Lung Protective Ventilation

Lung protective ventilation is a crucial strategy in mechanical ventilation, particularly for patients with acute respiratory distress syndrome (ARDS), aimed at minimising ventilator-induced lung injury (VILI). This approach involves specific ventilatory settings to reduce the risk of barotrauma, volutrauma, and biotrauma. Here are the key components and principles of lung protective ventilation:

Key Components

  1. Low Tidal Volume Ventilation
    • Description: Utilising lower tidal volumes to reduce over-distension of the alveoli.
    • Typical Setting: 4-6 mL/kg of predicted body weight.
    • Benefits: Reduces the risk of volutrauma and improves outcomes in ARDS patients.
  2. Positive End-Expiratory Pressure (PEEP)
    • Description: Applying sufficient PEEP to keep alveoli open at the end of expiration.
    • Typical Setting: Adjusted individually, often starting at 5-10 cmH2O and titrated based on oxygenation and compliance.
    • Benefits: Prevents alveolar collapse, improves oxygenation, and reduces atelectrauma.
  3. Limiting Plateau Pressure
    • Description: Maintaining plateau pressures below 30 cmH2O to prevent barotrauma.
    • Monitoring: Plateau pressure is measured during an inspiratory hold manoeuvre.
    • Benefits: Reduces the risk of barotrauma and enhances lung protection.
  4. Driving Pressure
    • Description: The difference between plateau pressure and PEEP.
    • Typical Setting: Aim to keep driving pressure below 15 cmH2O.
    • Benefits: Lower driving pressures are associated with better outcomes and reduced lung injury.
  5. Permissive Hypercapnia
    • Description: Allowing higher levels of CO2 to avoid high tidal volumes or pressures.
    • Typical Setting: Accepting PaCO2 levels that may be higher than normal, provided pH remains above 7.2.
    • Benefits: Reduces ventilator-induced lung injury by avoiding excessive ventilation pressures and volumes.

Clinical Application

  • ARDS Management: Lung protective ventilation is particularly critical in managing ARDS. Guidelines recommend the use of low tidal volume ventilation to improve survival and reduce the duration of mechanical ventilation.
  • Patient Monitoring: Continuous monitoring of ventilatory parameters, blood gases, and lung mechanics is essential to adjust settings and ensure lung protection.

Practical Considerations

  1. Individualised Settings: Adjust ventilator settings based on the patient’s lung mechanics, compliance, and gas exchange requirements.
  2. Multidisciplinary Approach: Collaboration among healthcare providers, including intensivists, respiratory therapists, and nurses, to optimise ventilation strategies and monitor for complications.
  3. Education and Protocols: Implementing protocols and regular training for healthcare teams on lung protective strategies to ensure consistent and effective application.

References

  1. Intensive Care Society – ARDS Guideline
  2. British Thoracic Society