Changes in intracranial pressure, coagulation, and neurologic outcome after resuscitation from experimental traumatic brain injury with hetastarch

Background. In a model of traumatic brain injury (TBI), 2 protocols compared changes in intracranial pressure (ICP), coagulation, and neurologic outcome after intravenous fluid (IVF) resuscitation with either Hextend (HEX, 6% hetastarch in lactated electrolyte injection) or standard of care, crystalloid plus mannitol (MAN). Methods. In the nonsurvivor protocol, swine (n = 28) received a fluid percussion TBI and hemorrhage (27 ± 3 mL/kg). At 30 minutes, resuscitation began with lactated Ringer’s (LR) or HEX. After 60 minutes, MAN (1 g/kg) or placebo was given plus supplemental IVF to maintain cerebral perfusion pressure (CPP) $70 mm Hg for 240 minutes. Swine in the survivor group (n = 15) also underwent TBI and hemorrhage, and resuscitation with HEX was compared to that of normal saline (NS)+MAN. Neurologic outcome and coagulation were evaluated for 72 hours. Results. In the nonsurvivor protocol, HEX, LR+MAN, and HEX+MAN attenuated the time-related rise of ICP and prevented ICP >20 mm Hg versus LR alone (P < .05). HEX alone maintained CPP (relative to baseline) and decreased total IVF by 50% versus LR ± MAN (P < .05). MAN had no additive effect with HEX. Coagulation, measured by thromboelastograph reaction time (R), was 11 ± 1 and 9 ± 1 minutes at baseline and after TBI (before randomization). At 240 minutes after HEX or LR+MAN, R was 6 ± 1o r 7± 2 minutes, which indicates a hypercoagulable state, but there was no difference between treatments. In the survivor protocol, ICP and CPP were similar with NS+MAN versus HEX, but IVF requirement was 161 ± 20 versus 28 ± 3 mL/kg (P < .05). Motor scores were higher on days 2 and 3 with HEX (P < .05). At 72 hours, R was 28 ± 14 versus 26 ± 6 minutes with NS+MAN versus HEX, which indicates a hypocoagulable state, but there was no difference between treatments. Conclusions. Hextend as the sole resuscitation fluid after severe TBI reduces fluid requirement, obviates the need for mannitol, improves neurologic outcome, and has no adverse effect on the coagulation profile relative to the crystalloid plus mannitol standard of care. (Surgery 2004;136:355-63.)