[Show abstract][Hide abstract] ABSTRACT: To build a questionnaire to assess health-related quality of life (HRQL) in patients suffering from slowly progressive neuromuscular disease (NMD) using item response theory (IRT).
A pool of 64 items and a validated questionnaire (WHOQOL-BREF) were administered to 159 patients recruited in eight NMD referral centers. Exploratory statistical analysis included methods derived from both IRT and classical test theory.
We constructed a questionnaire named QoL-NMD which is composed of two general items and 24 items classified in three domains: (1) "Impact of Physical Symptoms," (2) "Self-perception" and (3) "Activities and Social Participation." Each domain has good psychometric properties (Cronbach's alpha > 0.77, test-retest ICC > 0.81, Loevinger's H > 0.41) and meets IRT assumptions. Comparison with the WHOQOL-BREF enabled assessing similarities and discrepancies with a generic questionnaire.
This study enabled the development of a new HRQL questionnaire specifically designed for slowly progressive NMD patients. The QoL-NMD is short enough to be used in clinical practice (26 items). The next steps will be to validate QoL-NMD by re-assessing psychometrics in an independent sample of patients and calibrate the IRT scoring system.
Quality of Life Research 07/2015; DOI:10.1007/s11136-015-1013-8 · 2.86 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Purpose: We have developed a software that automatically calculates respiratory effort indices, including intrinsic end expiratory pressure (PEEPi) and esophageal pressure-time product (PTPeso). The aim of this study was to validate this software.
Materials and Methods: The software first identifies respiratory periods. Then, pressure or flow waveforms with artifacts are automatically excluded from analyses. Clean signals are averaged to provide a reference mean cycle from which respiratory parameters are extracted. The onset of the inspiratory effort is detected automatically by looking backward from the onset of inspiratory flow to the first point where the esophageal pressure derivative is equal to zero (inflection point). PEEPi is derived from this point. Twenty-three recordings from 16 patients were analyzed with the algorithm and compared with experts' manual analysis of signals: 15 recordings were performed during spontaneous breathing, 1 during non-invasive mechanical ventilation, and 7 under both conditions.
Results: For all values, the coefficients of determinations (r2) exceeded 0.94 (p<0.001). The bias (mean difference) between PEEPi calculated by hand and automatically was -0.26 ± 0.52 cmH2O during spontaneous breathing and the precisions (standard deviations of the differences) was 0.52 cmH2O with limits of agreement of 0.78 and -1.30 cmH2O. The mean difference between PTPeso calculated by hand and automatically was -0.38 ± 1.42 cmH2O.sec/cycle with limits of agreement of 2.46 and -3.22 cmH2O.sec/cycle.
Conclusions: Our program provides a reliable method for the automatic calculation of PEEPi and respiratory effort indices, which may facilitate the use of these variables in clinical practice. The software is open source and can be improved with the development and validation of new respiratory parameters.
[Show abstract][Hide abstract] ABSTRACT: We have developed a software that automatically calculates respiratory effort indices, including intrinsic end expiratory pressure (PEEPi) and esophageal pressure-time product (PTPeso). The aim of this study was to validate this software.
The software first identifies respiratory periods. Then, pressure or flow waveforms with artifacts are automatically excluded from analyses. Clean signals are averaged to provide a reference mean cycle from which respiratory parameters are extracted. The onset of the inspiratory effort is detected automatically by looking backward from the onset of inspiratory flow to the first point where the esophageal pressure derivative is equal to zero (inflection point). PEEPi is derived from this point. Twenty-three recordings from 16 patients were analyzed with the algorithm and compared with experts' manual analysis of signals: 15 recordings were performed during spontaneous breathing, 1 during non-invasive mechanical ventilation, and 7 under both conditions.
For all values, the coefficients of determinations (r(2)) exceeded 0.94 (p<0.001). The bias (mean difference) between PEEPi calculated by hand and automatically was -0.26±0.52 cmH2O during spontaneous breathing and the precisions (standard deviations of the differences) was 0.52 cmH2O with limits of agreement of 0.78 and -1.30 cmH2O. The mean difference between PTPeso calculated by hand and automatically was -0.38±1.42 cmH2O.sec/cycle with limits of agreement of 2.46 and -3.22 cmH2O.sec/cycle.
