Effects of brain hypothermia for the patients with severe head injury and post-resuscitation encephalopathy

Cerebral and extracerebral effects of mild hypothermia (core temperature 34°C) and moderate hypothermia (32°C) were studied in four patients with severe head injury and two patients in post-resuscitation encephalopathy. According to our cooling criteria, three patients applied in moderate hypothermia, and three patients who were thought to be unable to receive moderate hypothermia applied mild hypothermia. Hypothermia was induced by cooling the patient's body surface with water-circulating blankets within a mean of 6 h. The cooling period was determined with intracranial pressure (ICP) and other monitoring parameters, and the range was 35 h to 9 days. The patients were rewarmed at the rate of 0.5°C per 5 h, and the temperature change was maintained within 2°C in a day.

Good recovery was observed in two out of three patients in the moderate hypothermia group, and two out of three patients in the mild hypothermia group. Two patients died from sepsis and disseminated intravascular coagulation. As to extracerebral effects, patients had more or less systemic complications, including hypotension, paralytic ileus, hypokalemia, and decrease in platelet count. The moderate hypothermia group was likely to have higher incidence and greater extent of complication.

The tendency toward better outcome may indicate that hypothermia for severe head injury and post-resuscitation encephalopathy is effective in recovering the brain damage. Further investigation for indication and method is required.