Automatic Derivation of Continuous Positive Airway Pressure Settings: Comparison with In-Laboratory Titration

Abstract

Background and Purpose This study was designed to investigate differences in the final recommended pressure setting between that derived from an autotitrating continuous positive airway pressure (APAP) device and manual in-laboratory continuous positive airway pressure (CPAP) titration, as well as the factors that influence pressure differences in patients with obstructive sleep apnea (OSA). Methods This study enrolled 50 patients with OSA. All patients underwent both APAP titration and manual CPAP titration. We obtained the average device pressure <= 90% of the time (APAP(90)) from the downloaded manual for the APAP machine and the optimal pressure obtained by manual CPAP titration (CPAP(manual)). We placed the subjects into three groups based on the pressure difference (Delta P) obtained by subtracting CPAP(manual) from APAP(90): 1) Pr-equal (Delta P=0), 2) CPAP(manual)+ (Delta P <=-1), and 3) APAP(90)+ (Delta P >= 21). Regression analysis was conducted to identify predictive factors associated with Delta P. Results The values of APAP(90) and CPAP(manual) were 9.50 +/- 3.03 cmH(2)O and 9.48 +/- 2.71 cmH(2)O (mean SD), respectively (p=0.95). The Pr-equal, CPAP(manual)+, and APAP(90)+ groups comprised 9 (18%), 23 (46%), and 18 (36%) subjects, respectively. Regression analyses revealed that male sex [beta=3.539, 95% confidence interval (CI)=0.040-7.039], body mass index (BMI) (beta=0.186, 95% CI=0.020-0.352), and average usage per day (beta=0.768, 95% CI=0.077-1.459) were associated with Delta P. Conclusions While the mean pressure in the overall cohort did not differ significantly between APAP(90) and CPAP(manual), there was a discordance majority showing different single pressures obtained when applying the two titration methods. Being Male, having an increased BMI, and having an increased average usage per day of APAP were significantly correlated with increased Delta P in this study.