1. Objectives of the Talk

• Review prone positioning inARDS
• Explore theimpact of COVID-19 on proning practices
• Discussprone positioning during ECMO support:
  • Is it safe?
  • How to perform it?
• Highlightfuture research directions

2. Background

• First described byCharles Bryan (1974): repositioning improves oxygenation by expanding dependent lung regions and reducing V/Q mismatch.
• Early devices (1976 “rotating bed”) suggested PO₂ improvement and better secretion clearance.

3. Physiological Benefits

Lung Performance

• Improvesventilation-perfusion (V/Q) matching
• Expandsdependent lung regions
• Reducesalveolar compression (less abdominal pressure on diaphragm)

Hemodynamics

• ReducesRV preload and afterload
• Improvesright ventricular function in severe ARDS

4. Evidence in ARDS (Pre-COVID)

• Early studies (2001–2010): inconsistent mortality benefit
  • Short proning durations, higher tidal volumes (~10 mL/kg)
• PROSEVA trial (2013):
  • Severe ARDS, early proning (<24 hrs)
  • 17 hrs/day prone, protective ventilation (TV 6 mL/kg)
  • Showedclear mortality benefit

Key Concept:

Effectiveness depends on timing, duration, and protective ventilation strategy.

5. Awake Prone Positioning During COVID-19

• Positive studies:
  • Awake proning withHFNC or NIV → improved oxygenation, reduced intubation rates
• Negative studies:
  • Large multicenter and RCTs showedno reduction in mortality and only temporary delay of intubation

6. Prone Positioning During ECMO

• Why question arose:If proning helps ARDS, could it help during ECMO?
• COVID-19 data:
  • International consortium + French multicenter cohorts:
    • Proning on ECMO reduced mortality(49% vs 60%)
    • Especially effective when startedearly (<1 week of ECMO) and continued ~17 hrs/day
  • Randomized trial (2023):
    • No significant difference in weaning/survival
    • Limitations: small sample size, single-center dominance → not generalizable

Conclusion: Evidence remains mixed.

7. Safety & Practical Considerations

• Generally safeif:
  • Properpatient selection
  • Multidisciplinary trained team
  • Strict cannula monitoring
• Complications:
  • Most common:minor bleeding at cannula site
  • Rare:cannula dislodgement
• Requiresprotocols & checklists
  • Manual proning vs ceiling lifts
  • Continuous observation of circuit integrity

8. Debate: Proning vs Awake ECMO

• Proning on ECMO:
  • Improves gas exchange, shown survival benefit in some studies
  • Often requiresdeep sedation → risk of delirium, weakness, cognitive impairment
• Awake ECMO strategy:
  • Extubate early, mobilize patient, minimize sedation
  • Reduces long-term complications but may miss proning benefit
• Key Balance:
  • Lung restvs patient mobilization
  • Avoiding sedation harms vs preventing severe hypoxemia

9. Key Takeaways

1. ARDS + Proning: Proven mortality benefit when early, prolonged, and combined with lung-protective ventilation.
2. COVID-19 awake proning: Mixed evidence; may help oxygenation, but no clear survival advantage.
3. Proning during ECMO:
   • Retrospective data suggest benefit
   • RCTs inconclusive → more large, multicenter studies needed
4. Safety: Feasible with trained team, structured protocol, and cannula monitoring.
5. Future direction: Balanceprone positioning vs awake ECMO strategies; tailor approach with imaging, gas exchange trials, and patient-specific assessment.