Cerebral and extracerebral effects of moderate hypothermia (core temperature 32.5 degrees C-33.0 degrees C) were prospectively studied in 10 patients with severe closed head injury (Glasgow Coma Scale score < 7) in the intensive care unit of a university hospital. Hypothermia was induced by cooling the patient's body surface with water-circulating blankets. Before cooling, a conventional intracranial pressure (ICP) reduction therapy was applied, which remained unchanged throughout the study. Cerebral blood flow (CBF), cerebral metabolic rates for oxygen (CMRO2) and lactate (CMRL), and ICP were simultaneously measured prior to inducing hypothermia, after obtaining hypothermia, after 24 hours of hypothermia, and after rewarming. With respect to extracerebral effects, supplemental investigations were conducted 24 and 72 hours after rewarming. The median delay between injury and induction of hypothermia was 16 hours. Hypothermia reduced CMRO2 by 45% (p < 0.01), whereas CBF did not change significantly. Before cooling, six patients had elevated CMRL indicating cerebral ischemia. Cooling normalized CMRL in all patients (p < 0.01). The intracranial hypertension present prior to cooling declined markedly during hypothermia (p < 0.01) without significant rebound effects after rewarming. Cardiac index decreased by 18% after hypothermia was reached (p < 0.05), recovered at 24 hours of hypothermia, and surpassed baseline values after rewarming. Platelet counts dropped continuously up to 24 hours after rewarming (p < 0.01). Plasma coagulation tests did not show significant worsening. Creatinine clearance decreased during cooling (p < 0.01) and recovered by 24 hours after rewarming. Twenty-four hours after cooling had begun, eight patients had elevated serum lipase activity (p < 0.01) and four of them acquired pancreatitis. Rewarming normalized both pancreatic alterations. Seven patients made a good recovery; one survived severely disabled; and two patients died. Moderate hypothermia is effective in preventing secondary brain damage while reducing cerebral ischemia. However, there are potentially hazardous side effects that require additional monitoring.

We investigated the time course of neuron specific enolase (NSE) and S-100 protein after severe head injury in correlation to outcome. We included 30 patients (GCS < 9), who had been admitted within 5 hours after injury, in a prospective study. Blood samples were taken on admission, 6, 12, and 24 hours and every 24 hours up to the fifth day after injury. The outcome was estimated on discharge using the Glasgow Outcome Scale. 70% reached a good outcome. All concentrations of NSE and 83% of the S-100 samples were elevated concerning the first probe (30.2 micrograms/l NSE mean and 2.6 micrograms/l S-100 mean). Patients with bad outcome had an NSE concentration of 38 micrograms/l (mean) compared with 26.9 micrograms/l (mean) in patients with good outcome. Patients with bad outcome had an S-100 concentration of 4.9 micrograms/l (mean) compared with 1.7 micrograms/l (mean) in patients with good outcome (p < 0.05). The mean values of NSE and S-100 decreased during the first 5 days. Four patients with increasing intracranial pressure showed a quick increasing concentration of NSE, in two patients the S-100 level showed a slower rise. The NSE serum levels did not correlate with intracranial pressure values. Our results show that the first serum concentration of S-100 seems to be predictive for outcome after severe head injury.

S-100 appears to be a promising marker for the severity of head injury and neuronal damage.

No abstract