Early versus late fluid resuscitation: lack of effect in porcine hemorrhagic shock.

The benefit of IV fluid therapy in the prehospital management of hemorrhagic shock is unproven. We used a reproducible, lightly anesthetized model of porcine continuous hemorrhage to evaluate the usefulness of pre-hospital IV fluid therapy. Incorporated into the model were time delays associated with ambulance request and dispatch, patient evaluation and treatment, and transport to the hospital in the average urban prehospital care system. Treatment occurred concurrently with hemorrhage. Twenty-eight immature swine (15 to 20 kg) were bled at a rate of 1.25 mL/kg/min. Animals in the prehospital IV group (n = 14) received fluid resuscitation at 1 mL/kg/min beginning 20 minutes after initiation of hemorrhage; those in the in-hospital IV group (n = 14) received fluid at a rate of 3 mL/kg/min beginning 35 minutes after hemorrhage. Both groups received blood and saline at 3 mL/kg/min 45 minutes after hemorrhage began, and both groups had hemorrhage controlled 25 minutes after simulated hospital arrival. Survival was 57% in both groups, and there were no statistically significant differences seen in measured hemodynamic or biochemical parameters. We conclude that early administration of IV normal saline has no effect on hemodynamics or survival in this porcine hemorrhagic shock model simulating an urban prehospital care system.