Recommended Ventilatory Settings for ARDS
For all patients with ARDS, mechanical ventilation should use lower tidal volumes (4-8 ml/kg predicted body weight) and lower inspiratory pressures (plateau pressure <30 cmH2O) to reduce mortality. 1, 2
Core Ventilation Strategy
- Use tidal volumes of 6 ml/kg predicted body weight (not actual weight) for all ARDS patients to reduce mortality 2, 3
- Maintain plateau pressure <30 cmH2O to prevent ventilator-induced lung injury 1, 2
- Monitor driving pressure (plateau pressure minus PEEP) as it may be a better predictor of outcomes than tidal volume or plateau pressure alone 2
- Calculate predicted body weight using height and sex, not actual weight, to avoid excessive tidal volumes 2, 3
- Set respiratory rate between 20-35 breaths per minute to maintain adequate ventilation 4
PEEP Strategy Based on ARDS Severity
- For mild ARDS: Use lower PEEP strategy (<10 cmH2O) 2
- For moderate to severe ARDS: Use higher PEEP strategy (>10 cmH2O) 1, 2
- Titrate PEEP to optimize oxygenation while monitoring for hemodynamic compromise 2
- Consider recruitment maneuvers in moderate or severe ARDS (conditional recommendation) 1
Adjunctive Strategies for Severe ARDS
- Implement prone positioning for >12 hours per day in severe ARDS (PaO2/FiO2 <150 mmHg) - strong recommendation 1, 2
- Consider neuromuscular blocking agents for ≤48 hours in severe ARDS with PaO2/FiO2 <150 mmHg to improve ventilator synchrony 2, 5
- Maintain a conservative fluid strategy for established ARDS without evidence of tissue hypoperfusion 2, 5
- Consider extracorporeal membrane oxygenation (ECMO) as an adjunct for very severe ARDS cases 1, 5
Interventions to Avoid
- Avoid high tidal volumes (>8 ml/kg PBW) as they increase risk of ventilator-induced lung injury 2, 3
- Do not routinely use high-frequency oscillatory ventilation in moderate or severe ARDS (strong recommendation against) 1, 2
- Avoid beta-2 agonists for ARDS treatment unless bronchospasm is present 2
- Prevent hyperoxia by titrating FiO2 to SpO2 levels of 88-95% 4
Special Considerations
- For obese patients, still use predicted body weight for tidal volume calculation, not actual weight 2
- Elevate head of bed 30-45 degrees to reduce risk of ventilator-associated pneumonia 2
- Implement a weaning protocol when patients are ready (arousable, hemodynamically stable, low ventilatory requirements) 2
- Early application of Airway Pressure Release Ventilation (APRV) may be considered as it has shown improved oxygenation, respiratory system compliance, and reduced duration of mechanical ventilation in some studies 6
Pitfalls to Avoid
- Using actual body weight instead of predicted body weight for tidal volume calculations can lead to excessive volumes and ventilator-induced lung injury 2, 3
- Inadequate PEEP in moderate/severe ARDS can lead to atelectrauma 1, 2
- Delaying prone positioning in severe ARDS can miss the window of opportunity for mortality reduction 1, 2
- Excessive fluid administration can worsen lung edema and gas exchange 2