not the same in all OSA patients. Thus, this study aimed to identify whether less head rotation has an effect on airway patency and determine the responder characteristics to the head rotation maneuver (HRM).
Methods
We recruited 221 patients who underwent overnight polysomnography and drug-induced sleep endoscopy (DISE) in a tertiary hospital from June 2019 to July 2020. Airway patency and the site of airway collapse were determined in the supine position with the head at 0, 30, and 60 degrees of rotation (HRM0°, HRM30°, and HRM60°, respectively) during DISE. The site of collapse was determined using the VOTE classification system: the velum (palate), oropharyngeal lateral walls, tongue base, and epiglottis. Each structure was labeled as 0, 1, or 2 (patent, partially obstructed, and completely obstructed, respectively). Airway response to the HRM30° and 60° and the clinical characteristics associated with airway opening were analyzed.
Results
The study population had a median age of 52 (25–61) years, a body mass index of 26.7(24.6–29.4) kg/m ² , and the apnea-hypopnea index (AHI) of 28.2(13.7–71.9) events/h. HRM influenced airway patency positively not only with HRM60° (p<0.001) but also following limited rotation (HRM30°, p <0.001). Patients with tongue base (40.0% with HRM 60°) and epiglottic (52.6% with HRM 60°) collapse responded particularly well to HRM. Multivariate analysis revealed that lower AHI ( p <0.001) and an absence of oropharyngeal lateral walls collapse ( p = 0.011) were significant predictors of responders to HRM.
Conclusion
Head rotation improved airway obstruction in OSA patients, even with a small degree of rotation, and should be further explored as a potential form of therapy in appropriately selected patients.
Obstructive sleep apnoea (OSA) is challenging medical problem due to its prevalence, its impact on quality of life and performance in school and profession, the implications on risk of accidents and comorbidities and mortality. Current research has carved out a broad spectrum of clinical phenotypes and defined major pathophysiological components. These findings indicate to the concept of personalised therapy, oriented on both the distinct clinical presentation and the most relevant pathophysiology in the individual patient. This leads to the question if sufficient therapeutical options other than positive airway pressure (PAP) alone are available, for which patients they may be useful, if there are specific indications for single or combined treatment, and if there is solid scientific evidence for recommendations. This review describes our knowledge on PAP and non-PAP therapies to address upper airway collapsibility, muscle responsiveness, arousability and respiratory drive. The spectrum is broad and heterogeneous, including technical and pharmaceutical options, already in clinical use or in an advanced experimental stage. Although there is an obvious need for more research on single or combined therapies, the available data demonstrate the variety of effective options, which should replace the unidirectional focus on PAP therapy.
Continuous positive airway pressure (CPAP) is the mainstay treatment option for obstructive sleep apnea (OSA). The upper airway in patients with OSA becomes partially or completely obstructed by an imbalance between collapsing and dilating forces. There is a critical closing pressure demonstrated by equalization of extraluminal and intraluminal pressure of the pharyngeal airway, the segment of the airway prone to collapse, at which collapse of the lumen will occur obstructing the airway. CPAP acts as a pneumatic splint for the upper airway limiting or preventing obstruction. CPAP as therapy for OSA in patients with cardiovascular disorders has been associated with improved outcomes in observational studies, but not in most randomized controlled trials. The uncertainties surrounding the suspected benefit of CPAP use necessitate further investigation.
Purpose
Positional obstructive sleep apnea (POSA) has been defined as a difference of 50% or more in Apnea–Hypopnea Index (AHI) between supine and non-supine position. Sleep position is fundamental in the evaluation of obstructive sleep apnea syndrome (OSAS) severity but most tools used in the diagnosis of OSAS are not free from potential bias in the evaluation of usual sleep positions. The aim of this investigation was to evaluate a novel sleep questionnaire with the purpose of exploring sleep habits and evaluating if sleep assessment can identify the usual body position assumed for sleep.
Materials and methods
The questionnaire was administered to patients recruited from October to November 2018. Questions concerned sleeping positions and conditions that could influence sleeping positions. Patients who had previously undergone polysomnography (PSG) were asked how they slept during the study night. Whenever present during the examination, the patient’s bed partner was also asked about the patient’s usual body positions during sleep.
Results
Of 315 patients (211 men) enrolled, 35% were affected by OSAS and 69% of patients with OSAS had POSA. POSA was more prevalent among men (75%) compared to women (43%). The new questionnaire provided a discordant result from PSG recordings about sleeping positions and revealed a difference between usual sleeping position and the position during PSG recording. Reported sleep quality was much worse on PSG than at home suggesting that the “first night effect” is real and may lead to over-estimation of POSA cases.
Conclusions
Information about sleeping positions is fundamental to the assessment of OSAS severity. Knowledge gained from the new questionnaire as described may represent a valuable addendum to develop a more detailed polygraphic report. Such a tool may be used in practice with the aim of better identifying patients with true positional OSAS. Such patients may benefit from targeted positional therapy.
The prevalence of sleep-disordered breathing (SDB) is reportedly very high. Among SDBs, the incidence of obstructive sleep apnea (OSA) is higher than previously believed, with patients having moderate-to-severe OSA accounting for approximately 20% of adult males and 10% of postmenopausal women not only in Western countries but also in Eastern countries, including Japan. Since 1998, when health insurance coverage became available, the number of patients using continuous positive airway pressure (CPAP) therapy for sleep apnea has increased sharply, with the number of patients about to exceed 500,000 in Japan. Although the “Guidelines for Diagnosis and Treatment of Sleep Apnea Syndrome (SAS) in Adults” was published in 2005, a new guideline was prepared to indicate the standard medical care based on the latest trends, as supervised by and in cooperation with the Japanese Respiratory Society and the “Survey and Research on Refractory Respiratory Diseases and Pulmonary Hypertension” Group, of Ministry of Health, Labor and Welfare and other related academic societies, including the Japanese Society of Sleep Research, in addition to referring to the previous guidelines. Since sleep apnea is an interdisciplinary field covering many areas, this guideline was prepared including 36 clinical questions (CQs). In the English version, therapies and managements for SAS, which were written from CQ16 to 36, were shown. The Japanese version was published in July 2020 and permitted as well as published as one of the Medical Information Network Distribution Service (Minds) clinical practice guidelines in Japan in July 2021.
The prevalence of sleep disordered breathing (SDB) is reportedly very high. Among SDBs, the incidence of obstructive sleep apnea (OSA) is higher than previously believed, with patients having moderate-to-severe OSA accounting for approximately 20% of adult males and 10% of postmenopausal women not only in Western countries but also in Eastern countries, including Japan. Since 1998, when health insurance coverage became available, the number of patients using continuous positive airway pressure (CPAP) therapy for sleep apnea has increased sharply, with the number of patients about to exceed 500,000 in Japan. Although the “Guidelines for Diagnosis and Treatment of Sleep Apnea Syndrome (SAS) in Adults” was published in 2005, a new guideline was prepared in order to indicate the standard medical care based on the latest trends, as supervised by and in cooperation with the Japanese Respiratory Society and the “Survey and Research on Refractory Respiratory Diseases and Pulmonary Hypertension” Group, of Ministry of Health, Labor and Welfare and other related academic societies, including the Japanese Society of Sleep Research, in addition to referring to the previous guidelines. Because sleep apnea is an interdisciplinary field covering many areas, this guideline was prepared including 36 clinical questions (CQs). In the English version, therapies and managements for SAS, which were written from CQ16 to 36, were shown. The Japanese version was published in July 2020 and permitted as well as published as one of the Medical Information Network Distribution Service (Minds) clinical practice guidelines in Japan in July 2021.
Background and Objective Patients with position-dependent obstructive sleep apnea have a > 2-fold higher apnea-hypopnea index when sleeping in a supine position compared with a non-supine position. We investigated the effect of body pillow use on sleeping body position and sleep architecture in healthy young adults.
Methods In experiment 1, we evaluated the body pressure distribution with or without body pillow use in 8 healthy young adults [age, 36.5 ± 13.0 years; body mass index (BMI); 20.6 ± 1.2 kg/m2]. In experiment 2, we performed a randomized-crossover intervention study to evaluate the effects of body pillow use on sleeping position and sleep architecture in 10 healthy young adults (age, 24.3 ± 7.8 years; BMI, 21.4 ± 1.7 kg/m2). Sleep architecture was characterized by polysomnography, and body positions were monitored using a sensor. Subjective sleep quality was evaluated with the Oguri-Shirakawa-Azumi sleep inventory, middle age and aged version.
Results In experiment 1, body pillow use significantly reduced mean body pressure on the shoulder, hip, and whole body. In experiment 2, mean time spent in the supine, lateral, and prone body positions did not differ significantly between the 2 trials. Body pillow use, however, significantly extended the sustained time spent in the lateral body position compared with the control trial. Subjective sleep quality and sleep architecture did not differ significantly between the 2 trials, but body pillow use decreased the number of short (30 s) slow-wave sleep episodes.
