How to recruit lungs in pediatric Acute Respiratory Distress Syndrome (ARDS)?

Lung Recruitment Strategies in Pediatric ARDS

In pediatric Acute Respiratory Distress Syndrome (ARDS), high positive end-expiratory pressure (PEEP) should be used as the primary recruitment strategy, with careful monitoring for hemodynamic tolerance. 1

Initial Ventilation Settings for Pediatric ARDS

• Tidal Volume: Use 6-8 ml/kg predicted body weight 2
• PEEP: Start with high PEEP (higher than standard settings) 1
  • Exact level has not been determined specifically for pediatric ARDS
  • Consider using ARDS-network PEEP to FiO2 grid for titration
• Plateau Pressure: Maintain ≤30 cmH2O to minimize ventilator-induced lung injury 2
• Driving Pressure: Monitor and minimize (Pplat-PEEP) 2
• pH Target: 7.2-7.4 (permissive hypercapnia) 1

Specific Recruitment Maneuvers

When considering recruitment maneuvers for refractory hypoxemia, the following approaches can be used:

1. Stepwise PEEP Titration (Preferred Method):

   • Use incremental and decremental PEEP titration rather than sustained inflation 1
   • The "Open Lung Tool" approach has shown a 53% improvement in PaO2/FiO2 ratio immediately after recruitment with benefits lasting up to 12 hours 3

2. Prone Positioning:

   • Recommended for severe pediatric ARDS 1
   • Should be maintained for at least 12 hours per day as tolerated 1
   • Has been shown to improve oxygenation by opening dependent lung regions 2

3. Neuromuscular Blockade:

   • Suggested for severe pediatric ARDS 1
   • Typically administered for 24-48 hours after ARDS onset 1
   • Helps prevent ventilator dyssynchrony and excessive transpulmonary pressure 2

Adjunctive Therapies

• Inhaled Nitric Oxide (iNO):

  • Not recommended for routine use in all pediatric ARDS 1
  • Can be used as rescue therapy for refractory hypoxemia after optimizing other oxygenation strategies 1

• Non-invasive Ventilation:

  • Consider a trial in children with sepsis-induced ARDS without clear indication for intubation 1
  • Requires careful and frequent re-evaluation 1

Monitoring During Recruitment

• Closely monitor hemodynamic parameters during recruitment maneuvers 1
• Watch for signs of barotrauma
• Assess for improvement in oxygenation (target SpO2 88-92%) 2
• Monitor for tolerance of the maneuver 1

Cautions and Contraindications

• Avoid recruitment maneuvers in hemodynamically unstable patients
• Be cautious with high PEEP in patients with septic shock as adverse hemodynamic effects may be more prominent 1
• Monitor for increases in PaCO2 during recruitment maneuvers, as significant increases occurred in some patients 3

Efficacy of Recruitment Strategies

Research has demonstrated that properly executed recruitment maneuvers can:

• Increase PaO2/FiO2 ratio by up to 53% immediately post-recruitment 3
• Provide sustained improvement in oxygenation (80% improvement at 4 hours, 40% at 12 hours) 3
• Potentially decrease PaCO2 at 4 hours post-recruitment 3

The evidence suggests that a strategic approach to lung recruitment in pediatric ARDS, focusing on high PEEP, prone positioning for severe cases, and careful monitoring, can improve oxygenation while minimizing potential complications.