Monitoring cerebral oxygen saturation in elderly patients undergoing general abdominal surgery: a prospective cohort study

Background and objectives: The aim of this prospective, observational study was to evaluate changes in regional cerebral oxygen saturation (rSO 2 ) and incidence of intraoperative cerebral desaturation in a cohort of elderly patients undergoing major abdominal surgery. Methods: rSO 2 was continuously monitored on the left and right sides of the forehead in 60 patients older than 65 yr (35 males and 25 females; ASA II-III; age: 72 ± 5 yr; without pre-existing cerebral pathology, and baseline Mini Mental State Examination (MMSE) score > 23) undergoing sevoflurane anaesthesia for major abdominal, non-vascular surgery >2 h. Results: Baseline rSO 2 was 63 ± 8%; cerebral desaturation (rSO 2 decrease 10min%, and 10 (4-30) days in those with an AUC rSO2<50% < 10min% (P = 0.0005). Conclusions: In a population of healthy elderly patients, undergoing non-vascular abdominal surgery cerebral desaturation can occur in up to one in every four patients, and the occurrence of cerebral desaturation is associated with a higher incidence of early postoperative cognitive decline and longer hospital stay.