JUGULAR BULB TEMPERATURE - COMPARISON WITH BRAIN SURFACE AND CORE TEMPERATURES IN NEUROSURGICAL PATIENTS DURING MILD HYPOTHERMIA

Blood temperature at the jugular bulb was monitored in 10 patients und ergoing neurovascular procedures that used induced mild hypothermia, a nd its correlation with surface brain, core, and peripheral temperatur es was determined. The study was motivated by the difficulty encounter ed in directly measuring global brain temperature and the poor correla tions between various core and peripheral sites temperatures and brain temperature, particularly during deep hypothermia. Although not stati stically significant, previous studies have suggested a trend toward h igher brain temperatures. Temperatures from the jugular bulb (collecte d using a No. 5 French Swan-Ganz catheter) as well as from subdural, p ulmonary artery, esophagus, tympanic membrane, and bladder sites were analyzed during three surgical conditions: prior to incision, with the dura open, and after closure of the dura. No complications related to placement of the jugular bulb catheter, induced hypothermia, or tempe rature monitoring were seen. The authors found that jugular bulb tempe rature was similar to pulmonary artery and esophageal temperatures; al though prior to incision it tended to be higher than that found at the pulmonary artery, most commonly by 0.2 degrees C. Surface brain tempe rature was cooler than all other temperatures (p < 0.05), except that of the tympanic membrane, and was particularly sensitive to environmen tal variations. Finally, as has been shown by others, bladder temperat ure lagged substantially behind core temperatures particularly during rapid cooling and rewarming of the patient. In summary, monitoring of jugular bulb temperature is a feasible technique, and temperatures mea sured in the jugular bulb are similar to core temperatures.