Sleep differences in auto-adjustable CPAP devices and manual standard CPAP titration in a sleep laboratory

Abstract

Continuous positive airway pressure (CPAP) and auto-adjusting positive airway pressure (APAP) devices are the mainstay of treatment for moderate to severe obstructive sleep apnea (OSA). The normalizing of sleep architecture may be one of the consequences of the treatment and may be related to treatment compliance and the relief of sleepiness. Determination the positive pressure required by a patient may be determined by standard CPAP (s-CPAP) or APAP, but there isn’t a universally accepted method to determine the optimal positive pressure value. Knowledge of the night sleep architecture in unselected OSAs patients by using s-CPAP or APAP devices during the determination the positive pressure by means of a full polysomnography (PSG) in the sleep lab attended by a sleep technician. 107 OSAS patients were one night full PSG controlees to titrated CPAP pressure, 63 of them (41 males and 22 females) by using APAP device and 44 patients (32 males and 12 females) by using s-CPAP. All patients were previously treated almost three months before (the pressure was calculated with a prediction formula). The groups were not different in their respective ages or BMIs. The PSG did not show differences in both groups in Total sleep time, sleep efficiency, sleep stage N1 or R, but the proportion of stage N3 was higher ( p = 0.035) and stage N2 was lower ( p = 0.022) in the APAP group. Other variables, such as taking hypnotics, CPAP tolerance, improving clinical manifestation with CPAP use, Epworth sleepiness scale, sleep position and previous randomized pressure did not show significant differences between groups. This is especially interesting taking into account that the APAP group had slept more hours the previous night. The mean CPAP pressure of the APAP group was higher (10.553 ± 1.78) than that of the s-CPAP group (9.250 ± 1.69) p = 0.000. The sleep structure was better on the APAP adjusted group than on the s-CPAP group, despite its mean CPAP pressure being higher. Only a minority of studies found in the bibliography are in agreement with this last observation. Both findings cannot be explained, but they could be a consequence of the slower increase of pressure in s-CPAP than in APAP. Therefore, it can be concluded that the use of APAP devices could be considered a good method for the adjustment of pressure levels and for normalizing sleep structure.