Positive end-expiratory pressure setting in adults with acute lung injury and ARDS
ExPress trial design and results
Design
Multicentre randomised controlled trial
Treatment
PEEP set to increase alveolar recruitment while limiting hyperinflation
Control
Minimal distension strategy
Population
767 patients with acute lung injury and ARDS
Follow-up
Hospital discharge
Primary endpoint
28-day mortality
Result
28-day mortality was 31.2% in the minimal distension group versus 27.8% in the increased recruitment group (relative risk 1.12, 95% CI 0.90 to 1.40, p=0.31). Hospital mortality was 39.0% versus 35.4%. Lung function improved and both duration of mechanical ventilation and duration of organ failure were reduced in the recruitment group.
Secondary endpoints
Hospital mortality, ventilator-free days, organ failure-free days
A strategy for setting PEEP aimed at increasing alveolar recruitment while limiting hyperinflation did not significantly reduce mortality. However, it did improve lung function and reduced the duration of mechanical ventilation and the duration of organ failure.
The trial authors, in the published abstract
How it has aged
The most encouraging of the three PEEP trials on secondary endpoints, and still neutral on the one that matters. Together ALVEOLI, LOVS and ExPress moved the field from 'how much PEEP' to 'which patients', with severity the leading candidate.
Publications
Positive end-expiratory pressure setting in adults with acute lung injury and acute respiratory distress syndrome: a randomized controlled trial
Mercat A, Richard JC, Vielle B, et al. Positive end-expiratory pressure setting in adults with acute lung injury and acute respiratory distress syndrome: a randomized controlled trial. JAMA 2008 Feb 13;299(6):646-55.
No significant mortality difference at 28 days or hospital discharge
Shorter duration of mechanical ventilation and organ failure