What is the treatment for Acute Respiratory Distress Syndrome (ARDS)?

Treatment of Acute Respiratory Distress Syndrome (ARDS)

All patients with ARDS must receive lung-protective mechanical ventilation with tidal volumes of 4-8 mL/kg predicted body weight and plateau pressures ≤30 cmH₂O, as this is the only intervention proven to reduce mortality regardless of ARDS severity or etiology. 1

Severity Classification and Initial Assessment

• Classify ARDS severity using PaO₂/FiO₂ ratio: mild (201-300 mmHg), moderate (101-200 mmHg), severe (<100 mmHg) 1
• For mild ARDS only, consider high-flow nasal cannula (30-40 L/min, FiO₂ 50-60%) or noninvasive ventilation with close monitoring, but proceed to intubation within 1 hour if deterioration occurs 1, 2
• Intubate immediately in moderate-to-severe ARDS rather than attempting noninvasive support 2

Core Mechanical Ventilation Strategy (All Patients)

Implement these settings immediately upon intubation:

• Tidal volume: 4-8 mL/kg predicted body weight (strong recommendation) 1
• Plateau pressure: ≤30 cmH₂O (strong recommendation) 1
• Target SpO₂: 88-96% to avoid oxygen toxicity 2
• PEEP strategy: Use higher PEEP (typically 10-15 cmH₂O) in moderate-to-severe ARDS without prolonged recruitment maneuvers 1
• Strongly avoid prolonged lung recruitment maneuvers due to high probability of hemodynamic harm (strong recommendation, moderate certainty) 1

Adjunctive Therapies Based on Severity

For Severe ARDS (PaO₂/FiO₂ <100 mmHg):

Prone positioning is mandatory and should be implemented immediately:

• Position prone for >12 hours daily (strong recommendation with proven mortality reduction) 1, 3, 2
• Apply deep sedation and analgesia during prone positioning 2
• This is a performance measure that should not be delayed 3, 2

Consider neuromuscular blocking agents:

• Use cisatracurium infusion for 48 hours in early severe ARDS 1, 2
• Particularly beneficial when ventilator-patient dyssynchrony persists despite sedation 2
• Improves ventilator synchrony and reduces oxygen consumption 3, 4

Consider systemic corticosteroids:

• Use corticosteroids for all patients with ARDS (conditional recommendation, moderate certainty) 1
• This represents updated 2024 guidance with evolving evidence 3

For Refractory Severe ARDS:

VV-ECMO in selected patients:

• Consider venovenous ECMO only in patients with severe ARDS who fail conventional management and have potentially reversible disease 1, 2
• Implement only at centers with ECMO expertise 2
• Blood is pumped from femoral vein and returns to right atrium through internal jugular vein after membrane oxygenation 2

Fluid Management Strategy

Implement conservative fluid management:

• Minimize pulmonary edema while maintaining adequate organ perfusion 3, 4, 2
• Limit total crystalloid to <4000 mL in first 24 hours 3, 4
• Use non-aggressive resuscitation at 1.5 mL/kg/hr after initial 10 mL/kg bolus 4
• Monitor fluid balance carefully as excessive fluid worsens oxygenation, promotes right ventricular failure, and increases mortality 2

Monitoring Requirements

• Continuously monitor oxygen saturation, respiratory mechanics, and hemodynamics 3, 2
• Use echocardiography to assess right ventricular function and detect acute cor pulmonale 3, 4, 2
• Monitor for barotrauma, particularly with higher PEEP strategies 3
• Assess for ventilator-patient dyssynchrony 2

Weaning Strategy

• Perform daily spontaneous breathing trials once patient's condition improves, as this consistently reduces duration of mechanical ventilation 2
• Use noninvasive ventilation after extubation for patients at high risk for extubation failure 2

Critical Pitfalls to Avoid

These errors are associated with increased mortality:

• Underutilization of lung-protective ventilation and prone positioning 3, 4, 2
• Aggressive fluid resuscitation worsening pulmonary edema 3, 4
• Delaying prone positioning in severe ARDS 3, 4
• Using prolonged lung recruitment maneuvers with high PEEP 1, 3, 4
• Failing to recognize ARDS early and implement evidence-based interventions 1

Interventions NOT Recommended

• High-frequency oscillatory ventilation: Strong recommendation against routine use in moderate or severe ARDS (high certainty) 1
• Inhaled nitric oxide: Not indicated for ARDS treatment; ineffective in adult ARDS despite acute improvements in oxygenation 5
• Hydroxyethyl starch fluids: Avoid in resuscitation 4