Adequacy of prescribing positive airway pressure therapy by mask for sleep apnea on the basis of a partial-night trial.

We tested the hypothesis that a prescription for positive-pressure therapy (including pressure level, patient-device interface, and positive-pressure modality, e.g., CPAP or BiPAP) for obstructive sleep apnea (OSA) can be developed on the same night as the polysomnographic (PSG) diagnosis is made. Fifty consecutive patients with OSA in whom a partial-night PSG diagnosis was made (PSGD) underwent a therapeutic trial of positive-pressure therapy during the remainder of the night (PSG-PPP). The average apnea index during PSGD was 54.96 +/- 36.3 (mean +/- SD). On a subsequent full-night PSG (PSG-PPF), the prescription was tested. Thirty-one of the 50 patients were satisfactorily treated with CPAP, without variation of the interface during both PSG-PPP and PSG-PPF. In these patients the average pressure prescription while receiving PSG-PPF was statistically higher than during PSG-PPP (11.77 +/- 3.6 versus 10.56 +/- 3.6 cm H2O, respectively, p = 0.002). In 14 of these 31 patients (45%) some alteration in pressure requirement was necessary during PSG-PPF. Eleven patients required 2.5 cm H2O higher pressure and three patients required 5 cm H2O higher pressure during PSG-PPF than during PSG-PPP. There was a change of interface across the two therapeutic trials in 15 patients.(ABSTRACT TRUNCATED AT 250 WORDS)