[Split night polysomnography to titrate continuous positive airway pressure therapy in adult patients with obstructive sleep apnea].

BACKGROUND Nasal continuous positive airway pressure therapy (CPAP) in the treatment of choice for adult obstructive sleep apnea (OSA). The diagnosis is established with polysomnography, but this study is expensive and must be repeated in those patients that require CPAP, to titrate the pressure of the therapy. Split polysomnography during one night to establish the diagnosis and titrate the pressure has been proposed to reduce costs. AIM To assess if CPAP pressure can be adequately titrated in patients with OSA using a split-night polysomnography. MATERIAL AND METHODS One hundred fifty six patients with OSA were studied with split night polysomnography. CPAP pressure titration was considered adequate when there were less than five apnea/hypopnea episodes per hour, the registry time was more than 30 min, REM sleep occurred in more than 15% of the time and measurements were made in supine position. RESULTS An adequate titration was achieved in 80% of patients. The variables associated with an adequate titration were a higher registry time during the titration period, a higher percentage of stage III/IV or REM sleep during such period and the comfort experienced by the patient during the study. On the other hand, patients with an inadequate titration had a longer basal registry period. CONCLUSIONS An adequate CPAP pressure can be prescribed to 80% of patients subjected to a split-night polysomnography. The basal registry period should not be longer than three hours, to allow an adequate titration lapse.