Conclusions Sleeping with a body pillow effectively extends sustained time in a lateral sleeping position and prevents segmentation of slow-wave sleep episodes.
Key Words: Body pillow, Sleeping body position, Lateral position, Sleep architecture, Energy expenditure
Rationale:
Approximately 60% of the patients with obstructive sleep apnoea suffer from a positional effect, and approximately 25% of these patients present events only in the supine position.
Objective:
To validate a new positional vibrating device and evaluate its efficacy in reducing the Apnoea-Hypopnoea Index and the total sleep time in the supine position without disturbing sleep.
Methods:
A total of 128 patients were recruited for this multicentre, prospective, parallel, randomised controlled trial and were distributed in three arms (general recommendations, inactive and active device). Full overnight polysomnography was performed at baseline and at 12 weeks. Anthropometric variables and sleep and quality of life questionnaires were collected at 4, 8 and 12 weeks.
Results:
The Apnoea-Hypopnoea Index decreased from 30.6 per hour to 20.4 per hour (p<0.001) in the active device (AD) group. In this group the reduction was 2.3-fold and 3.3-fold than the ones in the general recommendations (GR) and inactive device (ID) groups, respectively (p=0.014). Sleep time in supine position decreased 17.7%±26.3% in GR group (p<0.001), 13.0%±22.4% with ID group (p<0.001) and 21.0%±25.6% in the AD group (p<0.001). Furthermore, total sleep time increased significantly only in the AD group (22.1±57.5 min, p=0.016), with an increased percentage of time in the N3 (deep sleep) and N3+REM (rapid eye movement) stages, without sleep fragmentation.
Conclusion:
The device was effective in reducing the Apnoea-Hypopnoea Index and time spent in the supine position also in improving sleep architecture. Therefore, the device could be a good option for the management of patients with positional obstructive sleep apnoea.
Trial registration details:
The trial was registered at www.clinicaltrials.gov (NCT03336515).
PurposeThe objective of this study was to evaluate the prevalence, the clinical characteristics, and the possible predictors of Chinese patients with positional obstructive sleep apnea (POSA) according to the Amsterdam Positional Obstructive Sleep Apnea Classification (APOC).MethodsA retrospective study in the sleep unit of Peking Union Medical College Hospital was conducted to analyze the clinical and polysomnography data of Chinese patients with obstructive sleep apnea (OSA).ResultsOf 372 patients with OSA, 54% met the APOC criteria for POSA. The prevalence of POSA was significantly higher in women with OSA than in men. Chinese patients with POSA had a lower apnea–hypopnea index, oxygen desaturation index, and the percentage of time spent at oxygen saturation below 90% in total sleep time; and a higher mean oxygen saturation (SaO2) and minimum SaO2 during sleep, which were remarkable in the APOC I group. By multivariate logistic regression analyses, the higher mean SaO2 (≥95%) during sleep and mild and moderate OSA were positive predictors of POSA. Mild and moderate OSA was the independent predictor of POSA in women. Higher mean SaO2 (≥95%) during sleep was the independent predictor of POSA in men.Conclusion
According to the APOC, the prevalence of POSA is high in Chinese patients with OSA, especially in women. Chinese patients with POSA had less severe OSA and a lower degree of nocturnal hypoxia, which was remarkable in the APOC I group.
Purpose of Review
Recognition and treatment of sleep apnea is an important but easily overlooked aspect of care in the heart failure patient. This review summarizes the data behind the recommendations in current practice guidelines and highlights recent developments in treatment options.
Recent Findings
Neuromodulation using hypoglossal nerve stimulation has been increasingly used for treatment of OSA; however, it has not been studied in the heart failure population. Alternatively, phrenic nerve stimulation for treatment of CSA is effective for heart failure patients, and cardiac resynchronization therapy can be effective in improving CSA in pacing-induced cardiomyopathy.
Summary
In patients suspected to have sleep apnea, polysomnography is recommended to better understand the prognosis and treatment options. Positive airway pressure is the standard treatment for sleep apnea; however, neurostimulation can be especially effective in those with predominantly central events. Understanding the pathophysiology of sleep apnea can guide further management decisions.
The interaction between obstructive sleep apnea (OSA), obesity and sleeping position is complex. Obesity explains about 60% of the variance of the apnea hypopnea index (AHI) definition of OSA, mainly in those patients aged < 50 years and less so in the elderly. About 1 in 4 patients with OSA have respiratory events that occur exclusively in the supine sleep position. Weight loss, by either medical or surgical techniques, has a beneficial, yet unpredictable, effect upon sleep apnea, especially in those with a short jaw length. The fall in the overall AHI with weight loss, appears to be associated with a larger drop in the non-supine AHI, than supine AHI, thus converting some patients from non-positional to positional (i.e., supine only) OSA. Side sleeping can be beneficial in such patients as can other positional modifications such as a raised bed head, chin extension and closing of the mouth.
PurposeSleep apnea is a multifactorial illness which can be differentiated in various physiological phenotypes as a result of both anatomical and non-anatomical contributors (e.g., low respiratory arousal threshold, high loop gain). In addition, the frequency and duration of apneas, in the majority of patients with OSA, are influenced by sleeping position. Differences in characteristics between non-positional patients (NPP) and positional patients (PP) suggest another crucial phenotype distinction, a clinical phenotype focusing on the role of sleeping position on sleep apnea. Since this clinical phenotype distinction has therapeutic implications, further research is necessary to better understand the pathophysiology behind this phenotypic trait and to improve management of PP. Therefore, we suggest a standardized framework that emphasizes the role of sleeping position when reporting clinical and research data on sleep apnea.Methods
We identified 5 key topics whereby a standardized framework to report on the role of sleeping position would be of added value: (1) sleep study data, (2) anatomical, morphological and physiological factors, (3) drug-induced sleep endoscopy (DISE) findings, (4) sleep apnea management, and (5) effectiveness versus efficacy of positional therapy in sleep apnea management. We performed a literature search to identify evidence to describe and support the rationale behind these 5 main recommendations.ResultsIn this paper, we present the rationale behind this construct and present specific recommendations such as reporting sleep study indices (disease severity) and sleep time spent in various sleeping positions. The same is suggested for DISE findings and effect of treatment. Sleep study indices (disease severity), anatomical, morphological, and physiological factors in sleep apnea patients should be reported separately for PP and NPP.Conclusion
Applying these suggestions in future research will improve patient care, assist in better understanding of this dominant phenotype, and will enhance accurate comparisons across studies and future investigations.
Obstructive sleep apnea (OSA) is a common disorder caused by repetitive collapse of the upper airway during sleep. Continuous positive airway pressure (CPAP) is the gold standard treatment for OSA but suboptimal adherence and poor tolerance to CPAP limits treatment effectiveness. It is not uncommon for patients to seek an alternate treatment for management of OSA. Given the chronic nature of the condition, its detrimental effects on sleep quality, quality of life, executive functioning, and the long-term metabolic and cardiovascular sequela of untreated moderate-to-severe OSA, alternatives to CPAP may be necessary for these patients who are unable or unwilling to use CPAP. Often these alternatives may reduce the burden of sleep-disordered breathing with a treatment strategy that is acceptable to, and tolerated by the patient. This chapter highlights several alternatives to CPAP for management of OSA. Therapies reviewed include medical and surgical weight loss, positional therapy, nasal expiratory positive airway pressure, oral pressure therapy, and hypoglossal nerve stimulation. For oral appliance therapy and surgical interventions, please refer to separate chapters in this textbook.
Study objectives:
Approximately 20% of North Americans are afflicted with chronic pain with 3% being opioid users. The objective was to determine whether patients on opioids for chronic pain with newly diagnosed sleep apnea attended sleep clinic review and followed treatment recommendations.
Methods:
The study was a post-hoc analysis from a multicenter perspective cohort study. Inclusion criteria included: adults taking opioid medications for chronic pain for >3 months. Demographic data and daily opioid dose were collected. Sleep apnea was diagnosed via level 1 polysomnography. Patients who attended sleep clinic review were grouped based on the types of treatment they received.
Results:
204 patients completed polysomnography and 58.8% were diagnosed to have sleep apnea (AHI ≥5). Of those with sleep apnea, 58% were recommended to have evaluation by a sleep physician. The body mass index and age were 29.5 ± 6 kg/m² and 56 ± 12 years respectively. Of the newly diagnosed sleep apnea, 25% received treatment with the majority being treated with positive airway pressure (PAP) therapy, whereas the rest received positional therapy and opioids/sedative reduction. The adherence rate of PAP therapy was 55% at 1-year. Over 50% of participants on opioids for chronic pain with newly diagnosed sleep apnea declined attendance for sleep clinic review or treatment.
