Beta1-adrenergic blockade during cardiopulmonary resuscitation improves survival

The short-acting beta1-selective adrenergic blocking agent, esmolol, was administrated during cardiopulmonary resuscitation with the hypothesis that initial resuscitation and postresuscitation survival would be improved.

Prospective, randomized, controlled study.

Animal research laboratory.

Male Sprague-Dawley rats.

Ventricular fibrillation was induced in 18 male Sprague-Dawley rats, which were then left untreated for 6 mins before attempted resuscitation with precordial compression, mechanical ventilation, and electrical defibrillation. Animals were randomized to receive 300 microg/kg esmolol in a volume of 200 microL or an equivalent volume of saline placebo during cardiopulmonary resuscitation. Electrical defibrillation was attempted after 12 mins of ventricular fibrillation.

Esmolol-treated animals required a significantly smaller number of electrical shocks before resuscitation. Each of the esmolol-treated but only five of nine placebo-treated animals were successfully resuscitated. Postresuscitation contractile and left ventricular diastolic functions of resuscitated animals were significantly better after esmolol administration and duration of survival was significantly increased.

A short-acting beta1-selective adrenergic blocking agent, when administered during cardiopulmonary resuscitation, significantly improved initial cardiac resuscitation, minimized postresuscitation myocardial dysfunction, and increased the duration of postresuscitation survival.