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5031797 
Journal Article 
Dobutamine is the optimal inotrope for the fetus 
Baker, S; Lam, C; Lubbers, W; Clark, K; Eghtesady, P 
2006 
Yes 
American Journal of Obstetrics & Gynecology
ISSN: 0002-9378
EISSN: 1097-6868 
195 
English 
OBJECTIVE: Recent clinical experience has shown significant declines in fetal cardiac output with open fetal surgery and improved fetal survival with intraoperative use of resuscitative measures. While some have looked at effects on placental function or uterine blood flow, none have evaluated the effects of commonly used inotropes on fetal cardiac output identifying the optimal agent for the fetus. STUDY DESIGN: Four ovine fetuses at gestational day 104-111 were chronically instrumented to measure maternal and fetal hemodynamics including fetal cardiac output and umbilical blood flow. Fetal dose response studies were carried out using clinically-relevant doses of milrinone (0.25- 1 mcg/kg/min), dopamine (3-15 mcg/kg/min), dobutamine (3-15 mcg/kg/min) and epinephrine (0.02-2 mcg/kg/min). Random assignments to each infusion were carried out on separate days. Student and #146;s t-test (2-tailed) was used to determine significance at p and lt;0.05. RESULTS: Except milrinone, the other three inotropes increased fetal cardiac output and umbilical blood flow in a dose dependent fashion. Dobutamine had the most profound increase in fetal cardiac output (39+/-28%, Mean+/-SD) versus both dopamine (23+/-31%) and epinephrine (18+/-14%), (p and lt;0.05 for all). These three inotropes increased umbilical blood flows up to 18%, but only dobutamine significantly decreased umbilical vascular resistance by 19+/-3%, (p and lt;0.05 for all). All hemodynamics normalized 30 min after the infusions. Epinephrine infusion was associated with significant lactic acidosis and fetal hyperglycemia. Fetal gas exchange was preserved with all agents at all times. Fetal inotrope infusions did not alter maternal hemodynamics. CONCLUSION: Not all inotropes are equal for fetal support. Dobutamine may be superior because of its salutary effects on placental vascular resistance. Epinephrine may be the least optimal agent because of its metabolic effects on the fetus.