Response of Home-Use Adaptive Pressure Modes to Simulated Transient Hypoventilation

Adaptive servoventilation (ASV) is a recently developed ventilation mode designed to stabilize ventilation in patients with central sleep apnea and Cheyne-Stokes respiration. Alternatively, modes aiming to maintain average ventilation over several breaths, such as average volume-assured pressure support (AVAPS) and intelligent volume-assured pressure support (iVAPS), could be efficient during ventilation instability by reducing central events. These modes are available on a variety of devices. This bench evaluation studied the response of these different modes and devices to simulated transient hypoventilation events.

Three home ventilation devices operating in ASV modes (AirCurve S10 VAuto, ResMed; DreamStation autoSV, Philips; Prisma CR, Löwenstein) and 2 ventilators with the AVAPS mode (DreamStation BiPAP, Philips; Lumis iVAPS, ResMed) were evaluated during transient central hypopnea/hypoventilation simulations characterized by a constant breathing frequency of 15 breaths/min and a progressive decrease of tidal volume (V_T) from 500 mL to 50 mL, in 18, 12, 9, and 6 breaths, respectively, followed by a progressive return to the baseline at the same rate.

The AirCurve S10 VAuto reacted to a V_T decrease between 80% and 50% of baseline V_T. DreamStation BiPAP and Prisma CR reacted when V_T decreased to between 60% and 30% of baseline V_T, whereas the AVAPS response to hypopnea occurred during the crescendo phase of hypopnea/hypoventilation V_T. The iVAPS response was between that of the AirCurve S10 VAuto and the other ASV devices. Among the ASV devices, the minimum V_T was higher with AirCurve S10 VAuto, followed by the Prisma CR and the DreamStation BiPAP. Minimum V_T was not influenced by AVAPS and was improved by iVAPS without outperforming the AirCurve S10 VAuto. Maximum V_T was increased by iVAPS, whereas ASV devices did not induce a significant V_T overshoot.

ASV devices improved central hypopnea/hypoventilation events without inducing hyperpnea events and therefore were better adapted than AVAPS and iVAPS devices, with notable differences in their responses to hypoventilation events.