What are the step-wise maneuvers for lung recruitment in patients with respiratory failure?

Step-wise Maneuvers for Lung Recruitment in Respiratory Failure

Lung recruitment maneuvers should be performed using a pressure-controlled recruitment maneuver (PCRM) with PEEP of 15 cmH2O and pressure control above PEEP of 35 cmH2O for 2 minutes, followed by individualized PEEP titration to maintain recruitment. 1

Patient Selection

• Most beneficial in patients with moderate to severe ARDS (PaO₂/FiO₂ < 200 mmHg) 1
• Contraindications include:
  • Hemodynamic instability
  • Elevated intracranial pressure
  • High risk of barotrauma 1

Pre-Recruitment Preparation

1. Position patient with head of bed elevated 30 degrees to optimize respiratory mechanics 2
2. Ensure adequate hemodynamic monitoring (continuous arterial pressure and oxygen saturation) 1
3. Consider non-invasive positive pressure ventilation or CPAP before intubation to attenuate anesthesia-induced respiratory changes 2

Recruitment Maneuver Techniques

Pressure-Controlled Recruitment Maneuver (Preferred Method)

1. Set PEEP to 15 cmH2O
2. Apply pressure control of 35 cmH2O above PEEP (total peak pressure 50 cmH2O)
3. Maintain for 2 minutes
4. Monitor hemodynamics continuously 1, 3

This method is better tolerated hemodynamically than sustained inflation maneuvers 1.

Alternative: Sustained Inflation Maneuver

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 1

Alternative: Slow Lower Pressure Recruitment

1. Elevate PEEP to 15 cmH2O
2. Apply end-inspiratory pauses for 7 seconds twice per minute
3. Continue for 15 minutes
4. Note: This method causes less circulatory depression (21% vs. 44-63% decrease in cardiac output) 4

Post-Recruitment PEEP Titration

1. Initial PEEP setting: 5 cmH2O (minimum) 2, 1
2. Titrate PEEP based on severity of ARDS:
   • Mild ARDS: 5-10 cmH2O
   • Moderate ARDS: 10-15 cmH2O
   • Severe ARDS: 15-20 cmH2O 5
3. Monitor driving pressure (plateau pressure - PEEP), aiming to keep it below 14 cmH2O 2
4. Avoid zero end-expiratory pressure (ZEEP) 2

Ventilator Settings

1. Set tidal volume to 6-8 ml/kg predicted body weight 2, 1
2. Monitor plateau pressure, keeping it below 30 cmH2O 2
3. Monitor dynamic compliance and driving pressure continuously 2
4. Adjust FiO2 as needed for oxygenation, but note that increasing FiO2 alone will not improve dynamic compliance 2

Monitoring During and After Recruitment

1. Continuously monitor:
   • Hemodynamic parameters (blood pressure, heart rate)
   • Oxygen saturation
   • Dynamic compliance
   • Driving pressure 2, 1
2. Discontinue recruitment maneuver immediately if:
   • Significant hemodynamic deterioration occurs
   • Oxygen saturation decreases 1
3. Evaluate effectiveness by:
   • Improvement in oxygenation
   • Improvement in lung compliance
   • Reduction in driving pressure 1

Maintaining Recruitment

1. Apply adequate PEEP (typically 15-16 cmH2O in severe ARDS) to prevent derecruitment 1
2. Note that without adequate post-maneuver PEEP, benefits are quickly lost 1
3. Consider repeating recruitment maneuver if deterioration in oxygenation or compliance occurs 6

Special Considerations

1. In patients with right ventricular dysfunction, monitor for signs of RV failure during recruitment 2
2. Recruitment maneuvers should be part of a comprehensive lung-protective ventilation strategy 1
3. The effects may be limited when baseline PEEP levels exceed 10-12 cmH2O 1

By following these step-wise maneuvers, lung recruitment can improve oxygenation and respiratory mechanics in patients with respiratory failure while minimizing potential hemodynamic compromise and barotrauma.