Postoperative Cognitive Function After Different Anesthetic Techniques in Obese Patients

Overview

Obese patients are at increased risk of postoperative cognitive dysfunction (POCD). The effects of different anesthetic techniques on postoperative cognitive function remain controversial. This prospective randomized study aimed to compare the effects of low-flow sevoflurane anesthesia, normal-flow sevoflurane anesthesia, and total intravenous anesthesia (TIVA) on postoperative cognitive function and recovery characteristics in obese patients undergoing elective laparoscopic abdominal surgery. Cognitive function was assessed using the Mini-Mental State Examination (MMSE) before surgery, at postoperative 30 minutes, and on postoperative day 3.

Obesity is associated with physiological alterations that may increase the risk of postoperative cognitive dysfunction (POCD). The influence of anesthetic techniques on postoperative cognitive outcomes in obese patients remains uncertain. This prospective randomized study was conducted in obese patients (BMI ≥30 kg/m²) aged 18-65 years undergoing elective laparoscopic abdominal surgery under general anesthesia. Patients were randomly assigned to one of three groups: low-flow sevoflurane anesthesia, normal-flow sevoflurane anesthesia, or total intravenous anesthesia (TIVA). Anesthetic depth was monitored using bispectral index (BIS) monitoring and maintained between 40 and 60 in all groups. The primary objective was to compare postoperative cognitive function among the three anesthetic techniques using the Mini-Mental State Examination (MMSE). MMSE scores were evaluated preoperatively, at postoperative 30 minutes, and on postoperative day 3. Secondary objectives included comparison of recovery characteristics, including eye-opening time, extubation time, Modified Aldrete Recovery Scores, and perioperative hemodynamic parameters. The study was approved by the Marmara University Faculty of Medicine Clinical Research Ethics Committee (Approval No. 09.2022.744) and written informed consent was obtained from all participants before enrollment.