Effects of milrinone versus epinephrine on grafted internal mammary artery flow after cardiopulmonary bypass.
Author(s): Lobato EB, Urdaneta F, Martin TD, Gravenstein N
Affiliation(s): Department of Anesthesiology, University of Florida College of Medicine, Gainesville, USA.
Publication date & source: 2000-02, J Cardiothorac Vasc Anesth., 14(1):9-11.
Publication type: Clinical Trial; Comparative Study ; Randomized Controlled Trial; Research Support, Non-U.S. Gov't
OBJECTIVE: To compare changes on grafted internal mammary artery (IMA) flow after cardiopulmonary bypass in response to the administration of milrinone or epinephrine. DESIGN: Prospective and randomized. SETTING: University-affiliated hospital. PARTICIPANTS: Twenty consenting, adult patients undergoing CABG. INTERVENTIONS: 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. MEASUREMENTS AND MAIN 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.
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