Abstract:  Objective To investigate the effect of ultrasound-guided serratus anterior plane block (SAPB) on postoperative analgesia in patients undergoing thoracoscopic lobectomy. Methods Sixty patients scheduled for thoracoscopic lobectomy under general anesthesia were randomly divided into two groups, group P (intravenous patient- controlled analgesia) and group S (intravenous patient-controlled analgesia+SAPB). Patients received morphine intravenous patient-controlled analgesia (PCIA) after operation in the two groups. Patients of group S were given ultrasound-guided SAPB with 0.4 mL/kg of either 0.375% ropivacaine after the operation immediately. Morphine cumulative consumption at the 6th, 12th and 24th postoperative hours and NRS (numerical rating scale) pain scores at the 30 min, 1, 2, 6, 12 and 24 postoperative hours were recorded respectively in both two groups. Flurbiprofen axetil 50 mg was injected intravenously when the NRS pain score was greater than 4, and it could be repeated if necessary. Adverse reactions such as analgesic rescue cases, postoperative RASS sedation score and nausea, vomiting, pruritus, respiratory depression, bradycardia and hypotension were recorded. Results The NRS pain scores at the 30 min and 1, 2, 6 h were significantly lower in group S than those in group P (P＜0.01). There were no significant differences in NRS pain scores at 12 and 24 h after operation between two groups. NRS pain scores were gradually reduced with the prolongation of postoperative time in two groups. There was no interaction between groups and processing times (P＞0.05). Morphine cumulative consumption were significantly lower at 6, 12 and 24 postoperative hours in group S than those in group P (P＜0.01). No significant differences were found in the incidence of adverse reactions, RASS sedation scores and analgesic rescue cases between two groups. Conclusion Ultrasound-guided SAPB can significantly reduce postoperative morphine consumption and early pain scores in patients undergoing thoracoscopic lobectomy, without increasing the incidence of adverse reactions.

Key words:  thoracoscopes, pneumonectomy, analgesia, morphine, ultrasound-guide, serratus anterior plane block, thoracoscopic lobectomy of lung