0709 Using The Sleep Adjusted Residual Apnea Hypopnea Index In The Real-World Monitoring Of Obstructive Sleep Apnea

Abstract

Abstract Introduction Treatment efficacy of obstructive sleep apnea (OSA) depends on controlling respiratory events for the majority of sleep time. Apnea-hypopnea index (AHI) and adherence are frequently used to determine efficacy of continuous positive airway (CPAP) therapy, but fail to capture the effect of residual events during untreated sleep-time. The Sleep Adjusted Residual AHI (SARAHI) consolidates treated and untreated AHI and CPAP use into a single number: SARAHI = [(Untreated AHI × Hours Untreated) + (Treated AHI × Hours Treated)] / (Total Sleep Hours). We attempted to determine the clinical applicability of this index as a determinant of OSA control and its relation with sleepiness improvement. Methods As part of a quality assessment project, a convenience sample was haphazardly collected from a database of patients initiated on CPAP in a Veteran’s Affairs Hospital. Patients initiating treatment after OSA diagnosis by polysomnogram or portable sleep study were included. Information from a CPAP-download within a year of diagnosis and Epworth Sleepiness Scale (ESS) at diagnosis and follow-up were collected. SARAHI was calculated using two different measures of “total sleep hours”: 8 hours (SARAHI-8hrs) or recorded sleep time during sleep study (SARAHI-PSG). Results Thirteen patients (12 male) with a mean age of 53.3 years were included. At diagnosis, mean AHI was 26.0 events/hour and ESS was 14.6. At follow-up, CPAP mean adherence was 338 min and average use was 61.8% of days; mean residual AHI was 4.4 events/hour and mean ESS 13.7. SARAHI-8hrs was 16.0 events/hour and SARAHI-PSG was 13.8 events/hr. Simple linear regression did not show a significant correlation between ESS improvement and either of these indexes or with improvement in AHI. Conclusion SARAHI showed no correlation with ESS in this small sample. We recommend further research as SARAHI is simple to use and provides more information than currently used parameters. Support None