The effects of veno-venous extracorporeal membrane oxygenation on hypoxic fetal lambs.
OBJECTIVE
The purpose of this study was to determine the applicability of veno-venous extracorporeal membrane oxygenation (V-V ECMO) to support fetal oxygenation in utero.


METHODS
An ECMO system with a centrifugal pump was applied to ten chronically instrumented fetal lambs, at 126 or 127 days of gestation. Blood was obtained through a double-lumen catheter inserted into the right atrium. After oxygenation, the blood was returned through a single-lumen catheter into either the carotid artery (veno-arterial; V-A ECMO) or the right atrium (V-V ECMO). After fetal hypoxia had been experimentally produced, V-A ECMO or V-V ECMO was instituted to maintain fetal oxygenation. We compared fetal blood gases with both routes of ECMO.


RESULTS
Oxygen partial pressure (pO(2)) in the fetal cranial carotid artery decreased to 12.9 +/- 0.6 mmHg after reducing the fraction inspiratory oxygen of the mother. After instituting V-A ECMO, pO(2) was found to be 23.5 +/- 2.6 mmHg; after instituting V-V ECMO, pO(2) was found to be 20.3 +/- 1.9 mmHg. Thus, fetal acidosis increased under both procedures. Fetal heart rate and blood pressure were not altered significantly during the experiments.


CONCLUSIONS
This study indicates that V-V ECMO could more effectively and less traumatically maintain oxygenation in hypoxic fetal lambs.
Fujimori
K
K
Department of Obstetrics and Gynecology, Fukushima Medical University, Japan.
Nomura
Y
Y
Kato
K
K
Shiroto
T
T
Ishida
T
T
Sato
A
A
D000818:Animals; D001784:Blood Gas Analysis; D001794:Blood Pressure; D002339:Carotid Arteries / Q000502:physiology*; D004195:Disease Models, Animal; D015199:Extracorporeal Membrane Oxygenation / Q000295:instrumentation / Q000379:methods*; D005260:Female; D005333:Fetus / Q000098:blood supply*; D006340:Heart Rate, Fetal; D006863:Hydrogen-Ion Concentration; D000860:Hypoxia / Q000628:therapy; D010100:Oxygen / Q000097:blood*; D011247:Pregnancy; D012039:Regional Blood Flow; D012756:Sheep
D010100:Oxygen