Effects of 30% stable xenon on regional cerebral blood flow in patients with intracranial pathology.

ABSTRACT

Regional cerebral blood flow was assessed continuously in 22 patients with severe intracranial pathology undergoing xenon-enhanced computed tomography by means of an intraparenchymal thermodiffusion based microprobe. Thirty-four blood flow studies were analysed revealing an overall xenon-induced flow activation from about 12%. Regional CBF rose from 25 +/- 17 ml/100 g/min (mean +/- sd; range 5.2-41.8 ml/100 g/min) before xenon administration to 28 +/- 21 ml/100 g/min (p = 0.012; range 6.5-46.4 ml/100 g/min) when "steady-state" during xenon "wash-in" was reached. Flow activation curve demonstrated a logarithmic shape with an increase in rCBF between 3% and 7% within the first 90 seconds of xenon "wash-in", 12% after 160 seconds, and showed no further augmentation until the end of the blood flow study after 310 seconds. It is concluded that xenon inhalation leads to flow augmentation in patients with cerebral insult, which does not exceed flow activation obtained in normal subjects. The impact of the results on xenon-enhanced computed tomography cerebral blood flow calculations remains to be established.