[The influence of etomidate and thiopentone on the intracranial pressure elevated by nitrous oxide (author's transl)]

Abstract

Intracranial pressure (ICP), arterial blood pressure (BP) and the calculated cerebral perfusion pressure (CPP) were investigated under standard conditions in 14 patients with severe brain injury. The influence of etomidate 0.3 mg/kg in comparison with thiopentone 6.0 mg/mg was evaluated both in patients with primarily elevated ICP (group I) and with an increase of ICP produced by nitrous oxide in oxygen (group II). In both groups of patients a marked ICP reduction (42%/26%) was produced by etomidate as well as by thiopentone. Whereas the reduction of CPP caused by thiopentone was enhanced by a moderate fall in BP, no influence on either BP or CPP was observed with etomidate. A regular fall in BP by about 10-15% was observed under nitrous oxide in oxygen alone, subsequently reducing the CPP by about 25%. These results emphasize the importance of the actions and interactions of different combinations of anesthetics in patients with acute brain injury in the prevention of further brain ischaemia. We believe that etomidate like thiopentone has brain protective properties in patients with cerebral hypoxia and must therefore be considered as an important therapeutic agent in such patients.