Experimental Cardiac Arrest Treatment with Adrenaline, Vasopressin, or Placebo

Abstract

BackgroundThe effect of vasoconstrictors in prolonged cardiopulmonary resuscitation (CPR) has not been fully clarified.ObjectivesTo evaluate adrenaline and vasopressin pressure effect, and observe the return of spontaneous circulation (ROSC).MethodsA 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.ResultsCoronary 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).ConclusionThe 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.

Long term outcomes of participants in the PARAMEDIC2 randomised trial of adrenaline in out-of-hospital cardiac arrest

“…Most studies, including animal models, [21][22][23] observational studies 6,7 and one randomised controlled trial, 24 focused on the survival up to 30 days or hospital discharge. However, the decreasing trend of the effect to 12-months indicated the survival benefit of adrenaline is likely to fade over time.…”

Efeito do azul de metileno como adjuvante no desfecho da parada cardíaca: estudo experimental em ratos

“…A epinefrina aumenta o fluxo coronariano, melhorando o fluxo de nutrientes e oxigênio ao miocárdio, evitando a estase e eliminando metabólitos como ácido láctico e CO 2 (14,(16)(17)(18) .…”