Arginine vasopressin during cardiopulmonary resuscitation: laboratory evidence, clinical experience and recommendations, and a view to the future.

When stimulating adult pigs with ventricular fibrillation or postcountershock pulseless electrical activity for cardiopulmonary resuscitation, vasopressin improved vital organ blood flow, cerebral oxygen delivery, ability to be resuscitated, and neurologic recovery better than epinephrine. In pediatric preparations with asphyxia, epinephrine was superior to vasopressin, whereas in both pediatric pigs with ventricular fibrillation and adult porcine models with asphyxia, combinations of vasopressin and epinephrine proved to be highly effective. This may suggest that a different efficiency of vasopressors in pediatric vs. adult preparations and different effects of dysrhythmic vs. asphyxial cardiac arrest on vasopressor efficiency may be of significant importance. Whether these theories can be extrapolated to humans is unknown at this time. In patients who experienced out-of-hospital ventricular fibrillation, a larger proportion of patients treated with vasopressin survived 24 hrs compared with patients treated with epinephrine; during in-hospital cardiopulmonary resuscitation, comparable short-term survival was found in groups treated with either vasopressin or epinephrine. Currently, a large trial comprising patients who experience out-of-hospital cardiac arrest and who are treated with vasopressin vs. epinephrine is ongoing in Germany, Austria, and Switzerland. The new cardiopulmonary resuscitation guidelines of both the American Heart Association and the European Resuscitation Council consider 40 units of vasopressin intravenously and 1 mg of epinephrine intravenously equally effective for the treatment of adult patients with ventricular fibrillation; however, because of a lack of clinical data, no recommendation for vasopressin has been made for adult patients with asystole and pulseless electrical activity or for pediatric patients.