The impact of PEEP on mechanical power and driving pressure in children with pediatric acute respiratory distress syndrome

Background: Positive end-expiratory pressure (PEEP) is widely used to improve oxygenation and avoid alveolar collapse in mechanically ventilated patients with pediatric acute respiratory distress syndrome (PARDS). However, its improper use can be harmful, impacting variables associated with ventilation-induced lung injury, such as mechanical power (MP) and driving pressure (∆P). Our main objective was to assess the impact of increasing PEEP on MP and ∆P in children with PARDS.

Interventions: Mechanically ventilated children on pressure-controlled volume-guaranteed mode were prospectively assessed for inclusion. PEEP was sequentially changed to 5, 12, 10, 8, and again to 5 cm H₂O. After 10 min at each PEEP level, ventilatory data were collected and then variables of interest were determined. Respiratory system mechanics were measured using the least squares fitting method.

Results: Thirty-one patients were included, with median age and weight of 6 months and 6.3 kg. Most subjects were admitted for acute viral bronchiolitis (45%) or community-acquired pneumonia (32%) and were diagnosed with mild (45%) or moderate (42%) PARDS. There was a significant increase in MP and ∆P at PEEP levels of 10 and 12 cm H₂O. When PEEP was increased from 5 to 12 cm H₂O, there was a relative increase in MP of 60.7% (IQR 49.3-82.9) and in ΔP of 33.3% (IQR 17.8-65.8). A positive correlation was observed between MP and ΔP (ρ = 0.59).

Conclusions: Children with mild or moderate PARDS may experience a significant increase in MP and ∆P with increased PEEP. Therefore, respiratory system mechanics and lung recruitability must be carefully evaluated during PEEP titration.