Adaptive support ventilation for complete ventilatory support in acute respiratory distress syndrome: a pilot, randomized controlled trial

Abstract

Background and objective: Low tidal volume ventilation has been shown to improve survival in acute respiratory distress syndrome (ARDS). Adaptive support ventilation (ASV), a closed-loop ventilatory mode, can minimize the work of breathing, and thus potentially improve the outcomes in ARDS. The aim of this pilot, randomized clinical trial was to compare the outcomes of ASV versus volume-cycled ventilation (VCV) in ARDS.

Methods: Patients with ARDS were randomly allocated to either ASV or VCV. The primary outcomes were duration of mechanical ventilation, new-onset organ dysfunction and hospital length of stay. The secondary outcomes were ease of use of the ventilator mode (assessed using the visual analogue scale (VAS)), number of daily arterial blood gas analyses, daily requirements of sedative and neuromuscular blockers, and mortality.

Results: Forty-eight patients (28 males, 20 females) with ARDS were randomized to receive either ASV (n = 23) or VCV (n = 25) during the study period. The baseline characteristics were almost similar in the two groups. The duration of mechanical ventilation, delta sequential organ failure assessment scores, intensive care unit and hospital stay were comparable in the two groups. The mortality (VCV-36% vs ASV-34.7%), ease of use of mechanical ventilation, daily midazolam and vecuronium doses, and the number of arterial blood gas analyses performed were also similar in the two groups.

Conclusions: There was no significant difference in the outcomes of patients with ARDS ventilated with either VCV or ASV in this study.

Trial registration: ClinicalTrials.gov NCT01165528.

Keywords: acute lung injury; acute respiratory distress syndrome; adaptive support ventilation; mechanical ventilation.