The sleep supine position has a major effect on optimal nasal continuous positive airway pressure - Relationship with rapid eye movements and non-rapid eye movements sleep, body mass index, respiratory disturbance index, andage

Study objectives: To evaluate the impact of sleep position on optimal nasal continuous positive airway pressure (nCPAP [op-nCPAP]) in obstructive slee p apnea (OSA) patients and to investigate how rapid eye movements (REM) and Non-REM (NREM) sleep, body mass index (BMI), respiratory disturbance index (RDI), and age are related to this effect. Design: Retrospective analysis. Setting: Sleep Disorders Unit at Loewenstein Hospital Rehabilitation Center . Patients: Eighty-three consecutive adult OSA patients who underwent a compl ete nCPAP titration. From this group, GO patients who spent at least 30 min in both the supine (Sup) and lateral (Lat) positions and 46 patients who h ad data on both positions during REM and NREM sleep were included in the an alysis. Results: In most OSA patients (52; 86.7%), the recommended op-nCPAP was obt ained when the patients slept in the Sup posture. The mean op-nCPAP was sig nificantly higher in the Sup posture (10.00 +/- 2.20 cm H2O) than it was in the Lat posture (7.61 +/- 2.69 cm H2O). The op-nCPAP was significantly hig her in the Sup position than it was in the Lat position in both REM and NRE M sleep, as well as in the severe BMI group (BMI greater than or equal to 3 0) and in the less obese group (BMI < 30). Similarly, in the severe (RDI gr eater than or equal to 40) and less severe groups (RDI < 40), as well as in both age groups (< and > 60 years of age), the op-nCPAP was significantly higher in the Sup posture than it was in the Lat posture. Irrespective of t he four parameters mentioned, the actual differences in op-nCPAP between th e two body postures were almost identical, ranging between 2.31 and 2.66 cm H2O. Conclusions: For most OSA patients, the op-nCPAP level is significantly hig her in the Sup position than it is in the Lat position. This is true for RE M and NREM sleep, for obese and nonobese patients, for patients with differ ent degrees of severity, and for young and old OSA patients. Since the op-n CPAP was highest in the Sup posture during REM sleep, no nCPAP titration sh ould be considered complete without the patient having slept in the Sup pos ture during REM sleep.