PULMONARY MECHANICS IN VENTILATED PRETERM INFANTS WITH RESPIRATORY-DISTRESS-SYNDROME AFTER EXOGENOUS SURFACTANT ADMINISTRATION - A COMPARISON BETWEEN 2 SURFACTANT PREPARATIONS

The effects of two surfactant preparations on lung mechanics have been studied on 24 ventilated premature infants with respiratory distress syndrome (RDS): 13 were given artificial surfactant (Exosurf Neonatal, Burroughs-Wellcome) and II natural porcine surfactant (Curosurf, Laboratoire Serono France). Measurements of respiratory system compliance (C-dyn, C-rs) and resistance (R(rs)) were performed immediately before surfactant administration and repeated 6, 18, 24, 48, and 72 hours later. With Exosurf treatment, 6 hours after surfactant administration inhaled O-2 concentration (F-102) could be lowered from (0.72 +/- 0.20, to 0.62 +/- 0.33; P < 0.05), whereas C-rs did not change (0.37 mL/cmH(2)O/kg, +/- 0.14 vs. 0.39 +/- 0.12, NS). After 24 hours and during the following days a significant increase in C-rs occurred (24 hours post-Exosurf: 0.51 +/- 0.18, P < 0.05). With Curosurf treatment, the improvement in oxygenation was greater and F-102 could be lowered much more after 6 hours (from F-102 0.78 +/- 0.23 to 0.34 +/- 0.11, P < 0.01). This was associated with an increase in C-rs (from 0.39 +/- 0.09 to 0.59 +/- 0.17, P < 0.05). During the following days, C-rs was significantly higher in the group treated with Curosurf. Resistance was not altered by the type of surfactant preparation used except after 72 hours, when R(rs) increased in the group treated with Exosurf. In conclusion, Curosurf appears to be more effective than Exosurf with regard to immediate pulmonary changes in ventilator treated premature infants with RDS. A rapid increase in C-rs after Curosurf treatment indicates that recruitment of new functional areas of the lung is likely to be associated with a stabilization of small airways and alveolar units. (C) 1994 Wiley-Liss, Inc.