title: Repeated epinephrine doses during prolonged cardiopulmonary resuscitation have limited effects on myocardial blood flow: a randomized porcine study.
abstract: BACKGROUND
  In current guidelines, prolonged cardiopulmonary resuscitation (CPR) mandates administration of repeated intravenous epinephrine (EPI) doses. This porcine study simulating a prolonged CPR-situation in the coronary catheterisation laboratory, explores the effect of EPI-administrations on coronary perfusion pressure (CPP), continuous coronary artery flow average peak velocity (APV) and amplitude spectrum area (AMSA).
  
  
  METHODS
  Thirty-six pigs were randomized 1:1:1 to EPI 0.02 mg/kg/dose, EPI 0.03 mg/kg/dose or saline (control) in an experimental cardiac arrest (CA) model. During 15 minutes of mechanical chest compressions, four EPI/saline-injections were administered, and the effect on CPP, APV and AMSA were recorded. Comparisons were performed between the control and the two EPI-groups and a combination of the two EPI-groups, EPI-all.
  
  
  RESULTS
  Compared to the control group, maximum peak of CPP (Pmax) after injection 1 and 2 was significantly increased in the EPI-all group (p = 0.022, p = 0.016), in EPI 0.02-group after injection 2 and 3 (p = 0.023, p = 0.027) and in EPI 0.03-group after injection 1 (p = 0.013). At Pmax, APV increased only after first injection in both the EPI-all and the EPI 0.03-group compared with the control group (p = 0.011, p = 0.018). There was no statistical difference of AMSA at any Pmax. Seven out of 12 animals (58%) in each EPI-group versus 10 out of 12 (83%) achieved spontaneous circulation after CA.
  
  
  CONCLUSIONS
  In an experimental CA-CPR pig model repeated doses of intravenous EPI results in a significant increase in APV only after the first injection despite increments in CPP also during the following 2 injections indicating inappropriate changes in coronary vascular resistance during subsequent EPI administration.
authors.affiliation: Department of Cardiology, Lund University, Lund, Sweden. henrik.wagner@med.lu.se.
authors.forename: Henrik
authors.initials: H
authors.lastname: Wagner
authors.forename: Michael
authors.initials: M
authors.lastname: Götberg
authors.forename: Bjarne
authors.initials: B
authors.lastname: Madsen Hardig
authors.forename: Malin
authors.initials: M
authors.lastname: Rundgren
authors.forename: Jonas
authors.initials: J
authors.lastname: Carlson
authors.forename: Matthias
authors.initials: M
authors.lastname: Götberg
authors.forename: David
authors.initials: D
authors.lastname: Zughaft
authors.forename: David
authors.initials: D
authors.lastname: Erlinge
authors.forename: Göran K
authors.initials: GK
authors.lastname: Olivecrona
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D003326:Coronary Circulation / Q000187:drug effects*; D004195:Disease Models, Animal; D004837:Epinephrine / Q000008:administration & dosage*; D006323:Heart Arrest / Q000503:physiopathology / Q000628:therapy; D007275:Injections, Intravenous; D011897:Random Allocation; D013552:Swine
chemical_list: D004837:Epinephrine