Abnormal surfactant composition and activity in severe bronchiolitis

A prospective study of infants under ly of age, ventilated for severe viral bronchiolitis, was carried out in four paediatric intensive care units in order to study surfactant activity and composition in this condition. Lung lavage fluid from 24 infants with bronchiolitis, 19 with bronchiolitis and sepsis or cardiac Failure and 12 controls were analysed by the "click test" for surfactant activity and for phospholipids. Surfactant activity was pre sent in all controls, but in only 2 of the 24 infants with bronchiolitis al one. The presence of phosphatidylglycerol correlated perfectly with the cli ck test, suggesting that reduced activity is due to changes in surfactant l ipid composition. In those with bronchiolitis plus coexisting disease, surf actant activity and phosphatidylglycerol were absent in only half. Surfacta nt activity and phosphatidylglycerol re-appeared by extubation. Severe vira l bronchiolitis is associated with an absence of surfactant activity and PG , which resolves by clinical recovery. infants with coexisting conditions a re not always surfactant deficient. Surfactant administration is likely to be beneficial, but requires a selective approach.