EFFECTS OF SURFACTANT THERAPY IN PREMATUR E-INFANTS WITH SEVERE RESPIRATORY-DISTRESS SYNDROME

BACKGROUND: From January 1992 to June 1993 a study was performed to sh ow whether the administration of surfactant to low birth weight infant s with respiratory distress decreased the need for ventilatory support and improved survival. METHOD: Twenty three infants born at a single hospital received the surfactant (one dose of a 100 mg/kg divided in f our aliquots) and they were eligible for the treatment if they met the following criteria: 1) Weight between 650 g and 2000 g; 2) postnatal age 4 to 24 hours; 3) clinical-radiographic signs of respiratory distr ess, and 4) need of mechanical ventilation with FiO(2) greater than or equal to 0.6. The results of the treatment were evaluated comparing t he arterial-alveolar oxygenation ratio, maximal inspiratory pressure a nd the oxygenation index before and after the administration of surfac tant, The last consecutive eighteen infants born at our hospital, befo re our study was started, that met the same criteria were elected as c ontrol group. RESULTS: In the group of infants treated with surfactant the arterial-alveolar oxygenation ratio increased from 0.10 +/- 0.009 before treatment to 0.28 +/- 0.02 six hours after treatment (p < 0.01 ); the oxygenation index decreased from 37.79 +/- 4.27 to 12.71 +/- 1. 17 (p < 0.01) and the maximal inspiratory pressure from 22.13 +/- 0.81 cmH(2)O to 19.52 +/- 0.76 (p < 0.001) in the same period of time, Thi s improvement was maintained during the following 72 hours. In the gro up of infants treated with surfactant, mortality decreased (p < 0.01), the frequency of neumothorax diminished (p < 0.001) and the frequency of pulmonary haemorrhage increased (p < 0.05). The ventilatory time w as similar in both groups of infants but the global length of stay of the newborn that received surfactant was longer due to the fact that t he non survivors of the control group died before the 72 hours of life , CONCLUSIONS: Treatment with surfactant improves the initial evolutio n of the respiratory distress syndrome of the newborn and decreases mo rtality.