FiO2 Predicts Outcome in Infants With Respiratory Syncytial Virus-Induced Acute Respiratory Distress Syndrome

ObjectiveRespiratory syncytial virus (RSV) infection can progress to acute respiratory distress syndrome (ARDS) in infants. ARDS is a life-threatening condition that is characterized by severe hypoxemia, defined as PaO2/FiO(2) ratio <300mmHg. This ratio is used in many trials as the sole oxygenation criterion for ARDS. Recently, however, it has been shown in adults with ARDS that FiO(2), independently of the PaO2/FiO(2) ratio predicts mortality. Because epidemiology and outcome of ARDS differ strongly between children and adults, we determined if FiO(2) on admission (baseline FiO(2)) independently predicted the duration of mechanical ventilation (MV) and length of stay (LOS) in the pediatric intensive care unit (PICU) in infants with RSV-induced ARDS. DesignRetrospective observational study. SettingA 14-bed pediatric intensive care unit. PatientsOne hundred twenty-nine mechanically ventilated infants with RSV-induced ARDS. InterventionsNone. Measurements and main resultsIndependent predictors for outcome, including baseline FiO(2) and PEEP, were analyzed using the cox regression model. Endpoints were duration of MV and LOS in the PICU. A higher baseline FiO(2) was independently associated with a longer duration of MV (HR 0.12, CI 0.02-0.87, P=0.036) and increased LOS in the PICU (HR 0.09, CI 0.01-0.57, P=0.023). Neither baseline PEEP nor PaO2/FiO(2) ratio correlated with outcome. ConclusionsFiO(2) level independently predicted outcome in infants with RSV-induced ARDS, whereas both PEEP and the PaO2/FiO(2) ratio did not. This suggests that FiO(2) should be taken into account in defining disease severity in infants with RSV-induced ARDS. Pediatr Pulmonol. 2014; 49:1138-1144. (c) 2013 Wiley Periodicals, Inc.