Vasopressin versus epinephrine during neonatal cardiopulmonary resuscitation of asphyxiated post-transitional piglets

Background: Epinephrine is currently the only recommended cardio-resuscitative medication for use in neonatal cardiopulmonary resuscitation (CPR), as per the consensus of science and treatment recommendations. An alternative medication, vasopressin, might be beneficial in neonatal CPR due to its combined pulmonary vasodilation and systemic vasoconstriction properties. Aim: We aimed to compare the time to return of spontaneous circulation (ROSC) with administration of vasopressin or epinephrine during CPR of asphyxiated post-transitional piglets. Methods: Newborn piglets (n = 8/group) were anesthetized, tracheotomized and intubated, instrumented, and exposed to 50 min normocapnic hypoxia followed by asphyxia and cardiac arrest. Piglets were randomly allocated to receive vasopressin (Vaso, 0.4 U/kg) or epinephrine (Epi, 0.02 mg/kg) during CPR. Piglets were resuscitated with chest compressions superimposed with sustained inflations, and were administered either Vaso or Epi intravenously every 3 min until ROSC (max. 3 doses). Hemodynamic and cardiac function parameters were collected. Main Results: The median (IQR) time to ROSC was 106 (93–140) s with Vaso and 128 (100–198) s with Epi (p = 0.28). The number of piglets that achieved ROSC was 8 (100%) with Vaso and 7 (88%) with Epi (p = 1.00). Vaso-treated piglets had a significantly longer post-resuscitation survival time (240 (240–240) min) than Epi-treated piglets (65 (30–240) min, p = 0.02). Vaso-treated piglets had significantly improved carotid blood flow immediately after ROSC (p < 0.05), had longer duration of post-resuscitation hypertension (p = 0.05), and had significantly improved heart rate, arterial pressure, and cerebral blood oxygen saturation 4 h after ROSC (p < 0.05). Conclusions: Vasopressin improved post-resuscitation survival and hemodynamics, and might be an alternative cardio-resuscitative medication during neonatal CPR, but further studies are warranted