Non-invasive EEG-based anaesthesiological monitoring in geriatric patients during ENT surgery.

Abstract

Objectives: This study evaluates the effectiveness of electroencephalography-based monitoring during general anesthesia in geriatric ENT surgery patients. Methods: A randomized prospective study included 99 patients (ages 70–85, ASA III–IV) undergoing ENT surgery. They were divided into three groups: Group A (n=33) had CONOX monitoring, Group B (n=33) had no cerebral monitoring, and Group C (n=33) had BIS monitoring. We analyzed dosages of propofol, fentanyl, and sevoflurane, intraoperative hemodynamic data, rates of intraoperative awakening, postoperative nausea and vomiting (PONV), additional pain relief needs, and cognitive function testing before and after surgery. Results The propofol dose (mg/kg) during induction was higher in Group B (1.76 [1.54 – 1.90]) than in Group A (1.6 [1.30 – 1.77], p=0.016) and Group C (0.71 [0.62–1.14], p=0.012). Fentanyl dosage (mcg/kg/h) was significantly greater in all groups with OA duration 120 min (2.56 [1.87 – 3.75]) compared to 120 min (1.75 [1.22 – 2.08], p=0.001). Sevoflurane concentration (MAC) in Group C (1 [0.80-1.07]) was lower than Groups A and B (1 [1 – 1], p=0.016). In Group A, postoperative cognitive scores (MMSE) after OA 120 min (fentanyl dose 1.70 [1.06-1.86] mcg/kg/hour) were higher (28 [27-29]) than that for OA 120 min (2.85 [1.75-3.56] mcg/kg/hour; 27 [27-27], p=0.044). Conclusion 1) EEG-based anesthetic monitoring in geriatric ENT patients optimizes sedation and analgesia dosing, reducing hemodynamic disturbances, intraoperative awakenings, and PONV more effectively than standard monitoring. 2) Combined EEG monitoring with clinical assessment accelerates recovery and improves surgical outcomes. 3) Optimization of the dosing of opioid analgesics under the control of the analgesia depth index (qNOX) has a beneficial effect on the postoperative cognitive status of geriatric patients.