Conclusions:
There was a high refusal rate to attend clinic for treatment. Adherence to PAP therapy was low at 55%. This sheds light on the high rate of treatment non-adherence and the need for further research.
Clinical trial registration:
Registry: ClinicalTrials.gov; Identifier: NCT02513836.
Study objectives:
To assess the use of a novel magnetic polymer implant in reversing airway collapse and identifying potential anatomical targets for airway implant surgery in an in-vivo porcine model.
Methods:
Target sites of airway collapse were genioglossus muscle, hyoid bone and middle constrictor. Magnetic polymer implants were sutured to these sites and external magnetic forces, through magnets with pull forces rated at 102 kg and 294 kg, were applied at the skin. The resultant airway movement was assessed via nasendoscopy. Pharyngeal plexus branches to the middle constrictor muscle were stimulated at 0.5 mA, 1.0 mA and 2.0 mA and airway movement assessed via nasendoscopy.
Results:
At the genioglossus muscles large magnetic forces were required to produce airway movement. At the hyoid bone, anterior movement of the airway was noted when using a 294 kg rated magnet. At the middle constrictor muscle, an anterolateral (or rotatory) pattern of airway movement was noted when using the same magnet. Stimulation of pharyngeal plexus branches to the middle constrictor revealed contraction and increasing rigidity of the lateral walls of the airway as stimulation amplitude increased. The resultant effect was prevention of collapse as opposed to typical airway dilation, a previously unidentified pattern of airway movement.
Conclusions:
Surgically implanted smart polymers are an emerging technology showing promise in the treatment of airway collapse in obstructive sleep apnea. Future research should investigate their biomechanical role as an adjunct to treatment of airway collapse through nerve stimulation.
Study objectives:
To assess, in a large cohort of patients with obstructive sleep apnea (OSA), the factors that are independently associated with positional OSA (POSA) and exclusive POSA (e-POSA) and determine their prevalence. The secondary objective was to evaluate the outcome of positive airway pressure (PAP) therapy for POSA and e-POSA patients.
Methods:
This retrospective study included 6,437 typical mild-to-severe OSA patients from the Pays de la Loire sleep cohort. Patients with POSA and e-POSA were compared to those with non POSA (NPOSA) for clinical and polygraphic characteristics. In a subgroup of patients (n=3,000) included in a PAP follow-up analysis, we determined whether POSA and e-POSA phenotypes were associated with treatment outcomes at 6 months.
Results:
POSA and e-POSA had a prevalence of 53.5% and 20.1% respectively and were independently associated with time in supine position, male gender, younger age, lower AHI and lower BMI. After adjustment for confounding factors, patients with POSA and e-POSA had a significantly lower likelihood of treatment adherence (PAP daily use ≥4h) at 6 months and were at higher risk of PAP treatment withdrawal compared to NPOSA.
Conclusions:
The prevalence and independent predictors of POSA and e-POSA were determined in this large clinical population. POSA and e-POSA patients have lower PAP therapy adherence and this choice of treatment may not be optimal. Thus, there is a need to offer these patients an alternative therapy.
There has been a recent surge in the number of potential alternative therapies that have been proposed and marketed for adults with OSA. This Perspective finds that many of these alternatives do not have high-quality studies showing clear benefits. Health care providers must treat adults with OSA using treatments either supported by high-quality, peer-reviewed publications showing benefit or as part of ongoing rigorous clinical trials.
Positional therapy appears to be an attractive strategy for many patients with positional obstructive sleep apnea (OSA). However, under the American Academy of Sleep Medicine OSA guidelines, positional therapy is considered as only an alternative therapy, because previous research has demonstrated poor treatment tolerance and adherence. Recent technological advances have renewed interest in positional therapy, with the invention of new sophisticated vibratory positional therapy devices. These devices have shown great promise with efficacy, markedly improved patient tolerance, and long-term adherence. We review the literature on positional therapy and explore the most current evidence on the new positional therapy devices.
None:
Night-to-night variability (NNV) of the degree of obstructive sleep apnea (OSA) over the long term is not well investigated. In our case, we investigated the NNV of the apnea-hypopnea index (AHI) with regard to sleep structure. Unattended polysomnography (PSG) at home was used to determine the AHI in the course of 4 weeks in a single patient with a mild-to-moderate OSA, by using the Somnocheck R&K system. The mean sleep period was 6.7 ± 1.1 hours and the mean AHI was 14.1 ± 5.7 events/h (range: 5.1-28.3 events/h; coefficient variability [CV] 40.4%). Independent of non-rapid eye movement and rapid eye movement (REM) sleep, the AHI in supine position (43.6 ± 16.9 events/h; CV 38.8%) was greater than during lateral-recumbent sleep (4.8 ± 4.1 events/h; CV 85.4%, P < .0001). A negative correlation was found for both: the AHI in supine position with the duration of supine position sleep (r = .59, P < .001), as well as the AHI in REM with the duration of REM sleep (r = -.37, P < .025). The AHI shows no rhythmicity neither from day to day nor from week to week. We found a high long-term NNV of the AHI, which was typically not influenced by the particular day of the week. Supine AHI is evidently dependent on the duration spent in that position throughout the night. We found it advisable to consider the existence of NNV in association with the degree of OSA, especially for patients with questionable therapeutic indication. Citation: Fietze I, Glos M, Zimmermann S, Penzel T. Long-term variability of the apnea-hypopnea index in a patient with mild to moderate obstructive sleep apnea. J Clin Sleep Med. 2020(16):XXX-XXX.
Study objectives:
Compare treatment efficacy and objective adherence between the NightBalance sleep position treatment (SPT) device and auto-adjusting positive airway pressure (APAP) in patients with exclusive positional obstructive sleep apnea (ePOSA) defined as a supine apnea-hypopnea index (sAHI) ≥ 2 times the nonsupine AHI (nsAHI) and a nsAHI < 10 events/h.
Methods:
This prospective multicenter randomized crossover trial enrolled treatment naive participants with ePOSA (AHI ≥ 15 events/h and nsAHI < 10 events/h) or (AHI > 10 and < 15 events/h with daytime sleepiness and nsAH < 5 events/h). Polysomnography and objective adherence determination (device data) were performed at the end of each 6-week treatment. Patient device preference was determined at the end of the study.
Results:
A total of 117 participants were randomized (58 SPT first, 59 APAP first). Of these, 112 started treatment with the second device (adherence cohort) and 110 completed the study (AHI cohort). The AHI on SPT was higher (mean ± standard deviation, 7.29 ± 6.8 versus 3.71 ± 5.1 events/h, P < .001). The mean AHI difference (SPT-APAP) was 3.58 events/h with a one sided 95% confidence interval upper bound of 4.96 events/h (< the prestudy noninferiority margin of 5 events/h). The average nightly adherence (all nights) was greater on SPT (345.3 ± 111.22 versus 286.98 ± 128.9 minutes, P < .0001). Participants found the SPT to be more comfortable and easier to use and 53% reported a preference for SPT assuming both devices were equally effective.
Conclusions:
Treatment with SPT resulted in non-inferior treatment efficacy and greater adherence compared to APAP in ePOSA suggesting that SPT is an effective treatment for this group.
Clinical trial registration:
Registry: ClinicalTrials.gov; Title: The POSAtive Study: Study for the Treatment of Positional Obstructive Sleep Apnea; Identifier: NCT03061071; URL: https://clinicaltrials.gov/ct2/show/NCT03061071.
Purpose
To develop a non-invasive MRI-based methodology to visually and quantitatively assess the impact of head and chest rotations on the airway caliber.
Methods
An MRI table set-up was developed for independent rotations of the head and chest along B0 field and tested for feasibility using phantom scans. The accuracy of the head and chest rotations was validated with ten volunteer scans. A 3T MRI protocol was optimized to image the regions of interest (ROIs) that were the retropalatal (RP) and retroglossal (RG) sections of the upper airway. A workflow for data analysis was developed to assess the changes of the airway caliber following the independent head and chest rotations.
Results
A prototype MRI table setup was established with two separate plates each supporting and rotating the head or chest independently. Subject positioning and image acquisition were finished within seven minutes for each position. Thus, each subject MRI was set up with seven positions and completed for less than one hour. The implemented angles were within 0.3-degree deviation from the targeted angles. The data analysis workflow provided 2D and 3D visualization and quantification with the measurements of cross-sectional area, lateral and anterior-posterior distances of the ROIs. Sharp contrast of the airway and its surrounding tissues facilitated an automatic approach to ROI placement to minimize subjectivity.
