Clinical impact of adaptive servoventilation compared to other ventilatory modes in patients with treatment-emergent sleep apnea,central sleep apnea and Cheyne-Stokes respiration

Introduction: adaptive servoventilation is a recent ventilatory mode initially designed to treat cheyne-stokes respiration (csr). recently,the efficacy of asv has been discussed for the treatment of central sleep apnea (csa) and treatment-emergent central sleep apnea (treatment-emergent csa) where other forms of traditional positive airway pressure (pap) may be insufficient. objectives: to compare the clinical impact of asv with other forms of pap in treating patients with treatment-emergent csa,csa and csr. methods: medical data of all the patients who underwent polysomnography (psg) with asv titration were evaluated. the patients were divided into two groups according to the mode of ventilation reimbursed: asv and pap (autocpap/cpap/bipap). all patients had a minimal follow-up of 6 months. both groups were compared in terms of symptoms,apnea hypopnea index,compliance,cardiac function and cardiovascular events. results: asv titration was performed in 33 patients (30m/3f) with a mean age of 69 ± 8 years. the majority (58%) present a treatment-emergent sa and 42% a csa and or csr. the median initial diagnostic ahi was 46 ± 22 events/h.after the initial diagnosis,28 patients were treated with pap and 5 with servoventilation. all of the patients treated with pap were posteriorly submitted to psg and asv titration because of suboptimal response to pap. despite a clear indication for asv,due to differences in reimbursement,15 patients continued treatment with pap (12 with autocpap,1 with bipap and 2 with cpap) and 16 changed to asv. two patients were lost in follow-up.in both groups,most of patients present a treatment-emergent sa (53% in asv group vs. 67% in pap group) or a csa/csr (29.4% in asv group vs. 20% in pap). after asv titration,the mean follow-up was 25 ± 14 months. both groups (asv vs. pap) were similar in terms of compliance (77 ± 23% vs.88 ± 14%) and in terms of epworth sleepiness scale score (6 ± 5 vs. 7 ± 5). there was a statistical difference in terms of residual ahi: mean ahi was 4 ± 3 in asv group and 9 ± 3 in pap group (p = 0.005). we found no differences in terms of left ventricular fractional shortening (asv 33 ± 10% vs. pap 32 ± 10%). although no difference was observed between the 2 groups in terms of non-fatal cardiovascular events (3 events in each group),2 fatal cardiovascular events occurred in the pap group (sudden death). conclusions: these data confirm that asv is an efficient treatment in patients with treatment-emergent csa,csa/csr significantly decreasing residual ahi. in both groups,compliance rate was high and sleepiness improved. it is relevant that the 2 patients who died of sudden death were treated with pap. © 2014 sociedade portuguesa de pneumologia.