Correlation Between Sevoflurane Anesthesia Depth Monitoring and Postoperative Oxidative Stress Response and Hemodynamic Stability in Elderly Patients with Rectal Cancer

To investigate the effect of bispectral index (BIS) monitoring anesthesia depth on postoperative oxidative stress response and hemodynamic stability in elderly patients with rectal cancer during sevoflurane anesthesia. A retrospective study design was adopted to include 105 elderly patients who underwent laparoscopic or open radical resection of rectal cancer in our hospital from January 2021 to December 2023. According to the application of BIS monitoring or not, patients were divided into monitoring group ( n = 53, BIS value was maintained at 40–60 under BIS monitoring) and control group ( n = 52, routine clinical judgment of anesthesia depth). The hemodynamic indexes and oxidative stress indexes at indicated time points were recorded. The incidence of adverse events within 72 h after operation was also recorded. In terms of hemodynamics, the monitoring group had much higher SBP and significantly lower HR than the control group At T1-T3 ( P < 0.05). MAP in the monitoring group was significantly lower than that in the control group at T1 and significantly higher than that in the control group at T2 ( P < 0.05). At 72 h after operation, the monitoring group had much higher MDA and lower SOD than the control group ( P < 0.05). Besides, the time from the end of operation to spontaneous breathing recovery, eye opening time, extubation time and PACU residence time were significantly shorter in the monitoring group than the control group ( P < 0.05). The MMSE scores of the two groups at 24 h after operation were significantly lower than those before operation ( P < 0.05). In addition, the monitoring group had significantly higher MMSE scores than the control group at 24 h and 72 h after operation (all P < 0.05). In sevoflurane anesthesia for elderly patients with rectal cancer, monitoring and maintaining appropriate anesthesia depth (BIS 40–60) is related to the improvement of perioperative hemodynamic stability, the reduction of early postoperative oxidative stress, the reduction of sevoflurane dosage and the promotion of postoperative recovery, which has good clinical application value.