Objective:To investigate the effect of esketamine combined with erector spinae plane block(ESPB)on postop-erative pain and sleep quality in patients undergoing lobectomy.Methods:88 patients with thoracoscopic lobectomy were divided into control group and observation group according to different anesthesia scheme,44 cases in each group.ESPB was performed in both groups,and the same anesthesia induction and maintenance were given.Before skin incision,the observation group was given intravenous injection of esketamine 0.5 mg/kg,and 0.25 mg·kg-1·h-1 was pumped during the operation until 30 min be-fore the end of the operation.The control group was injected with the same dose of normal saline.The pain scores of the two groups were recorded at 2,6,24 and 48 h after operation.The intraoperative dosage of propofol and remifentanil was recorded,and the pressing times of analgesia pump in the two groups were counted.The Pittsburgh sleep quality index(PSQI)was eval-uated on the 1 st day before operation and on the 1 st and 2 nd day after operation.The levels of serum interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α)were detected before and 24 h after operation.Statistically analyzed the occurrence of adverse reactions.Results:Compared with the control group,the pain score of the observation group was lower at 2,6,24 h after opera-tion(P＜0.05).48 hours after surgery,there was no statistically significant difference in pain scores between the two groups(P＞0.05).Compared with the control group,the dosage of propofol and remifentanil in the observation group was less(P＜0.05).Compared with the control group,the PSQI score of the observation group was lower at 1 and 2 d after operation(P＜0.05).At 24 h after operation,the levels of serum TNF-α and IL-6 in the two groups increased(P＜0.05),and the observation group were lower than the control group(P＜0.05).There was no statistically significant difference in the incidence of adverse reactions between the two groups(P＞0.05).Conclusion:Esketamine combined with ESPB in thoracoscopic lobectomy can not only reduce postoperative pain,but also inhibit inflammatory response,improve postoperative sleep,and has good safety.