Relationship between brain temperature, brain chemistry and oxygen delivery after severe human head injury: The effect of mild hypothermia

J. Soukup, A. Zauner, E. M.R. Doppenberg, M. Menzel, C. Gilman, R. Bullock, H. F. Young

Research output: Contribution to journalArticle

54 Scopus citations


We studied brain temperature and the effect of mild hypothermia in 58 patients after severe head injury (SHI). Brain tissue oxygen tension (ptiO2), carbon dioxide tension (ptiCO2), tissue pH (pHti) and temperature (Tbr) were measured using a multiparameter probe. Microdialysis was performed to measure glucose, lactate, glutamate, and aspartate in the extracellular fluid. Mild hypothermia (34°-36°C) was employed in 33 selected patients who had persistent increased intracranial pressure (ICP > 20 mmHg). Mild induced hypothermia decreased brain oxygen significantly from 33 ± 24 mmHg to 30 ± 22 mmHg (p < 0.05). The ptiCO2 (46 ± 8 mmHg) was also significantly lower during mild hypothermia (40.4 ± 4.0 mmHg), p < 0.0001). The pHti increased from 7.13 ± 0.15 to 7.24 ± 0.10 (p < 0.0001) under hypothermic conditions. Induced hypothermia may protect patients from secondary ischemic events by lowering the critical ptiO2 threshold, reducing anaerobic metabolism, and decreasing the release of excitatory aminoacids. However, patients with spontaneous brain hypothermia on admission (Tbr < 36.0°C) showed significantly higher levels of glutamate as well as lactate, compared to all other patients, and had a worse outcome. Spontaneous brain hypothermia carries a poor prognosis, and was characterized by markedly abnormal brain metabolic indices.

Original languageEnglish (US)
Pages (from-to)161-168
Number of pages8
JournalNeurological Research
Issue number2
StatePublished - Mar 5 2002



  • Brain oxygen
  • Excitatory aminoacids
  • Mild hypothermia
  • Severe head injury

ASJC Scopus subject areas

  • Clinical Neurology
  • Neuroscience(all)

Cite this