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.
24 consecutive patients diagnosed with Obstructive apnea hypopnea syndrome (AHI >15/hr) after undergoing split-night study in sleep lab. After SNS patients were prescribed a 2-week Auto CPAP trial (Resmed Auto Set @). The pressures obtained by SNS(Peff) were compared to optimal pressures (95th percentile and maximum)obtained by Auto-CPAP trial at home. Demographics and clinical outcomes were also evaluated.
Out of 23 patients (one patient was excluded due to noncompliance with Auto-CPAP) 78% were males. Mean BMI was 34.5 and Mean time spent on CPAP titration was during SNS was 173 mins. 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 cm of H2O versus mean 95th percentile pressure on Auto-CPAP of 11.3 cm of H2O (P<0.001) and mean maximum pressure on Auto-CPAP of 12.5 cm of H2O (P<0.001). 20 out of 23 patients (87%) had more than 2 cm H2O difference between SNS titration(Peff) and maximum optimal pressure obtained by Auto-CPAP ( P< 0.003).
There is a significant difference in threapeutic 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.
S. Sharma, None.