Effects of milrinone versus epinephrine on grafted internal mammary artery flow after cardiopulmonary bypass.
OBJECTIVE
To compare changes on grafted internal mammary artery (IMA) flow after cardiopulmonary bypass in response to the administration of milrinone or epinephrine.


METHODS
Prospective and randomized.


METHODS
University-affiliated hospital.


METHODS
Twenty consenting, adult patients undergoing CABG.


METHODS
Patients were randomized to receive either milrinone, 50 microg/kg, or epinephrine, 0.03 microg/kg/min, immediately after cardiopulmonary bypass. IMA flow was measured with a laser Doppler flow probe before and after the administration of either drug.


RESULTS
Baseline grafted IMA flow was similar for both groups (milrinone, 38+/-14 mL/min; epinephrine, 33+/-10 mL/min). In patients who received milrinone, flow increased by 24% to 50+/-17 mL/min, p<0.05; whereas with epinephrine, it remained essentially unchanged (33+/-10 v. 31+/-11 mL/min).


CONCLUSIONS
This study confirms that the vasodilatory effect of milrinone on the IMA is also present after its anastomosis, whereas low-dose epinephrine exhibits neither beneficial nor adverse effects. It is suggested that in the absence of excessive vasodilation, milrinone should be considered as a first-line inotrope after coronary artery bypass graft surgery, to achieve an increase in contractility and IMA artery flow.
Lobato
E B
EB
Department of Anesthesiology, University of Florida College of Medicine, Gainesville, USA.
Urdaneta
F
F
Martin
T D
TD
Gravenstein
N
N
D000368:Aged; D001783:Blood Flow Velocity / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D002315:Cardiopulmonary Bypass; D002316:Cardiotonic Agents / Q000494:pharmacology*; D001026:Coronary Artery Bypass; D004837:Epinephrine / Q000494:pharmacology*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008297:Male; D008323:Mammary Arteries / Q000187:drug effects* / Q000637:transplantation; D020105:Milrinone / Q000494:pharmacology*; D009200:Myocardial Contraction / Q000187:drug effects; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology*; D011446:Prospective Studies; D014665:Vasodilator Agents / Q000494:pharmacology*
D002316:Cardiotonic Agents; D010726:Phosphodiesterase Inhibitors; D014665:Vasodilator Agents; D020105:Milrinone; D004837:Epinephrine