Effects of Low-dose Milrinone on Weaning from Cardiopulmonary Bypass and after in Patients with Mitral Stenosis and Pulmonary Hypertension

Abstract

The phosphodiesterase inhibitor milrinone is usually preferred in patients with pulmonary hypertension and myocardial dysfunction after cardiopulmonary bypass. We investigated the eŠects of low-dose milrinone on pulmonary hypertension in the immediate pre-and postoperative period. Forty-seven patients were randomized to the control and milrinone groups. All patients had mean pulmonary artery pressure greater than 30 mmHg and pulmonary capillary wedge pressure greater than 20 mmHg and were candidates for mitral valve replacement for rheumatic mitral stenosis. Twenty-four patients received a loading dose of milrinone 25 mg/kg -1 during weaning from cardiopulmonary bypass, followed by a maintenance dose of 0.25 mg/kg -1 /min -1 to the end of the surgery. Cardiac output and other hemodynamic variables were noted at induction, weaning from bypass, and postoperative 1 h. Pulmonary artery pressure, capillary wedge pressure, and central venous pressure were signiˆcantly lower in the milrinone group during weaning after cardiopulmonary bypass, while other variables were roughly similar. However, patients in the control group required higher doses of vasodilators, inotropes, and antiarrhythmic agents. Mean arterial pressure in the milrinone group was signiˆcantly lower at 1 h postoperatively than in the control group; however, the patients did not need many more vasopressors. Fluid restriction and diuretic agent use were more signiˆcant in the control group. Systemic arterial hypotension and vasopressor requirements with milrinone use at inotropic doses were not observed at the doses used for the study. A total of 21.7％ of the patients in the control group required vasopressors in the perioperative period. Both groups demonstrated similar hematologic variables except that the hemoglobin level in the control group was signiˆcant-ly lower during postoperative days 1 and 7. Low-dose milrinone for a short-term during weaning from cardiopulmonary bypass may be used in patients with mitral stenosis and pulmonary hypertension for its eŠects on pulmonary artery pressures, less inotropic and vasopressor requirements, and ‰uid balance.

Pulmonary vascular and right ventricular dysfunction in adult critical care: current and emerging options for management: a systematic literature review

“…They are most suited to short-term use because of tachyphylaxis [159], and mild tachycardia is common. Milrinone is most frequently used and has been shown to reduce pulmonary pressures and augment RV function in many studies in patients with pulmonary vascular dysfunction [160-164]. Enoximone improves RV function in pulmonary vascular dysfunction after cardiac surgery [165,166] and in patients with decompensated chronic obstructive pulmonary disease (COPD) [167].…”

Management of Acute Right Ventricular Failure in the Intensive Care Unit

“…Milrinone is frequently the agent of choice in patients with pulmonary hypertension from biventricular failure, and in those recovering after ventricular assist or cardiac transplantation (90)(91)(92). Several small studies have also examined the use of inhaled milrinone in patients with pulmonary vascular disease to avoid systemic hypotension (93)(94)(95)(96).…”

Effect of peri-operative milrinone on pulmonary artery pressure in patients undergoing mitral valve replacement

“…Only a couple of studies have previously examined milrinone in pulmonary hypertension occurring during mitral valve surgery. Oztekin et al [16] reported that using milrinone caused significant reduction in pulmonary artery pressure, central venous pressure and pulmonary capillary wedge pressure in patients with mitral valve stenosis and PHT undergoing mitral valve replacement. They also found that it facilitated weaning from cardiopulmonary bypass with less side effects.…”