Continuous positive airways pressure for obstructive sleep apnoea in adults

Background Obstructive sleep apnoea is the periodic reduction (hypopnoea) or cessation (apnoea) of breathing due to narrowing or occlusion of the upper airway during sleep. The main symptom is daytime sleepiness and it has been suggested it is linked to premature death, hypertension, ischaemic heart disease, stroke and road traffic accidents. Objectives The main treatment for sleep apnoea is with the use of continuous positive airways pressure (CPAP), which requires a flow generator and mask. These are used at night to prevent apnoea, hypoxia and sleep disturbance. The objective was to assess the effects of CPAP in the treatment of obstructive sleep apnoea in adults. Search methods We searched the Cochrane Airways Group Trials Register and reference lists of articles. We consulted experts in the field. Searches were current to July 2005. Selection criteria We included randomised trials comparing nocturnal CPAP with an inactive control or oral appliances in adults with obstructive sleep apnoea (an apnoea and hypopnoea index greater than five per hour). Trials had a minimum intervention period of two weeks. Data collection and analysis Trial quality was assessed and two review authors extracted data independently. Study authors were contacted for missing information. Parallel and crossover group trials were analysed separately. Main results Thirty‐six trials involving 1718 people met the inclusion criteria. Study quality was mixed. Compared with control, CPAP showed significant improvements in certain objective and subjective sleepiness, measures of quality of life and cognitive function (parallel‐group studies: Epworth sleepiness scale (ESS) ‐3.83 units, 95% CI ‐4.57 to ‐3.09; crossover studies: ESS ‐1.84 units, 95% CI ‐2.57 to ‐1.11). Twenty‐four hour systolic and diastolic blood pressures were lower with CPAP compared with control (parallel‐group trials). Compared with oral appliances, CPAP significantly reduced the apnoea and hypopnoea index (crossover studies: ‐7.97 events/hr, 95% CI ‐9.56 to ‐6.38) and improved sleep efficiency (crossover studies: 2.31%, 95% CI 0.02 to 4.6) and minimum oxygen saturation (4.14%, 95% CI 3.25 to 5.03). Responders to both treatments expressed a strong preference for the oral appliance. However, participants were more likely to withdraw on OA than on CPAP therapy. Authors' conclusions CPAP is effective in reducing symptoms of sleepiness and improving quality of life measures in people with moderate and severe obstructive sl