What is the initial management of acute respiratory distress syndrome (ARDS) in pediatric patients?

Initial Management of Pediatric Acute Respiratory Distress Syndrome

Begin with lung-protective mechanical ventilation using tidal volumes of 4-8 mL/kg predicted body weight and plateau pressures ≤30 cmH₂O as the foundation of PARDS management, with higher PEEP strategies for moderate-to-severe disease. 1, 2

Initial Respiratory Support Decision

For Mild PARDS (PaO₂/FiO₂ 200-300 mmHg)

• Consider a trial of non-invasive ventilation (NIV) or high-flow nasal cannula (HFNC) only in children without clear intubation indications who are responding to initial resuscitation. 2
• Start HFNC at 30-40 L/min with FiO₂ 50-60% if attempting non-invasive support. 3
• Proceed immediately to intubation in a controlled setting if deterioration occurs within 1 hour, FiO₂ exceeds 70%, or flow exceeds 50 L/min. 3
• Absolute contraindications to non-invasive support include hypercapnia, hemodynamic instability, multi-organ failure, or altered mental status. 3

For Moderate-to-Severe PARDS (PaO₂/FiO₂ <200 mmHg)

• Proceed directly to intubation in a controlled setting rather than attempting non-invasive ventilation, as failure rates are unacceptably high. 3

Lung-Protective Ventilation Protocol (Implement Immediately Upon Intubation)

Tidal Volume and Pressure Targets

• Set tidal volume at 4-8 mL/kg predicted body weight (not actual body weight). 1, 2, 4
• Maintain plateau pressure ≤30 cmH₂O at all times. 1, 3
• This strategy has been associated with decreased mortality in pediatric patients (adjusted HR 0.37,95% CI 0.16-0.88). 4

PEEP Strategy

• Use higher PEEP in moderate-to-severe PARDS, guided by the ARDS-network PEEP-to-FiO₂ grid with caution for hemodynamic effects. 1
• Typical PEEP ranges are 8-10 cmH₂O, adjusted based on oxygenation response and hemodynamic tolerance. 4
• Monitor carefully for adverse hemodynamic effects, particularly in children with septic shock. 1

Oxygenation and Ventilation Targets

• Target SpO₂ 92-96% to avoid oxygen toxicity—do not exceed 96%. 3
• Accept permissive hypercapnia with PaCO₂ 44-57 mmHg unless contraindicated by increased intracranial pressure or severe pulmonary hypertension. 4
• Target PaO₂ 70-90 mmHg. 5

Fluid Management

• Implement conservative fluid management once respiratory status is stabilized to minimize pulmonary edema. 1, 2, 3
• Avoid excessive fluid administration, which worsens oxygenation, promotes right ventricular failure, and increases mortality. 1, 3
• Monitor fluid balance meticulously while maintaining adequate organ perfusion. 3

Adjunctive Therapies for Severe PARDS (PaO₂/FiO₂ <100 mmHg)

Prone Positioning (First-Line Adjunct)

• Implement prone positioning for at least 12 hours per day in severe PARDS, as this has demonstrated significant mortality reduction. 1, 2, 3
• Apply deep sedation and analgesia during prone positioning. 3
• Continue prone positioning as tolerated until oxygenation improves. 2

Neuromuscular Blockade

• Consider neuromuscular blockade (typically cisatracurium) for 24-48 hours after ARDS onset in severe PARDS to improve ventilator synchrony and reduce oxygen consumption. 1, 2, 3
• Particularly beneficial when ventilator-patient dyssynchrony persists despite adequate sedation. 3

Inhaled Nitric Oxide

• Do not use inhaled nitric oxide routinely in all children with PARDS. 1, 2
• Consider as rescue therapy only for refractory hypoxemia after optimizing all other oxygenation strategies (lung-protective ventilation, PEEP optimization, prone positioning, neuromuscular blockade). 2
• Discontinue if no rapid improvement in oxygenation occurs. 3

Monitoring Requirements

• Continuously monitor oxygen saturation, respiratory mechanics (plateau pressure, driving pressure, tidal volume), and hemodynamics. 3
• Assess right ventricular function via echocardiography, as RV failure significantly worsens outcomes. 3
• Monitor for ventilator-patient dyssynchrony. 3

Advanced Rescue Therapies for Refractory Hypoxemia

• Consider VV-ECMO only at centers with ECMO expertise for patients with severe ARDS failing conventional management, particularly those with potentially reversible disease. 3
• Blood is pumped from the femoral vein and returns to the right atrium through the internal jugular vein after membrane oxygenation. 3

Common Pitfalls to Avoid

• Never use actual body weight for tidal volume calculations—always use predicted body weight based on height. 1, 4
• Do not delay intubation in moderate-to-severe PARDS attempting non-invasive support, as emergent intubation carries significantly higher risk than controlled intubation. 3
• Avoid targeting SpO₂ >96%, as hyperoxia causes oxygen toxicity without benefit. 3
• Do not apply the ARDS-network PEEP-to-FiO₂ grid rigidly in children with septic shock without monitoring hemodynamics, as high PEEP can worsen shock. 1