Porcine-derived lung surfactant. A review of the therapeutic efficacy and clinical tolerability of a natural surfactant preparation (Curosurf) in neonatal respiratory distress syndrome.

Porcine-derived lung surfactant (PLS; Curosurf) has shown efficacy in neonatal respiratory distress syndrome. PLS consists of phospholipids, mainly dipalmitoylphosphatidylcholine, the primary surface-active agent of natural lung surfactant, and pulmonary surfactant-associated proteins which facilitate spreading and adsorption of the surface-active agent at the air-alveolar interface. Intratracheal administration of a single dose of PLS 200 mg/kg significantly improves the survival rate and reduces the incidence of bronchopulmonary dysplasia at 28 days in premature infants (birthweight 700 to 2000g) with severe respiratory distress syndrome (fraction of inspired oxygen > or = 0.60). PLS also reduces the incidence of air leak events such as pulmonary interstitial emphysema and pneumothorax. The response rate may be further improved by administration of additional 100 mg/kg doses at 12-hour intervals to infants showing a poor response or relapse after a single dose. PLS prophylaxis reduces the incidence and severity of respiratory distress syndrome in premature infants at high risk of developing the disease; however, it remains unclear whether the eventual clinical outcome is similar or superior to that observed in infants who receive rescue treatment. PLS is well tolerated and does not appear to increase the incidence of complications of prematurity or respiratory distress syndrome, including patent ductus arteriosus and intraventricular haemorrhage. Although its effect on long term development require further investigation, early indications are that PLS is not associated with any long term adverse sequelae. Comparative trials are clearly warranted to determine the efficacy and tolerability of PLS relative to that of other available surfactant preparations, particularly to explore preliminary indications that a more rapid effect of natural surfactants such as PLS (compared with synthetic products) may correlate with improved clinical outcomes, and that PLS may result in fewer complications than synthetic preparations. Thus, available data show PLS to be a very effective agent for the treatment and prophylaxis of neonatal respiratory distress syndrome, and that it may have some advantages over synthetic preparations.