Date of Award

2007

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

College

College of Graduate Studies

First Advisor

Gail Stuart

Second Advisor

Thomas C. Hulsey

Third Advisor

Tara Hulsey

Fourth Advisor

Yvonne Michel

Abstract

Based on literature in Adult Respiratory Distress Syndrome in humans and evidence of surfactant activation in vitro and vivo, and our clinical observations of secondary respiratory decompensation in premature infancies recovering from RDS, a study was designed to look at the possibility of benefit from secondary surfactant administration in premature infancies with secondary decompensation after recovery from respiratory distress syndrome (RDS). A prospective pilot study was performed to study the effects of secondary surfactant administration on oxygenation, ventilation and pulmonary function of neonates who had respiratory decompensation after recovery from RDS. A secondary data analysis was performed looking at pulmonary function related to ventilatory efficiency index (VEI), modified ventilatory index (MVI) and respiratory severity score (RSS). Entry criteria included infants admitted with RDS who were 7 days to 3 months of age, with birth weights ≥ 500 grams. Infants qualified if they demonstrated recovery from RDS with a secondary respiratory decompensation defined prospectively as an acute pulmonary decompensation after 6 days of age, which was non-cardiac in origin and accompanied by diffuse parenchymal lung disease on chest x-ray, in conjunction with sustained increase in fraction of inspired oxygen (FiO2; ≥20%) and mean airway pressure (MAP; ≥2 cm) above base-line for at least 4 hours prior to surfactant administration. Infants meeting all enter criteria received surfactant within four hours of the qualifying decompensation and again 12 hours later. Oxygenation, ventilation and pulmonary function were compared before and after administration at 12 and 24 hours. Twenty neonates qualified for secondary surfactant administration. The PCO2, pH, MAP, FiO2, MVI and RSS all improved significantly at 12 and 24 hours after surfactant administration. Infants who received Curosurf had improvement in pH and PCO2 within 2 hours of surfactant administration. The rates of adverse events were low. These findings suggest that secondary surfactant administration may be effective in reducing short term oxygen and ventilatory requirements and improving pulmonary function in neonates who have a respiratory decompensation after recovery from initial RDS. Secondary surfactant replacement may improve outcomes in this subset of patients and further randomized controlled trials are needed to confirm these preliminary findings.

Rights

All rights reserved. Copyright is held by the author.

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