Monitoring brain PO2, PCO2, and pH during graded levels of hypoxemia in rabbits.
Brain ischemia and hypoxia are of concern when they occur following traumatic brain injury because they frequently result in potentially preventable secondary brain damage. In this study, we examined the ability of an implantable catheter (Paratrend 7; Diametrics Medical, St. Paul, MN) to continuously measure brain tissue pH, PCO2, and PO2 during graded levels of hypoxia. Values obtained from this catheter were compared with simultaneous measurements of arterial and sagittal sinus blood. As expected, there was a good correlation between the changes in pH, PCO2, and PO2 in brain tissue and sagittal sinus blood. Brain tissue PO2 was numerically lower than sagittal sinus blood at all inspired levels of oxygen. These data suggest that the Paratrend 7 may be useful in monitoring brain tissue oxygen tension in patients at risk for regional cerebral ischemia and hypoxia.
Martinez-Tica
J F
JF
Department of Anesthesiology, The University of Texas Medical Branch, Galveston 77555-0591, USA.
Berbarie
R
R
Davenport
P
P
Zornow
M H
MH
D000818:Animals; D001921:Brain / Q000098:blood supply / Q000503:physiopathology*; D001930:Brain Injuries / Q000097:blood / Q000503:physiopathology*; D002245:Carbon Dioxide / Q000097:blood / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D002534:Hypoxia, Brain / Q000097:blood / Q000209:etiology / Q000503:physiopathology*; D008991:Monitoring, Physiologic; D010100:Oxygen / Q000097:blood / Q000378:metabolism*; D010313:Partial Pressure; D011817:Rabbits
D002245:Carbon Dioxide; D010100:Oxygen