Vasopressin administration in refractory cardiac arrest

Background: Successful outcomes after cardiopulmonary resuscitation remain disappointingly infrequent. In animal studies, administration of exogenous vasopressin during closed- and open-chest cardiopulmonary resuscitation has recently been shown to be more effective than optimal doses of epinephrine in improving vital organ blood flow. Objective: To describe the clinical effects and outcomes of administering vasopressin to patients in cardiac arrest refractory to current medical therapies. Design: Case reports. Setting: University hospital. Patients: 8 adults with in-hospital cardiac arrest. Interventions: After intravenous epinephrine (administered according to American Heart Association guidelines) and defibrillation efforts had failed, patients in cardiac arrest who were having cardiopulmonary resuscitation received 40 U of vasopressin intravenously and then defibrillation. Measurements: Return of spontaneous circulation and hospital discharge rates. Results: After administration of vasopressin, spontaneous circulation was promptly restored in all patients. Three patients were discharged from the hospital with intact neurologic function; the other five lived for between 30 minutes and 82 hours. Conclusion: In the presence of ventricular fibrillation with severe hypoxia and acidosis, vasopressin seems to be more potent and effective than adrenergic vasopressors for restoring spontaneous cardiovascular function. These results do not justify the widespread use of vasopressin for refractory cardiac arrest. However, on the basis of these cases, further studies comparing vasopressin with epinephrine are warranted in an effort to improve the currently dismal prognosis of patients after cardiac arrest.