Evidence of fetal pulmonary aspiration of intra-amniotic administered surfactant in animal experiment.
BACKGROUND
The instillation of surfactant into the airways of patients with respiratory distress syndrome (RDS), especially in the neonatal period, is a proven therapy. The preventive therapy of RDS through intra-amniotic injection of surfactant has been reported recently. It has not been conclusively shown, however, that the surfactant administered in this way actually reaches the fetal pulmonary airways.


OBJECTIVE
To study the distribution in fetal organs of a natural surfactant labeled with technetium-99m and injected through amniocentesis into the amniotic sac of guinea pigs in the last third of pregnancy.


METHODS
After stimulating fetal respiratory movements with aminophylline 0.3 ml of an aqueous suspension containing 0.75 mg of phospholipids of a natural bovine surfactant labeled with technetium-99m, together with 0.1 ml of the biological dye carmine indigo, were injected into the amniotic sac. One hour later fetuses were delivered by cesarean section. In those that were dye-stained, dosimetric and gammagraphic tests were applied to trachea, lungs, esophagus, stomach, heart, liver, kidneys and placenta.


RESULTS
Significant radio isotopic activity was found in both lungs of six treated fetuses, with a dose capture of between 1.0% and 5.3% of total dose. The level of activity in the stomachs was similar to that in the lungs (0.9% to 3.0% dose capture), whereas activity in other organs was negligible except in two placentae. No radio isotopic activity was found in non-injected control fetuses.


CONCLUSIONS
In the present animal model natural surfactant injected intra-amniotically is aspirated into the lungs within one hour.
Illia
Ricardo
R
Hospital Alemán, Department of Obstetrics, Nuclear Medicine, and General Medicine Units, Buenos Aires, Argentina. rillia@hospitalaleman.com.ar
Solana
Claudio
C
Oliveri
Pedro
P
Toblli
Jorge
J
Imaz
Matias Uranga
MU
Häbich
Diego
D
D000653:Amniotic Fluid; D000818:Animals; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism; D006168:Guinea Pigs; D006801:Humans; D007231:Infant, Newborn; D007267:Injections; D008168:Lung / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000378:metabolism; D023421:Models, Animal; D010920:Placenta / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism; D011247:Pregnancy; D011663:Pulmonary Surfactants / Q000008:administration & dosage / Q000494:pharmacology*; D011877:Radionuclide Imaging; D012127:Respiratory Distress Syndrome, Newborn / Q000517:prevention & control*; D013270:Stomach / Q000000981:diagnostic imaging / Q000187:drug effects
D011663:Pulmonary Surfactants