OBJECTIVE: Because hypothermia enhances human tolerance for cerebral ischemia, profound hypothermia is induced in many centers so that the circulation can be arrested while clips are applied to high-risk giant cerebral aneurysms. Brain temperature is measured directly with an intracerebral probe that avoids the uncertainty of surrogate monitoring. However, when there is a large thermal gradient between brain temperature and that of the operating room, even direct measurements can sometimes be misleading. This study was undertaken to determine how deeply a thermal sensor must be embedded in the cerebral parenchyma to ensure that the ambient environment does not distort the measurement of brain temperature. METHODS: Each of 39 normothermic patients had a thermocouple sensor inserted into a temporal lobe seizure focus just before its resection. Brain temperature was measured as the sensor was withdrawn in stages. RESULTS: At both 3 and 2 cm beneath the cortical surface, the temperature of the brain was essentially the same. However, when the sensor was withdrawn to 1 cm, recorded temperature decreased from 35.7 +/- 0.9 to 34.3 +/- 1.4 degrees C (P < 0.001) and irrigation in the vicinity caused major thermal change. At shallower depths, even lower brain temperatures were recorded. No morbidity was attributable to the temperature measurements. CONCLUSION: Direct intraoperative measurement of human brain temperature is feasible and safe, but accuracy requires that the temperature sensor be inserted at least 2 cm into the cerebral cortex.
OBJECTIVE: Because hypothermia enhances human tolerance for cerebral ischemia, profound hypothermia is induced in many centers so that the circulation can be arrested while clips are applied to high-risk giant cerebral aneurysms. Brain temperature is measured directly with an intracerebral probe that avoids the uncertainty of surrogate monitoring. However, when there is a large thermal gradient between brain temperature and that of the operating room, even direct measurements can sometimes be misleading. This study was undertaken to determine how deeply a thermal sensor must be embedded in the cerebral parenchyma to ensure that the ambient environment does not distort the measurement of brain temperature. METHODS: Each of 39 normothermic patients had a thermocouple sensor inserted into a temporal lobe seizure focus just before its resection. Brain temperature was measured as the sensor was withdrawn in stages. RESULTS: At both 3 and 2 cm beneath the cortical surface, the temperature of the brain was essentially the same. However, when the sensor was withdrawn to 1 cm, recorded temperature decreased from 35.7 +/- 0.9 to 34.3 +/- 1.4 degrees C (P < 0.001) and irrigation in the vicinity caused major thermal change. At shallower depths, even lower brain temperatures were recorded. No morbidity was attributable to the temperature measurements. CONCLUSION: Direct intraoperative measurement of human brain temperature is feasible and safe, but accuracy requires that the temperature sensor be inserted at least 2 cm into the cerebral cortex.
Authors: Eero Pesonen; Marja Silvasti-Lundell; Tomi T Niemi; Riku Kivisaari; Juha Hernesniemi; Marja-Tellervo Mäkinen Journal: J Clin Monit Comput Date: 2019-02-15 Impact factor: 2.502
Authors: Huan Wang; Bonnie Wang; Kieran P Normoyle; Kevin Jackson; Kevin Spitler; Matthew F Sharrock; Claire M Miller; Catherine Best; Daniel Llano; Rose Du Journal: Front Neurosci Date: 2014-10-08 Impact factor: 4.677
Authors: Eric Jüttler; Peter D Schellinger; Alfred Aschoff; Klaus Zweckberger; Andreas Unterberg; Werner Hacke Journal: Crit Care Date: 2007 Impact factor: 9.097