Adrenal gland blood flow and noradrenaline plasma concentration during CPR in pigs

Aim of the studyIn comparison to adrenaline, administration of vasopressin increases adrenal gland perfusion, but decreases catecholamine plasma concentrations when compared to saline placebo. We directly compared the effects of adrenaline with different doses of vasopressin on adrenal gland perfusion, and noradrenaline plasma concentrations during CPR.MethodsTwenty-one pigs received either 0.2 mg kg−1 adrenaline (n = 7), 0.2 U kg−1 vasopressin (n = 7), or 0.8 U kg−1 vasopressin (n = 7) after 4 min of cardiac arrest and 3 min of CPR. Adrenal gland perfusion was determined using radiolabeled microspheres, noradrenaline plasma concentration was measured by high pressure liquid chromatography.ResultsBefore administration of vasopressor drugs during CPR, adrenal gland perfusion, and noradrenaline plasma concentrations were not different between groups. Ninety seconds and 5 min after drug administration, adrenal gland perfusion was significantly higher with both doses of vasopressin when compared with adrenaline, but was not different between the vasopressin groups. Noradrenaline plasma concentrations were 23684 ± 5036 pg ml−1 with adrenaline, 11455 ± 2450 pg ml−1 with 0.2 U kg−1 vasopressin, and 12119 ± 2921 pg ml−1 with 0.8 U kg−1 vasopressin at 90 s after administration of vasopressors (p < .05 for both doses of vasopressin vs adrenaline). Five of seven animals in the adrenaline group, five of seven animals in the 0.2 U kg−1 vasopressin group, and six of seven animals in the 0.8 U kg−1 vasopressin group were successfully defibrillated.ConclusionsVasopressin enhances adrenal gland perfusion, but decreases noradrenaline plasma concentration when compared to adrenaline during CPR. Neither adrenal gland perfusion nor noradrenaline plasma concentration affect survival in this pig model of cardiac arrest.