超声引导非麻醉下足月及近足月臀位外倒转术的学习曲线

Learning curve for ultrasound-guided external cephalic version without anesthesia in full-term and near-term pregnancies

目的:评估操作者技能对于臀位外倒转术(external cephalic version,ECV)成功率的影响,探讨操作者掌握ECV过程中的学习曲线。方法:回顾性分析2019年3月至2021年8月在南京医科大学第一附属医院97例行ECV患者的临床资料。分析经产妇和初产妇ECV的成功率以及并发症发生情况。采用累积和分析法(cumulative sum analysis,CUSUM)分析ECV的学习曲线。结果:(1)经产妇仅年龄大于初产妇[(29.2±3.0)岁与(33.0±3.4)岁, t=-5.57, P<0.001],其余一般资料的差异无统计学意义。(2)ECV总体成功率为61.9%(60/97),经产妇成功率高于初产妇[93.3%(28/30)与47.8%(32/67), χ^(2)=18.24, P<0.001]。主要并发症为胎心减慢(5.2%,5/97),以及阴道流血、胎膜早破和胎儿窘迫(均为1.0%,1/97)。初产妇与经产妇并发症发生率差异无统计学意义。(3)初产妇ECV可接受的失败率为50%时, R2=0.91, H=-3.27, Y=52.16,即达到50%的目标需要积累学习53例;经产妇ECV可接受的失败率为30%时, R2=0.99, H=-1.635, Y=6.60,即需要积累学习7例即可达到70%成功率。 结论:经过规范培训的手术者,经过约50例的学习,可熟练掌握非麻醉下足月及近足月初产ECV的操作技能,经产妇需要约10例的训练积累。临床实践建议以经产妇作为学习的切入点,有利于建立操作者的学习信心,也有利于在孕产妇中进行ECV的推广实施。

Objective To evaluate the effects of physician skills on the success rate of the external cephalic version(ECV)and investigate the learning curve for ECV.Methods A retrospective study of 97 pregnant women who underwent ECV at the First Affiliated Hospital of Nanjing Medical University from March 2019 to August 2021 was performed.Patients were divided into multipara and primipara groups.The success rate of ECV and morbidity were compared between the two groups,and the learning curve for ECV was evaluated using cumulative sum analysis(CUSUM).Results(1)Patients in the multipara group were older than those in the primipara group[(33.0±3.4)vs(29.2±3.0)years,t=-5.57,P<0.001].No significant difference was found in other baseline data between the two groups.(2)The overall ECV success rate was 61.9%(60/97),and a higher success rate was observed in the multipara group[93.3%(28/30)vs 47.8%(32/67),χ^(2)=18.24,P<0.001].Fetal heart rate deceleration(5.2%,5/97),vaginal bleeding(1.0%,1/97),premature rupture of membranes(1.0%,1/97),and fetal distress(1.0%,1/97)were the main complications.(3)The CUSUM analysis showed that it needed 53 primiparas for a physician to obtain a 50%consistent success rate(R^(2)=0.91,H=-3.27,Y=52.16)and seven multiparas to achieve a 70%consistent success rate(R^(2)=0.99,H=-1.635,Y=6.60).Conclusions Parity and operator skills have a significant influence on the success of ECV.A physician with standardized training will manage non-anesthesia ECV skillfully in full-term and near-term pregnancies after practice on 50 primiparae or approximately ten multiparae.It is recommended to start with the multiparae for learning ECV to build up confidence and promote the implementation of ECV.