The effects of synthetic and natural surfactant on fluid balance in acute respiratory distress syndrome.

UNLABELLED: To evaluate the effect of different surfactants on fluid balance in respiratory distress syndrome, we studied 24 premature infants who were randomised to receive either natural or synthetic surfactant. Data were collected on ventilatory parameters, daily urine output, daily weight, fluid intake and serum electrolytes. Ventilatory requirements decreased more rapidly in babies receiving natural surfactant, with significantly greater reductions in mean airway pressure from 1 to 48 h and oxygenation index from 1-18 h (P < 0.05). There were no differences in fluid intake and serum electrolytes. Mean daily urine output was higher in the group receiving natural surfactant (87 ml versus 61 ml, P < 0.05). This group also had a greater weight loss from birth weight (-146 g versus -65 g, P < 0.05). CONCLUSION: Natural surfactant produces an earlier reduction in ventilatory requirements with an earlier diuresis. This should influence fluid management in respiratory distress syndrome.