What are the primary recommendations for managing Acute Respiratory Distress Syndrome (ARDS)?

Management 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, and patients with severe ARDS (PaO₂/FiO₂ <100-150 mmHg) require prone positioning for >12 hours daily. 1

Universal ARDS Management: Apply to All Patients

Lung-Protective Ventilation (Strong Recommendation)

• Set tidal volume at 6 mL/kg predicted body weight (acceptable range 4-8 mL/kg PBW) 1
  • Calculate predicted body weight: Males = 50 + 0.91 × [height (cm) - 152.4] kg; Females = 45.5 + 0.91 × [height (cm) - 152.4] kg 2
• Maintain plateau pressure <30 cmH₂O at all times 1, 3
• Accept permissive hypercapnia (pH >7.20) as a consequence of lung protection 2
• This is the only intervention with consistent mortality benefit across all ARDS severity levels 1

Corticosteroids (Conditional Recommendation - New 2024)

• Administer systemic corticosteroids to all mechanically ventilated ARDS patients 1
• This represents updated guidance from the 2024 American Thoracic Society guidelines with moderate certainty of evidence 1

Fluid Management

• Use conservative fluid strategy in established ARDS without tissue hypoperfusion 2
• Conservative management improves ventilator-free days without increasing non-pulmonary organ failures 2

Severity-Based Management Algorithm

Mild ARDS (PaO₂/FiO₂ 201-300 mmHg)

• Apply lung-protective ventilation as above 1
• Use lower PEEP strategy (typically <10 cmH₂O) 2
• Monitor for progression to moderate/severe disease 1

Moderate ARDS (PaO₂/FiO₂ 101-200 mmHg)

• Apply lung-protective ventilation as above 1
• Use higher PEEP (typically 10-15 cmH₂O) without recruitment maneuvers 1, 2
  • The 2024 guidelines provide conditional recommendation for higher PEEP with low-to-moderate certainty 1
• Consider neuromuscular blockade for up to 48 hours if PaO₂/FiO₂ approaches <150 mmHg 1
• Monitor closely for progression requiring prone positioning 1

Severe ARDS (PaO₂/FiO₂ <100-150 mmHg)

• Apply lung-protective ventilation as above 1
• Implement prone positioning for at least 12-16 hours daily immediately 1, 2
  • This is a strong recommendation with moderate confidence; prone positioning reduces mortality (RR 0.74) 1, 2
  • Duration matters: trials with >12 hours/day showed mortality benefit, shorter durations did not 2
• Use higher PEEP (typically 10-15 cmH₂O) 1, 2
• Administer neuromuscular blocking agents for up to 48 hours 1, 2
  • Use intermittent boluses rather than continuous infusion when possible 2
  • Reserve continuous infusion for persistent ventilator dyssynchrony, need for deep sedation, prone positioning, or persistently high plateau pressures 2

Refractory Severe ARDS

• Consider VV-ECMO only at experienced centers for carefully selected patients 1, 2
  • This is a conditional recommendation with low certainty of evidence 1
  • Reserve for patients with severe refractory ARDS despite optimized ventilation, proning, and other rescue therapies 2

Strong Recommendations AGAINST Specific Interventions

High-Frequency Oscillatory Ventilation

• Do NOT use high-frequency oscillatory ventilation routinely 1, 2
• This is a strong recommendation against with high confidence in effect estimates 1

Prolonged Recruitment Maneuvers

• Do NOT use prolonged lung recruitment maneuvers 1
• The 2024 guidelines provide a strong recommendation against this practice with moderate certainty 1
• While brief recruitment maneuvers received conditional recommendation in 2017 guidelines, the 2024 update specifically recommends against prolonged maneuvers 1

Critical Pitfalls to Avoid

• Never prioritize normocapnia over lung-protective ventilation—accept permissive hypercapnia as necessary 2
• Never use tidal volumes >8 mL/kg PBW even if plateau pressures are acceptable—both parameters must be optimized simultaneously 1, 2
• Never delay prone positioning in severe ARDS—early implementation improves outcomes and this is now a strong recommendation 1, 2
• Never apply higher PEEP indiscriminately—tailor to ARDS severity (higher for moderate-severe, lower for mild) 1, 2
• Never use recruitment maneuvers routinely or for prolonged periods—these are associated with harm in the most recent evidence 1

Oxygenation Targets

• Target SpO₂ of 88-95% to avoid hyperoxia while maintaining adequate oxygenation 2
• Start supplemental oxygen if SpO₂ <92%, definitely if <90% 2
• Maintain SpO₂ no higher than 96% in acute hypoxemic respiratory failure 2

Key Evidence Updates

The 2024 American Thoracic Society guidelines represent the most recent high-quality evidence and supersede the 2017 recommendations in several areas 1. The major updates include new conditional recommendations for corticosteroids, VV-ECMO, and neuromuscular blockade, plus a strong recommendation against prolonged recruitment maneuvers (which previously had conditional support) 1. The core lung-protective ventilation strategy and prone positioning for severe ARDS remain unchanged as strong recommendations from 2017 1.