Conclusions
The 3T MRI data acquisition and analysis methodology could reliably assess the impact of head and chest rotations on the upper airway caliber to identify the optimal position for obstructive sleep apnea patients.
Purpose
Positional change during sleep influences upper airway patency. However, few studies have used imaging techniques to demonstrate the change. This study aims to determine the effect of positional change on the upper airway space.
Methods
A total of 118 subjects with sleep breathing disorders were analyzed. Participants underwent upper airway CT scans in the supine and lateral decubitus positions (right and left). They were divided into non-obstructive sleep apnea (n = 28) and obstructive sleep apnea (n = 90) groups. We measured the minimal cross-sectional area of the retropalatal/retroglossal spaces and compared the differences of those two spaces in the supine and lateral positions. CT was performed while patients were awake.
Results
The minimal cross-sectional area in the OSA group was significantly smaller than non-OSA group in both supine (median[interquartile range], 8.3[0.0–25.1] vs 22.2[1.0–39.6]; P = 0.018) and lateral decubitus positions (5.2[0.0–16.9] vs 21.3[6.1–38.4]; P = 0.002). As the body position of OSA patients shifted from supine to lateral, the retroglossal space increased significantly (67.3[25.1–116.3] vs 93.3[43.4–160.1]; P < 0.001). However, there was no significant difference in the retropalatal space between the supine and lateral decubitus positions.
Conclusions
Positional change from the supine to lateral decubitus position expands the upper airway lumen, especially the retroglossal space. Positional OSA may be related to anatomical change of the upper airway lumen based on body position.
Purpose
Positional obstructive sleep apnea (OSA) is prevalent. We hypothesized that by incorporating positional therapy into a diagnosis-treatment algorithm for OSA it would frequently be prescribed as an appropriate first-line therapy.
Methods
Fifty-nine members (45 males, 49±9 yrs, BMI 35.2±5.6 kg/m²) of the Law Enforcement Health Benefits (LEHB), Inc. of Philadelphia with clinically suspected OSA were evaluated. Patients completed an Epworth Sleepiness Scale (ESS) questionnaire and a home sleep test (HST). Patients diagnosed with positional OSA (non-supine apnea-hypopnea index [AHI] < 5 events/hr) were offered positional therapy. A cost comparison to continuous positive airway pressure (CPAP) therapy was performed.
Results
Fifty-four (92%) of the patients (43 males, 49±9 yrs, BMI 35.2±5.3 kg/m²) had OSA on their HST (AHI 24.2±20.1 events/hr). Sixteen (30%) patients had positional OSA. Compared to non-positional patients, patients with positional OSA were less heavy (32.4±5.1 vs. 36.4±5.1 kg/m², respectively [p=0.009]), less sleepy (ESS 8±5 vs. 12±5, respectively [p=0.009]), and had less severe OSA (AHI 10.4±4.3 vs. 30.0±21.3 events/hr, respectively [p<0.001]). Thirteen of the 16 patients with positional OSA agreed to positional therapy and 31 non-positional OSA patients agreed to CPAP therapy. Based on initial costs, incorporating positional therapy ($189.95/device compared to CPAP therapy at $962.49/device) into the treatment algorithm resulted in a 24% cost savings compared to if all the patients were initiated on CPAP therapy.
Conclusion
With the high prevalence of positional OSA, using a diagnosis-treatment algorithm that incorporates positional therapy allows it to be more frequently considered as a cost effective first-line therapy for OSA.
Background:
The modalities of therapy for obstructive sleep apnoea (OSA) include behavioural and lifestyle modifications, positional therapy, oral appliances, surgery and continuous positive airway pressure therapy (CPAP). Though CPAP has proven efficacy in treating OSA, adherence with CPAP therapy is suboptimal. Positional therapy (to keep people sleeping on their side) is less invasive and therefore expected to have better adherence. This review considered the efficacy of positional therapy compared to CPAP as well as positional therapy against no positional therapy. Devices designed for positional therapy include lumbar or abdominal binders, semi-rigid backpacks, full-length pillows, a tennis ball attached to the back of nightwear, and electrical sensors with alarms that indicate change in position.
Objectives:
To compare the efficacy of positional therapy versus CPAP and positional therapy versus inactive control (sham intervention or no positional therapy intervention) in people with OSA.
Search methods:
We identified studies from the Cochrane Airways' Specialised Register (including CENTRAL, MEDLINE, Embase, CINAHL, AHMED and PsycINFO), ClinicalTrials.gov, and the World Health Organization trials portal (ICTRP). It also contains results derived from handsearching of respiratory journals and abstract books of major annual meetings. We searched all databases from their inception to September 2018, with no restrictions on language of publication or publication type.
Selection criteria:
We included randomised controlled trials comparing positional therapy with CPAP and positional therapy with inactive control.
Data collection and analysis:
Two review authors independently selected studies and extracted the data. We used a random-effects model in the meta-analysis to estimate mean differences and confidence intervals. We assessed certainty of evidence using the GRADE approach.
Main results:
We included eight studies. The studies randomised 323 participants into two types of interventions. The comparison between positional therapy and CPAP included 72 participants, while the comparison between positional therapy and inactive control included 251 participants. Three studies used supine vibration alarm devices, while five studies used physical positioning like specially designed pillows or semirigid backpacks.Positional therapy versus CPAPThe three studies included for this comparison were randomised cross-over trials. Two studies found that there was no difference in Epworth Sleepiness Scale (ESS) scores between CPAP and positional therapy. Two studies showed that CPAP produced a greater reduction in Apnoea-Hypopnoea Index (AHI) with a mean difference (MD) of 6.4 events per hour (95% CI 3.00 to 9.79; low-certainty evidence) compared to positional therapy. Subjective adherence, evaluated in one study, was found to be significantly greater with positional therapy (MD 2.5 hours per night, 95% CI 1.41 to 3.59; moderate-certainty evidence).In terms of secondary outcomes, one study each reported quality-of-life indices and quality-of-sleep indices with no significant difference between the two groups. One study reported cognitive outcomes using multiple parameters and found no difference between the groups. There were insufficient data to comment on other secondary outcomes like respiratory disturbance index (RDI), and frequency and duration of nocturnal desaturation. None of the studies clearly reported adverse effects.Positional therapy versus inactive controlThree studies of positional therapy versus no intervention were randomised cross-over trials, while two studies were parallel-arm studies. Data from two studies showed that positional therapy significantly improved ESS scores (MD -1.58, 95% CI -2.89 to -0.29; moderate-certainty evidence). Positional therapy showed a reduction in AHI compared with control (MD -7.38 events per hour, 95% CI -10.06 to -4.7; low-certainty evidence). One study reported adherence. The number of participants who continued to use the device at two months was no different between the two groups (odds ratio (OR) 0.80, 95% CI 0.33 to 1.94; low-certainty evidence). The same study reported adverse effects, the most common being pain in the back and chest, and sleep disturbance but there was no significant difference between the two groups in terms of device discontinuation (OR 1.25, 95% CI 0.5 to 3.03; low-certainty evidence). One study each reported quality-of-life indices and quality-of-sleep indices, with no significant difference between the two groups. One study reported cognitive outcome, and found no difference between the groups. There was insufficient evidence to comment on other secondary outcomes (RDI, frequency and duration of nocturnal desaturation).
Authors' conclusions:
The review found that CPAP has a greater effect on improving AHI compared with positional therapy in positional OSA, while positional therapy was better than inactive control for improving ESS and AHI. Positional therapy may have better adherence than CPAP. There were no significant differences for other clinically relevant outcomes such as quality of life or cognitive function. All the studies were of short duration. We are unable to comment on the long-term effects of the therapies. This is important, as most of the quality-of-life outcomes will be evident only when the therapies are given over a longer period of time. The certainty of evidence was low to moderate.
Purpose
The aim of the present study was to assess the efficacy of a sleep position trainer (SPT) in patients with an established diagnosis of positional obstructive sleep apnea and to evaluate the adherence after 1-year follow-up.
Methods
Polysomnography (PSG) was performed at baseline and after 1 year of SPT use. Patients received questionnaires to assess treatment satisfaction and subjective adherence. Data on objective adherence and number of vibrations initiated by the SPT were collected from the SPT device.
Results
Nine out of 58 patients stopped using the SPT during the first year of treatment (16%). Thirty-four middle-aged and overweight patients underwent a PSG after 1 year of SPT use (male/female ratio, 28/6; overall apnea/hypopnea index (AHI), 16/h). A significant reduction in overall AHI to 6/h was observed using treatment (p < 0.001). The median percentage of supine sleep decreased significantly to 1% with SPT (p < 0.001). The mean objective SPT use in 28 patients was 7.3 ± 0.9 h/night and 69 ± 26% of the nights. Furthermore, 75% of the patients reported a better sleep quality since the start of SPT treatment.
