59 The Pediatric Alien Study: Incidence and Outcome of the Acute Respiratory Distress Syndrome in Children

Introduction The incidence and outcome of the acute respiratory distress syndrome (ARDS) in children is not well known, especially under current ventilatory practices. The goal of this study was to determine the incidence, etiology and outcome of ARDS in the pediatric population in the setting of lung protective ventilation. Method A 1-year, prospective, multicenter, observational study in 12 geographical areas of Spain covered by 21 pediatric intensive care units (PICUs). Results Data on ventilatory management, gas-exchange, hemodynamics, and organ dysfunction were collected. A total of 146 mechanically ventilated patients fulfilled the ARDS definition, representing an incidence of 3.9/100,000 population ≤15 years of age/year. Pneumonia, sepsis and respiratory syncytial virus-related infection were the most common causes of ARDS. At the time of meeting ARDS criteria, mean PaO 2 /FiO 2 was 99±41 mmHg, mean tidal volume was 7.6±1.8 ml/kg predicted body weight, mean plateau pressure was 27±6 cmH 2 O, and mean PEEP was 8.9±2.9 cmH 2 O. Overall ARDS PICU and hospital mortality was 26% (95%CI: 19.6–33.7) and 27.4% (95%CI: 20.8–35.1), respectively. At 24 h, after assessment of oxygenation under standard ventilatory settings, 118 (80.8%) patients continued to meet ARDS criteria (PaO 2 /FiO 2 104±36 mmHg; PICU mortality 30.5%) whereas 28 patients (19.2%) had a PaO 2 /FiO 2 >200 mmHg (PICU mortality 7.1%) (p=0.014). Conclusions This is the largest study to estimate prospectively the pediatric population-based ARDS incidence and the first incidence study performed during the routine application of lung protective ventilation in children. Our findings support a lower ARDS incidence and mortality than those reported for adults.