Comparison between dobutamine and levosimendan for management of postresuscitation myocardial dysfunction

To investigate the effects of levosimendan, a nonadrenergic inotropic calcium sensitizer, in comparison with adrenergic dobutamine for the management of postresuscitation myocardial dysfunction following resuscitation from prolonged cardiac arrest.

Randomized prospective animal study.

Animal research laboratory.

Male Yorkshire-cross domestic pigs

Ventricular fibrillation was induced in male domestic pigs weighing between 35 and 40 kg. Cardiopulmonary resuscitation, including precordial compression and mechanical ventilation, was started after 7 mins of untreated cardiac arrest. Electrical defibrillation was attempted after 5 mins of cardiopulmonary resuscitation. Each animal was successfully resuscitated without pharmacologic intervention. Resuscitated animals were randomized to treatment with levosimendan, dobutamine, or saline placebo. The inotropic agents or an equivalent volume of placebo diluents was administered 10 mins after restoration of spontaneous circulation. Levosimendan was administered in a loading dose of 20 microg.kg over 10 mins followed by a 220-min infusion of 0.4 microg.kg.min. Dobutamine was infused into the right atrium in an amount of 5 microg.kg.min. Treatment was continued for a total of 230 mins.

Levosimendan and dobutamine produced comparable increases in cardiac output. However, levosimendan produced significantly greater left ventricular ejection fraction and fractional area changes compared with dobutamine and saline placebo.

Levosimendan has the potential of improving postresuscitation myocardial function. It is likely to serve as an alternative to dobutamine as an inotropic agent for management of postresuscitation myocardial dysfunction.