Our experience supports that treatment of OSA improves symptoms in patients whose primary complaint is insomnia. While Krakow's study [1] suggests that ResMed's ASV is preferable to CPAP for management of insomnia patients with OSA, it does not answer whether ASV is any better than CPAP that controls respiratory disturbance index (RDI).
They acknowledge that respiratory effort related arousals (RERAs) should be eliminated during PAP titration [2], but did not accomplish that. While both ASV and CPAP improved apnea-hypopnea index (ASV AHI 15 to 0.5; CPAP AHI 23 to 2.3), ASV controlled RERAs much better than CPAP (ASV RDI 28.8 to 8.8; CPAP RDI 38.8 to 20.7).
The details of PAP titration and ASV settings need to be described. Was CPAP not titrated higher because patients developed treatment emergent central sleep apneas and hypopneas? What CPAP settings were used? What ASV expiratory pressure and pressure support minimum and maximum were used. Were AutoCPAP or AutoASV used?
We determine optimal PAP first by titrating CPAP. Then if there is hypercapnia or central sleep apnea titrate bilevel PAP (BPAP). Often BPAP worsens central events [3] meeting insurance requirements for PAP with a backup rate with central AHI>5/h at BPAP with obstructive AHI<5/h. Patients without hypercapnia are then titrated with ASV, otherwise to volume assured pressure support. We generally prescribe ASV with PSmin 3 and PSmax 15, and do not prescribe ASV for patients whose baseline sleep apnea is primarily central and have LVEF<45% (although the SERVE-HF study supports not using ASV when LVEF< 30% [4]).
Declaration of Competing Interest
The authors have nothing to disclose.
References
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