Endobronchial vasopressin improves survival during cardiopulmonary resuscitation in pigs

Background: Intravenous administration of vasopressin during cardiopulmonary resuscitation (CPR) has been shown to be more effective than optimal doses of epinephrine. This study evaluated the effect of endobronchial vasopressin during CPR. Methods: After 4 min of untreated ventricular fibrillation and 3 min of CPR, 21 pigs were randomized to be treated with 0.8 U/kg intravenous vasopressin (n = 7), 0.8 U/kg endobronchial vasopressin (n = 9), or an endobronchial placebo of normal saline (n = 5). Defibrillation was performed 5 min after drug administration to attempt return of spontaneous circulation. Results: All animals in the intravenous and endobronchial vasopressin group were resuscitated successfully, but only two of five animals in the placebo group were. At 2 and 5 min after drug administration, coronary perfusion pressure in the intravenous and endobronchial vasopressin group was significantly higher than in the placebo group (50 ± 10, 34 ± 5 vs. 16 ± 6 mmHg, respectively; and 35 ± 10, 39 ± 10 vs. 19 ± 5 mmHg, respectively; P < 0.05). Conclusions: Endobronchial vasopressin is absorbed during CPR, coronary perfusion pressure is increased significantly within a short period, and the chance of successful resuscitation is increased in this porcine model of CPR. Endobronchial vasopressin may be an alternative for vasopressor administration during CPR, when intravenous access is delayed or not available.