article170

PROSEVA

"Prone Positioning in Severe Acute Respiratory Distress Syndrome". The New England Journal of Medicine. 2013. 368(23):2159-2168. PubMed • Full text • PDF

Clinical Question

Does the early application of prone positioning improve outcomes in patients with severe acute respiratory distress syndrome (ARDS)?

Bottom Line

Early application of prolonged prone-positioning sessions significantly decreased 28-day and 90-day mortality in patients with severe ARDS.

Major Points

Prone positioning has long been used to improve oxygenation in mechanically ventilated patients with ARDS, but previous trials failed to show survival benefits. This study demonstrated a lower mortality rate at both 28 days and 90 days in patients with ARDS and severe hypoxemia who received early application of prone positioning.

Guidelines

Not discussed in this article.

Design

Multicenter, prospective, randomized, controlled trial
N=466 patients with severe ARDS
Prone group (n=237)
Supine group (n=229)
Setting: 26 ICUs in France and 1 in Spain
Enrollment: January 1, 2008, to July 25, 2011
Analysis: Intention-to-treat
Follow-up: 90 days
Primary outcome: Mortality at day 28

Population

Inclusion Criteria:
- Adults with ARDS as defined by the American–European Consensus Conference criteria
- Mechanical ventilation for ARDS for less than 36 hours
- Severe ARDS (PaO2:FiO2 ratio of <150 mm Hg, FiO2 ≥0.6, PEEP ≥5 cm H2O, tidal volume close to 6 ml/kg of predicted body weight)

Exclusion Criteria:
See the Supplementary Appendix of the full text article

Baseline Characteristics:
- Similar between groups, except for SOFA score and use of neuromuscular blockers and vasopressors.

Interventions

- Prone group: Prone positioning within one hour after randomization for at least 16 consecutive hours
- Supine group: Patients remained in semirecumbent position

Outcomes

Primary Outcome:
- 28-day mortality: 16.0% in the prone group vs. 32.8% in the supine group (P<0.001)
Secondary Outcomes:
- 90-day mortality: 23.6% in the prone group vs. 41.0% in the supine group (P<0.001)
- Higher rate of successful extubation in the prone group

Criticisms

- Skilled units were utilized, limiting generalizability to centers without such expertise.
- Potential imbalance due to baselines differences in SOFA score, vasopressor use, and neuromuscular blocker use.
- Higher mortality in the control group could be argued, though mortality rates were consistent with recent trials.

Funding

Programme Hospitalier de Recherche Clinique National 2006 and 2010 of the French Ministry of Health