目的 研究重症超声评估二尖瓣环收缩期运动峰值速度（Sm）在静脉⁃动脉体外膜肺氧合 （VA⁃ECMO）撤机前的应用价值。方法 选取 2019 年 2 月至 2023 年 2 月在宁夏医科大学总医院接受 VA⁃ ECMO治疗的患者40例，均行撤机试验，A组为撤机试验成功者（n = 28），B组为撤机试验失败者（n = 12）。 在撤机试验前，应用重症超声监测患者的 Sm、左室射血分数（left ventricular ejection fraction，LVEF）、左心室舒张末期内径（left ventricular end diastolic dimension，LVEDD），并对两组数据进行统计学分析。将撤机 成功与否作为结局变量，将两组间存在有统计学差异的超声参数作为观察变量，进行 VA⁃ECMO 撤机试验 成功与否的 ROC 曲线分析。结果 A 组撤机试验前 Sm 大于 B 组，差异均有统计学意义（均 P < 0.05）；两组患者撤机试验前 LVEDD 比较差异无统计学意义（P > 0.05）。Sm、LVEF 的 AUC 分别为 0.896、0.479， 其中Sm有统计学意义（均P < 0.05），Sm、EF的最佳临界值分别为0.821、0.321。结论 重症超声评估Sm对 VA⁃ECMO 患者成功撤机具有重要的指导意义。 

Objective To investigate the application of critical ultrasound in evaluating the systolic move⁃ ment（Sm）peak velocity of mitral annula before weaning vein artery extracorporeal membrane oxygenation（VA ⁃ ECMO）. Methods The weaning test was conducted in 40 patients who received VA⁃ECMO treatment in General Hospital of Ningxia Medical University from February 2019 to February 2023. There were 28 cases having success⁃ fully weaning VA⁃ ECMO（group A）and 12 cases failing to wean（group B）. Before weaning test，Sm，left ventric⁃ ular ejection fraction（LVEF），and left ventricular end diastolic diameter（LVEDD）were measured by critical ultrasonography，and the data of two group were analyzed compared . The predicting values of Sm measured by critical ultrasonography for successful weaning were evaluated with ROC curve. Results Before the weaning test，the Sm of group A were higher than those of group B（P < 0.05）. While there was no significant difference in LVEDD between the two groups before weaning test（P > 0.05）. The area under ROC curve（AUC）of Tei index，Sm and LVEF were 0.896，0.479，respectively. The difference of Sm was statistically significant between two groups（all P < 0.05）， and the optimal cut⁃off values were 0.821 and 0.321，respectively. Conclusion Critical ultrasound evaluation of Sm can be used to predict successful weaning of VA⁃ ECMO in ICU patients.