Cerebral oximetry in dead subjects.
Near-infrared spectroscopy is a technique used to monitor cerebral oxygenation. To validate the method, we measured regional oxygen saturation (rSo2) in the brains of 18 dead subjects (mean age, 74.4 +/- 14.6 years) 19.8 +/- 18.2 h (range, 1-73) after cessation of systemic circulation, and in 15 healthy probands (mean age, 34.2 +/- 8.7 years) with an INVOS 3100 cerebral oximeter. The mean (+/-SD) rSo2 in the dead subjects was 51.0 +/- 26.8% [range, 6-88%; left, 48.4 +/- 28.0% (n = 21); right, 54.4 +/- 25.7% (n = 16)]. The mean rSo2 in the control group was 68.4 +/- 5.2% (range, 60-76%; left, 68.1 +/- 5.0%; right, 68.7 +/- 5.6%). After removal of the brain at autopsy in five of the dead subjects, the rSo2 was 73.4 +/- 13.3% (15 measurements). Six of 18 of the dead subjects had values above the lowest values found in the healthy adults (> or = 60%). These findings raise concerns about the validity of cerebral rSo2 data in adults obtained by the INVOS 3100 system.
Schwarz
G
G
Department of Anesthesiology, University of Graz, Austria.
Litscher
G
G
Kleinert
R
R
Jobstmann
R
R
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001344:Autopsy; D001923:Brain Chemistry; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010092:Oximetry / Q000295:instrumentation*; D010100:Oxygen / Q000032:analysis*; D013055:Spectrophotometry, Infrared / Q000295:instrumentation*
D010100:Oxygen