BENEFITS OF NOCTURNAL NASAL CPAP IN PATIENTS WITH CYSTIC-FIBROSIS

Patients with cystic fibrosis (CF) often hypoventilate during sleep wi th marked falls in oxygen saturation (SaO(2)%). This occurs most commo nly during REM sleep, when there is a reduction in rib cage excursion and a fall in end-expiratory lung volume (EELV). The aim of this study was to examine the effect of nocturnal nasal continuous positive airw ay pressure (nCPAP) on SaO(2) and the respiratory disturbance index (R DI) during sleep in patients with CF and severe lung disease. Seven pa tients (FEV(1)% pred, 23 +/- 5; range, 14 to 28%,) were evaluated duri ng sleep on two nights, control and nCPAP (11+/-2 cm H2O; range, 8 to 16 cm H2O), with four patients breathing room air and three patients b reathing supplemental oxygen on both nights. Mean awake SaO(2) was 91/-1%(range, 89 to 93%). All patients showed significant oxyhemoglobin desaturation and respiratory disturbance in the control study. The max imal falls in SaO(2) (15 +/- 10%) were most often associated with phas ic eye movements, and a decline in rib cage excursion and the sum sign al (Respitrace) during REM sleep. Nasal CPAP resulted in a significant improvement in the mean minimum oxygen saturation (MMOS) during both NREM (nCPAP 91 +/- 3% vs control 88 +/- 2%, p<0.05) and REM sleep (nCP AP 89 +/- 6% vs control 83 +/- 6%, p<0.05). Transcutaneous CO2 measure ments were not significantly different between the control and the nCP AP studies. The RDI was also significantly reduced with nCPAP especial ly during REM sleep (9 +/- 7 events per hour vs control 25 +/- 11 even ts per hour, p<0.05). Nasal CPAP caused no change in total sleep time or sleep efficiency yet significantly reduced the RDI and improved bas eline SaO(2) during both NREM and REM sleep.