Cerebral oximetry monitoring in geriatric patients undergoing ENT surgery

Objective. To investigate the relationship between intraoperative hemodynamic variability, cerebral oximetry parameters, cerebral autoregulation, and cognitive status in early postoperative period in elderly patients undergoing ENT surgery. Material and methods. A prospective observational study included 85 patients aged ≥70 years (ASA III—IV) divided into two groups: group A (n=52) — anesthesia with cerebral oximetry monitoring (Invos 5100C) and group B (n=33) with standard monitoring. Group A was further divided into two subgroups: subgroup 1 (n=19) with high CO variability and subgroup 2 (n=33) with stable CO. Episodes of mean arterial pressure (MAP) variability ≥25% and CO variability >20% were assessed along with cognitive function using the MMSE, postoperative delirium (POD), and cerebral oximetry index (COx). Results. In group A, postoperative MMSE scores improved compared to preoperative values (p=0.046). Both cases of POD in this group were associated with MAP and CO variability. COx exceeded 0.9 in patients with hemodynamic variability. In subgroup 1, baseline heart rate was lower and MAP was higher than in subgroup 2 (p=0.025 and p=0.013, respectively). Conclusion. In elderly patients undergoing ENT surgery, cerebral oximetry revealed a correlation between intraoperative variability of MAP and CO, as well as between CO fluctuations and previous hypertension. Increased CO variability reflects impaired cerebral autoregulation. These hemodynamic and oxygenation disturbances may predispose to postoperative delirium. Further multiple-center studies with larger samples are needed to confirm these findings.