Effect of esketamine combined with ropivacaine for erector spinae plane block on postoperative analgesia of thoracoscopic surgery: a randomized clinical trial

Background There are few studies on the combination of esketamine and local anesthetic (LA) in interfascial plane block. The erector spinae plane (ESP) block can be used for postoperative pain of thoracoscopic surgery. This trial aimed to investigate the effect of esketamine combined with ropivacaine for the ESP block on postoperative analgesia in thoracoscopic surgery. Methods Patients undergoing elective thoracoscopic surgery were included. They were randomly assigned to receive the ESP block before thoracoscopic surgery using 20 mL of 0.375% ropivacaine (group R),20 mL of 0.375% ropivacaine with 0.25 mg/kg esketamine (Group K1) or 0.5 mg/kg esketamine (Group K2). The primary outcome was the analgesia in the ESP block. Secondary outcomes included postoperative pain score, satisfaction, anxiety and depression scores. Results A total of 139 patients were randomized to group R (n = 47), K1 (n = 45) and K2 (n = 47). The analgesia during the ESP block was significantly longer in group K1 (845.0 ± 134.4 min) and K2 (894.5 ± 129.7 min) than in group R (784.2 ± 130.9 min) (p < 0.001), although without significant differences between K1 and K2 groups. Postoperative pain score and satisfaction showed significant differences among the three groups, postoperative depression and anxiety scores did not differ between the groups. Multivariable logistic regression revealed preoperative anxiety, depression scores and smoking were identified as risk factors associated with postoperative rescue analgesia. Conclusions Esketamine combined with ropivacaine for the ESP block prolonged analgesia and increase postoperative pain relief and postoperative satisfaction in thoracoscopic surgery.