What is the recommended plateau pressure on event to minimize lung injury during mechanical ventilation?

Recommended Plateau Pressure for Mechanical Ventilation

Plateau pressure should be maintained below 30 cmH2O in mechanically ventilated patients to minimize lung injury, with efforts to achieve even lower plateau pressures when possible. 1

Understanding Plateau Pressure

Plateau pressure is the pressure measured in the airways during an end-inspiratory pause when there is no airflow. It represents the alveolar pressure at the end of inspiration and is a key parameter for assessing the risk of ventilator-induced lung injury.

Evidence-Based Recommendations

Target Plateau Pressure

• Keep plateau pressure < 30 cmH2O as an initial upper limit goal 1
• Consider targeting even lower plateau pressures (< 25 cmH2O) when possible, as lower plateau pressures are associated with decreased in-hospital mortality 2
• If plateau pressure exceeds 30 cmH2O despite using low tidal volumes (6 mL/kg predicted body weight), further reduce tidal volume to as low as 4 mL/kg predicted body weight 1

Lung-Protective Ventilation Strategy

1. Start with tidal volume of 6 mL/kg predicted body weight 1, 3
2. Monitor plateau pressure regularly
3. Adjust ventilation parameters to maintain plateau pressure < 30 cmH2O 1
4. Accept permissive hypercapnia (elevated CO2) if needed to maintain safe plateau pressures 1
   • Maintain arterial pH > 7.20 1
   • Consider sodium bicarbonate or THAM infusion in selected patients to manage acidosis 1

Factors Affecting Plateau Pressure

Several factors can contribute to elevated plateau pressure even when using low tidal volumes:

• Severity of lung injury 4
• Higher body mass index 4
• Younger age 4
• Non-white race 4
• Strong spontaneous breathing efforts (can generate high transpulmonary pressures) 5

Special Considerations

ARDS Severity

For patients with Acute Respiratory Distress Syndrome (ARDS), plateau pressure management should be tailored to severity:

• Mild ARDS (PaO₂/FiO₂ 201-300 mmHg): Lower PEEP (5-10 cmH₂O) with plateau pressure < 30 cmH2O 3
• Moderate to severe ARDS (PaO₂/FiO₂ ≤ 200 mmHg): Higher PEEP with careful monitoring of plateau pressure 3

Spontaneous Breathing

• Strong spontaneous breathing efforts can generate high transpulmonary pressures even when plateau pressure is < 30 cmH2O 5
• In patients with strong spontaneous breathing efforts, closely monitor both plateau pressure and transpulmonary pressure 5

Neuromuscular Blockade

• Consider neuromuscular blocking agents (NMBAs) in moderate to severe ARDS when plateau pressures exceed 30-35 cmH2O 1
• A 48-hour cisatracurium infusion has been shown to reduce mortality in ARDS patients with high plateau pressures 1

Clinical Implications

Recent evidence suggests there may be no true "safe" plateau pressure threshold, as lower plateau pressures (< 25 cmH2O) are associated with better outcomes compared to pressures between 25-30 cmH2O 2.

Common Pitfalls to Avoid

1. Focusing only on plateau pressure: Remember to consider other parameters like driving pressure (plateau pressure minus PEEP) 3
2. Delaying tidal volume reduction: Don't wait for plateau pressure to exceed 30 cmH2O before reducing tidal volume 1
3. Ignoring patient effort: Strong spontaneous breathing can increase transpulmonary pressure despite acceptable plateau pressures 5
4. Neglecting reassessment: Plateau pressure should be monitored regularly as the patient's condition changes 3
5. Setting arbitrary PEEP: PEEP should be individualized based on oxygenation response and plateau pressure constraints 1, 3

By maintaining plateau pressure below 30 cmH2O and striving for even lower pressures when possible, clinicians can significantly reduce the risk of ventilator-induced lung injury and improve outcomes in mechanically ventilated patients.