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

ARDS Management Guidelines

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 <150 mmHg) require prone positioning for at least 12-16 hours daily. 1, 2

Core Ventilation Strategy: Lung-Protective Ventilation (STRONG RECOMMENDATION)

This is the foundation of ARDS management and applies to ALL severity levels:

• Set tidal volume at 6 mL/kg predicted body weight (acceptable range 4-8 mL/kg PBW) 1, 2
• Maintain plateau pressure ≤30 cmH₂O as an absolute ceiling 1, 2
• Calculate predicted body weight precisely: Males = 50 + 0.91 × [height (cm) - 152.4] kg; Females = 45.5 + 0.91 × [height (cm) - 152.4] kg 2
• Accept permissive hypercapnia (pH >7.20) as a necessary consequence of lung protection 2

Critical pitfall: Never exceed 8 mL/kg PBW even if plateau pressures appear acceptable—both parameters must be optimized simultaneously. 2, 3

PEEP Strategy: Titrate to Disease Severity

The 2024 ATS guideline provides updated recommendations on PEEP management:

• For moderate-to-severe ARDS (PaO₂/FiO₂ <200 mmHg): Use higher PEEP (typically >10 cmH₂O) 1, 2
• For mild ARDS (PaO₂/FiO₂ 200-300 mmHg): Lower PEEP may be appropriate 2
• Conditional recommendation with low-to-moderate certainty of evidence 1

The evidence evolved from the 2017 guideline (which gave conditional recommendation for higher PEEP) 1 to the 2024 update suggesting higher PEEP specifically for moderate-to-severe disease. 1

Important considerations:

• Monitor for barotrauma when using PEEP >10 cmH₂O 2
• In patients with cirrhosis or hemodynamic instability, use lower PEEP (<10 cmH₂O) for mild ARDS to avoid impairing venous return 2

Prone Positioning: Essential for Severe ARDS (STRONG RECOMMENDATION)

For severe ARDS with PaO₂/FiO₂ <150 mmHg, implement prone positioning immediately—this reduces mortality (RR 0.74): 1, 2, 3

• Position patient prone for at least 12-16 hours daily 1, 2
• Duration matters critically: Trials with >12 hours/day proning showed mortality benefit, while shorter durations did not 2
• This is a strong recommendation with moderate confidence in effect estimates 1

Corticosteroids: Now Recommended (NEW 2024 GUIDELINE)

The 2024 ATS guideline represents a significant update—systemic corticosteroids are now suggested for mechanically ventilated patients with ARDS: 1, 2

• This is a conditional recommendation with moderate certainty of evidence 1
• This represents the most recent high-quality guideline recommendation supporting corticosteroid use 2, 3
• The 2017 guideline did not address corticosteroids; the 2024 update fills this gap based on new evidence 1

Neuromuscular Blockade: Early Use in Severe ARDS

For early severe ARDS with PaO₂/FiO₂ <150 mmHg, use neuromuscular blocking agents for up to 48 hours: 1, 2

• Administer as intermittent boluses rather than continuous infusion when possible 2
• Use continuous infusion only for persistent ventilator dyssynchrony, need for deep sedation, prone positioning, or persistently high plateau pressures 2
• This is a conditional recommendation with low certainty of evidence 1

Recruitment Maneuvers: AVOID (STRONG RECOMMENDATION AGAINST)

The 2024 ATS guideline now strongly recommends AGAINST using prolonged lung recruitment maneuvers in moderate-to-severe ARDS: 1

• Strong recommendation with moderate certainty of evidence 1
• This represents an important evolution from the 2017 guideline, which gave a conditional recommendation FOR recruitment maneuvers 1
• New evidence demonstrated harm with prolonged recruitment maneuvers 2, 3

VV-ECMO: Rescue Therapy for Refractory Severe ARDS

For severe refractory ARDS despite optimized ventilation, proning, and rescue therapies, consider VV-ECMO in carefully selected patients at experienced centers: 1, 2

• This is a conditional recommendation with low certainty of evidence 1
• The 2017 guideline stated additional evidence was necessary; the 2024 update now provides a conditional recommendation 1
• ECMO should only be considered in carefully selected patients due to resource-intensive nature 2

Fluid Management: Conservative Strategy

Use a conservative fluid strategy in established ARDS without tissue hypoperfusion: 2, 4

• Conservative fluid management improves ventilator-free days without increasing non-pulmonary organ failures 2

Oxygenation Targets

Target SpO₂ of 88-95% to avoid hyperoxia while maintaining adequate oxygenation: 2, 5

• Start supplemental oxygen if SpO₂ <92%, and definitely if <90% 2
• Maintain SpO₂ no higher than 96% in acute hypoxemic respiratory failure 2

Interventions to STRONGLY AVOID

High-frequency oscillatory ventilation (HFOV) is strongly recommended AGAINST for moderate-to-severe ARDS: 1, 2

• Strong recommendation with high confidence in effect estimates 1
• This intervention is associated with harm 3

Additional interventions to avoid:

• Do not routinely use pulmonary artery catheters for ARDS management 2, 3
• Do not use β-2 agonists for ARDS treatment without bronchospasm 2, 3

Sedation and Weaning

• Minimize continuous or intermittent sedation, targeting specific titration endpoints 2, 3
• Use spontaneous breathing trials in patients ready for weaning 2, 3
• Implement a weaning protocol for patients who can tolerate weaning 2, 3

Critical Pitfalls to Avoid

Do not prioritize normocapnia over lung-protective ventilation—accept permissive hypercapnia as necessary: 2, 3

Do not use tidal volumes >8 mL/kg PBW even if plateau pressures are acceptable—both parameters must be optimized: 2, 3

Do not delay prone positioning in severe ARDS—early implementation improves outcomes: 2, 3

Do not apply higher PEEP indiscriminately—tailor to ARDS severity (moderate-to-severe vs. mild) and hemodynamic tolerance: 1, 2