Continuous Positive Airway Pressure In Subjects Research Articles

PAP Adherence and Nasal Resistance. A Randomized Controlled Trial of CPAPflex versus CPAP in World Trade Center Responders.

Rationale: Continuous positive airway pressure (CPAP) adherence is often poor in obstructive sleep apnea (OSA) and may be influenced by nasal resistance. CPAP with a reduction of expiratory pressure (CPAPflex) may reduce discomfort in those with high nasal resistance and improve adherence in this subgroup.Objectives: To evaluate the association of positive airway pressure (PAP) treatment adherence to nasal resistance and examine if CPAPflex improves adherence over CPAP in subjects with high nasal resistance.Methods: A randomized double-blind crossover trial of 4 weeks each of CPAPflex versus CPAP in subjects exposed to World Trade Center dust with OSA stratified by nasal resistance, measured by 4-Phase Rhinomanometry.Results: Three hundred seventeen subjects with OSA (mean, apnea-hypopnea index with 4% O2 desaturation for hypopnea = 17 ± 14/h) were randomized. Overall, PAP adherence was poor, but adherence to CPAP (n = 239; mean hours per night [95% confidence interval (CI)]), 1.97 h (1.68 to 2.26) was greater than adherence to CPAPflex (n = 249; 1.65 h [1.39 to 1.91]; difference of 0.31 h [0.03; 0.6]; P < 0.05). Contrary to our hypothesis there was no correlation between nasal resistance and adherence to CPAP (r = 0.098; P = not significant) or CPAPflex (r = 0.056; P = not significant). There was no difference in adherence between CPAP and CPAPflex (mean Δ hours [95% CI]) in subjects with low resistance (0.33 h [-0.10 to 0.76]) or high nasal resistance (0.26 h [-0.14 to 0.66]). No significant differences were observed in any of the secondary outcomes between PAP modes.Conclusions: Contrary to expectations, our data do not show better adherence to CPAPflex than to CPAP in subjects with high or low nasal resistance and do show clinically insignificant better adherence overall with CPAP.Clinical trial registered with www.clinicaltrials.gov (NCT01753999).

How to treat patients that do not tolerate continuous positive airway pressure

Educational aims To outline recommendations concerning the proper management of obstructive sleep apnoea/hypopnoea syndrome (OSAHS) patients that cannot be treated adequately with continuous positive airway pressure (CPAP) due to intolerance, poor compliance or CPAP refusal. To provide information about the selection of appropriate patients for alternative non-CPAP treatment modalities. To better understand the different aspects of OSAHS treatment with oral appliances, including indications, contraindications, medical work-up and clinical protocol, and expected short- and long-term results. To discuss the different surgical options for the treatment of OSAHS and to provide information on the important issue of a proper patient selection for upper airway surgery, as most OSAHS surgical outcomes are associated with the pre-operative assessment of the level(s) of upper airway collapse. Finally, to present future perspectives in sleep apnoea surgery. Summary The effectiveness of continuous positive airway pressure (CPAP) is potentially high for the treatment of obstructive sleep apnoea/hypopnoea syndrome (OSAHS), but accounting for the relatively low acceptance and compliance, and correcting for sleep time, its actual effect and use, the adjusted CPAP effectiveness remains relatively low. Oral appliance therapy has emerged as a noninvasive alternative to CPAP in subjects with OSAHS who do not tolerate or comply with CPAP. Surgical procedures can be performed successfully in carefully selected patients. Moreover, concerning the surgical treatment options, it appears from the available evidence that maxillomandibular advancement is a safe and highly effective surgical treatment modality for OSAHS that should be indicated more readily in clinical practice. Two methods of pre-treatment airway evaluation will be discussed. First, newer technologies using imaging techniques coupled with computational fluid dynamics methods allow investigation of the flow characteristics and aerodynamic forces within the upper airway of the OSAHS patient. Secondly, routine application of drug-induced sleep endoscopy to assess the site(s) of flutter and upper airway obstruction during drug-induced sleep can increase the success rate of both upper airway surgery and oral appliance therapy.

Link between obstructive sleep apnea and increased bone resorption in men

The bone metabolic abnormalities in patients with obstructive sleep apnea (OSA) were examined. Severity-dependent increases in the serum/urinary levels of bone resorption markers and their attenuation following continuous positive airway pressure therapy in subjects with OSA provide the first evidence of a link between OSA and abnormal bone metabolism. Hypoxia, microinflammation and oxidative stress, well-known pathophysiological features of obstructive sleep apnea (OSA), are also known to affect bone metabolism. We examined the bone metabolic abnormalities in patients with OSA and also the effects of continuous positive airway pressure (CPAP) therapy on these abnormalities. A cross-sectional and prospective study was conducted in 50 consecutive male subjects visiting a sleep clinic and 15 age-matched control subjects without OSA. Plasma concentrations of IL-1beta, IL-6, TNF-alfa, 3-nitrotyrosine, osteocalcin, bone-specific alkaline phosphatase (BAP), and urinary concentrations of cross-linked C-terminal telopeptide of type I collagen (CTX) were examined before and after 3 months' CPAP in subjects with OSA. The plasma levels of the cytokines as well as the urinary CTX levels were higher in subjects with severe OSA than in those with mild OSA or control subjects. Significant decrease of the urinary excretion of CTX (before: 211+/-107 vs. after: 128+/-59 microg/mmol/creatinine; p<0.01) as well as of the plasma levels of the cytokines was observed following 3 months' CPAP. Severity-dependent increases in the serum/urinary levels of bone resorption markers and their reversal following CPAP in subjects with OSA provide the first evidence of a link between OSA and abnormal bone metabolism.

