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.

Vasopressin and epinephrine in the treatment of cardiac arrest: an experimental study.

BACKGROUND: Epinephrine remains the drug of choice for cardiopulmonary resuscitation. The aim of the present study is to assess whether the combination of vasopressin and epinephrine, given their different mechanisms of action, provides better results than epinephrine alone in cardiopulmonary resuscitation. METHODS: Ventricular fibrillation was induced in 22 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 during cardiopulmonary resuscitation: 11 animals who received saline as placebo (20 ml dilution, bolus) + epinephrine (0.02 mg/kg) (Epi group); and 11 animals who received vasopressin (0.4 IU/kg/20 ml dilution, bolus) + epinephrine (0.02 mg/kg) (Vaso-Epi group). Electrical defibrillation was attempted after 10 minutes of ventricular fibrillation. RESULTS: Ten of 11 animals in the Vaso-Epi group restored spontaneous circulation in comparison to only 4 of 11 in the Epi group (p = 0.02). Aortic diastolic pressure, as well as, coronary perfusion pressure were significantly increased (p < 0.05) during cardiopulmonary resuscitation in the Vaso-Epi group. CONCLUSION: The administration of vasopressin in combination with epinephrine during cardiopulmonary resuscitation results in a drastic improvement in the hemodynamic parameters necessary for the return of spontaneous circulation.