Mount Sinai Hospital Critical Care Research - Current Studies

Lung Open Ventilation Strategy Study

A mutlicentre CHRI funded study. PI's Dr. Tom Stewart and Dr. Maureen Meade

Critically ill patients developing acute respiratory distress syndrome (ARDS) often require mechanical ventilatory support for maintenance of adequate gas exchange until recovery from the acute lung injury (ALI) occurs. Clinicians and researchers are, however, becoming increasingly conscious of the potential harmful effects of mechanical ventilation, and are focusing on methods of ventilation that may reduce ventilator-induced lung injury (VILI). A consensus conference on mechanical ventilation has called for further studies evaluating the use of ventilatory strategies that avoid lung over-distension while concurrently maintaining adequate inflation, thus avoiding atelectasis.

Clinicians can minimize over-distension by limiting tidal volumes to the physiologic range and plateau airway pressures to a level less than that associated with maximal distention in normal lung tissue. Pressure and volume limited ventilation (PVLV) improves survival for patients with ALI. However, limitation of tidal volumes results in progressive alveolar collapse, a reduction in total lung volume, higher oxygen requirements, and elevation in PaCO2.

LOVS replicates, as a control arm, a PVLV strategy utilized by the NIH study group that proved to be beneficial for ALI patients who were mechanically ventilated. The LOVS experimental arm incorporates similar volume limitation, but also utilizes lung recruitment maneuvers and subsequently higher levels of PEEP to investigate the potential reduction of progressive alveolar collapse and related VILI.

The primary objective of this study is to determine the effect of LOVS, in comparison to pressure and volume limited ventilation alone, on all-cause 28-day mortality for patients with acute lung injury. Secondary objectives of this study are to examine the effects of LOVS in comparison to pressure and volume limitation, alone, on respiratory mortality, the duration of mechanical ventilation, the incidence of barotrauma, and other organ dysfunction.

This study compares a "Lung Open" ventilatory strategy, with a control strategy which is identical to the ARDS Network ventilation protocol. The "lung open" strategy includes recruitment maneuvers and a more aggressive PEEP titration. This multicenter study has recruited over 600 patients in more than 20 centers in Canada.