Lobato E B, Gravenstein N, Martin T D
Department of Anesthesiology, University of Florida College of Medicine, Gainesville 32610-0254, USA.
J Cardiothorac Vasc Anesth. 2000 Aug;14(4):374-7. doi: 10.1053/jcan.2000.7921.
To compare the effects of milrinone versus epinephrine administered after cardiopulmonary bypass (CPB) on left ventricular compliance.
Prospective and randomized.
University-affiliated hospital.
Twenty consenting adult patients.
Patients undergoing aortocoronary bypass surgery were randomized to receive 50 microg/kg of milrinone (group M; n = 10) or 0.03 microg/kg/min of epinephrine (group E; n = 10) shortly after separation from CPB. Left ventricular compliance was assessed by observing changes in left ventricular end-diastolic area (LVEDA) in the short-axis view with transesophageal echocardiography, while maintaining a constant left atrial pressure. Measurements were performed (1) before CPB, (2) after separation from CPB, and (3) after either milrinone or epinephrine.
Baseline LVEDA decreased by 20% after CPB in the milrinone group (from 16.6 +/- 3.1 cm2 to 14.3 +/- 2.4 cm2; p < 0.05) and by 22% in the epinephrine group (from 19.4 +/- 4.1 cm2 to 17.2 +/- 3.8 cm2; p < 0.05). LVEDA increased by 15% after milrinone (from 14.3 +/- 2.4 cm2 to 15.6 +/- 2.8 cm2; p < 0.05) but remained unchanged after epinephrine (from 17.2 +/- 3.8 cm2 to 17.1 +/- 4.2 cm2; p = ns).
Left ventricular compliance was decreased after CPB. The administration of milrinone, but not epinephrine, was associated with a partial return to prebypass values. The exact mechanism of action remains to be determined.
