A comparison of vasopressin and glucagon in beta-blocker induced toxicity

Objective . We compared the efficacy of vasopressin and glucagon in a porcine model of ss-blocker toxicity. Our primary outcome was survival over 4 hours. Methods . Sixteen pigs received a 1-mg/kg bolus of propranolol IV followed by continuous infusion at 0.25 mg/kg/minute. Toxicity was defined as a 25% decrease in the product of heart rate (HR) and mean arterial pressure (MAP), at which point 20 mL/kg normal saline was rapidly infused. Each pig was randomly assigned to receive either vasopressin or glucagon after the saline bolus. The vasopressin group received a continuous infusion at 0.0028 U/kg/minute, titrated up to a maximum of 0.014 U/kg/minute. The glucagon group received a 0.05-mg/kg bolus followed by continuous infusion at 0.15 mg/kg/hour. The HR, MAP, systolic BP (SBP), cardiac output (CO), glucose, and pH were monitored for 4 hours from toxicity or until death. Results . One pig survived at 4 hours (vasopressin group). Analysis of the 4-hour Kaplan-Meier survival curves found no differences between the groups (log-rank test 0.059, p = 0.81). No overall differences were identified in MAP, systolic BP, cardiac output, glucose, pH, or HR. However, over the first hour MAP and SBP were significantly higher in the vasopressin group (p = 0.004, p = 0.006, respectively). Conclusion . In this ss-blocker toxicity model, there were no differences in the survival curves between vasopressin- and glucagon-treated pigs during a 4-hour analysis period. No overall differences were noted in MAP, systolic BP, CO, HR, pH, or glucose levels, although vasopressin treatment yielded higher MAP and systolic BP early in resuscitation.