Evaluation of postoperative delirium, early and long-term postoperative neurocognitive changes in lumbar surgery patients who measured regional cerebral oxygenation by near infrared spectroscopy (NİRS)

Aim: Postoperative delirium (POD) and Postoperative Cognitive Disorders (POCD) are important complications that cause increased morbidity and mortality in the postoperative period and decrease the quality of life. In patients undergoing lumbar surgery, prone position, bleeding and long general anesthesia periods may pose a risk in terms of POD and POCD. Continuous monitoring of cerebral oxygen saturation with near infrared spectroscopy (NIRS) devices and prevention of desaturation with algorithms can reduce these complications. In this study, we aimed to investigate the effect of treating cerebral desaturation with NIRS-based algorithms on POD and POCD. Materials and Method: Preoperative cognitive tests (Mini Mental State test (MMDT, appendix-1) and Addenbrook Congestive Examination test battery (ACE-R, appendix 2)) were applied to patients scheduled for lumbar surgery. Those with an MMDT score of 25 and above were included in the study. Bispectral index (BIS) and NIRS monitoring were performed on all patients included in the study. The patients were divided into two groups as the control group (Group-K, n=30) and those who applied NIRS-based algorithms (Group-N, n=30). When the basal NIRS value decreased by more than 20% or the NIRS value was less than 50% in Group-N, NIRS values were tried to be kept at normal levels by applying the NIRS-based cerebral oximetry algorithm. In the control group, NIRS values were recorded only blindly. Patients admitted to the postoperative recovery unit were evaluated with the Nursing Delirium Screening Test (NuDESC, appendix 3) for delirium detection. In the postoperative period, the patients were contacted at the 1st week, 3rd month and 6th month and cognitive tests were performed again. Results: Twenty-six (50,0%) of the patients were in Group-K and 26 (50,0%) were in Group N. The mean age of the patients was 55,60±7,13. When the demographic data of the patients in both groups were evaluated, no significant difference was observed between the two groups. In Group-N, anesthesia time, surgery time, time in prone position, and presence of intraoperative bleeding were significantly higher in patients with a decrease of more than 20% in NIRS compared to patients with normal NIRS values (p=0,001, p=0,001, p=0,001, respectively). and p=0,011). Patients in Group-N who had more than 20% reduction in NIRS value had higher ACE score at week 1, ACE score at month 3, while duration of anesthesia, surgery time, and time in prone position were longer compared to Group-K (p=5, respectively). 0.013, p=0.018, p=0.040, p=0.044, p=0.048, p=0.001). While the ACE score at 6 months was similar to preoperative values in patients in Group-N, it was lower than preoperative values in Group-K. According to the NuDESC scan, none of the patients had delirium in the postoperative period. Conclusion: Although better management of intraoperative hemodynamics as a result of BIS monitoring of the depth of anesthesia in patients who underwent lumbar surgery in the prone position was protective in terms of POD development, it was insufficient to reduce the occurrence of POCD. Postoperative cognitive results of patients whose cerebral desaturation was treated according to the algorithm were more similar to preoperative values, and POCD occurred in patients whose NIRS values were followed blindly and whose cerebral desaturation was not treated. In lumbar surgeries performed in the prone position, with a long expected surgical time, with a large amount of bleeding, NIRS monitoring in addition to conventional anesthesia may be beneficial in preventing early and late cognitive impairments. Key Words: Postoperative Delirium (POD), Postoperative Cognitive Disorders (POCD), regional cerebral oxygenation (rSO2), lumbar surgery