Study objectives: To describe our clinical experience with autoadjusting positive airway pressure (APAP) trials carried out on patients with moderate-to-severe obstructive sleep apnea (OSA).
Methods: Consecutive CPAP-naive adults underwent a non-attended home APAP trial (ResMed, Autoset, Spirit). Diagnoses of OSA were established by simplified polygraphy.
Results: Data from 208 men and 71 women. The median age (interquartile range) was 51 years (41-59), with an Epworth Sleepiness Scale score of 13.5 (9-19), body mass index of 33 kg/m2 (29-38) and respiratory disturbance index (RDI) of 53 events/h (35-74). The APAP trial results included: hours used per night, 5.5 (4-7); 95th percentile pressure, 10.6 cm H2O (9.4-11.7); 95th percentile leak, 0.3 UL/sec (0.1-0.6); residual RDI, 6.2 events/h (3.9-11.4); and percentage change in RDI, 87% (74-93). The proportion of patients with residual RDI >10 events/h was 29% (95% CI 23.6-34.3). Adherence (> 70% of nights and > 4 h/night) was observed in 72.4% of subjects (95% CI 67-78). Patients with APAP adherence tended to require higher CPAP pressures, had higher rates of residual RDI, and had a lower percentage change in RDI than those with no adherence. As the 95th percentile CPAP pressure increased so too did residual RDI.
Conclusions: The APAP trial was effective in decreasing RDI with an acceptable adherence rate; however, residual OSAwas a frequent finding. Our results support that in up to one-third of patients evaluated by a simplified diagnostic approach, CPAP titration based on 95th percentile pressure may not be sufficient if residual RDI < 10 events/h is considered as a therapeutic target.