부산대학교 도서관

THE FIRST THERAPEUTIC USE OF HYPOTHERMIA DATES BACK to the battlefields during the French invasion of Russia in 1812. Then, Laron Larrey, the surgeon of Napoleon Bonaparte, used ice packs to numb injured limbs prior to amputation on the field. More than a hundred years later, first reports proposed a potential benefit of induced hypothermia on neurological outcome. However, given the undefined patient cohorts, variability of depth and duration of hypothermia treatment and the lack of control groups, the clinical value of these early series remained limited. In 1956, Rosomoff provided the first experimental evidence demonstrating neuroprotective properties of hypothermia. He showed that severe hypothermia (22-24 degrees) reduced the amount of infarcted brain tissue and improved neurological outcomes following occlusion of the middle cerebral artery in dogs. It is believed that beneficial effects of hypothermia on neurological outcome are due to reduction of free radical production, decrease of excitatory amino-acid release, and limitation of blood brain barrier disruption with concomitant decrease of brain edema. To date, the use of hypothermia for treatment of traumatic brain injury remains controversial. The Brain Trauma Foundation Guidelines from 2007 found level III evidence that prophylactic hypothermia was not significantly associated with decreased mortality when compared to normothermic controls. However, preliminary evidence suggested that better results could be achieved if the target temperature was maintained for > 48 hours. The National Acute Brain Injury Study: Hypothermia II (NABIS:HII) was initiated because an earlier multicenter trial of hypothermia for traumatic brain injury suggested a tendency toward better outcomes in patients who were hypothermic at the time of admission and continued to be cooled compared to patients maintained in normothermia (P = 0.09). Thus, the authors suggested that hypothermia may be more efficacious when initiated very early following the trauma. The current randomized, multicenter trial with very early hypothermia (NABIS:HII) included 97 patients with severe traumatic brain injury (GCS < 8) without life-threatening associated injuries and without pronounced hypotension. The target temperature was reached in 4.4 hours and patients were re-warmed 48 hours later. After an interim analysis, the study was terminated with the conclusion that hypothermia did not improve neurological outcome, defined as GSC at 6 months or reduce mortality. However, the conclusions are limited due to the premature termination of the study. [ABSTRACT FROM AUTHOR]