These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Correlation between cerebral blood flow, substrate delivery, and metabolism in head injury: a combined microdialysis and triple oxygen positron emission tomography study.
    Author: Hutchinson PJ, Gupta AK, Fryer TF, Al-Rawi PG, Chatfield DA, Coles JP, O'Connell MT, Kett-White R, Minhas PS, Aigbirhio FI, Clark JC, Kirkpatrick PJ, Menon DK, Pickard JD.
    Journal: J Cereb Blood Flow Metab; 2002 Jun; 22(6):735-45. PubMed ID: 12045672.
    Abstract:
    Microdialysis continuously monitors the chemistry of a small focal volume of the cerebral extracellular space. Conversely, positron emission tomography (PET) establishes metabolism of the whole brain, but only for the duration of the scan. The objective of this study was to apply both techniques to head-injured patients simultaneously to assess the relation between microdialysis (glucose, lactate, lactate/pyruvate [L/P] ratio, and glutamate) and PET (cerebral blood flow [CBF], cerebral blood volume, oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen) parameters. Microdialysis catheters were inserted into the frontal cerebral cortex and adipose tissue of the anterior abdominal wall of 17 severely head-injured patients. Microdialysis was performed during PET scans, with regions of interest defined by the location of the microdialysis catheter membrane. An intervention (hyperventilation) was performed in 13 patients. The results showed that combining PET and microdialysis to monitor metabolism in ventilated patients is feasible and safe, although logistically complex. There was a significant relation between the L/P ratio and the OEF (Spearman r = 0.69, P = 0.002). There was no significant relation between CBF and the microdialysis parameters. Moderate short-term hyperventilation appeared to be tolerated in terms of brain chemistry, although no areas were sampled by microdialysis where the OEF exceeded 70%. Hyperventilation causing a reduction of the arterial carbon dioxide tension by 0.9 kPa resulted in a significant elevation of the OEF, in association with a reduction in glucose, but no significant elevation in the L/P ratio or glutamate.
    [Abstract] [Full Text] [Related] [New Search]