BACKGROUND: Prone position in non-intubated spontaneously breathing patients is becoming widely applied in practice alongside non-invasive respiratory support. This systematic review and meta-analysis evaluate the effect, timing and populations that might benefit from awake proning regarding oxygenation, mortality and intubation compared to supine position in hypoxemic acute respiratory failure. METHODS: Systematic literature search of PUBMED/MEDLINE, COCHRANE Library, EMBASE, CINHAL and BMJ Best practice until August 2021 (PROSPERO Registration: CRD42021250322). Studies included comprise leastwise 20 adult patients with hypoxemic respiratory failure secondary to acute respiratory distress syndrome (ARDS) or Coronavirus disease (SARS-CoV-2). PRISMA guidelines were followed, and studies quality was assessed using the Newcastle-Ottawa score and the Cochrane risk-of-bias tool. RESULTS: Fourteen studies fulfilled selection criteria and 2352 patients were included, of those 99% (n=2332/2352) had SARS-CoV-2. Among 1041 (44%) proned, 1021 were SARS-CoV-2 positive. The meta-analysis revealed significant improvement in PaO(2)/FiO(2) ratio (MD= -23.10, 95% CI: -34.80–11.39; p=0.0001, I(2) = 26%) after prone position. In SARS-CoV-2 patients lower mortality was found in the proned group (150/771 proned versus 391/1457 supine; OR= 0.51 95% CI: 0.32–0.80; p=0.003, I(2) = 48%), but intubation rate was unchanged (284/824 proned versus 616/1271 supine; OR= 0.72 95% CI: 0.43–1.22; p=0.220, I(2) = 75%). Overall proning was tolerated for a median of 4 hours (IQR: 2-16). CONCLUSION: Prone positioning can improve oxygenation among non-intubated patients with hypoxemic acute respiratory failure when applied for at least 4 hours over repeated daily episodes. Awake proning appears safe, but the effect on intubation rate and survival remains uncertain.
Prone position for non-intubated spontaneously breathing patients with hypoxic respiratory failure: a systematic review and meta-analysis