Vasopressin is a novel vasopressor agent used for intractable hypotension. There is little published data available on its use in the poisoned patient. We performed a randomized, controlled, blinded trial in a porcine model to study the effects of vasopressin infusion on mean arterial pressure after verapamil poisoning.
Eighteen anesthetized monitored swine received a verapamil infusion of 1 mg/kg/hr until the mean arterial pressure (MAP) had decreased to 70% of baseline. At this time, a continuous infusion of either vasopressin (0.01 U/kg/min) or an equal volume of normal saline was initiated. The swine were monitored for 60 minutes after initiation of the study infusion. The primary outcome was MAP.
There was no statistically significant difference between the two groups in MAP, cardiac output or systemic vascular resistance. One half (four of eight) of the animals in the vasopressin group died, compared with 20% (two of ten) of those in the saline group.
Vasopressin infusion decreased the survival of verapamil-poisoned swine when compared to those treated with saline alone in this experimental model.