To evaluate the effect of continuous low-dose intravenous infusion of esketamine on postoperative sleep quality of patients undergoing laparoscopic colorectal cancer surgery.

Eighty patients (18-65 years old, ASAⅠ-Ⅲ) undergoing laparoscopic radical resection of colorectal cancer in Changde Hospital, Xiangya School of Medicine were randomly divided into the esketamine group (E group) and the control group (C group), with 40 cases in each group. After induction and intubation, group E were continuously infused 0.2 mg·kg^-1·h^-1 of esketamine until the end of the operation. Group C were infused with 0.9% physiological saline of the same volume. Other anesthetic drugs, surgical procedures and postoperative treatment were the same. Pittsburgh Sleep Quality Index (PSQI) and Self Rating Depression Scale (SDS) were used to assess the patients’ sleep quality and depression on the first day before operation (D_-1), the first day after operation (D₁), and the morning of the 7th day (D₇). Wearing a sports watch 2 nights before surgery (D_-2), the same night after surgery (D₀), and the 6th night after surgery (D₆), a polysomnography was performed at D₆ to record the sleep structure from 22:00 to 6:00 the next day. The patients’ general surgical information and postoperative NRS pain scores on the 1st (D₁), 2nd (D₂), and 3 (D₃) day were recorded.

Compared with Group C, Group E had lower PSQI and SDS scores at D₁ (t=5.528, 4.517, P<0.001, <0.001) and D₇ (t=4.162, 2.976, P<0.001, 0.031), while Group E had longer sleep time (t=5.185, 4.662, P<0.001, <0.001), higher sleep efficiency (t=4.485, 2.717, P<0.001, 0.041), and shorter awakening time after falling asleep (t=3.852, 3.906, P=0.003, <0.001) at D₀ and D₆. The latency for falling asleep (t=5.586, P<0.001) at D₀ was shorter, and the NRS pain score was lower at D₁ (t=4.112, P<0.001). The number of D₁, D₂ analgesic pump compressions (χ²=5.168, 4.926, P<0.001, <0.001) and cases of rescue analgesia (χ²=2.558, 3.887, P=0.041, <0.001) were fewer. The amount of remifentanil used during surgery was less, and the differences were statistically significant (t=3.262, P=0.011).

Continuous low-dose infusion of esketamine during operation can improve the sleep quality of patients undergoing laparoscopic colorectal cancer surgery, and promote the rapid recovery of patients after surgery.