Pediatric Acute Lung Injury Epidemiology and Natural History Study: Incidence and outcome of the acute respiratory distress syndrome in children

Objectives: The incidence and outcome of the acute respiratory distress syndrome in children are not well-known, especially under current ventilatory practices. The goal of this study was to determine the incidence, etiology, and outcome of acute respiratory distress syndrome in the pediatric population in the setting of lung protective ventilation. Design: A 1-yr, prospective, multicenter, observational study in 12 geographical areas of Spain (serving a population of 3.77 million <= 15 yrs of age) covered by 21 pediatric intensive care units. Subjects: All consecutive pediatric patients receiving invasive mechanical ventilation and meeting American-European Consensus Criteria for acute respiratory distress syndrome. Interventions: None. Measurements and Main Results: Data on ventilatory management, gas exchange, hemodynamics, and organ dysfunction were collected. A total of 146 mechanically ventilated patients fulfilled the acute respiratory distress syndrome definition, representing a incidence of 3.9/100,000 population <= 15 yrs of age/yr. Pneumonia and sepsis were the most common causes of acute respiratory distress syndrome. At the time of meeting acute respiratory distress syndrome criteria, mean Pao(2)/Fio(2) was 99 mm Hg +/- 41 mm Hg, mean tidal volume was 7.6 mL/kg +/- 1.8 mL/kg predicted body weight, mean plateau pressure was 27 cm H2O +/- 6 cm H2O, and mean positive end-expiratory pressure was 8.9 cm +/- 2.9 cm H2O. Overall pediatric intensive care unit and hospital mortality were 26% (95% confidence interval 19.6-33.7) and 27.4% (95% confidence interval 20.8-35.1), respectively. At 24 hrs, after the assessment of oxygenation under standard ventilatory settings, 118 (80.8%) patients continued to meet acute respiratory distress syndrome criteria (Pao(2)/Fio(2) 104 mm Hg +/- 36 mm Hg; pediatric intensive care units mortality 30.5%), whereas 28 patients (19.2%) had a Pao(2)/Fio(2) > 200 mm Hg (pediatric intensive care units mortality 7.1%) (p = .014). Conclusions: This is the largest study to estimate prospectively the pediatric population-based acute respiratory distress syndrome incidence and the first incidence study performed during the routine application of lung protective ventilation in children. Our findings support a lower acute respiratory distress syndrome incidence and mortality than those reported for adults. Pao(2)/Fio(2) ratios at acute respiratory distress syndrome onset and at 24 hrs after onset were helpful in defining groups at greater risk of dying (clinical trials registered with http://www.clinicaltrials.gov; NCT 01142544) (Crit Care Med 2012; 40:3238-3245)