title: Experimental cardiac arrest treatment with adrenaline, vasopressin, or placebo.
abstract: BACKGROUND
  The effect of vasoconstrictors in prolonged cardiopulmonary resuscitation (CPR) has not been fully clarified.
  
  
  OBJECTIVE
  To evaluate adrenaline and vasopressin pressure effect, and observe the return of spontaneous circulation (ROSC).
  
  
  METHODS
  A prospective, randomized, blinded, and placebo-controlled study. After seven minutes of untreated ventricular fibrillation, pigs received two minutes cycles of CPR. Defibrillation was attempted (4 J/kg) once at 9 minutes, and after every cycle if a shockable rhythm was present, after what CPR was immediately resumed. At 9 minutes and every five minutes intervals, 0.02 mg/kg (n = 12 pigs) adrenaline, or 0.4 U/kg (n = 12) vasopressin, or 0.2 mL/kg (n = 8) 0.9% saline solution was administered. CPR continued for 30 minutes or until the ROSC.
  
  
  RESULTS
  Coronary perfusion pressure increased to about 20 mmHg in the three groups. Following vasoconstrictors doses, pressure level reached 35 mmHg versus 15 mmHg with placebo (p < 0.001). Vasopressin effect remained at 15-20 mmHg after three doses versus zero with adrenaline or placebo. ROSC rate differed (p = 0.031) among adrenaline (10/12), vasopressin (6/12), and placebo (2/8). Time-to-ROSC did not differ (16 minutes), nor the number of doses previously received (one or two). There was no difference between vasoconstrictors, but against placebo, only adrenaline significantly increased the ROSC rate (p = 0.019).
  
  
  CONCLUSIONS
  The vasoconstrictors initial pressure effect was equivalent and vasopressin maintained a late effect at prolonged resuscitation. Nevertheless, when compared with placebo, only adrenaline significantly increased the ROSC rate.
authors.forename: Manoel Ângelo Gomes
authors.initials: MÂ
authors.lastname: Palácio
authors.forename: Edison Ferreira de
authors.initials: EF
authors.lastname: Paiva
authors.forename: Luciano Cesar Pontes de
authors.initials: LC
authors.lastname: Azevedo
authors.forename: Ari
authors.initials: A
authors.lastname: Timerman
mesh_terms: D000818:Animals; D016887:Cardiopulmonary Resuscitation; D004195:Disease Models, Animal; D004311:Double-Blind Method; D004353:Drug Evaluation, Preclinical; D004837:Epinephrine / Q000008:administration & dosage*; D006323:Heart Arrest / Q000188:drug therapy*; D011446:Prospective Studies; D011897:Random Allocation; D013552:Swine; D014662:Vasoconstrictor Agents / Q000008:administration & dosage*; D014667:Vasopressins / Q000008:administration & dosage*; D014693:Ventricular Fibrillation / Q000188:drug therapy*
chemical_list: D014662:Vasoconstrictor Agents; D014667:Vasopressins; D004837:Epinephrine