title: Lower extracellular glucose level prolonged in elderly patients with severe traumatic brain injury: a microdialysis study.
abstract: Age may be an independent predictor of outcomes in traumatic brain injury (TBI), but the causes of the poor outcomes in elderly patients remain unclear. To clarify the differences between elderly and young patients with TBI, brain metabolism parameters were monitored with the microdialysis method in 30 patients with severe TBI (Glasgow Coma Scale scores 3-8). The microdialysis probe was inserted in the penumbra area of the brain and extracellular levels of glucose, glutamate, glycerol, lactate, and pyruvate were measured hourly for the initial 168 hours (7 days) after operation. The lactate/pyruvate ratio, which is considered to be a good indicator of neuronal ischemia, was also calculated. The patients were divided into the elderly group aged 65 years or older and the young group aged less than 65 years, and the biochemical markers were compared daily between these two groups. The value of extracellular glucose concentration was significantly lower in the elderly group than in the young group, and continued until the 7th day after injury. Moreover, the lactate/pyruvate ratio peaked on the 5th day after injury in the elderly group, later than in the young group. We concluded that neural vulnerability persisted longer in elderly patients than in young patients with TBI, and this should be considered to prevent the occurrence of additional secondary brain injury.
authors.affiliation: Department of Emergency and Critical Care Medicine, Nippon Medical School, Tokyo, Japan. shoji@nms.ac.jp
authors.forename: Shoji
authors.initials: S
authors.lastname: Yokobori
authors.forename: Akihiro
authors.initials: A
authors.lastname: Watanabe
authors.forename: Gaku
authors.initials: G
authors.lastname: Matsumoto
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Onda
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Masuno
authors.forename: Akira
authors.initials: A
authors.lastname: Fuse
authors.forename: Shigeki
authors.initials: S
authors.lastname: Kushimoto
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yokota
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001786:Blood Glucose / Q000378:metabolism; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D001923:Brain Chemistry / Q000502:physiology; D001930:Brain Injuries / Q000378:metabolism* / Q000473:pathology; D045604:Extracellular Fluid / Q000378:metabolism; D005260:Female; D015577:Geriatric Assessment; D015600:Glasgow Coma Scale; D023261:Glasgow Outcome Scale; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D017551:Microdialysis; D008875:Middle Aged; D019289:Pyruvic Acid / Q000378:metabolism; D020127:Recovery of Function / Q000502:physiology; D012720:Severity of Illness Index; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D019344:Lactic Acid; D019289:Pyruvic Acid; D005947:Glucose