What are the guidelines for prone ventilation with and without Extracorporeal Membrane Oxygenation (ECMO)?

Guidelines for Prone Ventilation With and Without ECMO

For patients with moderate to severe ARDS, prone ventilation should be implemented for 12-16 hours daily, and can be safely combined with ECMO therapy in selected cases of refractory hypoxemia. 1

Prone Positioning Without ECMO

Indications and Timing

• Prone positioning is strongly recommended for invasively ventilated patients with ARDS and impaired arterial oxygenation (PaO₂/FiO₂ < 150 mmHg) 1
• Implementation should occur at an early stage once indicated, as early intervention is associated with better outcomes 1
• Duration should be at least 12 hours, preferably 16 hours per session 1

Implementation Protocol

• Complete (180°) prone positioning is recommended over incomplete positioning as it has a stronger effect on oxygenation and better clinical outcomes 1
• Maintain lung-protective ventilation strategies during prone positioning, including:
  • Low tidal volume ventilation (4-8 mL/kg predicted body weight)
  • Plateau pressures < 30 cm H₂O
  • Prevention of derecruitment
  • Integration of spontaneous breathing components when appropriate 1

Patient Selection and Contraindications

• Relative contraindications where prone positioning should be considered only after interdisciplinary risk-benefit assessment include:
  • Open abdomen
  • Spinal instability
  • Increased intracranial pressure (ICP)
  • Cardiac arrhythmias with hemodynamic consequences
  • Shock 1
• For patients with increased ICP risk, continuous monitoring is required with the head positioned in a centered position and lateral rotation avoided 1

Discontinuation Criteria

• Consider terminating prone positioning if improvement in supine oxygenation persists (4 hours after repositioning: PaO₂/FiO₂ ≥ 150 with PEEP ≤ 10 cm H₂O and FiO₂ ≤ 0.6) 1
• Discontinue prone therapy if at least two positioning attempts have been unsuccessful in improving oxygenation 1

Special Considerations

• Hemodynamic stabilization and volume status optimization should occur prior to prone positioning, though catecholamine use is not a contraindication 1
• For post-abdominal surgery patients or those with abdominal pathologies/obesity, carefully weigh benefits (improved oxygenation) against risks (increased intra-abdominal pressure) 1
• Carefully examine pressure points to minimize pressure ulcer development 1

Prone Positioning With ECMO

Indications for Combined Therapy

• Prone positioning is suggested for ARDS patients receiving veno-venous ECMO therapy 1
• Consider ECMO if hypoxemia persists (PaO₂ < 55 mmHg) despite optimal mechanical ventilation and other rescue therapies including prone positioning 1

Implementation Protocol

• The same principles of prone positioning apply when combined with ECMO 2, 3
• Requires a coordinated team approach with at least one physician and three nurses following a standardized protocol to minimize risks 2
• Maintain ECMO settings during positioning changes, with close monitoring of cannula position and circuit integrity 2

Safety Considerations

• Studies have demonstrated that prone positioning during ECMO is safe when performed by experienced teams 2, 3
• No significant increase in serious adverse events such as cannula dislocation has been observed in clinical studies 2, 3
• Potential benefits include improved oxygenation that persists even after returning to supine position 3

Timing and Sequence

• Optimization of conventional treatments (lung-protective ventilation, prone positioning) should always be undertaken before considering ECMO 1
• Some evidence suggests that prone positioning before ECMO initiation may have protective effects and is not associated with increased mortality 4
• For patients already on ECMO, prone positioning can be implemented as a complementary strategy to improve oxygenation 5

Organizational Requirements for ECMO Centers

• ECMO should only be considered in carefully selected patients with COVID-19 and severe ARDS due to its resource-intensive nature 1
• ECMO programs require:
  • Highly experienced staff and minimum case volumes per year
  • Organized regional or national networks with mobile ECMO teams
  • Regular staff training and continuing education
  • Quality assurance through regular audits 1
• For hospitals without ECMO capabilities, establishing relationships with ECMO-capable institutions is advisable to facilitate timely transfer of eligible patients 1

Recent Evidence and Outcomes

• Meta-analyses show that combining prone positioning with ECMO may improve early survival rates, particularly in non-COVID ARDS patients 5
• Earlier and more frequent prone positioning sessions during ECMO may shorten mechanical ventilation duration and ICU stays 5
• The 2024 American Thoracic Society guidelines suggest VV-ECMO in selected patients with severe ARDS (conditional recommendation, low certainty of evidence) 1

Common Pitfalls and Caveats

• Failure to implement prone positioning early enough in the course of ARDS 1
• Inadequate duration of prone sessions (should be at least 12 hours) 1
• Poor coordination during positioning changes, increasing risk of complications 2
• Delaying ECMO consideration in appropriate candidates with refractory hypoxemia despite optimal conventional management 1
• Lack of established protocols for combined prone positioning and ECMO therapy 1