Effects of Abdominal Wall Blocks on Postoperative Delirium in Elderly Patients Undergoing Laparoscopic Surgery: A Randomized Controlled Study

BACKGROUND: Postoperative delirium (POD) seriously affects the rapid postoperative recovery of elderly patients. We investigated the effect of abdominal wall blocks on POD in elderly patients undergoing laparoscopic radical resection of colon cancer and underlying mechanisms. MATERIAL/METHODS: A total of 100 patients undergoing laparoscopic radical resection of colon cancer were randomly assigned to group C (control) and group R (regional nerve blocks). In group R, 20 mL of local anesthesia-mixed solution was injected into the bilateral transverse abdominis muscle plane and 10 mL was injected into the bilateral posterior sheath of the rectus abdominis muscle. In group C, the same amount of saline was used for nerve block. The consumption of propofol and remifentanil during surgery was recorded. Levels of serum interleukin (IL)-6 and highly sensitive C-reactive protein (hs-CRP) during surgery were evaluated. The Confusion Assessment Method for the Intensive Care Unit Scale and the Richmond Agitation-Sedation Scale were adopted to evaluate POD. RESULTS: The incidence of POD was lower in group R than in group C (P=0.048). The consumption of propofol and remifentanil was significantly reduced in group R, compared with group C (P<0.05). Compared with T0, serum IL-6 and hs-CRP levels in both groups were significantly increased at T1 and T2 (P<0.05). Moreover, serum IL-6 and hs-CRP were lower at T1 and T2 in group R compared with group C (P<0.05). CONCLUSIONS: Abdominal wall blocks may alleviate POD in elderly patients undergoing laparoscopic surgery, which may be related to the reduction of anesthetic consumption and inflammatory response.