Effect of a Targeted Obstructive Sleep Apnea Consult to Improve Access and Quality at a Sleep Disorders Center

We sought to evaluate whether a targeted obstructive sleep apnea (OSA) consult (TOSAC) protocol that reduced sleep-specialist time spent with patients suspected of having OSA would improve quality of care compared with the previous clinical method for evaluation of patients internally referred for suspected OSA. Prospective cohort design. TOSAC patients received oximetry and criteria screening prior to a split-night polysomnography and a 45-minute sleep-specialist consult, while control patients received consult, testing, and a follow-up visit (90 minutes of sleep-specialist time). We enrolled 186 TOSAC and 94 control patients. TOSAC patients completed their evaluation in a median of 7.0 days compared with 60.0 days for the controls (p < .001). At baseline, the TOSAC group was sleepier (Epworth Sleepiness Scale 13.9+/-4.5 vs 11.0+/-4.3; p < .001) and had a slightly lower quality of life (Functional Outcomes of Sleep Questionnaire 15.0+/-3.0 vs 16.8+/-2.2, p < .001) than controls. The apnea-hypopnea index noted at polysomnography was similar in TOSAC and control patients (28.6+/-29.5 vs 23.1+/-23.9, p = .156), and the prevalence of OSA was similar in both groups (75% vs 72%, p = .616). At 1 month of therapy, improvement in the Epworth Sleepiness Scale and overall patient satisfaction were similar between groups (all p > .10), while TOSAC patients had a slightly greater improvement on the Functional Outcomes of Sleep Questionnaire (p = .010). TOSAC patients reported better subjective continuous positive airway pressure compliance (median 42.0 vs 32.5 hours/week; p = .037). A protocol-driven evaluation pathway for OSA that used screening with oximetry and less sleep-specialist time shortened access and produced similar diagnoses, improvements in sleepiness and quality of life, and overall satisfaction.

Is obstructive sleep apnea syndrome a neurological disorder? A continuous positive airway pressure follow-up study

Abnormal sensory responses have been found in the upper airway of obstructive sleep apnea patients, but no long-term study has been published previously regarding the evolution of obstructive sleep apnea syndrome and persistence of abnormal pharyngeal sensory evaluation in response to continuous positive airway pressure (CPAP) treatment. Over 5 years, we managed healthy, nonobese subjects compliant with nasal CPAP. Only 47 subjects completed this prospective study, due to protocol requirements. They underwent regular clinical evaluation, subjective scales, four polysomnographies without nasal CPAP, recalibration of nasal CPAP with polysomnography, regular downloading of home data, and a palatal two-point discrimination study. None of the subjects presented normal results at any checkpoint when they had been without CPAP for two or three nights. By the completion of the study, all subjects required an increase in nasal CPAP (1-7 cm H(2)O) and demonstrated abnormal two-point palatal discrimination compared with control subjects. Despite initial control of clinical symptoms with regular usage of nasal CPAP in subjects without weight change, abnormal sensory palatal evaluation was present at the conclusion of the study. Obstructive sleep apnea syndrome involves abnormal upper airway sensory input, which may be responsible for the development of apneas and hypopneas. These neurological lesions are persistent despite nasal CPAP treatment.

Self-Reported Use of CPAP and Benefits of CPAP Therapy: A Patient Survey

The benefits of continuous positive airway pressure (CPAP) therapy in patients with the sleep apnea/hypopnea syndrome (SAHS) are poorly documented and patients use CPAP less than physicians recommend. To establish patients' perceptions of benefit from CPAP and to identify determinants of CPAP use, 204 CPAP users completed a questionnaire relating to use of CPAP therapy, sleepiness, and road traffic incident rate before and after CPAP, perceived change in daytime function and nocturnal symptoms with treatment, and problems with CPAP. Variables from these domains of interest were examined, reduced through principal components analysis and correlated to assess associations between these and polysomnographic measures of illness severity. Self-reported CPAP use averaged 5.8 +/- SD 2 h a night. Subjective sleepiness rated by the Epworth sleepiness scale and road traffic incident rate were significantly reduced by CPAP (p<0.0001). A broad range of function and symptom items were highly significantly improved with CPAP (p<0.0001), corroborating the cost to community and industry from SAHS and the preventive value of CPAP. Road traffic incident rate before treatment was correlated with pre-CPAP sleepiness and SAHS severity. Subjective CPAP use correlated with sleepiness before treatment but not with SAHS severity. CPAP mask problems and side effects were not associated with reduced CPAP use, but "nuisance" complaints of awakenings, noise, and sore eyes from CPAP correlated negatively with reported use. Greater reported CPAP use was associated with better resolution of sleepiness and greater improvement in daytime function and nocturnal symptoms.