Surfactant replacement therapy in utero for prevention of hyaline membrane disease in the preterm baboon.
OBJECTIVE
A previous study of intraamniotic administration of surfactant in preterm rabbit fetuses demonstrated that exogenous surfactant can be taken up into the lungs from amniotic fluid in quantities sufficient to alter pulmonary mechanical properties. On the basis of these findings we chose to test the hypothesis that intraamniotic administration of surfactant to the preterm baboon 24 hours before delivery will prevent the development of clinical and pathological aspects of hyaline membrane disease.


METHODS
Characteristics of hyaline membrane disease in the preterm baboon model include atelectasis, the formation of hyaline membranes in the airways and distal air saccules, overexpansion of distal airways, and disruption of airways by barotrauma associated with neonatal intensive care practices. Nine preterm baboons were treated with either saline solution (n = 4) or surfactant (n = 5) by intraamniotic injection on 136 to 137 days' gestation. One day later fetuses were delivered by cesarean section and maintained for 24 hours with standard neonatal intensive care techniques.


RESULTS
All neonates completed the protocol, and surfactant-treated animals had better clinical courses as documented by Pao2/PAO2 (p < 0.05), FIO2 (p < 0.005), and Paco2 (p < 0.05). Significant radiographic differences (p < 0.02) were noted to be the result of surfactant treatment. No differences in ventilator pressures or neonatal cardiovascular parameters were found. Significant differences in pulmonary pathologic conditions (p < 0.01) were also found, but all animals had some degree of pathologic pulmonary changes associated with hyaline membrane disease.


CONCLUSIONS
Therefore a single treatment with surfactant in utero significantly improved the clinical course but did not completely prevent hyaline membrane disease in an established animal model.
Galan
H L
HL
Scott and White Clinic and Memorial Hospital, Temple, TX 76508.
Cipriani
C
C
Coalson
J J
JJ
Bean
J D
JD
Collier
G
G
Kuehl
T J
TJ
D000649:Amniocentesis; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D002245:Carbon Dioxide / Q000097:blood; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D006819:Hyaline Membrane Disease / Q000000981:diagnostic imaging / Q000473:pathology / Q000517:prevention & control*; D007231:Infant, Newborn; D008168:Lung / Q000503:physiopathology; D008297:Male; D010100:Oxygen / Q000097:blood; D010215:Papio; D011247:Pregnancy; D011663:Pulmonary Surfactants / Q000008:administration & dosage / Q000627:therapeutic use*; D011859:Radiography; D012129:Respiratory Function Tests; D013997:Time Factors
D011663:Pulmonary Surfactants; D002245:Carbon Dioxide; D010100:Oxygen