Compared to angiotensin II, epinephrine is associated with high myocardial blood flow following return of spontaneous circulation after cardiac arrest.
BACKGROUND
Epinephrine (adrenaline) and vasopressin are used currently to improve myocardial blood flow (MBF) during cardiac arrest. Angiotensin II has also been shown to improve MBF during CPR. We explored the effects of angiotensin II or epinephrine alone, and the combination of angiotensin with epinephrine, on myocardial and cerebral blood flows in a swine model of cardiac arrest.


METHODS
Swine were instrumented for regional blood flow measurements. Ventricular fibrillation was induced and CPR begun. Angiotensin II 50 mcg/kg (ANG), epinephrine 0.02 mg/kg (EPI) or the combination (ANG+EPI) was administered. Blood flow was measured during baseline normal sinus rhythm (NSR), before (CPR) and after drug administration (CPR+DRUG), and post reperfusion return of spontaneous circulation (ROSC).


RESULTS
All groups had a significant increase in MBF during CPR following drug administration (P<0.05). [table: see text] There was a trend toward higher flows in the EPI groups. The group receiving both EPI and ANG did not have higher blood flows than the EPI or ANG alone groups. Both groups that received EPI had markedly elevated MBF following ROSC compared with angiotensin II (P<0.05).


CONCLUSIONS
The combination of ANG and EPI did not improve MBF during cardiac arrest. Epinephrine may increase MBF compared with angiotensin II post-reperfusion.
Little
Charles M
CM
Division of Emergency Medicine, Department of Surgery, Health Sciences Center, University of Colorado, 4200 E. Ninth Avenue, Denver, CO 80262, USA.
Angelos
Mark G
MG
Paradis
Norman A
NA
D000704:Analysis of Variance; D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001783:Blood Flow Velocity; D016887:Cardiopulmonary Resuscitation / Q000379:methods; D003326:Coronary Circulation / Q000187:drug effects*; D004195:Disease Models, Animal; D004359:Drug Therapy, Combination; D004837:Epinephrine / Q000494:pharmacology*; D005260:Female; D006323:Heart Arrest / Q000188:drug therapy* / Q000401:mortality; D006439:Hemodynamics / Q000502:physiology; D008297:Male; D011336:Probability; D012016:Reference Values; D012680:Sensitivity and Specificity; D034421:Sus scrofa
D000804:Angiotensin II; D004837:Epinephrine