Epinephrine,vasopressin, and nitroglycerin improve neurologic outcome in porcine asphyxial cardiac arrest

Aim

The aim of the present study was to assess whether the combination of epinephrine, vasopressin, and nitroglycerin would improve initial resuscitation success, 24-hour survival, and neurologic outcome compared with epinephrine alone in a swine model of asphyxial cardiac arrest (CA).

Materials and Methods

This prospective randomized experimental study was conducted at a laboratory research department. Twenty male Landrace/Large-White pigs 12 to 15 weeks of age were investigated. Asphyxial CA was induced by occlusion of the endotracheal tube. Pigs remained untreated for 4 minutes before attempting resuscitation by unclamping the endotracheal tube, mechanical ventilation, chest compressions, and epinephrine (group E) or a combination of epinephrine with vasopressin and nitroglycerin (group EVN) administered intravenously. In case of restoration of spontaneous circulation, the animals were supported for 30 minutes and then observed for 24 hours.

Results

Coronary perfusion pressure and mean arterial pressure were significantly increased during cardiopulmonary resuscitation in group EVN. In both groups, restoration of spontaneous circulation and survival rates were comparable (P value, nonsignificant). At 24 hours after CA, neurologic deficit score was significantly better in animals treated with the combination pharmacotherapy (P < .001). Brain histologic damage score was also higher in group EVN compared with group E (P < .001). Total histologic damage score and neurologic deficit score showed a statistical significant correlation (P < .001).

Conclusion

In this porcine model of asphyxial CA, the addition of nitroglycerin to vasopressin and epinephrine maintained elevated coronary perfusion pressure during asphyxia CA and resulted in significantly better neurologic and histopathologic outcome in comparison with epinephrine alone.