What is the recommended management strategy for a patient with Acute Respiratory Distress Syndrome (ARDS)?

Management of ARDS

Implement lung-protective mechanical ventilation immediately with tidal volumes of 4-8 mL/kg predicted body weight and plateau pressures <30 cmH2O for all ARDS patients, and add prone positioning for at least 12-16 hours daily if PaO₂/FiO₂ <150 mmHg. 1, 2

Core Ventilation Strategy: Lung-Protective Ventilation

All ARDS patients require lung-protective ventilation as the foundation of management. 1

• Set tidal volume at 6 mL/kg predicted body weight (acceptable range 4-8 mL/kg PBW) 1, 2
• 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 as an absolute ceiling 1, 2
• Target driving pressure (plateau pressure - PEEP) ≤15 cmH₂O, as this predicts mortality better than tidal volume or plateau pressure alone 2, 3
• Accept permissive hypercapnia with pH >7.20 as a consequence of lung protection—do not prioritize normocapnia over lung-protective ventilation 2

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

PEEP Strategy: Titrate to Disease Severity

The PEEP strategy differs based on ARDS severity:

• **For moderate-to-severe ARDS (PaO₂/FiO₂ <200 mmHg):** Use higher PEEP (typically >10 cmH₂O) without lung recruitment maneuvers 1, 2
• For mild ARDS (PaO₂/FiO₂ 200-300 mmHg): Lower PEEP may be appropriate 2
• Strongly avoid prolonged lung recruitment maneuvers in moderate-to-severe ARDS, as these are associated with harm 1, 2

The 2024 American Thoracic Society guideline represents a shift from the 2017 recommendations, now explicitly recommending against prolonged recruitment maneuvers while supporting higher PEEP strategies. 1

Prone Positioning: Essential for Severe ARDS

For severe ARDS with PaO₂/FiO₂ <150 mmHg, implement prone positioning immediately—this is a strong recommendation that reduces mortality (RR 0.74). 1, 2

• Position patient prone for at least 12-16 hours daily 1, 2
• Duration matters: trials with >12 hours/day proning showed mortality benefit, while shorter durations did not 1, 2
• The mortality benefit is specific to severe ARDS; moderate ARDS showed less consistent benefit 1

Common pitfall: Do not delay prone positioning in severe ARDS—early implementation improves outcomes. 2

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 represents a conditional recommendation with low certainty of evidence from the 2024 guideline 1

Corticosteroids: Recommended for ARDS

Administer systemic corticosteroids to mechanically ventilated patients with ARDS. 1, 2

This is a new recommendation in the 2024 American Thoracic Society guideline, representing the most recent high-quality evidence supporting corticosteroid use. 1, 2 This is a conditional recommendation with moderate certainty of evidence, marking a shift from the 2017 guideline which made no recommendation on corticosteroids. 1

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
• Ensure adequate tissue perfusion is maintained before restricting fluids 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
• Titrate FiO₂ to achieve these targets rather than aiming for normoxia 5

Rescue Therapies for Refractory Hypoxemia

For severe refractory ARDS despite optimized ventilation, proning, and other interventions, consider VV-ECMO in carefully selected patients at experienced centers. 1, 2

• This is a conditional recommendation with low certainty of evidence from the 2024 guideline 1
• ECMO should only be considered in carefully selected patients due to resource-intensive nature and need for specialized expertise 2, 4

Interventions to AVOID

Do not use high-frequency oscillatory ventilation—this is strongly recommended against and associated with harm. 1, 2

• Do not routinely use pulmonary artery catheters for ARDS management 2
• Do not use β-2 agonists for ARDS treatment without bronchospasm 2
• Do not use recruitment maneuvers routinely or for prolonged periods—these are associated with harm 1, 2

Sedation and Weaning

• Minimize continuous or intermittent sedation, targeting specific titration endpoints 2
• Use spontaneous breathing trials in patients ready for weaning 2
• Implement a weaning protocol for patients who can tolerate weaning 2
• Most patients tolerate lung-protective mechanical ventilation well without excessive sedation 5

Supportive Care

• Provide prophylaxis for stress ulcers and venous thromboembolism 6
• Ensure adequate nutritional support 6
• Treat the underlying injury or infection causing ARDS 6