Conclusions
Long-term treatment with the SPT was found to be effective in reducing overall AHI. Time spent sleeping in supine position was reduced to almost zero in the continuing users. Patient satisfaction was high when using the SPT.
Background:
Approximately 60% of obstructive sleep apnea (OSA) diagnoses are position-dependent, and avoidance of the supine position could represent an effective treatment. Nevertheless, the majority of the available anti-supine treatments result in discomfort and low adherence. This study evaluated the effectiveness of a new vibrating supine avoidance device in reducing time spent in the supine position and the apnea-hypopnea index (AHI) without affecting sleep structure. Furthermore, the tolerability and satisfaction were also scored.
Methods:
Observational prospective study of patients suffering from positional OSA. They were treated with a vibrating device and followed up at the first and fourth weeks after starting the treatment, and further polysomnographic studies were conducted while patients' wore the device. The comparison of the results was carried out through non-parametric tests. Significance level was 5%.
Results:
Twelve patients had complete data. The device reduced time spent in the supine position (from 51.5 ± 14.8% to 25.2 ± 21.0%, p = 0.005), median AHI (from 30.7 (23.2-38.2) at baseline to 21.5 (12.4-24.3) at the fourth week, p = 0.002). Also an improvement in the minimum SaO2 (from 82.2 ± 7.5 to 87.2 ± 3.6 at the 4th week) was also observed. No variations in sleep quality or quantity were identified. All patients evaluated the device positively.
Conclusion:
Our device was effective in reducing the time spent in the supine position and improving AHI, SaO2 variables and sleep architecture. The device was well tolerated by the patients.
Positional therapy appears to be an attractive strategy for many patients with positional obstructive sleep apnea (OSA). However, under the American Academy of Sleep Medicine OSA guidelines, positional therapy is considered as only an alternative therapy, because previous research has demonstrated poor treatment tolerance and adherence. Recent technological advances have renewed interest in positional therapy, with the invention of new sophisticated vibratory positional therapy devices. These devices have shown great promise with efficacy, markedly improved patient tolerance, and long-term adherence. We review the literature on positional therapy and explore the most current evidence on the new positional therapy devices.
Obstructive sleep apnea (OSA) is a common chronic disorder that often requires lifelong care. Available practice parameters provide evidence-based recommendations for addressing aspects of care.
This guideline is designed to assist primary care providers as well as sleep medicine specialists, surgeons, and dentists who care for patients with OSA by providing a comprehensive strategy for the evaluation, management and long-term care of adult patients with OSA.
The Adult OSA Task Force of the American Academy of Sleep Medicine (AASM) was assembled to produce a clinical guideline from a review of existing practice parameters and available literature. All existing evidence-based AASM practice parameters relevant to the evaluation and management of OSA in adults were incorporated into this guideline. For areas not covered by the practice parameters, the task force performed a literature review and made consensus recommendations using a modified nominal group technique.
Questions regarding OSA should be incorporated into routine health evaluations. Suspicion of OSA should trigger a comprehensive sleep evaluation. The diagnostic strategy includes a sleep-oriented history and physical examination, objective testing, and education of the patient. The presence or absence and severity of OSA must be determined before initiating treatment in order to identify those patients at risk of developing the complications of sleep apnea, guide selection of appropriate treatment, and to provide a baseline to establish the effectiveness of subsequent treatment. Once the diagnosis is established, the patient should be included in deciding an appropriate treatment strategy that may include positive airway pressure devices, oral appliances, behavioral treatments, surgery, and/or adjunctive treatments. OSA should be approached as a chronic disease requiring long-term, multidisciplinary management. For each treatment option, appropriate outcome measures and long-term follow-up are described.
CPAP should be considered the first line of treatment in patients with moderate to severe obstructive sleep apnoea. In our centre in Sydney this generally means patients with more than 20 apnoea/hypopnoeas per hour with repeated dips in oxyhaemoglobin saturation and usually some symptomatology. Despite this first line role of nasal CPAP, recent objective studies question whether earlier enthusiastic reports on adherence to CPAP are correct. The role of technical innovations in new CPAP machines in improving usage remains to be tested. The "drop out" rate from physician selection for a CPAP trial to highly compliant user is certainly more than 50% of patients. What happens to these patients? Data from some studies suggest that surgical treatments are used, at least in the USA, but in all probability many of these patients remain untreated. The challenge in the next decade is either to improve CPAP devices to increase usage in this group or to develop other treatment options. The role of intensive inhospital "acclimatisation" to CPAP also has yet to be objectively tested. It is unclear whether "intelligent" CPAP will make huge inroads in increasing the number of patients who accept CPAP trials, prescriptions, or compliance. It will have minimal impact on patients with mask problems or claustrophobia or those who feel that CPAP is inconvenient. There is a high likelihood that it will reduce technologist workload during CPAP titration studies. "Intelligent" CPAP may help to reduce total overnight mouth leakage and therefore reduce nasal side effects. The current expense of developing such devices will mean that they are unlikely to supersede much cheaper standard "one pressure" CPAP machines in the next few years.
To compare anthropomorphic, nocturnal polysomnographic (PSG), and multiple sleep latency test (MSLT) data between positional (PP) and nonpositional (NPP) obstructive sleep apnea (OSA) patients.
This is a retrospective analysis of anthropomorphic, PSG, and MSLT data of a large group of OSA patients who underwent a complete PSG evaluation in our sleep disorders unit. The patients were divided in two groups: the PP group, those patients who had a supine respiratory disturbance index (RDI) that was at least two times higher than the lateral RDI, and the NPP group, those patients in whom the RDI in the supine position was less than twice that in the lateral position.
From a group of 666 consecutive OSA patients whose conditions were diagnosed in our unit from September 1990 to February 1995, 574 patients met the following criteria and were included in the study: RDI > 10; age > 20 years, and body mass index (BMI) > 20.
Of all 574 patients, 55.9% were found to be positional. No differences in height were observed but weight and BMI were significantly higher in the NPP group, these patients being on the average 6.5 kg heavier than those in the PP group. The PP group was, on average, 2 years younger than the NPP group. Nocturnal sleep quality was better preserved in the PP group. In this group, sleep efficiency and the percentages of deep sleep (stages 3 and 4) were significantly higher while the percentages of light sleep (stages 1 and 2) were significantly lower than in the NPP group. No differences for rapid eye movement (REM) sleep were found. In addition, wakefulness after sleep onset and the number of short arousals (< 15 s) were significantly lower in the PP group. Apnea index and total RDI were significantly higher and the minimal arterial oxygen saturation in REM and non-REM sleep was significantly lower in the NPP. No differences in periodic limb movements data were found between the two groups. The average MSLT was significantly shorter in the NPP group. Univariate and multivariate stepwise logistic regression analysis showed that the most dominant variable that correlates with positional dependency in OSA patients is RDI, followed by BMI which also adds a significant contribution to the prediction of positional dependency. Age, although significant, adds only a minor improvement to the prediction of this positional dependency phenomenon. A severe, obese, and older OSA patient is significantly less likely to be positional than a mild-moderate, thin, and young OSA patient. In four obese OSA patients who lost weight, a much more pronounced reduction was seen in the lateral RDI than in the supine RDI, and three of these cases who were previously NPP became PP.
In a large population of OSA patients, most were found to have at least twice as many apneas/hypopneas in the supine than in the lateral position. These so-called "positional patients" are on the average thinner and younger than "nonpositional patients." They had fewer and less severe breathing abnormalities than the NPP group. Consequently their nocturnal sleep quality was better preserved and, according to MSLT data, they were less sleepy during daytime hours. RDI was the most dominant factor that could predict the positional dependency followed by BMI and age. RDI showed a threshold effect, the prevalence of PP in those with severe RDI (RDI > or = 40) was significantly lower than in those OSA patients with mild-moderate RDI. BMI showed a major significant inverse relationship with positional dependency, while age had only a minor although significant inverse relationship with it. Body position during sleep has a profound effect on the frequency and severity of breathing abnormalities in OSA patients.
We previously showed that upper airway resistance can be inferred from the inspiratory flow contour during continuous positive airway pressure (CPAP) titration in obstructive sleep apnea syndrome (OSAS). The present study examines whether similar information can be obtained from inspiratory flow measured by a nasal cannula/pressure transducer. Ten symptomatic patients (snoring, upper airway resistance syndrome [UARS], or OSAS) and four asymptomatic subjects underwent nocturnal polysomnography (NPSG) with monitoring of flow (nasal cannula) and respiratory driving pressure (esophageal or supraglottic catheter). For each breath the inspiratory flow signal was classified as normal, flattened, or intermediate by custom software. "Resistance" was calculated from peak inspiratory flow and pressure, and normalized to the resistance during quiet wakefulness. Resistance in all stages of sleep was increased for breaths with flattened (387 +/- 188%) or intermediate (292 +/- 163%) flow contour. In combination with apnea-hypopnea index (AHI), identification of "respiratory events," consisting of consecutive breaths with a flattened contour, allowed differentiation of symptomatic from asymptomatic subjects. Our data show that development of a plateau on the inspiratory flow signal from a nasal cannula identifies increased upper airway resistance and the presence of flow limitation. In patients with symptoms of excessive daytime somnolence and low AHI this may help diagnose the UARS and separate it from nonrespiratory causes of sleep fragmentation.
