Brain ischemia detected by tissue-PO2 measurement and the lactate-oxygen index in head injury.
The aim of the study was to find out whether there is a correlation between the tissue-pO2 (ti-pO2) measurement and the lactate-oxygen index (mLOI). Both methods are to be considered as methods to detect brain ischemia. We studied 7 patients after severe head injury (GCS < 8) with a jugular bulb catheter and a tissue pO2 probe. Possible ischemia was defined with ti-pO2 below 10 mm Hg and mLOI above 0.08. 67 pairs of ti-pO2 and corresponding mLOI were found. In 5 cases out of the 7 cases with a ti-pO2 below 10 we found a pathological mLOI above 0.08. In 11 cases with pathological mLOI values, however, we found only 6 cases of decreased ti-pO2. The absolute values did not correlate. The sensitivity to predict normal values is above 85% with both methods. The specifity to predict ischemia is low (< 72%). The reason is the fact, that ti-pO2 is a local method in contrast to the mLOI values. In cases of diffuse brain injury without major contusions there should be a correlation between ti-pO2 and the mLOI.
Department of Neurosurgery, University of Regensburg, Federal Republic of Germany.
M
M
Holzschuh
C
C
Metz
C
C
Woertgen
R D
RD
Rothörl
A
A
Brawanski
D001921:Brain / Q000098:blood supply*; D001924:Brain Concussion / Q000175:diagnosis / Q000503:physiopathology; D001930:Brain Injuries / Q000503:physiopathology*; D002545:Brain Ischemia / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption / Q000502:physiology*; D012680:Sensitivity and Specificity
D019344:Lactic Acid; D010100:Oxygen