Objective: To assess the hemodynamic effects of the addition of small bolus doses of the phosphodiesterase inhibitor enoximone to adrenergic therapy in patients with severe heart failure.
Design: Open label, prospective study.
Setting: Multidisciplinary department of intensive care in a university academic hospital.
Patients: Twelve surgical patients after cardiac surgery and ten medical patients with ischemic or dilated cardiomyopathy who had signs of altered tissue perfusion associated with a low cardiac index (less than 2.25 L/min/m2), despite adrenergic therapy.
Interventions: Small iv bolus doses of 0.25 mg/kg of enoximone.
Measurements and main results: This treatment resulted in significant increases in cardiac index and left ventricular stroke work index without significant changes in heart rate or mean arterial pressure. Furthermore, the effects of half this dose (i.e., 0.125 mg/kg), studied in 11 patients, demonstrated a significant drug-induced increase in mean (+/- SD) cardiac index (from 1.58 +/- 0.29 to 1.84 +/- 0.27 L/min/m2, p less than .01) without change in mean arterial pressure (from 74.5 +/- 12.1 to 76.5 +/- 12.6 mm Hg, nonsignificant).
Conclusions: Direct iv injections of enoximone can significantly increase the cardiac index in critically ill patients treated by adrenergic agents for severe heart failure. The administration of small doses of enoximone is effective and has minimal effect on arterial pressure.