Evaluation of the relationship between sedation methods and postoperative delirium in geriatric patients operated with spinal anesthesia

Objective: With the rapidly aging population, the geriatric patient population is also increasing. Anesthesia management in these patients requires special attention, and the comorbidities encountered in most of the patients lead the anesthetist to regional anesthesia methods. It is known that sedative agents, which are frequently used during regional anesthesia, have negative effects on cognitive skills. No study has been found comparing the effect of dexmedetomidine with its procognitive features on postoperative delirium in geriatric patients with remifentanil. In our study, we aimed to understand the relationship between these two agents and intraoperative sedation and postoperative delirium in geriatric patients. Materials and Methods: This study was performed in ASA I-II-III patients aged 65 and over who were scheduled for lower extremity surgery under spinal anesthesia, after ethics committee approval. Preoperative CAM test was applied to all patients. The cases were divided into two groups as dexmedetomidine group (Group D, n = 38) and remifentanil group (Group R, n = 38). Intraoperative ECG, NIBP, SpO2 and BIS monitoring were performed on the patients. After spinal anesthesia, dexmedetomidine was given in Group D at a rate of 0.5 mcg/kg for 10 minutes and then infusion at a rate of 0.2 mcg/kg/hour. In Group R, after 5 minutes of loading at a rate of 0.1 mcg/kg, infusion was given at a rate of 0.05 mcg/kg/hour. Hemodynamic and respiratory data were recorded throughout the study. The level of sedation was followed by BIS and RASS and kept within the light sedation limits. After the cessation of sedation following the end of the surgery, the patients were followed up in the postoperative care unit until the Modified Aldrete Score was 9. CAM and RASS were repeated by the investigator who performed the first test at the postoperative 24th hour, 72nd hour, and postoperative 30th day. Results: Delirium was detected in 2 patients in the dexmedetomidine group in the first 72 hours, and in 1 patient in the remifentanil group on the 30th day of long-term follow-up, and no significant difference was found (p>0.05). Conclusion: The effects of dexmedetomidine and remifentanil use as sedation agents in geriatric patients are similar in terms of the frequency of postoperative delirium. Keywords: Dexmedetomidine, remifentanil, postoperative delirium, spinal anesthesia, sedation