EFFICACY OF AUTO-CPAP IN THE TREATMENT OF OBSTRUCTIVE SLEEP APNEA HYPOPNEA SYNDROME/

The auto-CPAP (Morphee Plus) is characterized by its ability to modify the positive-pressure level applied during the night for the presence or absence of sleep-induced respiratory disorders. The aim of the stu dy was to compare the efficacy of this new mode of CPAP therapy with t hat of conventional constant-CPAP in the treatment of sleep apnea/hypo pnea syndrome (SAHS). Sixteen patients with SAHS were randomly allocat ed to two groups that were paired for age, apnea/hypopnea index, and m ean sleep latency. In the auto-CPAP group, the pressure level could ch ange within fixed limits in both directions (+2 to -4 cm H2O) of the p reviously determined effective pressure level (Peff). In the constant- CPAP group, patients used the same apparatus (Morphee Plus) in a const ant mode at Peff level. At the beginning of the study, the Peff level was determined during a polysomnographic recording. Daytime vigilance was measured subjectively by a standardized questionnaire and objectiv ely by the maintenance of wakefulness test (MWT); Trailmaking tests (T MT) were used to evaluate cognitive functions. After 3 wk of home CPAP therapy, a control sleep study was done with the CPAP machine used in the protocol, and daytime vigilance and cognitive function tests were obtained. Baseline sleep and nocturnal breathing disorders characteri stics did not differ between the two groups, and daytime vigilance and cognitive function abnormalities were similarily altered. In both gro ups, the apnea/hypopnea index was within normal range at the final CPA P sleep study. In the auto-CPAP group, 49.3 +/- 14.9% (mean +/- SD) of home treatment time was spent at a pressure less than or equal to Pef f. Home amount of use estimated by the number of sleeping hours with a positive pressure applied was 6.5 +/- 1.0 h in the auto-CPAP group an d 5.1 +/- 1.1 h in the constant-CPAP group (p = 0.02). During the cont rol CPAP sleep study, the positive pressure level was significantly lo wer during Stage III-IV than during the other sleep stages (p = 0.004) . The improvement in the MWT and the TMT observed with CPAP therapy wa s identical in both groups. We conclude that (1) the amount of use dur ing CPAP treatment is higher with auto-CPAP than with constant-CPAP, a nd (2) Morphee + auto-CPAP is as efficient as conventional CPAP in cor recting nocturnal breathing disorders, daytime sleepiness, and cogniti ve impairment in SAHS.