ABSTRACT
Severe head injury is frequently associated with extracranial injuries causing hemorrhagic hypotension. Volume replacement with isotonic fluids not only is therapeutically of limited efficacy but may aggravate posttraumatic brain edema. On the other side, hypertonic/hyperoncotic saline/dextran solution (HHS) shown to restore cardiovascular function in hemorrhagic shock instantaneously, was found to decrease intracranial pressure in experimental head injury. Currently the therapeutic efficacy of HHS and mannitol on ICP was compared at 24 hrs after a focal cerebral lesion and inflation of an epidural balloon in rabbits. Both solutions given at an equimolar dose rapidly lowered the ICP. After the first injection, ICP reduction was longer maintained with mannitol (189 +/- 27 min) as compared to HHS (98 +/- 14 min), while no difference in duration of lowering ICP was found after the second injection. Due to its blood pressure effects, HHS afforded a higher cerebral perfusion pressure than mannitol. In animals with HHS, the water content of the traumatized hemisphere was increased while the contralateral hemisphere was dehydrated. With mannitol, no differences in water content were found between the injured and uninjured hemisphere. The efficiency of HHS in hemorrhagic shock and intracranial hypertension render the fluid mixture particularly promising in patients with polytrauma in combination with head injury.
