What's the step-wise approach for a lung recruitment maneuver?

Step-wise Approach to Lung Recruitment Maneuvers

Lung recruitment maneuvers should be performed using a ventilator-driven approach rather than manual techniques, with continuous monitoring of hemodynamics and oxygenation to prevent complications. 1

Patient Selection

• Most beneficial in patients with:

  • Moderate to severe ARDS (PaO₂/FiO₂ < 200 mmHg) 2
  • Severe refractory hypoxemia despite optimizing ventilation 1
  • Post-intubation atelectasis with hypoxemia 2

• Contraindications:

  • Hemodynamic instability
  • Elevated intracranial pressure
  • Severe emphysema or risk of barotrauma 1, 2

Preparation

1. Ensure adequate sedation and consider neuromuscular blockade if needed
2. Confirm hemodynamic stability before proceeding
3. Set FiO₂ to 1.0 during the maneuver 3
4. Monitor vital signs, SpO₂, and if available, arterial pressure

Recommended Technique: Ventilator-Driven Recruitment

Option 1: Pressure-Controlled Recruitment Maneuver (PCRM)

1. Set PEEP at 15 cmH₂O
2. Apply pressure control above PEEP of 35 cmH₂O (total pressure 50 cmH₂O)
3. Maintain for 2 minutes
4. This method is better tolerated hemodynamically than sustained inflation 2

Option 2: Stepwise PEEP Titration

1. Start at baseline PEEP
2. Increase PEEP by 5 cmH₂O increments every 2 minutes
3. Continue until PaO₂ reaches 250 mmHg or maximum plateau pressure/PEEP of 60/45 cmH₂O 3
4. Then decrease PEEP by 2 cmH₂O every 2 minutes until a drop in PaO₂ >10% is observed
5. Set PEEP 2 cmH₂O above this "collapse" point 3

Option 3: Sustained Inflation (Less Preferred)

1. Apply continuous positive airway pressure of 30-40 cmH₂O
2. Maintain for 30-40 seconds
3. Note: This method may cause greater hemodynamic compromise 2

Important Cautions

• Avoid staircase (incremental PEEP) recruitment maneuvers as recommended by the Surviving Sepsis Campaign 1
• Continuously monitor hemodynamics during the procedure
• Discontinue immediately if:
  • Significant hypotension occurs
  • Desaturation worsens
  • Arrhythmias develop 2

Post-Recruitment Management

1. Set appropriate PEEP (typically 15-16 cmH₂O) to maintain recruitment 2
2. Without adequate post-maneuver PEEP, benefits are quickly lost
3. Return to lung-protective ventilation strategy:
   • Low tidal volumes (4-8 mL/kg predicted body weight)
   • Plateau pressure <30 cmH₂O 1
4. Reassess oxygenation 15-30 minutes after the maneuver 4
5. Consider repeating if oxygenation deteriorates

Evaluation of Response

• Responders: ≥20% improvement in PaO₂/FiO₂ ratio 4
• Non-responders: <20% improvement in PaO₂/FiO₂ ratio
• In responders, dead space to tidal volume ratio (Vds/Vte) typically remains stable
• In non-responders, Vds/Vte may increase, suggesting overdistention 4

Recruitment maneuvers should be considered as part of a comprehensive lung-protective ventilation strategy rather than just a means of improving oxygenation 5. The slow, moderate pressure approach may minimize negative circulatory effects while achieving similar recruitment compared to higher pressure methods 6.