Background: The aim of this study was (i) to determine the incidence and risk factors of severe leaky lung syndrome (sLLS), persistent pulmonary edema characterized by massive tracheal secretions and resistance to surfactant therapy, in extremely low gestational age newborns requiring ventilatory support; and (ii) to evaluate the effects of hydrocortisone (HC) therapy for sLLS on tracheal aspirate fluid (TAF) volume and β2-microglobulin levels in TAF.
Methods: Infants born at <28 weeks gestation requiring ventilation beyond day of life (DOL) 7 were included. Daily TAF volume changes were assessed using a TAF scoring system. Levels of TAF β2-microglobulin, an indicator of capillary leakage, were measured at DOL0, 7, before, and 4 days after starting HC therapy (started at 4 mg/kg/day; tapered for 1-3 weeks).
Results: Of the 54 infants enrolled, 24 (44%) were diagnosed with sLLS. Lower gestational age, lower birthweight, and higher TAF β2-microglobulin levels at DOL7 were independent risk factors for sLLS. Seventeen infants with sLLS received HC therapy starting at DOL17 (median), with subsequent decreases in TAF volume and β2-microglobulin levels.
Conclusions: The incidence of sLLS, as defined in this study, was 44% in extremely low gestational age newborns requiring ventilator support beyond a week. HC therapy effectively reduced TAF volume and β2-microglobulin levels, suggesting suppression of increased permeability of pulmonary capillaries in infants with sLLS.
© 2012 The Authors. Pediatrics International © 2012 Japan Pediatric Society.