Sleep-disordered breathing is prevalent in the general population and has been linked to chronically elevated blood pressure in cross-sectional epidemiologic studies. We performed a prospective, population-based study of the association between objectively measured sleep-disordered breathing and hypertension (defined as a laboratory-measured blood pressure of at least 140/90 mm Hg or the use of antihypertensive medications).
We analyzed data on sleep-disordered breathing, blood pressure, habitus, and health history at base line and after four years of follow-up in 709 participants of the Wisconsin Sleep Cohort Study (and after eight years of follow-up in the case of 184 of these participants). Participants were assessed overnight by 18-channel polysomnography for sleep-disordered breathing, as defined by the apnea-hypopnea index (the number of episodes of apnea and hypopnea per hour of sleep). The odds ratios for the presence of hypertension at the four-year follow-up study according to the apnea-hypopnea index at base line were estimated after adjustment for base-line hypertension status, body-mass index, neck and waist circumference, age, sex, and weekly use of alcohol and cigarettes.
Relative to the reference category of an apnea-hypopnea index of 0 events per hour at base line, the odds ratios for the presence of hypertension at follow-up were 1.42 (95 percent confidence interval, 1.13 to 1.78) with an apnea-hypopnea index of 0.1 to 4.9 events per hour at base line as compared with none, 2.03 (95 percent confidence interval, 1.29 to 3.17) with an apnea-hypopnea index of 5.0 to 14.9 events per hour, and 2.89 (95 percent confidence interval, 1.46 to 5.64) with an apnea-hypopnea index of 15.0 or more events per hour.
We found a dose-response association between sleep-disordered breathing at base line and the presence of hypertension four years later that was independent of known confounding factors. The findings suggest that sleep-disordered breathing is likely to be a risk factor for hypertension and consequent cardiovascular morbidity in the general population.
The primary aim of this study was to determine the prevalence of positional obstructive sleep apnea using a functional definition. Positional sleep apnea was defined as a total apnea-hypopnea index (AHI) > or = 5 with a > 50% reduction in the AHI between the supine and nonsupine postures, and an AHI that normalizes (AHI < 5) in the nonsupine posture. A secondary aim was to determine if positional sleep apnea can be diagnosed accurately during a split-night study.
Retrospective chart review.
Two sleep centers in Buffalo, NY, one a Veterans Affairs Western New York Healthcare System Sleep Center (VAWNY) and the other a freestanding ambulatory center (Associated Sleep Center [ASC]).
Three hundred twenty-six patients from the VAWNY, including 57 patients who underwent a split-night study and 242 patients from the ASC who underwent polysomnography.
None.
Patient characteristics and sleep study results.
Positional sleep apnea was seen in 49 of 99 patients (49.5%) with mild sleep apnea (AHI, 5 to 15/h), 14 of 72 patients (19.4%) with moderate sleep apnea (AHI, 15 to 30/h), and 5 of 77 patients (6.5%) with severe sleep apnea (AHI > 30/h). Sufficient sleep (> 15 min) in both postures was not seen in 104 of 269 patients (38.7%) and 80 of 242 overnight studies (33.1%) at the VAWNY and ASC, respectively, and was not seen in 47 of 57 split-night studies (82.5%). The percentage of studies with insufficient sleep in both postures was significantly greater for split-night studies (p < 0.0001).
Positional sleep apnea is common particularly in patients with mild disease. Positional sleep apnea cannot usually be assessed during a split-night study.
Previous studies have suggested that the obstructive sleep apnea syndrome may be an important risk factor for stroke. It has not been determined, however, whether the syndrome is independently related to the risk of stroke or death from any cause after adjustment for other risk factors, including hypertension.
In this observational cohort study, consecutive patients underwent polysomnography, and subsequent events (strokes and deaths) were verified. The diagnosis of the obstructive sleep apnea syndrome was based on an apnea-hypopnea index of 5 or higher (five or more events per hour); patients with an apnea-hypopnea index of less than 5 served as the comparison group. Proportional-hazards analysis was used to determine the independent effect of the obstructive sleep apnea syndrome on the composite outcome of stroke or death from any cause.
Among 1022 enrolled patients, 697 (68 percent) had the obstructive sleep apnea syndrome. At baseline, the mean apnea-hypopnea index in the patients with the syndrome was 35, as compared with a mean apnea-hypopnea index of 2 in the comparison group. In an unadjusted analysis, the obstructive sleep apnea syndrome was associated with stroke or death from any cause (hazard ratio, 2.24; 95 percent confidence interval, 1.30 to 3.86; P=0.004). After adjustment for age, sex, race, smoking status, alcohol-consumption status, body-mass index, and the presence or absence of diabetes mellitus, hyperlipidemia, atrial fibrillation, and hypertension, the obstructive sleep apnea syndrome retained a statistically significant association with stroke or death (hazard ratio, 1.97; 95 percent confidence interval, 1.12 to 3.48; P=0.01). In a trend analysis, increased severity of sleep apnea at baseline was associated with an increased risk of the development of the composite end point (P=0.005).
The obstructive sleep apnea syndrome significantly increases the risk of stroke or death from any cause, and the increase is independent of other risk factors, including hypertension.
Therapies for obstructive sleep apnea other than positive airway pressure, oral appliances, and surgical modifications of the upper airway are reviewed in this practice parameter. Several of these therapies such as weight loss and positional therapy hold some promise. Others, such as serotonergic agents, may gain credibility in the future but lack well-designed clinical trials. No practice parameters could be developed for a number of possible therapeutic modalities that had little or no evidence-based data on which to form a conclusion. The role of an organized, targeted weight-loss program either as a single therapy or as a supplement to PAP needs to be clarified. Although bariatric surgery is increasingly performed for refractory medically complicated obesity, its long-term effectiveness in treatment of obstructive sleep apnea in morbidly obese patients is not yet demonstrated. Positional therapy, or methods for preventing sleep in the supine position, has probably been underutilized due to lack of easily measured predictive factors and randomized controlled trials.
Context
Sleep-disordered breathing (SDB) and sleep apnea have been linked to
hypertension in previous studies, but most of these studies used surrogate
information to define SDB (eg, snoring) and were based on small clinic populations,
or both.Objective
To assess the association between SDB and hypertension in a large cohort
of middle-aged and older persons.Design and Setting
Cross-sectional analyses of participants in the Sleep Heart Health Study,
a community-based multicenter study conducted between November 1995 and January
1998.Participants
A total of 6132 subjects recruited from ongoing population-based studies
(aged ≥40 years; 52.8% female).Main Outcome Measures
Apnea-hypopnea index (AHI, the average number of apneas plus hypopneas
per hour of sleep, with apnea defined as a cessation of airflow and
hypopnea defined as a ≥30% reduction in airflow
or thoracoabdominal excursion both of which are accompanied by a ≥4% drop in oxyhemoglobin
saturation), obtained by unattended home polysomnography. Other measures include
arousal index; percentage of sleep time below 90% oxygen saturation; history
of snoring; and presence of hypertension, defined as resting blood pressure
of at least 140/90 mm Hg or use of antihypertensive medication.Results
Mean systolic and diastolic blood pressure and prevalence of hypertension
increased significantly with increasing SDB measures, although some of this
association was explained by body mass index (BMI). After adjusting for demographics
and anthropometric variables (including BMI, neck circumference, and waist-to-hip
ratio), as well as for alcohol intake and smoking, the odds ratio for hypertension,
comparing the highest category of AHI (≥30 per hour) with the lowest category
(<1.5 per hour), was 1.37 (95% confidence interval [CI], 1.03-1.83; P for trend=.005). The corresponding estimate comparing
the highest and lowest categories of percentage of sleep time below 90% oxygen
saturation (≥12% vs <0.05%) was 1.46 (95% CI, 1.12-1.88; P for trend <.001). In stratified analyses, associations of hypertension
with either measure of SDB were seen in both sexes, older and younger ages,
all ethnic groups, and among normal-weight and overweight individuals. Weaker
and nonsignificant associations were observed for the arousal index or self-reported
history of habitual snoring.Conclusion
Our findings from the largest cross-sectional study to date indicate
that SDB is associated with systemic hypertension in middle-aged and older
individuals of different sexes and ethnic backgrounds.
