Vasopressin: improving resuscitation?

Historically, epinephrine has been used in the treatment of cardiac arrest for its alpha effects of peripheral vasoconstriction to promote vital organ perfusion. Unfortunately, epinephrine, like many other pharmacological agents, targets other receptor sites that can have a detrimental effect on the patient in cardiac arrest. Vasopressin is an endogenous hormone that may be an ideal alternative or adjunctive to epinephrine in the setting of cardiac arrest. Vasopressin, like epinephrine, promotes selective but potent vasoconstriction of smooth muscle, but unlike epinephrine, without the potentially harmful side effects of increasing myocardial workload, therefore increasing oxygen demand and subsequent worsening of cardiac function. The newest data on the impact of vasopressin in cardiac arrest is promising. Further studies are required to determine if vasopressin has a significantly positive impact in outcome as measured by discharge of the neurologically intact patient in the North American EMS model.