Cerebral oxygenation in contusioned vs. nonlesioned brain tissue: monitoring of PtiO2 with Licox and Paratrend.
Brain tissue PO2 in severely head injured patients was monitored in parallel with two different PO2-microsensors (Licox and Paratrend). Three different locations of sensor placement were chosen: (1) both catheters into non lesioned tissue (n = 3), (2) both catheters into contusioned tissue (n = 2), and (3) one catheter (Licox) into pericontusional versus one catheter (Paratrend) into non lesioned brain tissue (n = 2). Mean duration of PtiO2-monitoring with both microsensors in parallel was 68.1 hours. Brain tissue PO2 varied when measured in lesioned and nonlesioned tissue. In non lesioned tissue both catheters closely correlated (delta Licox/Paratrend: mean PtiO2 < 5 mm Hg) after 20 hours post insertion. In pericontusional tissue PtiO2 was reduced relative to non lesioned tissue (delta lesioned/non lesioned: mean PtiO2: 10.3 mm Hg). In contusioned brain tissue PtiO2 was always below the "hypoxic threshold" of 10 mm Hg, independent of the type of microsensor used. During a critical reduction in cerebral perfusion pressure (< 60 mm Hg), PtiO2 decreased measured with both microsensors. Elevation of inspired oxygen fraction, normally followed by a rapid increase in tissue PO2, only increased PtiO2 when measured in pericontusional and nonlesioned brain. To recognize critical episodes of hypoxia or ischemia, PtiO2-monitoring of cerebral oxygenation is recommended in nonlesioned brain tissue.
Sarrafzadeh
A S
AS
Department of Neurosurgery, Virchow Medical Center, Humboldt-University, Berlin, Federal Republic of Germany.
Kiening
K L
KL
Bardt
T F
TF
Schneider
G H
GH
Unterberg
A W
AW
Lanksch
W R
WR
D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D001924:Brain Concussion / Q000175:diagnosis* / Q000503:physiopathology; D002545:Brain Ischemia / Q000175:diagnosis / Q000503:physiopathology; D002408:Catheters, Indwelling; D005260:Female; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D002534:Hypoxia, Brain / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption / Q000502:physiology*; D012680:Sensitivity and Specificity
D010100:Oxygen