Variable effects of high-dose adrenaline relative to standard-dose adrenaline on resuscitation outcomes according to cardiac arrest duration

Abstract

Aim of the studyAdjustment of adrenaline (epinephrine) dosage according to cardiac arrest (CA) duration, rather than administering the same dose, may theoretically improve resuscitation outcomes. We evaluated variable effects of high-dose adrenaline (HDA) relative to standard-dose adrenaline (SDA) on resuscitation outcomes according to CA duration. MethodsTwenty-eight male domestic pigs were randomised to the following 4 groups according to the dosage of adrenaline (SDA 0.02mg/kg vs. HDA 0.2mg/kg) and duration of CA before beginning cardiopulmonary resuscitation (CPR): 6min SDA, 6min HDA, 13min SDA, or 13min HDA. After the predetermined duration of untreated ventricular fibrillation, CPR was provided. ResultsAll animals in the 6min SDA, 6min HDA, and 13min HDA groups were successfully resuscitated, while only 4 of 7 pigs in the 13min SDA group were successfully resuscitated (p=0.043). HDA groups showed higher right atrial pressure, more frequent ventricular ectopic beats, higher blood glucose, higher troponin-I, and more severe metabolic acidosis than SDA groups. Animals of 13min groups showed more severe metabolic acidosis and higher troponin-I than animals of 6min groups. All successfully resuscitated animals, except two animals in the 13min HDA group, survived for 7 days (p=0.121). Neurologic deficit score was not affected by the dose of adrenaline. ConclusionHDA showed benefit in achieving restoration of spontaneous circulation in 13min CA, when compared with 6min CA. However, this benefit did not translate into improved long-term survival or neurologic outcome.