Does furosemide alter the hemodynamic response to rapid intravascular transfusion of the anemic fetal lamb?
The purpose of this study was to define the hemodynamic response to rapid intravascular transfusion of the anemic fetal lamb and to determine whether furosemide alters that response. Sixteen experiments were performed in nine chronically instrumented gravid ewes between 0.8 and 0.9 of timed gestation. On day 1 of each experiment, each fetus was subjected to hemorrhage (40 ml/kg of estimated fetal weight) over 1 hour. On day 2, plasma was withdrawn from the stored fetal blood until the hematocrit was approximately 70%, and the packed red blood cells were returned to the fetus intravenously over 10 minutes. Each fetus received either furosemide (2 mg/kg) or control saline solution intravenously at time zero and again at 5 minutes. The order of experiments was randomly determined for each animal. Hemorrhage resulted in a similar decrease in fetal hematocrit in the two groups. The mean +/- SEM fetal hematocrit before hemorrhage was 38 +/- 3% in the furosemide group (n = 8) and 36 +/- 2% in the control group (n = 8). On day 2, the mean +/- SEM fetal hematocrit before transfusion was 28 +/- 2% in the furosemide group and 25 +/- 1% in the control group. There was no significant difference between groups in the fetal hemodynamic response to transfusion. At the end of the transfusion, the fetal central venous pressure had increased from 4.9 +/- 0.5 to 6.2 +/- 0.5 mm Hg in the furosemide group (p = 0.01) and from 3.9 +/- 0.2 to 5.8 +/- 0.3 mm Hg in the control group (p = 0.0001). Fetal mean arterial pressure increased from 42 +/- 1 to 50 +/- 1 mm Hg in the furosemide group (p = 0.0001) and from 40 +/- 1 to 46 +/- 1 mm Hg in the control group (p = 0.0007). Fetal heart rate decreased from 187 +/- 2 to 169 +/- 5 beats/min in the furosemide group (p = 0.004) and from 188 +/- 4 to 170 +/- 5 beats/min in the control group (p = 0.0008). Transfusion did not significantly change fetal pH in either group. At 120 minutes, the fetal PO2 had increased from 17 +/- 1 to 19 +/- 1 mm Hg in the furosemide group (p = 0.03) and from 19 +/- 1 to 21 +/- 2 mm Hg in the control group (p = 0.05). We conclude that rapid transfusion of the anemic fetal lamb resulted in modest increases in fetal central venous pressure and mean arterial pressure.(ABSTRACT TRUNCATED AT 400 WORDS)
Chestnut
D H
DH
Department of Anesthesia, University of Iowa College of Medicine, Iowa City.
Pollack
K L
KL
Weiner
C P
CP
Robillard
J E
JE
Thompson
C S
CS
DeBruyn
C S
CS
D000743:Anemia, Hemolytic / Q000503:physiopathology* / Q000628:therapy; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001805:Blood Transfusion, Intrauterine; D005260:Female; D005315:Fetal Diseases / Q000503:physiopathology* / Q000628:therapy; D005665:Furosemide / Q000494:pharmacology*; D006340:Heart Rate, Fetal / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D011247:Pregnancy; D012756:Sheep
D005665:Furosemide