0550 Empiric ASV Settings for Central Sleep Apnea Following HSAT During SARS Covid-19 Pandemic- a Retrospective Analysis

Abstract Introduction Adaptive servo-ventilation (ASV) uses noninvasive ventilator to treat hyper ventilatory central sleep apnea (CSA)by delivering servo-controlled inspiratory pressure support on top of expiratory positive airway pressure. ASV devices appear to be effective for treatment of Central sleep apnea and Combined sleep apnea syndromes that are resistant to CPAP [1]. All the studies to date recommend ASV settings following in lab titration. However, during the SARS Covid-19 pandemic given the significant limitation of in lab studies, empiric ASV were prescribed for CSA following home sleep apnea studies. We retrospectively analyzed the empiric ASV settings and patient adherence in correlation to the BMI. Methods Retrospective chart review of 1582 pts (patients de-identified) who underwent HSAT at the NM VA clinic during 2021-2023 was done. Among the 1582 pts who underwent HSAT, 113 pts had predominant Central Sleep Apnea (CAI >10) . 21 pts were placed on empiric ASV. We retrospectively analyzed the adherence to ASV therapy in 2 week and 3 years follow up period.13 of the 21 pts did not meet the 2 week and 3-year compliance. The EPAP data is derived from the 8 pts who continued on the empiric ASV settings and success is based on their 2 week and 3-year adherence. Results Median EPAP ranged between 5-7 cwp for pts with BMI less than 30, EPAP of 7-8 cwp with BMI between 30-40 and an EPAP 10 for BMI>40. 8 pts had good compliance (>70% use of >4 hours every night) in 2 week download with median Apnea Index 0.1(SD 2.6), median pressure support used 4.6(SD1.1). Patients with cardiac concern had echocardiogram documented LVEF >45% prior to starting empiric ASV. Serum Bicarbonate ranged between 17-26. Conclusion Though not the most efficient way compared to in lab titration study, empiric ASV settings based on the BMI may be utilized in resource limited settings or inability to perform in lab studies due to patient limiting factors. Providers should also be cognizant about hypo ventilatory concerns and respiratory depression given ASV therapy utilizes minute ventilation. Caution must be exercised in patients with heart failure due to the potential increased mortality on ASV. Support (if any)