Hemodynamic effects of amrinone in children after cardiac surgery

Abstract

The hemodynamic effects of amrinone were assessed in seven children following cardiac surgery. Amrinone was administered as a bolus of 1 mg kg-1 body wt., followed by continuous infusion at 10 micrograms kg-1 min-1 for 1 h and two stepwise increases to 20 and 40 micrograms kg-1 min-1 for 30 min each. Hemodynamic data were obtained and plasma concentrations of amrinone measured 1 h after the bolus dose and immediately before each increment of the infusion rate. Amrinone levels ranged from 0.7 to 2.3 mg l-1. Administration of amrinone lowered systemic vascular resistance from 20.0 +/- 4.3 to 16.5 +/- 4.6 mmHg l-1 min-1 m-2 (p less than 0.05) and reduced mean arterial pressure from 71.7 +/- 9.5 to 62.6 +/- 13.5 mmHg (p less than 0.05) at the highest infusion rate, confirming the known vasodilative effect of the drug. However, these effects did not result in a statistically significant increase in stroke volume (35.0 +/- 7.5 to 35.5 +/- 7.0 ml m-2, NS) or cardiac index (3.10 +/- 0.50 to 3.20 +/- 0.40 l min-1 m-2). One additional patient, in whom a higher loading dose was tried in order to achieve a higher plasma concentration, developed systemic hypotension. A correlation was established between the plasma concentrations of amrinone and the percentage decrease in systemic resistance (r = 0.70, p less than 0.05). These results suggest that in children after open heart surgery, amrinone acts primarily as a systemic vasodilator, with questionable inotropic effect. Accordingly, its use should be restricted to children with severe cardiac failure and documented highly elevated afterload.

Cardiovascular effects of a phosphodiesterase III inhibitor, amrinone, in infants: Non‐invasive echocardiographic evaluation

“…Berner et al . reported a study in pediatric patients after heart surgery and found that amrinone reduced systemic vascular resistance, but did not increased cardiac output, concluding that amrinone is a vasodilator 18 . In contrast, Bailey et al .…”

Effect of amrinone during group B Strepfococcus‐induced pulmonary hypertension in piglets

“…In adults and children, amr has been used safely without deleterious effects and has been effective in nonseptic pulmonary hypertensive states. [21][22][23] Amr reduces serum TxB, levels in vitro in human whole blood and in vivo in rabbits by inhibiting thromboxane synthase…”

Neonatal and infant physiology—impact of cardiopulmonary bypass in the developing patient

“…In one series of eight patients ranging from 17 months to 17 years, it was demonstrated that there were no overt effects on stroke volume or cardiac index despite reduced systemic vascular resistance. 59 Another series of patients undergoing cardiopulmonary bypass treated with amrinone postoperatively demonstrated significant improvement in right and left ventricular ejection fractions. 60 On balance, most reports suggest its effects in younger patients undergoing cardiopulmonary bypass are predominantly vasodilatory rather than inotropic.…”