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

Abstract
Summary Background and objectives: The aim of this prospective, observational study was to evaluate changes in regional cerebral oxygen saturation (rSO2) and incidence of intraoperative cerebral desaturation in a cohort of elderly patients undergoing major abdominal surgery. Methods: rSO2 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 rSO2 was 63 ± 8%; cerebral desaturation (rSO2 decrease 10 min%, and 10 (4–30) days in those with an AUCrSO2<50% <10 min% (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.