Objective: The aim of the study was to evaluate the ability of home ventilators to maintain a minimal tidal volume during different conditions associated with alveolar hypoventilation.
Design: Bench evaluation coupled with an in vivo study on two healthy subjects.
Setting: Tertiary university hospital and research unit.
Interventions: Six ventilators having a "volume guarantee" module (Synchrony II, Philips Respironics; Vivo 40, Breas; Legendair, Airox; Elisee 150, Philips Respironics; Ventimotion, Weinmann; and VS III, Resmed) were tested on a lung bench in a baseline condition and in three conditions associated with alveolar hypoventilation: increase in airway resistance, decrease in lung compliance, and non-intentional leaks. An in vivo study completed the bench study for the non-intentional leak condition.
Measurements and results: The six ventilators were able to maintain a minimal tidal volume during an increase in airway resistance and a decrease in lung compliance. The maintenance of a minimal tidal volume during a non-intentional leak was more difficult and was associated with large variations in tidal volume, a default of pressure support delivery for some devices, and patient-ventilator dyssynchrony, both during the bench and the in vivo study.
Conclusions: The six home ventilators tested in the study were able to maintain a minimal tidal volume during an increase in airway resistance and a decrease in lung compliance, but not during a non-intentional leak.