All issues > Volume 42(10); 1999

Original Article

J Korean Pediatr Soc. 1999;42(10):1373-1380. Published online October 15, 1999.

Correlation between Changes of Intrapulmonary Right to Left Shunt and Improvements in Oxygenation after Exogenous Surfactant Administration in Preterm Respiratory Distress Syndrome

Sei Woo SW Chung¹

¹Department of Pediatrics, Inha University College of Medicine, Seongnam, Korea

Correspondence Sei Woo SW Chung ,Email: 1

Abstract

Purpose
: This study was aimed to investigate the relationship between changes in intrapulmonary right to left shunt(QSP/QT) and improvements in oxygenation during the 2-hr study period after Surfactant-TA(S-TA) administration.
Methods
: Umbilical arterial blood gases and corresponding respiratory indexes of 27 preterm neonates with respiratory distress syndrome were studied. The neonates were separated into group A(n=20) and group B(n=7) according to whether their initial QSP/QT was above or below 30 %, respectively. And the patients were studied immediately before and after endotracheal single- dose S-TA administration within 6 hours after birth.
Results
: In the case of P(a/A)O2, group A showed a significant increase throughout the study period(P<0.01, P<0.001), whereas group B showed an initial significant increase at 2 hr(P<0.05). Significant correlations between changes in QSP/QT and improvements in P(a/A)O2 were seen in both groups(P<0.001, P<0.05). Moreover in the case of PaO2/FIO2, group A showed a significant increase throughout the study period(P<0.01, P<0.001), whereas group B showed an initial significant increase at 30 min(P<0.05). Significant correlations between changes in QSP/QT and improvements in PaO2/FIO2 were also seen in both groups(P<0.01, P<0.05). And at 2 hr, VEI and VA showed a significant increase in both groups(P<0.05, P<0.01), whereas PaCO2 showed a significant decrease in both groups(P<0.001, P<0.05).
Conclusion
: Irrespective of initial QSP/QT, immediate improvements in oxygenation following surfactant replacement were accomplished by recruiting atelectatic alveoli and stablizing underventilated alveoli(namely by decreasing QSP/QT). Moreover, the patients with more severe respiratory failure had a more rapid and sustained improvement in oxygenation.

Keywords :Intrapulmonary right to left shunt(QSP/QT), Oxygenation, Respiratory distress syndrome, Surfactant-TA(S-TA), P(a/A)O2, PaO2/FIO2