Figures in this Article
Sleep-disordered breathing (SDB) and the related clinical syndrome,
sleep apnea, have been associated with hypertension in clinical reports since
the early 1980s.1- 4
Earlier studies of this association used self-reported history of "snoring"
as a surrogate for the presence of sleep apnea. Although some of these studies
showed an independent association between snoring and hypertension,5- 7 others found that this
relationship may be explained by confounding effects of age, sex, or obesity.8- 11 Two
recent studies have demonstrated that self-reported history of snoring is
associated with increased incidence of self-reported hypertension in middle-aged
men12 and women.13
Other studies have used polysomnography (PSG), a more objective measure of
SDB. Most of these studies,14- 19
but not all,20- 21 found an association
between sleep apnea and hypertension, independent of age, sex, body weight,
and other potential confounders. With the exception of the reports from the
Wisconsin Sleep Cohort Study of middle-aged employed persons,15,18
most previous studies were based on a small number of patients in clinical
settings.22
Given the strong association between SDB and obesity and adiposity measures,23 some researchers have cautioned that even in studies
controlling for body mass index (BMI), there is a potential for residual confounding,
since fat distribution may be the strongest confounding component of obesity.24
This study is based on baseline cross-sectional data from the Sleep
Heart Health Study (SHHS), a multicenter study of the cardiovascular consequences
of sleep apnea in participants recruited from ongoing population-based cohort
studies.25 Our results represent the largest
cross-sectional study to date of the association between SDB and hypertension
in apparently healthy middle-aged and older adults. We assessed SDB in the
subjects' homes using a portable PSG monitor. Its association with blood pressure
and hypertension is examined while controlling for the potential confounding
effects of demographic variables, body weight, and measures of body fat distribution.
Avoidance of sleep in the supine position is recommended in the management of position-dependent OSA hypopnoea syndrome (OSAHS). Our aim was to evaluate the efficacy of a thoracic anti-supine band (TASB), designed to mimic the so-called 'tennis ball technique', compared with nasal CPAP (nCPAP).
Twenty adults with mild to moderately severe position-dependent OSAHS (mean AHI +/- SD) 22.7 +/- 12.0/H (range 6.0-51.2); AHI supine, 59.6 +/- 27.5/H, were included in a randomized cross-over trial. Portable sleep studies were undertaken at baseline and after 1 month on each treatment. A successful treatment outcome was defined as AHI <or= 10/H.
Mean AHI was 12.0 +/- 14.5/H with the TASB and 4.9 +/- 3.9/H with nCPAP (P = 0.02; 95% confidence interval for the difference: -13.1 to -1.0). With the TASB, treatment 'success' was achieved in 13/18 subjects, whereas 'success' was achieved in 16/18 subjects using nCPAP (P = 0.004). In the two subjects with baseline AHI < 10/H, AHI remained below 10 for both therapies. The TASB successfully reduced time spent in the supine position. Mean percentage supine sleep time was 6.3 +/- 5.9% with the TASB, and 35.4 +/- 34.1% with nCPAP (P < 0.001). No significant differences in sleep efficiency or subjective responses were observed between treatments.
Control of body position during sleep using an anti-supine device mimicking the so-called 'tennis ball technique' provides benefit in the management of position-dependent OSAHS in subjects who meet strict inclusion criteria. The overall improvement is, however, less than for nCPAP.
Sixty male patients all with apnea plus hypopnea indices (A + HI) above 12.5, who met a criterion of positionality by having two or more times the rate of these events during supine sleep in comparison to their lateral sleep rate, were randomly assigned to one of four treatments for 8 weeks. All were restudied for two nights, one with and one without treatment devices. On treatment more than half the patients in each group reduced their A + HI to within normal limits and a third remained WNL without the use of devices. Half of those trained to sleep in the lateral position with the help of an alarm maintained this learning without the alarm as did half of those who were encouraged to learn this sleep posture on their own. There is an additive effect for the positional patient from wearing a tongue retaining device (TRD) if they continue to sleep in the supine position. Factors associated with successful treatment include overall severity, severity in the lateral position, weight, weight change, nasal patency and motivation to help their condition.
Ten male patients selected as having sleep apnea predominantly of the obstructive type associated with the supine sleep position on their evaluation night were trained for 1 additional night to avoid the back sleep position by wearing a gravity-activated position monitor/alarm on the chest. This device emitted an auditory signal if the patient remained supine for more than 15 s. The number of apneic events was significantly reduced, as were the number of episodes of significant O2 desaturation. While wearing the alarm, the apnea index of seven patients remained within or near normal limits. On a follow-up night, with only instructions to maintain the lateral decubitus posture, five patients remained significantly improved. Sleep position training may be appropriate as a single or interim treatment for a significant number of sleep apnea patients who have position-related obstruction.
Four patients who were evaluated for hypersomnia-sleep apnea syndrome were found in all-night sleep studies to have obstructive or mixed apneas related to their sleeping positions. All four were available for comprehensive follow-up and were subsequently restudied while avoiding the supine position. Supine, prone, and lateral decubitus apnea indices were calculated for each patient for each night. The supine sleeping position was associated with significantly more apneas than the non-supine positions. Keeping these patients off their backs when they slept was effective treatment. Additionally, when results of surgical or pharmacologic treatments of apnea are evaluated, positional apnea indices should be considered.
Thirty male patients evaluated sequentially for sleep apnea syndrome by all-night clinical polysomnography were compared for apnea plus hypopnea index (A + HI) during the time in the side versus time in the back sleep posture. For 24 subjects of this sample, who occupied both major body positions during the evaluation night, the apnea index was found to be twice as high during the time spent sleeping on their backs as it was when they slept in the side position. This difference is reliable and inversely related to obesity. Five patients meeting diagnostic criteria for sleep apnea on an all-night basis fell within normal limits while in the side sleep position. This suggests sleep position adjustment may be a viable treatment for some nonobese sleep apnea patients.
Limited data have suggested that sleep-disordered breathing, a condition of repeated episodes of apnea and hypopnea during sleep, is prevalent among adults. Data from the Wisconsin Sleep Cohort Study, a longitudinal study of the natural history of cardiopulmonary disorders of sleep, were used to estimate the prevalence of undiagnosed sleep-disordered breathing among adults and address its importance to the public health.
A random sample of 602 employed men and women 30 to 60 years old were studied by overnight polysomnography to determine the frequency of episodes of apnea and hypopnea per hour of sleep (the apnea-hypopnea score). We measured the age- and sex-specific prevalence of sleep-disordered breathing in this group using three cutoff points for the apnea-hypopnea score (> or = 5, > or = 10, and > or = 15); we used logistic regression to investigate risk factors.
The estimated prevalence of sleep-disordered breathing, defined as an apnea-hypopnea score of 5 or higher, was 9 percent for women and 24 percent for men. We estimated that 2 percent of women and 4 percent of men in the middle-aged work force meet the minimal diagnostic criteria for the sleep apnea syndrome (an apnea-hypopnea score of 5 or higher and daytime hypersomnolence). Male sex and obesity were strongly associated with the presence of sleep-disordered breathing. Habitual snorers, both men and women, tended to have a higher prevalence of apnea-hypopnea scores of 15 or higher.
The prevalence of undiagnosed sleep-disordered breathing is high among men and is much higher than previously suspected among women. Undiagnosed sleep-disordered breathing is associated with daytime hypersomnolence.
Obstruction of the upper airway during sleep (OSAS) is widely treated by having patients self-administer nasal continuous positive airway pressure (CPAP). To obtain objective evidence of the patterns of CPAP use, information was gathered from two urban sites on 35 OSAS patients who were prescribed CPAP for a total of 3,743 days. Patients were given CPAP machines that contained a microprocessor and monitor that measured actual pressure at the mask for every minute of each 24-h day for an average of 106 days per patient. They were not aware of the monitor inside the CPAP machines. Monitor output was compared with patients' diagnostic status, pretreatment clinical and demographic characteristics, and follow-up self-reports of CPAP use, problems, side effects, and aspects of daytime fatigue and sleepiness. Patients attempted to use CPAP an average of 66 +/- 37% of the days monitored. When CPAP was used, the mean duration of use was 4.88 +/- 1.97 h. However, patients' reports of the duration of CPAP use overestimated actual use by 69 +/- 110 min (p < 0.002). Both frequency and duration of CPAP use in the first month reliably predicted use in the third month (p < 0.0001). Although the majority (60%) of patients claimed to use CPAP nightly, only 16 of 35 (46%) met criteria for regular use, defined by at least 4 h of CPAP administered on 70% of the days monitored. Relative to less regular users, these 16 patients had more years of education (p = 0.05), and were more likely to work in professional occupations.(ABSTRACT TRUNCATED AT 250 WORDS)
The aim of this study was to compare the relative efficacy of continuous positive airway pressure (CPAP) and positional treatment in the management of positional obstructive sleep apnea (OSA), using objective outcome measures.