Our program provides a reliable method for the automatic calculation of PEEPi and respiratory effort indices, which may facilitate the use of these variables in clinical practice. The software is open source and can be improved with the development and validation of new respiratory parameters.
[Show abstract][Hide abstract] ABSTRACT: Battery life (BL) of portable home ventilators batteries are reported by manufacturers. The aim of the study was to evaluate the effects of ventilatory mode, respiratory frequency, positive end-expiratory pressure (PEEP), and leaks on the BL of 5 commercially available portable ventilators.
The effect of the ventilatory mode (volume controlled-continuous mandatory ventilation [VC-CMV] vs Pressure Support ventilation [PS]), PEEP 5 cmH2O, respiratory frequency (10, 15 and 20 cycles/min), and leaks during both VTV and PS on the BL of5 ventilators (Elisee 150, Monnal T50, PB 560, Vivo 50, and Trilogy 100) were evaluated. Each ventilator was ventilated with a test lung at a tidal volume of 700 ml and an inspiratory time 1.2 in the absence of leaks.
The switch of a VC-CMV mode for a PS mode or the addition of PEEP did not significantly change the ventilator BL. The increase of the respiratory frequency from 10 to 20 cycles/min decreased the BL of 18 ± 11% (P<0.005). Leaks were associated with an increase of the BL during the VC-CMV mode (18 ± 20%, P<0.05) whereas the BL decreased during the PS mode (-13 ± 15%, P<0.05).
The BL of home ventilators depends on the ventilatory settings. The BL is not affected by the ventilator mode (VC-CMV or PS) or the addition of PEEP. BL decreases with the increase in respiratory frequency and during leaks with a PS mode whereas leaks increase the duration of the ventilator BL during VC-CMV.
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: To maximise the likelihood of successful long term mechanical ventilation (MV) in patients with neuromuscular diseases, ventilators characteristics and settings must be chosen carefully taking into account both medical requisites and the patient's preference and comfort. The general objectives of the survey were 1) to evaluate patients comfort with, and knowledge about, their long term MV; 2) to compare patients and prescribers opinions and expectations regarding long term MV; 3) to compare the equipment used by the patients with prescribers present opinion. METHODS: Neuromuscular patients receiving long term MV and home MV prescribers in Belgium and France and MV prescribers were asked to respond to a questionnaire survey specifically developed for the study. RESULTS: Completed questionnaires were collected from 209 patients, mean age 35.4±15.9 years (range 3 to 86 years), ventilated since 11 ± 17 year, and 45 MV prescribers. Hundred sixty three (78%) patients correctly designed their MV mode as a volume or a pressure targeted mode and 86% considered their MV as "efficient". When an inspiratory trigger was available, 92% of the patients were able to use it but only 72% were satisfied. Prescribers were more prone than patients to use new technologies, such as an emergency system to release a noninvasive interface (visual analogue scale (VAS/10): 9.2±1.5 vs 6.8±3.3, P=0.0001), a humidification system (VAS: 8.6±1.4 vs 7.8±2.6, P=0.02), a contactor for providing larger inspiratory volumes (VAS: 8.4±1.7 vs 6.0±3.0, P=0.009), an in-built cough assistance mode (VAS: 9.2±1.4 vs 5.5±3.3 P=0.00001), new options to improve speech, or new MV modes such as a volume targeted-pressure controlled mode. CONCLUSIONS: Patient's and prescriber's opinion differ about the ideal home ventilator. Patients are less prone to use new technologies, mainly because of a lack of information, underlining the need of regular MV update in patients receiving long term MV.
