Hemodynamic effects of milrinone during weaning from cardiopulmonary bypass: comparison of patients with a low and high prebypass cardiac index.
OBJECTIVE
To compare the hemodynamic effects of milrinone during weaning from cardiopulmonary bypass (CPB) in patients with a low pre-CPB cardiac index (CI) <2.5 L/min/m2) and in patients with a high pre-CPB CI (> or =2.5 L/min/m2).


METHODS
Prospective, randomized, double-blind study.


METHODS
University hospital.


METHODS
Forty-eight patients scheduled for elective coronary artery bypass graft surgery.


METHODS
Patients were divided into 4 groups: (1) low pre-CPB CI/placebo, (2) low pre-CPB CI/milrinone, (3) high pre-CPB CI/placebo, and (4) high pre-CPB CI/milrinone. Patients received a loading dose of 20 microg/kg of milrinone followed by an infusion of 0.2 microg/kg/min or placebo 15 minutes before the anticipated weaning time.


RESULTS
In the low pre-CPB CI/ placebo group, low CIs and high systemic vascular resistances (SVRs) were observed after CPB. High doses of dopamine and dobutamine were needed, and infusion of epinephrine was used in 5 of the 12 patients for hemodynamic support. Milrinone improved CI and reduced SVR in the low pre-CPB CI/milrinone group. Norepinephrine was needed to maintain an adequate systemic blood pressure in 6 of the 12 patients, however. In the high pre-CPB CI/placebo group, satisfactory CIs and SVRs were observed during weaning from CPB with low doses of dopamine and dobutamine. Milrinone significantly increased CI and decreased SVR in the high pre-CPB CI/milrinone group: 10 of the 12 patients had CIs above the upper limit of normal, and 7 patients had SVRs below the lower limit of normal.


CONCLUSIONS
Milrinone was effective during weaning from CPB in patients with a low pre-CPB CI. Milrinone in combination with norepinephrine was a good alternative to epinephrine for the treatment of myocardial dysfunction after CPB.
Yamada
T
T
Department of Anesthesiology, School of Medicine, Keio University, Tokyo, Japan.
Takeda
J
J
Katori
N
N
Tsuzaki
K
K
Ochiai
R
R
D000368:Aged; D002302:Cardiac Output / Q000187:drug effects; D002315:Cardiopulmonary Bypass; D002316:Cardiotonic Agents / Q000627:therapeutic use*; D001026:Coronary Artery Bypass; D004311:Double-Blind Method; D005260:Female; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020105:Milrinone / Q000627:therapeutic use*; D010726:Phosphodiesterase Inhibitors / Q000627:therapeutic use*; D011446:Prospective Studies; D014655:Vascular Resistance / Q000187:drug effects
D002316:Cardiotonic Agents; D010726:Phosphodiesterase Inhibitors; D020105:Milrinone