Effect of long-term mild hypothermia therapy in patients with severe traumatic brain injury: 1-year follow-up review of 87 cases

Object. The goal of this study was to investigate the protective effects of long-term (3-14 days) mild hypothermia therapy (33-35 degrees C) on outcom e in 87 patients with severe traumatic brain injury (TBI) (Glasgow Coma Sca le score less than or equal to 8). Methods. In 43 patients assigned to a mild hypothermia group, body temperat ures were cooled to 33 to 35 degrees C a mean of 15 hours after injury and kept at 33 to 35 degrees C for 3 to 14 days. Rewarming commenced when the i ndividual patient's intracranial pressure (ICP) returned to the normal leve l. Body temperatures in 44 patients assigned to a normothermia group were m aintained at 37 to 38 degrees C. Each patient's outcome was evaluated 1 yea r later by using the Glasgow Outcome Scale. One year after TBI, the mortali ty rate was 25.58% (11 of 43 patients) and the rate of favorable outcome (g ood recovery or moderate disability) was 46.51% (20 of 43 patients) in the mild hypothermia group. In the normothermia group, the mortality rate was 4 5.45% (20 of 44 patients) and the rate of favorable outcome was 27.27% (12 of 44 patients) (p < 0.05). Induced mild hypothermia also markedly reduced ICP (p < 0.01) and inhibited hyperglycemia (p < 0.05). The rates of complic ation were not significantly different between the two groups. Conclusions. The data produced by this study demonstrate that long-term mil d hypothermia therapy significantly improves outcomes in patients with seve re TBI.