[Show abstract][Hide abstract] ABSTRACT: Objective: Communication is a major issue for patients with tracheostomy who are supported by mechanical ventilation. The use of positive end-expiratory pressure (PEEP) may restore speech during expiration; however, the optimal PEEP level for speech may vary individually. We aimed to improve speech quality with an individually adjusted PEEP level delivered under the patient's control to ensure optimal respiratory comfort. Methods: Optimal PEEP level (PEEPeff), defined as the PEEP level that allows complete expiration through the upper airways, was determined for 12 patients with neuromuscular disease who are supported by mechanical ventilation. Speech and respiratory parameters were studied without PEEP, with PEEPeff, and for an intermediate PEEP level. Flow and airway pressure were measured. Microphone speech recordings were subjected to both quantitative and qualitative assessments of speech, including an intelligibility score, a perceptual score, and an evaluation of prosody determined by two speech therapists blinded to PEEP condition. Results: Text reading time, phonation flow, use of the respiratory cycle for phonation, and speech comfort significantly improved With increasing PEEP, whereas qualitative parameters remained unchanged. This resulted mostly from the increase of the expiratory volume through the upper airways available for speech for all patients combined, with a rise in respiratory rate for nine patients. Respiratory comfort remained stable despite high levels of PEEPeff (median, 10.0 cm H2O; interquartile range, 9.5-12.0 cm H2O). Conclusions: Patient-controlled PEEP allowed for the use of high levels of PEEP with good respiratory tolerance and significant improvement in speech (enabling phonation during the entire respiratory cycle in most patients). The device studied could be implemented in home ventilators to improve speech and, therefore, autonomy of patients with tracheostomy.
[Show abstract][Hide abstract] ABSTRACT: L’appareillage par des techniques de ventilation à domicile (VAD) constitue un élément clé de
la prise en charge des maladies neuromusculaires (MNM). Les techniques de rééducation
respiratoire sont bien souvent un adjuvant indispensable pour une efficacité optimale de la
VAD. La mise en place de la VAD doit être encadrée par des équipes hospitalières habituées
et formées à l’exploration, au traitement et au suivi de la pathologie respiratoire des MNM.
Le relais avec l’équipe de ville suivant le patient au quotidien est une étape essentielle à la
bonne réalisation de la VAD.
[Show abstract][Hide abstract] ABSTRACT: ABSTRACT BACKGROUND: The objective was to determine whether optoelectronic plethysmography (OEP) can detect asymmetrical ventilation related to unilateral or asymmetrical diaphragmatic weakness, suggesting usefulness as a diagnostic tool. PATIENTS AND METHODS: 13 patients with suspected asymmetrical diaphragmatic weakness based on dyspnea and hemidiaphragm elevation on the chest radiograph were studied, as well as 3 patients with maltase acid deficiency (a cause of symmetrical diaphragmatic weakness). The transdiaphragmatic pressure response to unilateral magnetic stimulation (latPdiTw) and the diaphragm compound muscle action potentials (CMAPs) elicited by transcutaneous electrical stimulation of each phrenic nerve as well as OEP were performed. RESULTS: The CMAPs and latPdiTw showed unilateral or predominantly unilateral diaphragmatic weakness in 9 of the 13 patients. By OEP, the affected side of the thorax and abdomen contributed less than 45% of the inspiratory capacity in each of these 9 patients, whereas no asymmetry was noted in the other 4 patients or in the 3 patients with maltase acid deficiency. All patients preferred OEP over CMAP or latPdiTw. CONCLUSION: OEP detected asymmetric ventilation in all patients diagnosed with unilateral diaphragm weakness and in no patients without this diagnosis. Thus, OEP is an effective noninvasive alternative that is preferred by the patients over CMAP response and latPdiTw.
[Show abstract][Hide abstract] ABSTRACT: Bien que considérée comme une pathologie rare, la myasthénie généralisée auto-immune est la pathologie la plus fréquente de la jonction neuromusculaire. Elle ne touche que la musculature striée. Les signes cardinaux en sont la fatigabilité à l’effort et la fluctuation de l’atteinte motrice. C’est une pathologie chronique dont le risque évolutif est la survenue de poussées ou de crises myasthéniques, pouvant conduire le patient en réanimation et nécessiter l’intubation endotrachéale. La sévérité est liée essentiellement à l’atteinte des muscles respiratoires et des troubles de la déglutition qu’il faut pouvoir détecter précocement. Ces signes doivent être connus de l’infirmière. La prise en charge est en premier lieu symptomatique, les traitements immunomodulateurs comme les immunoglobulines intraveineuses et les échanges plasmatiques ont démontré leur efficacité sur l’évolution de la crise. Une corticothérapie associée à un traitement immunosuppresseur est en général nécessaire pour stabiliser la maladie au long cours. La recherche d’anomalie thymique est également systématique afin d’envisager une thymectomie.
