Regional cerebral oxygenation (measured by NIRS)
At baseline evaluation before anesthesia induction, RCO was significantly higher both at the right and left sides in the MF group compared to the NF group. This difference continued throughout the operation on the left side. However, this difference disappeared 10 min after intubation on the right side. Placing the patients in a prone position did not cause any alteration in RCO on the right side in any of the groups. However, on the left side, mean RCO decreased after PP in both MF and NF groups (