PROSEVA: Prone Positioning in Severe Acute Respiratory Distress Syndrome

Clinical Question

Does the early application of prone positioning improve mortality in severe ARDS?

  • Type of Trial: RCT - computer generated - stratified by ICU

  • Blinding: blinding of outcome assesors

  • Setting: 27 centers in France and Spain all with >5 years experience of proning from 01/01/2008 to 07/25/2011

  • Intention to treat analysis: yes


  • Population:

    • Randomized 474/3449 adult patients with severe ARDS who were intubated/ventilated for <36 hours at inclusion (PaO2/FiO2<150 mmHg with FiO2>0.6, PEEP >5, tidal volume 6 cc/kg, confirmed 12-24h after ventilaton)

      • Excluded if:

        • Contraindication to proning

  • Intervention:

    • Prone for 16 consecutive hours - for 28 days - or until improvement to set standard

  • Control:

    • Supine (semi-recumbent position)

  • Outcome:

    • Primary outcome: All cause mortality at 28d

      • 16% in intervention and 32.8% in supine (P<0.001); adjusted odds ratio 0.42 (0.26-0.66)


In patients with severe ARDS, early application of prolonged prone-positioning sessions significantly decreased 28-day and 90-day mortality.


  • Standardised ventilation and weaning strategy with use of PEEP-FiO2 table

  • Appropriate power calculation

  • Intention to treat analysis


  • 2015 patients not screened for inclusion in trial. ?selection bias

  • Differences in baseline characteristics. Comparing prone to supine group, at inclusion in the study:

    • SOFA score 10.4 vs. 9.6

    • Use of Vasopressors 83% vs. 72.6%

    • Use of neuromuscular blockers 82.3% vs. 91%

  • Centers all had >5 years with proning therefore results may not be generalisable to centers with limited experience

Take Note

  • Piedmont does NOT have 5 years of proning experience

  • Difficult to ignore these results; further studies are needed but this is awesome


Rachel MulderComment