目的：观察超声引导下前锯肌平面阻滞（SAPB）用于乳腺癌改良根治术中的镇痛效果。方法：选择择期行单侧乳腺癌改良根治术的患者60例随机分为两组：SAPB组（S组，n=30）和全身麻醉组（A组，n=30）。S组行超声引导下SAPB阻滞，术侧注射0.25%罗哌卡因30ml，待确定阻滞起效及平面固定后行全麻诱导，记录术前、术中、术后相关数据。比较围术期麻醉效果差异。结果：与A组比较，S组在术中各个时点的平均动脉压（MAP）和心率（HR）均降低（P＜0.05）；术中麻醉药物总消耗量减少（P＜0.05）；术后48h内各时点的静态VAS评分与术后12h内各时点的动态VAS评分均降低（P＜0.05），镇痛满意度评分提高（P＜0.05）。结论：对于行乳腺癌改良根治术的患者，超声引导下SAPB可有效控制患者术中及术后早期急性疼痛情况，使围术期镇痛效果更完善，促进其快速康复。 Objective: To observe the analgesic effect of anterior serratus muscle block (SAPB) guided by ultrasound in modified radical mastectomy.Methods:60 patients undergoing modified radical mastectomy were randomly divided into two groups: SAPB group (S group, n=30) and general anesthesia group (A group, n=30).SAPB block was performed under the guidance of ultrasound in group S, and 0.25% ropivacaine (30 ml) was injected into the operation side. After the onset of block and plane fixation, general anesthesia induction was performed. Relevant data before, during and after operation were recorded.To compare the effect of anesthesia in perioperative period.Results: Compared with group A, the mean arterial pressure (MAP) and heart rate (HR) of group S decreased at each time point during operation (P <0.05), the total consumption of anesthetic drugs decreased during operation (P <0.05), the static VAS score at each time point within 48 hours after operation and the dynamic VAS score at each time point within 12 hours after operation decreased (P <0.05), and the analgesia satisfaction score increased (P <0.05).Conclusion: For the patients undergoing modified radical mastectomy, SAPB guided by ultrasound can effectively control the acute pain during and early after operation, improve the perioperative analgesia effect and promote the rapid recovery.