Although considered as rare, generalized autoimmune myasthenia (GM) is the most frequent neuromuscular junction disease. GM only involves skeletal muscles. The cardinal signs are muscular fatigability during effort and fluctuation. GM is a chronic disease leading to acute episodes requiring admission to the intensive care unit and endotracheal intubation. Severity is mainly due to the impairment of respiratory and swallowing muscles which should be early detected. Nurses should be aware of these GM-related features. Treatment is supportive including mechanical ventilation. Immunomodulatory therapies including intravenous immunoglobulins and plasma exchanges have been shown efficient to reverse the course of GMcrisis. Corticosteroids in association with an immunosuppressive drug are generally required to stabilize the disease on a long-term. Thymectomy should be considered in the presence of thymus abnormalities.
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: To determine whether optoelectronic plethysmography accurately evaluated vital capacity (VC) in patients with respiratory muscle dysfunction of variable severity, including those with paradoxical abdominal movements. METHODS: In 20 patients, VC was measured in the supine position using both spirometry and optoelectronic plethysmography (six optoelectronic cameras and 52 reflective markers on the anterior chest wall). RESULTS: Spirometry VC correlated positively with optoelectronic VC (r²=0.993, p<0.0001) and the regression line was very close to the identity line (VCopto (mL) =-1.202 + 1.007*VCspiro (mL)). A Bland and Altman plot showed that the mean difference was -20 mL (95%CI: -63 mL to 24 mL) and the limits of agreement were 163 mL (95%CI: 106 mL to 231 mL) and -203 mL (95% CI: -271 mL to -146 mL). The difference between the two values expressed as the percentage of the mean value was less than 15% in all 20 participants, less than 10% in 17 (85%) participants, and less than 5% in 11 (55%) participants. The difference expressed as the percentage of the mean value was unrelated to the contribution of abdominal motion to VC (r =0.02 and p=0.94) but was significantly related to body mass index (r=0.53, p=0.015). CONCLUSIONS: Optoelectronic plethysmography is accurate and suitable for VC measurement in patients with various degrees of respiratory failure, including those with paradoxical abdominal movements. This non-invasive method may be an attractive alternative for accurately measuring VC in the event of air leakage (through the mouth or tracheostomy) or when patients are unable to breathe with the dead space added by the spirometer.
Respiratory care 08/2012; 58(4). DOI:10.4187/respcare.01916 · 1.84 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Inspiratory unintentional leaks (IULs) during noninvasive ventilation (NIV) adversely affect the sleep and the effectiveness of mechanical ventilation (MV). The aim of this study was to assess the effects of nocturnal IULs in Duchenne muscular dystrophy (DMD) patients with a tracheostomy and uncuffed tube comparatively with NIV patients.
Polysomnography with transcutaneous partial pressure of carbon dioxide (PtcCO(2)) recording and blood gas measurement was performed in 26 stable tracheostomized DMD patients using home MV, among whom 11 were matched with NIV patients.
IULs occurred during 29.4% [1.7-61.9%] (median [IQR]) of the total sleep time. By univariate regression analysis, the closest correlation with IUL duration was for daytime base excess (r(2)=0.69, P<0.0001), followed by daytime bicarbonate level. In a stepwise multiple regression analysis, only base excess remained significantly correlated. Sleep and respiratory parameters improved in the four patients who agreed to use cuffed tubes. Tracheostomized patients had lower maximal PtcCO(2) (P=0.02) and base excess values (P=0.045) compared to NIV controls.
Tracheostomy does not guarantee that MV is effective during sleep, as IULs may occur, but ensures better nocturnal gas exchanges than NIV. DMD patients should be evaluated using at least blood gas measurement, nocturnal oximetry, and PtcCO(2) monitoring.
Sleep Medicine 07/2012; 13(8):1056-65. DOI:10.1016/j.sleep.2012.05.014 · 3.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Ventilation improvements have led to an increased number of ventilator-dependent neuromuscular patients. In order to ensure adequate ventilation efficiency and security while maintaining quality of life, the check-list is large. Two « life support » ventilators are mandatory, while different interfaces may be required for nighttime and daytime ventilation, in order to maintain communication. Airways clearance is a major goal. It requires physiotherapists, cough assistance devices and the participation of the relatives. The decision of tracheostomy needs to be individually evaluated. Permanent anticipation is necessary.
Revue des Maladies Respiratoires Actualites 07/2012; 4(3):194–198. DOI:10.1016/S1877-1203(12)70225-2