Continuous monitoring of brain tissue oxygen pressure in patients with severe head injury during moderate hypothermia.
BACKGROUND
We studied the change of brain tissue oxygen pressure (PbrO2) value within 24 hours after trauma and during moderate hypothermia in patients with severe head injury. The PbrO2 value was used to differentiate patients at risk of brain ischemia and to predict outcome.


METHODS
A flexible microcatheter to be used for continuous monitoring of brain tissue oxygen was inserted into the normal frontal white matter, along with a thermocouple, in 14 patients with severe head injury within 1.5-12 hours (mean 6.1 +/- 5.2 hours) after trauma. Moderate hypothermia was also used within 24 hours in these patients.


RESULTS
(1) No complications related to the microcatheter were seen. (2) Low initial PbrO2 values (mean values <10 mmHg) were noted after severe head injury. (3) The occurrence of low initial PbrO2 values (< or = 5 mmHg) was significantly correlated with a poor outcome. (4) Moderate hypothermia can increase PbrO2, but hyperventilation reduced PbrO2. (5) The difference between RT and BT increased during moderate hypothermia.


CONCLUSIONS
The PbrO2 values were low in severe head injury, but hypothermia may improve these values. The technique of continuously monitoring brain tissue oxygen pressure may give better insight into cerebral oxygenation and warn of impending ischemia of brain tissue, especially in patients treated with hyperventilation. It will help to improve the management and final outcome of patients with severe head injuries.
Zhi
D S
DS
Department of Neurosurgery, Tianjin Neurological Central Hospital, Hexi District, China.
Zhang
S
S
Zhou
L G
LG
D000328:Adult; D000368:Aged; D001921:Brain / Q000378:metabolism*; D006259:Craniocerebral Trauma / Q000378:metabolism* / Q000628:therapy; D003422:Critical Care / Q000379:methods; D005260:Female; D015600:Glasgow Coma Scale; D006801:Humans; D007036:Hypothermia, Induced; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption
D010100:Oxygen