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(TM)) 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 (PSG(D)) underwent a therapeutic trial of positive-pressure therapy during the remainder of the night (PSG-PP(P)). The average apnea index during PSG(D) was 54.96 +/- 36.3 (mean +/- SD). On a subsequent full-night PSG (PSG-PP(F)), the prescription was tested. Thirty-one of the 50 patients were satisfactorily treated with CPAP, without variation of the interface during both PSG-PP(P) and PSG-PP(F). In these patients the average pressure prescription while receiving PSG-PP(F) was statistically higher than during PSG-PP(P) (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-PP(F). Eleven patients required 2.5 cm H2O higher pressure and three patients required 5 cm H2O higher pressure during PSG-PPF than during PSG-PP(P). There was a change of interface across the two therapeutic trials in 15 patients. Although the average pressure required by the 10 of these patients who continued to receive CPAP (i.e., did not require a change to BiPAP) was statistically the same across both trials (13 +/- 3.5 versus 14 +/- 2.9 cm H2O, PSG-PP(P) and PSG-PP(F), respectively, p = 0.22), six of them required 2.5 cm H2O more pressure, and one required 5 cm H2O less pressure during the full-night trial. This distribution of pressure changes appeared similar to that observed in patients who maintained the same interface during both PSG tests. Eight patients required a change in positive-pressure modality across the two trials. Of these, seven changed from CPAP to BiPAP during PSG-PP(F). We conclude that although a majority of patients with OSA can obtain a satisfactory prescription for positive-pressure therapy on the same night as the diagnosis is made, a substantial proportion of them will require alterations of that prescription, including changes in pressure, patient-device interface, or positive-pressure modality.