Correlation Between Neurocognitive Function Changes and Cerebral Oximetry in Thoracic Surgery Patients

Background: Postoperative cognitive dysfunction (POCD) is a significant complication following thoracic surgery. One-lung ventilation (OLV) during these procedures can lead to cerebral desaturation, potentially contributing to POCD. This study investigated the correlation between intraoperative cerebral oximetry, measured by near-infrared spectroscopy (NIRS), and neurocognitive function changes in patients undergoing thoracic surgery. Methods: In this prospective, observational pilot study, 54 adult patients undergoing OLV for thoracic surgery were enrolled. Cerebral oxygen saturation (rScO2) was monitored continuously using NIRS. Patients were categorized into two groups: Group N (normal NIRS values) and Group D (decreased NIRS values, defined as a drop of ≥20% from baseline or an absolute value <50%). Neurocognitive function was assessed preoperatively, on the 3rd postoperative day, and at 3 months using the Addenbrooke’s Cognitive Examination-Revised (ACE-R) battery. The correlation between intraoperative rScO2 values, postoperative complications, and neurocognitive outcomes was analyzed. Results: A significant association was found between intraoperative cerebral desaturation and a decline in ACE-R scores. Group D showed a significant decrease in ACE-R scores on the 3rd postoperative day and at 3 months compared to their baseline, while Group N showed no significant change. The most pronounced decline in Group D was observed in the “Fluency” cognitive domain. Interestingly, there was a significant difference in ICU admission rates (p = 0.004) between the two groups, with more admissions in Group D, despite no significant difference in intraoperative hypotension or peripheral desaturation. Patients with pre-existing hypertension were more likely to experience cerebral desaturation. Conclusion: Intraoperative cerebral desaturation, as detected by NIRS, is a strong predictor of both early and late postoperative neurocognitive decline and increased postoperative morbidity in thoracic surgery patients. This underscores the value of NIRS as a sensitive monitoring tool to identify patients at risk and guide timely interventions. These findings suggest a need for further research, including larger randomized controlled trials, to confirm these associations and evaluate the impact of a protocol-driven NIRS intervention strategy on patient outcomes.