A prospective, randomized, single blind crossover comparison of CPAP and positional treatment for 2 weeks each.
A university teaching hospital.
Thirteen patients with positional OSA, aged (mean+/-SD) 51+/-9 years, with an apnea-hypopnea index (AHI) of 17+/-8.
(1) Daily Epworth Sleepiness Scale scores; (2) overnight polysomnography, an objective assessment of sleep quality and AHI; (3) maintenance of wakefulness testing; (4) psychometric test battery; (5) mood scales; (6) quality-of-life questionnaires; and (7) individual patient's treatment preference.
Positional treatment was highly effective in reducing time spent supine (median, 0; range, 0 to 32 min). The AHI was lower (mean difference, 6.1; 95% confidence interval [CI], 2 to 10.2; p = 0.007), and the minimum oxygen saturation was higher (4%; 95% CI, 1% to 8%; p = 0.02) on CPAP as compared with positional treatment. There was no significant difference, however, in sleep architecture, Epworth Sleepiness Scale scores, maintenance of wakefulness testing sleep latency, psychometric test performance, mood scales, or quality-of-life measures.
Positional treatment and CPAP have similar efficacy in the treatment of patients with positional OSA.
Sleep-disordered breathing (SDB) and sleep apnea have been linked to hypertension in previous studies, but most of these studies used surrogate information to define SDB (eg, snoring) and were based on small clinic populations, or both.
To assess the association between SDB and hypertension in a large cohort of middle-aged and older persons.
Cross-sectional analyses of participants in the Sleep Heart Health Study, a community-based multicenter study conducted between November 1995 and January 1998.
A total of 6132 subjects recruited from ongoing population-based studies (aged > or = 40 years; 52.8% female).
Apnea-hypopnea index (AHI, the average number of apneas plus hypopneas per hour of sleep, with apnea defined as a cessation of airflow and hypopnea defined as a > or = 30% reduction in airflow or thoracoabdominal excursion both of which are accompanied by a > or = 4% drop in oxyhemoglobin saturation) [corrected], obtained by unattended home polysomnography. Other measures include arousal index; percentage of sleep time below 90% oxygen saturation; history of snoring; and presence of hypertension, defined as resting blood pressure of at least 140/90 mm Hg or use of antihypertensive medication.
Mean systolic and diastolic blood pressure and prevalence of hypertension increased significantly with increasing SDB measures, although some of this association was explained by body mass index (BMI). After adjusting for demographics and anthropometric variables (including BMI, neck circumference, and waist-to-hip ratio), as well as for alcohol intake and smoking, the odds ratio for hypertension, comparing the highest category of AHI (> or = 30 per hour) with the lowest category (< 1.5 per hour), was 1.37 (95% confidence interval [CI], 1.03-1.83; P for trend = .005). The corresponding estimate comparing the highest and lowest categories of percentage of sleep time below 90% oxygen saturation (> or = 12% vs < 0.05%) was 1.46 (95% CI, 1.12-1.88; P for trend <.001). In stratified analyses, associations of hypertension with either measure of SDB were seen in both sexes, older and younger ages, all ethnic groups, and among normal-weight and overweight individuals. Weaker and nonsignificant associations were observed for the arousal index or self-reported history of habitual snoring.
Our findings from the largest cross-sectional study to date indicate that SDB is associated with systemic hypertension in middle-aged and older individuals of different sexes and ethnic backgrounds.
Disordered breathing during sleep is associated with acute, unfavorable effects on cardiovascular physiology, but few studies have examined its postulated association with cardiovascular disease (CVD). We examined the cross-sectional association between sleep- disordered breathing and self-reported CVD in 6,424 free-living individuals who underwent overnight, unattended polysomnography at home. Sleep-disordered breathing was quantified by the apnea-hypopnea index (AHI)-the average number of apneas and hypopneas per hour of sleep. Mild to moderate disordered breathing during sleep was highly prevalent in the sample (median AHI: 4.4; interquartile range: 1.3 to 11.0). A total of 1,023 participants (16%) reported at least one manifestation of CVD (myocardial infarction, angina, coronary revascularization procedure, heart failure, or stroke). The multivariable-adjusted relative odds (95% CI) of prevalent CVD for the second, third, and fourth quartiles of the AHI (versus the first) were 0.98 (0.77-1.24), 1.28 (1.02-1.61), and 1.42 (1.13-1.78), respectively. Sleep-disordered breathing was associated more strongly with self-reported heart failure and stroke than with self-reported coronary heart disease: the relative odds (95% CI) of heart failure, stroke, and coronary heart disease (upper versus lower AHI quartile) were 2.38 (1.22-4.62), 1.58 (1.02- 2.46), and 1.27 (0.99-1.62), respectively. These findings are compatible with modest to moderate effects of sleep-disordered breathing on heterogeneous manifestations of CVD within a range of AHI values that are considered normal or only mildly elevated.
To determine what is known about neurobehavioral outcomes in patients with the obstructive sleep apnea hypopnea syndrome following treatment with continuous positive airway pressure (CPAP).
Medline was searched. Abstracts presented at international meetings were searched and authors were contacted for additional trials. Bibliographies of the retrieved articles were reviewed.
We reviewed all prospective studies that included: 1) a target population with obstructive sleep apnea, 2) CPAP as a study intervention, 3) evidence that the CPAP level was titrated until the AHI was < 5, and 4) standardized neurobehavioral outcomes appropriate for assessing sleep apnea.
Twenty-six studies contributed to this qualitative systematic review. Effect sizes were calculated and adjusted for small samples and multiple measurements. Studies were then scored according to the outcome of the study.
This qualitative systematic review supports the assertion that CPAP has a significant and positive impact on subjective sleepiness and depression when randomized controlled trials are considered, and on fatigue, generic health-related quality of life, vigilance, and driving performance when all prospective trials are considered. These parameters appear to be sensitive to treatment duration and compliance. These results should be considered when developing health policy and designing future clinical trials.
The relationship between sleep apnea syndrome (SAS) and posture during sleep has been noted and the beneficial effect of an optimal posture on sleep apnea has been empirically indicated. We investigated this effect in a group of subjects that included obese patients and found that the apnea-hypopnea index (AHI) may be normalized in the lateral position, even among patients severely affected with apnea. Among those with intermediate or lower AHI values sleeping in a lateral position markedly improved the symptoms, with AHI even approaching the normal range in many patients. A tendency was noted for AHI to rise regardless of posture but in proportion to the increase in body mass index (BMI). In other words, the improvement due to changes in posture became increasingly insignificant with increase in BMI.
To examine the utility of four methods used to detect increased upper airway resistance leading to arousal from sleep.
Ten overnight sleep studies were conducted on normal subjects who reported increased snoring and/or witnessed apneas following alcohol ingestion. Alcohol was used to increase upper airway resistance in these normal subjects before ovemight polysomnography. Four methods to detect the presence of increased upper airway resistance were used: esophageal pressure manometry; respiratory inductive plethysmography; a piezoelectrically treated stretch sensor adhered to the supraclavicular fossa; nasal flow measured with oxygen cannula and differential pressure transducer.
Private Sleep Laboratory.
Ten normal, healthy volunteers (5 male, 5 female).
Alcohol ingestion as red wine (14% alcohol), 180-540 mL one to two hours before overnight polysomnography. Esophageal catheterisation.
Two hundred twenty-seven electroencephalogram arousals were preceded by inspiratory flow limitation and/or increased respiratory effort. Flattening of the nasal flow profile preceded all 227 arousals. In contrast, only 40% of arousals were preceded by an increase in the size of the stretch sensor signal, 22% by more-negative deflection of the esophageal pressure signal and 21% by increase in the signal size of respiratory inductance plethysmography.
These findings indicate that the most reliable method of detecting increased upper airway resistance leading to arousal from sleep is the nasal cannula/pressure transducer method and suggest that many arousals induced by increased upper airway resistance may be caused by mechanoreceptor afferents.
Sleep-related breathing disorders in adults: recommendations for syndrome definition and measurement techniques in clinical research; the report of an American Academy of Sleep Medicine task force
Sleep-related breathing disorders in adults: recommendations for syndrome
definition and measurement techniques in clinical research; the report of an
American Academy of Sleep Medicine task force. Sleep 1999;22:667-89.
prospective study of the association between sleep-disordered breathing and hypertension
- Pe Peppard
- T Young
- M Palta
- J Skatrud
Peppard PE, Young T, Palta M, Skatrud J. prospective study of the association between sleep-disordered breathing and hypertension. N Engl J Med
2000;342:1378:84.