0683 Resolution of Central Sleep Apnea with Multimodality Therapy - CPAP plus Oxygen or Acetazolamide

Abstract Introduction CPAP therapy -first-line therapy for central sleep apnea (CSA)- rarely eliminates CSA. Other options include acetazolamide and low-flow oxygen (O2). The purpose of this investigation was to determine the efficacy of adding acetazolamide, low-flow O2, or both to CPAP therapy for central sleep apnea treatment. Methods A randomized, double-blinded, crossover study evaluated the efficacy of acetazolamide, O2, and their combination in improving CSA compared with PAP therapy. Participants completed full polysomnography at 1) baseline, 2) PAP therapy, and under three experimental conditions for 4 weeks: 3) Acetazolamide (250 mg qhs), 4) O2 (2-4 L/min), and 5) Acetazolamide plus O2. Conditions (3) and (4) were administered in random order. Participants received PAP therapy throughout the study. 24 participants completed an overnight apneic threshold study under conditions 1-3. Outcomes include the Central Apnea-Hypopnea Index (CAHI), Central Apnea Index (CAI), Total Apnea-Hypopnea Index (AHI), CO2 Reserve, Plant Gain, Controller Gain, and Controller Gain (Nadir). An analysis of variance (ANOVA) model compared intervention effects across groups with reference categories. Results 35 male participants with CSA (AHI ≥ 10/hour and a CAHI≥ 5/hour) were randomized (Age = 65 ± 12.5 years, BMI = 32.2 ± 5.3 kg/m2). At baseline, Epworth Sleepiness Scale (ESS) was 7.5 ± 4.7, and the Insomnia Severity Index (ISI) score was 7.1 ± 5.8. There was a statistically significant decrease in CAHI from baseline (30.9 ± 4.2) to PAP baseline (18.2 ± 2.9) and further decrease under acetazolamide (4.9 ± 1.6), O2 (4.1± 1.6), and both (4.8±.9). 24 participants completed the physiologic studies. There was no difference in the CO2 reserve under acetazolamide (-3.2 ± 0.16 mmHg), O2 (-3.2 ± 0.2) and both (-3.5 ± 0.2). Controller and plant gains were also not different across the experimental conditions. Conclusion 1) Nasal CPAP therapy ameliorated but did not resolve CSA. 2) Adding acetazolamide, low-flow O2, or both resulted in the resolution of CSA. 3) There is no difference between Acetazolamide and O2 for apneic threshold variables. 4) These findings support combined therapy with PAP plus a pharmacologic intervention. Support (if any)