Abstract P52: Evidence Suggesting the Beneficial Use of Beta Blockade in the Treatment of Cardiac Arrest
Objectives: According to the American Heart Association, the periodic use of a vasopressor, such as epinephrine, is recommended during cardiopulmonary resuscitation (CPR). Epinephrine posseses unwanted beta effects. The aim of the present study was to assess whether a beta-adrenergic blocking agent such as atenolol would improve the outcome of CPR.
Methods: Ventricular fibrillation (VF) was induced in 36 piglets, which were left untreated for 8 min before attempted resuscitation. Animals were randomized into 2 groups (16 animals each) to receive saline as placebo (20 ml dilution, bolus) + epinephrine (0.02 mg/kg) (Group A) or atenolol (0.05 mg/kg/20 ml dilution, bolus) + epinephrine (0.02 mg/kg) (Group B) by the end of the 8th min of untreated VF. Electrical defibrillation was attempted after 10 min of VF. Animals that restored spontaneous circulation were neurologically assessed 48 hours postresuscitation.
Findings: Six animals in Group A restored spontaneous circulation versus 16 animals in Group B (p<0.05). From these animals, 4 survived for 48 hours in Group A compared to 14 animals in Group B (p<0,05). During CPR, coronary perfusion pressure was significantly higher in Group B (Table⇓). The total number of ventricular dysrhythmias was significantly reduced, while thermodilution post-resuscitation cardiac output was significantly higher in Group B. Troponin I was significantly higher and arterial blood lactate significantly lower in Group A. Serum astroglial protein, Neuron Specific Enolase values and the neurological alertness score did not exhibit any statistical difference between Groups.
Conclusions: Atenolol, when administered during CPR, significantly improves initial resuscitation success, survival and improves hemodynamics. In the post-resuscitation phase atenolol improves myocardial dysfunction, without adversely affecting neurological outcome.