Exosurf rescue surfactant improves high ventilation-perfusion mismatch in respiratory distress syndrome Presented as a poster at the Midwest Society for Pediatric Research in Chicago, Illinois, November 3, 1993.

Abstract

Objective : To assess ventilation/perfusion (V˙ A /Q˙) mismatch of the high type, following rescue surfactant therapy for respiratory distress syndrome. Hypothesis: Surfactant therapy reduces such mismatch. Design : Randomized, double-blind, placebo-controlled study, assessing V˙ A /Q˙ with the arterial-alveolar difference of CO 2 tension c. This difference was determined with capnometry and arterial blood gases, using the equation: (P (a-A) CO 2 ) equals arterial CO 2 minus alveolar CO 2 partial pressure. Setting: A level III nursery. Patients : Ten intubated infants with respiratory distress syndrome. Intervention: Infants were randomized to each receive two doses of surfactant or two doses of air placebo. Results: P (a-A) CO 2 improved after surfactant and worsened after placebo ( P = 0.0021), comparing slopes of 12-hr regression lines. A similar pattern occurred with oxygenation. These changes in P( a-A )CO 2 and in oxygenation were minimally correlated within the surfactant group. Conclusion : Exosurf rescue surfactant reduced V˙ A /Q˙ mismatch of the high type, over several hours. Pediatr Pulmonol. 1994;18:279–283 © Wiley-Liss, Inc.