Comparison of CPAP titration pressures as obtained by split night study versus auto-CPAP titration at home for 2 weeks

The growing epidemic of sleep-related breathing disorders plus the high cost of polysomnography has led most labs across the country to switch to split-night studies (SNS). This has resulted in significant reduction in time allowed for titration. Hence the final effective pressure (Peff) as obtained by SNS may not reflect the ideal pressure needed to consistently overcome the sleep airflow limitation. This may potentially lead to therapeutic failure and poor compliance. Auto-CPAP has emerged as potential alternative which may provide a more physiological background to identify the optimal pressure for CPAP therapy.

33 consecutive patients diagnosed with Obstructive apnea hypopnea syndrome (AHI >15/hr) after undergoing split-night study in sleep laboratory were prescribed a 2-week Auto CPAP trial (Resmed Auto Set T). The pressures obtained by SNS (Peff) were compared to optimal pressures (95th percentile) and Maximum pressures (100^th percentile) as obtained by Auto-CPAP trial at home for two weeks. We also looked at pressure differences after segregating patients into positional/nonpositional sleep apnea and patients requiring pressures below or above 10 cm H2O. Demographics and patient preferences were also recorded.

Out of 32 patients (one patient was excluded due to noncompliance with Auto-CPAP) 72% were males. Mean BMI was 36.5 and Mean time spent on CPAP titration was during SNS was 159.8 min. Mean AHI (Apnea hypopnea Index) at final CPAP pressure(Peff) was 1.5 versus 6.1 with Auto-CPAP (P<0.001). Mean pressure on (Peff) on SNS titration was 8.8 (1.7) cm of H2O versus mean 95th percentile pressure See end of article for authors on Auto-CPAP of 11.3(1.4) cm of H2O (P<0.001) and mean maximum affiliations pressure on Auto-CPAP of 12.5(1.6) cm of H2O (P<0.001). We also found the pressure differences were more profound in the patient group with initial pressure requirements of 10 cm H2O or less. We also found no significant difference between positional and non-positional groups.

There is a significant difference in therapeutic pressures noted between CPAP titration by SNS and subsequent Auto-CPAP trial for 2 weeks.

By allowing greater sleep sampling time and a physiological background, use of Auto-CPAP device to derive maximum optimal pressures may provide an appropriate alternative to SNS.