A comparison of hypertonic to isotonic fluid in the resuscitation of brain injury and hemorrhagic shock.

We studied the early and late effects of hypertonic resuscitation (HR) on the injured brain using a porcine model of hemorrhagic shock and focal cryogenic brain injury. After shock, swine were randomly assigned to receive a bolus (4 cc/kg) of either Ringers lactate (RL) or 7.5% hypertonic saline in 6% Dextran 70, followed by either RL or hypertonic sodium lactate to restore mean arterial pressure to baseline. All animals were studied for 24 hr after the start of resuscitation. Bolus HR improved cerebral blood flow (CBF) with a lower intracranial pressure (ICP) than RL. Continued hypertonic resuscitation prolonged the period of improved CBF and low ICP. At 24 hr CBF had deteriorated in the region of injury in all study groups and in the uninjured hemisphere in swine receiving RL. These data suggest that rapid resuscitation without increasing ICP for up to 6 hr as seen with hypertonic fluid could conceivably allow adequate time for surgical evacuation of mass lesions and effectively prevent secondary brain injury. This work underscores the importance of prolonged periods of study when evaluating brain resuscitation from traumatic shock.