THE USE OF MODERATE THERAPEUTIC HYPOTHERMIA FOR PATIENTS WITH SEVERE HEAD-INJURIES - A PRELIMINARY-REPORT

Animal research suggests that moderate therapeutic hypothermia may imp rove outcome after a severe head injury, but its efficacy has not been established in humans. The authors randomly assigned 40 consecutively treated patients with a severe closed head injury (Glasgow Coma Scale score 3 to 7) to either a hypothermia or a normothermia group. Using cooling blankets and cold saline gastric lavage, patients in the hypot hermia group were cooled to 32-degrees to 33-degrees-C (brain temperat ure) within a mean of 10 hours after injury, maintained at that temper ature for 24 hours, and rewarmed to 37-degrees to 38-degrees-C over 12 hours. Patients in the normothermia group were maintained at 37-degre es to 38-degrees-C during this time. Deep-brain temperatures were moni tored directly and used for all temperature determinations. Intracrani al pressure (ICP), cerebral blood flow (CBF), and cerebral metabolic r ate for oxygen (CMRO2) were measured serially for all patients. Hypoth ermia significantly reduced ICP (40%) and CBF (26%) during the cooling period, and neither parameter showed a significant rebound increase a fter patients were rewarmed. Compared to the normothermia group, the m ean CMRO2 in the hypothermia group was lower during cooling and higher 5 days after injury. Three months after injury, 12 of the 20 patients in the hypothermia group had moderate, mild, or no disabilities; eigh t of the 20 patients in the normothermia group had improved to the sam e degree. Both groups had a similar incidence of systemic complication s, including cardiac arrhythmias, coagulopathies, and pulmonary compli cations. It is concluded that therapeutic moderate hypothermia is safe and has sustained favorable effects on acute derangements of cerebral physiology and metabolism caused by severe closed head injury. The tr end toward better outcome with hypothermia may indicate that its benef icial physiological and metabolic effects limit secondary brain injury .