Pulmonary mechanics in ventilated preterm infants with respiratory distress syndrome after exogenous surfactant administration: A comparison between two 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 11 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 I O 2 ) 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 I O 2 could be lowered much more after 6 hours (from (F I O 2 ), 0.78 2 ± 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. Pediatr Pulmonol. 1994;18:273–278 © Wiley‐Liss, Inc. © Wiley‐Liss, Inc.