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

ARDS Treatment Guidelines

The cornerstone of ARDS treatment is lung-protective mechanical ventilation using lower tidal volumes (4-8 ml/kg predicted body weight) and lower inspiratory pressures (plateau pressure <30 cm H2O), along with prone positioning for more than 12 hours per day in severe ARDS. 1

Initial Ventilation Strategy

Lung-Protective Ventilation

• Set tidal volume at 4-8 ml/kg predicted body weight 1
  • Calculate predicted body weight:
    • Men: 50 + 2.3 (height in inches - 60)
    • Women: 45.5 + 2.3 (height in inches - 60) 2
• Maintain plateau pressure ≤30 cm H2O 1
• Initial PEEP: 5-8 cmH2O with FiO2 titrated to maintain SpO2 92-95% 2
• Target PCO2: 35-45 mmHg and pH >7.20 2

PEEP and FiO2 Strategy Based on ARDS Severity

• Mild ARDS (PaO2/FiO2 201-300 mmHg): Lower PEEP (5-10 cmH2O) 2
• Moderate ARDS (PaO2/FiO2 101-200 mmHg): Higher titrated PEEP 1, 2
• Severe ARDS (PaO2/FiO2 ≤100 mmHg): Higher titrated PEEP plus consider advanced therapies 1, 2

Advanced Therapies for Moderate to Severe ARDS

Strongly Recommended

• Prone positioning for severe ARDS (PaO2/FiO2 <150 mmHg) for >12 hours per day 1, 2
  • Improves ventilation-perfusion matching and mortality
  • Should be implemented early in the course of severe ARDS

Conditionally Recommended

• Higher PEEP in moderate or severe ARDS 1
  • Helps prevent atelectrauma but must be balanced against risk of overdistention
• Recruitment maneuvers in moderate or severe ARDS 1
  • May improve oxygenation but have low confidence in effect estimates
• Neuromuscular blocking agents for ≤48 hours in severe ARDS 2
  • Improves patient-ventilator synchrony and reduces work of breathing
• Corticosteroids to reduce inflammatory response and pulmonary edema 2
• Venovenous ECMO (VV-ECMO) for selected patients with severe ARDS refractory to conventional therapy 2

Strongly Recommended Against

• High-frequency oscillatory ventilation in moderate or severe ARDS 1
  • High confidence in evidence showing lack of benefit

Fluid Management

• Initial resuscitation: Careful fluid administration to restore tissue perfusion 2
• After stabilization: Implement conservative fluid management strategy 2
  • Target neutral-to-negative fluid balance
  • Use diuretics based on CVP and urine output
  • Furosemide should be used with caution (maximum infusion rate 24 mg/h or 160 mg bolus, not exceeding 620 mg/day) 2

Monitoring and Assessment

• Regular assessment of:
  • Mean arterial pressure (target ≥60 mmHg) 2
  • Central venous pressure
  • Urine output
  • Plateau pressure, driving pressure, and PaO2/FiO2 ratio
  • Echocardiography to detect acute cor pulmonale 2

Prevention of Complications

• Elevate head of bed 30-45 degrees to prevent ventilator-associated pneumonia 2
• Prophylaxis for stress ulcers and venous thromboembolism 3
• Daily assessment for weaning readiness 2
• Implement structured weaning protocol when appropriate 2

Clinical Pitfalls to Avoid

1. Underrecognition of ARDS: ARDS is frequently underrecognized, leading to delayed implementation of lung-protective strategies 1
2. Excessive fluid administration: Can worsen pulmonary edema and oxygenation 2
3. Improper tidal volume calculation: Must use predicted body weight, not actual weight
4. Delayed prone positioning: Should be implemented early in severe ARDS
5. Neglecting right ventricular function: Can lead to inadequate fluid administration and worsened outcomes 2
6. Inappropriate weaning attempts: Follow structured protocols to minimize weaning failure

Long-term Considerations

Survivors of ARDS are at risk for:

• Diminished functional capacity
• Mental illness
• Decreased quality of life 2, 3

Ongoing care by primary care physicians is beneficial for these patients to address these long-term sequelae.