HIGH-DOSE EPINEPHRINE RESULTS IN GREATER EARLY MORTALITY AFTER RESUSCITATION FROM PROLONGED CARDIAC-ARREST IN PIGS - A PROSPECTIVE, RANDOMIZED STUDY

Objective: To determine whether high-dose epinephrine (0.2 mg/kg) duri ng cardiopulmonary resuscitation (CPR) results in improved outcome, co mpared with standard-dose epinephrine (0.02 mg/kg). Design: A prospect ive, randomized, blinded study. Setting: Research laboratory of a univ ersity medical center. Subjects and Interventions: Thirty domestic swi ne were randomized to receive standard- or high-dose epinephrine durin g CPR after 15 mim of fibrillatory cardiac arrest. Three minutes of CP R were provided, followed by advanced cardiac Life support per America n Heart Association guidelines. Animals that were successfully resusci tated were supported for 2 hrs in an intensive care unit (ICU) setting , and then observed for 24 hrs. Measurements and Main Results: Electro cardiogram, aortic blood pressure, right atrial blood pressure, and en d-tidal CO, were monitored continuously until the intensive care perio d ended.Survival and neurologic outcome were determined. Return of spo ntaneous circulation was attained in 14 of 15 animals in each group. F our of 14 high-dose epinephrine pigs died during the ICU period after return of spontaneous circulation vs. zero of the 14 standard-dose pig s (p < .05). Six standard-dose pigs survived 24 hrs vs. four high-dose pigs. Twenty-four-hour survival rate and neurologic outcome were not significantly different. Within 10 mins of defibrillation, severe hype rtension (diastolic pressure >120 mm Hg) occurred in 12 of 14 high-dos e pigs vs. two of 14 standard-dose pigs (p <.01). Severe tachycardia ( heart rate >250 beats/min) occurred in seven of 14 high-dose pigs vs. zero of 14 standard-dose pigs (p < .01). Ah four high-dose epinephrine pigs that died during the ICU period experienced both severe hyperten sion and tachycardia immediately postresuscitation. Conclusions: High- dose epinephrine did not improve 24-hr survival rate or neurologic out come. Immediately after return of spontaneous circulation, most animal s in the high-dose epinephrine group exhibited a hyperadrenergic state that included severe hypertension and tachycardia High-dose epinephri ne resulted in a greater early mortality rate.