Abstract
Purpose: To evaluate a possibility that the brain temperature (brain T) monitoring can be predictive for prognosis immediately after severe brain damage.
Method: The brain temperatures of 41 patients with severe brain damage due to a various insults, including cerebrovasular accident, head trauma and cardiopulmonary arrest, were monitored. Simultaneously, bladder temperature (bladder T), intracranial pressure (ICP), oxygen saturation of the internal jugular venous blood (SjO2) and systemic blood pressure were measured. Subsequently, the temperature gradients (ΔT) between the brain and bladder and the cerebral perfusion pressure (CPP) were calculated. The prognosis was retrospectively evaluated by Glasgow outcome scale (GOS). The perfusion volume and its geometry in the brain were measured by scintigrams.
Results: The patients with a persistently positive ΔT survived, having good recovery or suffered only moderate disability according to GOS. On the other hand, brain death occurred in the patients with continuously negative ΔT. The patients with fluctuating ΔT had a variable GOS. Differences in brain insults had no effect on these results. In patients with CPP of more than 50mmHg throughout the entire course of the measurement, the ΔT was constant with good correlation (r2=0.910). No correlation was identified in patients with CPP of less than 50mmHg (r2<0.50). The patients with a positive ΔT had a good cerebral perfusion volume (≥20ml·100g-1·min-1). On the other hand, in the patients with a negative ΔT, the brain perfusion volume was significantly diminished (≤10ml·100g-1·min-1). In the patients with a fluctuating ΔT, SjO2 was helpful in evaluating the severity of brain damage.
Conclusion: Brain temperature monitoring is effective in making a prognosis of brain damage because brain temperature depends on the CPP and the cerebral blood flow.
