Characteristics of apnea and hypopneas during sleep and relation to excessive daytime sleepiness

Sleep Disorders Center, University of Michigan, Ann Arbor, USA.
Sleep (Impact Factor: 4.59). 01/1999; 21(8):799-806.
Source: PubMed


One of the most important symptoms in patients evaluated for possible obstructive sleep apnea syndrome is excessive daytime sleepiness, but the measures of apnea severity and of sleepiness used most commonly have not generally shown strong associations. We explored whether information recorded during standard polysomnography, other than the overall rate of apneas and hypopneas per hour of sleep (AHI), might help explain the measured severity of sleepiness.
A clinical sleep laboratory in a university hospital
N = 1,146 patients evaluated for suspected sleep-disordered breathing with nocturnal polysomnograms and multiple sleep latency tests.
The AHI during supine sleep (recorded in a subgroup of n = 169 subjects), the rate of apneas (n = 1,146), and the rate of obstructive apneas (n = 1,146) were particularly useful in explaining variation in measured levels sleepiness; rates of hypopneas and central apneas were less useful (n = 1,146). In addition, the minimum recorded oxygen saturation (n = 1,097) was as important as the AHI to the level of sleepiness.
In an attempt to explain excessive daytime sleepiness among patients evaluated for sleep-disordered breathing, additional insight is provided by observation of supine sleep during polysomnography, by emphasis on apneas rather than hypopneas, by emphasis on obstructive rather than central events, and by consideration of the minimum oxygen saturation.

4 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: To develop and validate questionnaire scales that can be used in research to investigate the presence of childhood SRBDs and prominent symptom complexes, including snoring, daytime sleepiness, and related behavioral disturbances.Background: Obstructive sleep-related breathing disorders (SRBDs) are common but usually undiagnosed among children. Methods to help identify SRBDs without the expense of polysomnography could greatly facilitate clinical and epidemiological research.Methods: Subjects were children aged 2-18 years who had polysomnographically-confirmed SRBDs (n=54) or appointments at either of two general pediatrics clinics (n=108). Parents completed a Pediatric Sleep Questionnaire which contained items under consideration for inclusion in desired scales.Results: Item reduction, based on data from a randomly selected 50% of the subjects (group A), produced a 22-item SRBD score that was strongly associated with diagnosis of an SRBD (P<0.0001) in a logistic regression model that accounted for age and gender. Diagnosis was also strongly associated with subscores for snoring (four items, P<0.0001), sleepiness (four items, P=0.0003), and behavior (six items, P<0.0001) among group A subjects. The scales performed similarly well among group B subjects, and among subjects of different ages and gender. In group A and B subjects, respectively, a selected criterion SRBD score produced a sensitivity of 0.85 and 0.81; a specificity of 0.87 and 0.87; and a correct classification for 86 and 85% of subjects. The scales showed good internal consistency and, in a separate sample (n=21), good test-retest stability.Conclusions: These scales for childhood SRBDs, snoring, sleepiness, and behavior are valid and reliable instruments that can be used to identify SRBDs or associated symptom-constructs in clinical research when polysomnography is not feasible.
    Sleep Medicine 02/2000; 1(1):21-32. DOI:10.1016/S1389-9457(99)00009-X · 3.15 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Polysomnography has been accepted by many as a "gold standard" for the diagnosis of the Obstructive Sleep Apnoea/Hypopnoea Syndrome (OSAHS). Although polysomnography is a good method for diagnosing OSAHS, there is no evidence that the results of polysomnography more accurately identify patients with the syndrome than more simple investigations which may be done at lower cost in the patient's home. This article examines the evidence for and against home sleep studies and concludes that home sleep studies have a role. Precisely what that role is will depend on financial and organisational aspects for each sleep centre.
    Sleep Medicine Reviews 03/2003; 7(1):53-9. DOI:10.1053/smrv.2001.0205 · 8.51 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Sleep is a risk factor for respiratory failure in patients with chronic neuromuscular diseases (NMD). To explore the diagnostic value of monitoring sleep parameters in addition to nocturnal respiratory parameters. Thirty-one patients with chronic NMD underwent whole-night polysomnograms including EMG from accessory respiratory muscles. Sleep macrostructure was normal on average. The number of respiratory arousals per hour of sleep was above the upper limit observed in a control group (>2.1) in 71% of the patients, but was moderate in most cases. Nadir oxygen saturation <85% was the most common finding indicating respiratory dysfunction and was present in 80% of the patients. Noninvasive blood gas monitoring identified all but 2 patients with respiratory-induced sleep abnormalities. The respiratory arousal rate was correlated with the oxygen desaturation index, but otherwise there were no significant correlations between sleep and nocturnal respiratory parameters. Vital capacity was significantly positively correlated with obstructive apnea index and daytime base excess to nadir oxygen saturation. Inspiratory activity in accessory respiratory muscles was present during REM sleep and/or slow wave sleep in 70% of the patients. The severity of nocturnal respiratory dysfunction is not reflected in the extent of sleep impairment in patients with chronic neuromuscular diseases.
    Respiration 07/2003; 70(4):349-54. DOI:10.1159/000072896 · 2.59 Impact Factor
Show more