Exogenous surfactant supplementation in infants with respiratory syncytialvirus bronchiolitis

Infants with respiratory syncytial virus (RSV) bronchiolitis are deficient in surfactant, both In quantity and ability to reduce surface tension. New evidence suggests surfactant has a role in maintaining the patency of condu cting airways, which has implications for RSV bronchiolitis. A randomized, controlled pilot study was undertaken to assess the effects of exogenous su rfactant supplementation to RSV-positive infants on pulmonary mechanics, in dices of gas exchange, and the phospholipid composition of bronchoalveolar lavage fluid (BALF). Nineteen ventilated infants (median corrected age 4 wk ) received either two doses of surfactant (Survanta, 100 mg/kg) within 24 a nd 48 h of mechanical ventilation (n = 9), or air placebo (n = 10). Static lung compliance and resistance of infants in the placebo but not in the sur factant-treated group became progressively worse over the first 30 h follow ing enrollment. Although no significant acute changes in gas exchange param eters were seen following surfactant, infants in the surfactant group showe d a more rapid improvement in oxygenation and ventilation indices over the first 60 h of ventilation. Surfactant status was assessed from the concentr ation ratio in BALF of the disaturated phospholipid species dipalmitoylphos phatidylcholine to that of the monounsaturated species palmitoyloleoylphosp hatidylcholine. This ratio correlated with both lung compliance (positively ) and resistance (negatively), and over time increased in the treated group and declined in placebo infants. The data from this pilot study suggest th at functional surfactant has a role in maintaining small airway patency as well as lung compliance in infants infected with RSV and an outcome study i s now warranted.