Changes in intracranial pressure in severe head injured patients in hemodialysis

Two cases of acute post-traumatic renal failure in severely head injured patients are reported. An increase in intracranial pressure (ICP) was shown up by continuous monitoring during haemodialysis: it was more important during conventional haemodialysis than during continuous arteriovenous haemofiltration. Although this effect is well known experimentally, few cases of continuous ICP pressure monitoring have been reported in head injury patients undergoing haemodialysis. The increase in ICP is explained in the dog as a result of blood-brain differences in urea concentration and osmolality leading to an increase in cerebral spinal fluid volume and cerebral tissue swelling. If dialysis is necessary in these patients, it should be carried out early and progressively, the patient's ICP being monitored continuously.