BRAIN TEMPERATURE EXCEEDS SYSTEMIC TEMPERATURE IN HEAD-INJURED PATIENTS

Objective: To identify the temperature differences in readings taken f rom the brain, jugular bulb, and core body in head injured patients, D esign: Prospective, observational study, Setting: Neurosurgical intens ive care unit of a university-affiliated county hospital, Patients: Th irty patients with severe head injuries had measurements of brain and core body temperatures, Fourteen patients also had measurements of jug ular venous blood at the level of the jugular bulb. Interventions: Non e, Measurements and Main Results: Brain temperature was increased an a verage of 2.0 degrees F (1.1 degrees C) over the core body temperature , In individual patients, the average brain temperature increase over the core body temperature ranged from -0.5 degrees to 3.8 degrees F (- 0.30 degrees to 2.1 degrees C). Jugular vein and core body temperature s were similar, The difference in the brain and body temperatures incr eased when cerebral perfusion pressure decreased to between 20 and 50 mm Hg. The difference in the brain and body temperatures decreased in those patients treated with barbiturate coma. Conclusions: Direct meas urement of temperature in head in jured patients is a safe procedure, Temperatures in the brain are typically increased over the core body t emperature and the jugular bulb temperatures, Jugular vein temperature measurement is not a good measurement of brain temperature since it r eflects body, not brain temperature, These findings support the potent ial importance of monitoring brain temperature and the importance of c ontrolling fever in severely head injured patients since brain tempera ture may be higher than expected.