BRAIN-TISSUE PO(2) AND OUTCOME AFTER SEVERE HEAD-INJURY

Although the use of on-line monitoring of brain ti-pO(2) is increasing , so far the critical level of 10 mmHg is derived from animal experime nts and clinical analyses: no hard proof on outcome basis has been giv en until now. The authors present an outcome analysis of 35 patients w ith severe head injury. Inclusion criteria were: start of ti-pO(2) mon itoring less than or equal to 40 h post-injury, the probe lying in CT scan normal tissue and the GOS at 6 months being available. The good o utcome group (GOS 4 + 5, n = 17) showed a 17.7 +/- 9.1 h delay from th e injury to the monitoring compared to the bad outcome group (COS 1-3, n = 18) with (14.2 +/- 9.1 h) (p < 0.05). Age and initial Glasgow Com a Score were not different In the bad outcome group there were more pa tients with a diffuse injury type 3 and 4. The distribution of the ti- pO(2) values show in all the examined time intervals (day 0-6, 0-72 h, 0-48 h and 0-24 h) a left shift in the bad outcome group with most pr onounced difference for ti-pO(2) less than or equal to 10 mmHg. For th e period from 0-48 h and even more from 0-24 h post-injury, the differ ence between both groups was significant (p = 0.036 and p = 0.013). In the bad outcome group 35.5% of the values from 0-24 h were less than or equal to 10 mmHg (compared to 10.6% in the good outcome group. ti-p O(2) values greater than or equal to 50 mmHg were seen more often in t he bad outcome group; this occurred mainly after 48-72 h post-injury. The authors concluded that brain ti-pO(2) monitoring is able to detect the occurrence of early hypoxic insults. Brain ti-pO(2) monitoring is an important parameter in the multimodality monitoring system.