Fig. 3. Individual and mean (±SD) jugular venous oxygen saturation in patients under sevoflurane-nitrous oxide or propofol-remifentanil anesthesia. The baseline values obtained in supine position after induction of anesthesia and the lowest values reached within 10 min after the beach chair position are presented. *P < 0.05 versus  propofol-remifentanil anesthesia group. †P < 0.05 versus  baseline. The horizontal dashed line  represents 50% of jugular venous oxygen saturation, an indirect threshold of cerebral hypoperfusion. BCP = beach chair position; P/R = propofol-remifentanil anesthesia; S/N = sevoflurane-nitrous oxide anesthesia; SjvO²= jugular venous oxygen saturation.