Differences between brain and rectal temperatures during routine critical care of patients with severe traumatic brain injury

• Published in: Anaesthesia Vol. 60; no. 8; pp. 759 - 765
• Main Authors: Childs, C., Vail, A., Protheroe, R., King, A. T., Dark, P. M.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.08.2005; Blackwell; Blackwell Publishing Ltd
• Subjects: Abbreviated Injury Scale; Adult; Aged; Anesthesia; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Biological and medical sciences; Body Temperature; Brain - physiopathology; Brain damage; Brain Injuries - physiopathology; Brain Injuries - therapy; Comparative analysis; Critical care; Critical Care - methods; Female; Humans; Male; Medical sciences; Middle Aged; Monitoring, Physiologic - methods; Prospective Studies; Rectum - physiopathology; Temperature; Human; Anesthesia; Nervous system diseases; Head trauma; Rectum; Encephalon
• ISSN: 0003-2409; 1365-2044
• DOI: 10.1111/j.1365-2044.2005.04193.x

Summary Theoretical models suggest that small differences only exist between brain and body temperature in health. Once the brain is injured, brain temperature is generally regarded to rise above body temperature. However, since reports of the magnitude of the temperature gradient between brain and body vary, it is still not clear whether conventional body temperature monitoring accurately predicts brain temperature at all times. In this prospective, descriptive study, 20 adults with severe primary brain trauma were studied during their stay in the neurointensive care unit. Brain temperature ranged from 33.4 to 39.9 °C. Comparisons between paired brain and rectal temperature measurements revealed no evidence of a systematic difference [mean difference −0.04 °C (range −0.13 to 0.05 °C, 95% CI), p = 0.39]. Contrary to popular belief, brain temperature did not exceed systemic temperature in this relatively homogeneous patient series. The mean values masked inconsistent and unpredictable individual brain–rectal temperature differences (range 1.8 to −2.9 °C) and reversal of the brain‐body temperature gradient occurred in some patients. Brain temperature could not be predicted from body temperature at all times.