Response of Home-Use Adaptive Pressure Modes to Simulated Transient Hypoventilation
Abstract
BACKGROUND: 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. METHODS:
Three home ventilation devices operating in ASV modes (AirCurve S10 VAuto, ResMed;
DreamStation autoSV, Philips; Prisma CR, L€owenstein) 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 (VT) 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.
RESULTS: The AirCurve S10 VAuto reacted to a VT decrease between 80% and 50% of baseline
VT. DreamStation BiPAP and Prisma CR reacted when VT decreased to between 60% and
30% of baseline VT, whereas the AVAPS response to hypopnea occurred during the crescendo phase
of hypopnea/hypoventilation VT. The iVAPS response was between that of the AirCurve S10 VAuto
and the other ASV devices. Among the ASV devices, the minimum VT was higher with AirCurve
S10 VAuto, followed by the Prisma CR and the DreamStation BiPAP. Minimum VT was not influenced
by AVAPS and was improved by iVAPS without outperforming the AirCurve S10 VAuto.
Maximum VT was increased by iVAPS, whereas ASV devices did not induce a significant VT
overshoot. CONCLUSIONS: 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.