The effect of stable xenon on ICP.

Recent studies have suggested that under certain conditions, inhalation of stable xenon can cause an increase in CBF or intracranial pressure (ICP). We reviewed the ICP changes that occurred during 48 stable xenon/CT CBF studies in 23 comatose head-injured patients to determine if the concentration (32%) and duration of inhalation (4.5 min) of stable xenon we used caused an increase in ICP. In the group as a whole, there was no significant difference between the mean ICP at the start of xenon inhalation and the mean ICP immediately after completion of the studies. An increase in ICP also was not found in subgroups with low, normal, or high global CBF, or groups with or without intracranial hypertension. Changes in ICP that occurred during individual studies usually were related to corresponding changes in the arterial pCO2 (p less than 0.0001, Pearson's correlation test). Our data suggest that 32% stable xenon administered for 4.5 min does not cause a significant increase in ICP during xenon/CT CBF studies.