Abstract
Serial measurements of global cerebral blood flow (CBF) were made in 15 patients undergoing elective neurosurgical procedures in the sitting position, using a modified intravenous 133Xenon technique. The mean supine CBF rose from 43 (+/-3) ml/100g/min to 62 (+/-6) ml/100g/min in the sitting position and remained elevated at the end of surgery at 62 (+/-5) ml/100g/min. Both increases in CBF were statistically significant with respect to baseline supine values.