Use of average volume-assured pressure support as a therapeutic option in patients with central sleep apnea syndrome.

PURPOSE: Central sleep apnea (CSA) syndrome commonly occurs with other medical conditions such as congestive heart failure, opiate use, and brainstem disorders. Various treatment modalities have been used with varied effectiveness in an attempt to improve ventilation and reduce the apnea-hypopnea index (AHI) in patients with CSA. This study evaluated whether or not a bilevel positive airway pressure mode of noninvasive ventilation, average volume-assured pressure support (AVAPS) is effective in treating CSA. METHODS: This was a retrospective review of patients with CSA who underwent AVAPS titration studies at our institution. We included patients with CSA with apnea-hypopnea index (events/hour) (AHI) ≥ 15, and examined the effectiveness of AVAPS in reducing AHI, improving oxygenation parameters, and improving sleep architecture. RESULTS: There were 12 patients, with mean age 62.8 ± 11.5 years, body mass index (BMI) 33.5 ± 4.7 kg/m2, 8 men, and Epworth Sleepiness Scale 9.3 ± 4.9. Five patients had CSA attributed to opiate use, 4 patients had CSA with Cheyne-Stokes respiration, and 3 patients had primary CSA. The only significant change from baseline PSG was AHI reduction with AVAPS: 63.3 ± 19.1 to 30.5 ± 30.3 (p < 0.003). In 5 patients (42%), AHI was reduced to < 15 with AVAPS use. Improvement in AHI was not related to gender, BMI, opiate use, or age. Defining response to therapy as AHI reduced to < 15, we found that lack of hypertension was the only significant predictor of response (p = 0.045). No significant changes in sleep architecture between the two studies were found. CONCLUSION: AVAPS is an effective mode of treating CSA in a significant proportion of patients. More studies are needed to confirm these findings and determine what factors are associated with response to therapy.