Nitroglycerin and epinephrine improve coronary perfusion pressure in a porcine model of ventricular fibrillation arrest: a pilot study.

BACKGROUND: Cardiac arrest remains one of the leading causes of death worldwide. European Resuscitation Council Guidelines for Resuscitation 2005 recommend epinephrine for its treatment. OBJECTIVES: To estimate whether the administration of a vasodilatator such as nitroglycerin in combination with epinephrine during cardiopulmonary resuscitation would improve resuscitation outcome in an established model of ventricular fibrillation. DESIGN: Prospective, randomized, blinded, controlled study. SETTING: Animal research laboratory. Ventricular fibrillation was induced in 20 Landrace/Large-White pigs. It remained untreated for 8 min before attempting resuscitation precordial compressions, mechanical ventilation, and electrical defibrillation. Animals were randomized into two groups, 10 animals each. Group A received saline as placebo (10 mL dilution, bolus) and epinephrine (0.02 mg/kg). Group B received nitroglycerin (50 microg/kg) and epinephrine (0.02 mg/kg) during cardiopulmonary resuscitation. Electrical defibrillation was attempted after 10 min of ventricular fibrillation. RESULTS: Four animals in group A restored spontaneous circulation in comparison to eight in Group B. Coronary perfusion pressure (p < 0.0001) was significantly increased in Group B during cardiopulmonary resuscitation. CONCLUSION: A vasodilatator, when administered in combination with a vasopressor such as epinephrine during cardiopulmonary resuscitation, increases coronary perfusion pressure.

Atenolol in combination with epinephrine improves the initial outcome of cardiopulmonary resuscitation in a swine model of ventricular fibrillation.

STUDY OBJECTIVES: The aim of the present study was to assess whether a beta-adrenergic blocking agent such as atenolol, administered during cardiopulmonary resuscitation, would improve initial resuscitation success. METHODS: Ventricular fibrillation was induced in 20 Landrace/Large White piglets, which were left untreated for 8 minutes before attempted resuscitation with precordial compression, mechanical ventilation, and electrical defibrillation. Animals were randomized into 2 groups (10 animals each) to receive saline as placebo (20 mL dilution, bolus) + epinephrine (0.02 mg/kg) (group A) or atenolol (0.05 mg/kg per 20 mL dilution, bolus) + epinephrine (0.02 mg/kg) (group B) during cardiopulmonary resuscitation. Electrical defibrillation was attempted after 10 minutes of ventricular fibrillation. RESULTS: Nine animals in group B restored spontaneous circulation in comparison to only 4 in group A. Aortic systolic and diastolic pressures as well as coronary perfusion pressure were significantly increased during cardiopulmonary resuscitation in group B. Furthermore, postresuscitation heart rate of the atenolol-treated group was significantly decreased. CONCLUSIONS: A beta-adrenergic blocking agent, when administered during cardiopulmonary resuscitation, significantly improves initial resuscitation success and increases blood and coronary perfusion pressures during cardiopulmonary resuscitation.