From the Guidelines
The current best evidence-based recommendation for treating Acute Respiratory Distress Syndrome (ARDS) is to use lung-protective ventilation with low tidal volumes and plateau pressures below 30 cmH2O, combined with higher PEEP without lung recruitment maneuvers, and consideration of corticosteroids, venovenous extracorporeal membrane oxygenation, and neuromuscular blockers in selected patients, as suggested by the latest American Thoracic Society clinical practice guideline 1.
Key Recommendations
- Lung-protective ventilation with low tidal volumes (4-8 mL/kg predicted body weight) and plateau pressures below 30 cmH2O
- Higher PEEP without lung recruitment maneuvers in patients with moderate to severe ARDS
- Consideration of corticosteroids for patients with ARDS, particularly in COVID-19 related cases
- Use of venovenous extracorporeal membrane oxygenation in selected patients with severe ARDS
- Use of neuromuscular blockers in patients with early severe ARDS
Rationale
The latest American Thoracic Society clinical practice guideline 1 provides conditional recommendations for the use of corticosteroids, venovenous extracorporeal membrane oxygenation, and neuromuscular blockers in patients with ARDS. The guideline also suggests using higher PEEP without lung recruitment maneuvers in patients with moderate to severe ARDS. These recommendations are based on moderate to low certainty of evidence, but prioritize minimizing ventilator-induced lung injury, improving ventilation-perfusion matching, reducing inflammatory responses, and allowing the lungs time to heal while maintaining adequate oxygenation.
Additional Considerations
- Prone positioning may be considered in moderate-to-severe cases (PaO2/FiO2 < 150 mmHg) for at least 16 hours per day
- Conservative fluid management targeting neutral fluid balance after initial resuscitation
- Rescue therapies for refractory hypoxemia, such as venovenous extracorporeal membrane oxygenation, should be considered in specialized centers
- Corticosteroids (methylprednisolone 1-2 mg/kg/day for 7-14 days with gradual taper) may be beneficial, particularly in COVID-19 related ARDS, as suggested by recent studies 1
From the Research
Treatment Recommendations for Acute Respiratory Distress Syndrome (ARDS)
The latest recommendations for treating ARDS with the best available evidence include:
- The use of low tidal volumes (<6 ml/kg ideal body weight) and airway pressures (plateau pressure <30 cmH2O) during mechanical ventilation 2
- Prone positioning for at least 12 hours per day for patients with moderate/severe ARDS (PF ratio<20 kPa) 2
- A conservative fluid management strategy for all patients 2
- The use of neuromuscular blocking agents, such as cisatracurium, for 48 hours in patients with ARDS with PF ratios less than or equal to 20 kPa 2
- Extracorporeal membrane oxygenation as an adjunct to protective mechanical ventilation for patients with very severe ARDS 2
Rationale for Prone Positioning
Prone positioning has been shown to improve gas exchange, respiratory mechanics, lung protection, and hemodynamics in patients with ARDS 3, 4
- It redistributes transpulmonary pressure, stress, and strain throughout the lung and unloads the right ventricle 4
- Early initiation of prone positioning is more likely to improve oxygenation than initiation during the subacute phase 3
- Combining adjunctive therapies, such as high PEEP, recruitment maneuvers, and inhaled vasodilators, with prone positioning has an additive effect in improving oxygenation 3
Importance of Lung-Protective Ventilation
Lung-protective ventilation, using a tidal volume of 6 mL per kg of predicted body weight and a plateau airway pressure of less than 30 cm H2O, has been shown to reduce mortality in patients with ARDS 5, 6