Intracerebral microdialysis and intracranial compliance monitoring of patients with traumatic brain injury.

OBJECTIVE

The aims of this study were to get an impression of the relationships between intracranial compliance (IC) and Lactate/Pyruvate (L/P) ratio and temperature and L/P ratio, and to determine if patients with low IC had an increased vulnerability for the secondary insult hyperthermia (as reflected in the L/P ratio). The effects of coma treatment on the results were also studied.

METHODS

Ten TBI patients were monitored for IC, in vivo microdialysis (MD) and bladder temperature. Mean Glasgow Coma Scale (GCS) score was 7 (range 4-10). Three patients underwent induced coma treatment. Three statistical models were used to look at the relationships between IC, temperature and L/P ratio in patients with and without coma.

RESULTS

We found that with high temperature L/P ratios increased as IC decreased (P < 0.0001). The patients with coma treatment had significantly higher average L/P ratios (P < 0.02). The effect of IC on the L/P ratio differed by coma treatment (P < 0.02). The temperature effect was not dependent on coma treatment (P < 0.49).

CONCLUSIONS

These findings suggest the importance of avoiding hyperthermia in TBI patients, especially in patients with low or decreased IC (monitored or anticipated). The present technical solution seems promising for analysis of complex clinical data.