EFFECT OF MILD HYPOTHERMIA ON UNCONTROLLABLE INTRACRANIAL HYPERTENSION AFTER SEVERE HEAD-INJURY

Recent experimental studies have demonstrated that mild hypothermia at about 34-degrees-C can be effective in the control of intracranial hy pertension. A randomized controlled study of mild hypothermia was carr ied Out in 33 severely head-injured patients. All patients fulfilled t he following criteria: 1) persistent intracranial pressure (ICP) great er than 20 mm Hg despite fluid restriction, hyperventilation, and high -dose barbiturate' therapy; 2) an ICP lower than the mean arterial blo od pressure; and 3) a Glasgow Coma Scale score of 8 or less. The patie nts were divided into two groups: one received mild hypothermia (16 pa tients) and one served as a control group (17 patients). Mild hypother mia significantly reduced the ICP and increased the cerebral perfusion pressure. Eight patients (50%) in the hypothermia group and three (18 %) in the control group survived (p < 0.05), while five (31%) in the h ypothermia group and 12 (71%) in the control group died of uncontrolla ble intracranial hypertension (p < 0.05). In five patients in the hypo thermia group, cerebral blood flow was measured by the hydrogen cleara nce method and arteriojugular venous oxygen difference was evaluated b efore and during mild hypothermia. Mild hypothermia significantly decr eased the cerebral blood flow, arteriojugular venous oxygen difference , and cerebral metabolic rate of oxygen (p < 0.01). The results of thi s preliminary investigation suggest that mild hypothermia is a safe an d effective method to control traumatic intracranial hypertension and to improve mortality and morbidity rates.