0575 Parallel Comparison of Apnea Hypopnea Index with WatchPAT and CPAP Compliance Download

Abstract Introduction Some OSA patients have sleep associated hypoxemia, defined as time spent with oxygen (O2) saturation ◻88% for 5 minutes (T88). Positive airway pressure (PAP) is the gold standard treatment for OSA. Apnea-Hypopnea index (AHI) estimation from PAP download (DL) is used by clinicians to determine the treatment efficacy. Overnight oximetry with PAP therapy is usually used to check for resolution of hypoxemia. During the COVID-19 pandemic, we used WPAT to check for resolution of hypoxemia in OSA patients who were prescribed PAP therapy. However, this practice change allowed us to compare the AHI measured simultaneously by WPAT and PAP DL Methods A retrospective study of 42 patients from August - November 2021 seen at University of Minnesota Sleep Clinic. All patients had a previous diagnosis of OSA and sleep associated hypoxemia confirmed by either Noxturnal Nox MEDICAL HSAT or PSG. All patients were being treated with either CPAP or bilevel PAP. Single night of HSAT was obtained with WPAT 100 (Itamar Medical) while simultaneously using PAP at their usual prescribed settings. PAP data included usage time, adherence, 30-day and same night AHI. WPAT data included total AHI, rapid eye movement related AHI, and T88 Results Of the 42 patients, 60% were males with mean age 58.8 ± 14.6 years, body mass index (BMI) 38.9 ± 9.6 kg/m2 and Epworth sleepiness scale 10.7 ± 5.1. We identified an elevated AHI (≥ 5) with WPAT in more than half of the patients though hypoxemia resolved, ESS improved and OSA was optimally controlled with AHI 5 per PAP DL. There was a significant difference between the AHI on WPAT and same day PAP DL (AHI; 7.9 ± 12.2; p =0.0006). There was moderate correlation with BMI (r=0.51; p= 0.0017) and poor correlation with central AHI on WPAT (r = 0.29; p= 0.10) Conclusion There was discrepancy between AHIs with results from WPAT and PAP DL measured during the same night. Higher residual WPAT AHI could have significant implications with regards to validity of the algorithm used in these devices. This can potentially lower the threshold for performing titration PSGs to ensure optimal treatment of OSA Support (if any)