摘要目的:探讨超声全程引导穿刺和定位导管尖端在极低/超低出生体重儿（very/extremely low birth weight infant，VLBWI/ELBWI）经外周中心静脉置管中的应用。方法:选择南京医科大学第一附属医院新生儿重症监护病房2019年1月至2020年8月接受经外周中心静脉置管术的VLBWI/ELBWI进行前瞻性研究，以患儿住院号末位奇偶数分为超声组和X线组，超声组予床旁超声引导穿刺、定位导管尖端，X线组凭经验穿刺置管，予床旁X线定位导管尖端；再依据出生体重分为VLBWI组、ELBWI组。应用SPSS 25.0统计软件比较组间置管时间、一次性置管成功率、导管尖端清晰显示率、原发性异位率、继发性异位率、并发症发生率的差异。结果:共纳入118例患儿，超声组57例（VLBWI组50例、ELBWI组7例），X线组61例（VLBWI组54例、ELBWI组7例）。超声组置管时间［（23.2±7.1）min比（34.1±7.5）min］、一次性成功率（93.0%比65.6%）、尖端显示率（96.5%比83.6%）、原发性异位率（7.0%比24.6%）、并发症发生率（7.0%比21.3%）优于X线组，差异有统计学意义（ P<0.05）；超声ELBWI组以上5项均优于X线ELBWI组，超声VLBWI组仅置管时间、一次性成功率优于X线VLBWI组，差异有统计学意义（ P<0.05）。 结论:超声引导VLBWI/ELBWI经外周中心静脉置管定位便捷、精确，可提高置管成功率，减少放射暴露和重复置管损伤；超声追踪定位导管并及时调整可减少置管后并发症的发生，值得在VLBWI/ELBWI中推广应用。

abstractsObjective:To study the clinical application of ultrasound-guided puncture and catheter tip positioning in peripherally inserted central catheter (PICC) among very/extremely low birth weight infants (VLBWI/ELBWI).Method:From January 2019 to August 2020, VLBWI/ELBWI admitted to NICU of our hospital and received PICC were prospectively enrolled in the study. Based on the last digit of medical record number was odd or even, the infants were assigned into ultrasound group and X-ray group. In the ultrasound group, puncture and catheter tip positioning were performed at bedside guided by ultrasound, while in the X-ray group, these procedures were performed empirically. The differences of catheterization procedure duration, first-time success rate, the visibility of catheter tip, primary dislocation rate, secondary dislocation rate and complication rate were compared between the two groups using SPSS 25.0.Result:A total of 118 premature infants were enrolled, including 57 cases in ultrasound group (50 cases VLBWI and 7 cases ELBWI) and 61 cases in X-ray group (54 cases VLBWI and 7 cases ELBWI). The catheterization procedure duration [(23.2±7.1) min vs. (34.1±7.5) min], first-time success rate (93.0% vs. 65.6%), the visibility of catheter tip (96.5% vs. 83.6%), primary dislocation rate (7.0% vs. 24.6%) and complication rate (7.0% vs. 21.3%) in ultrasound group were all better than X-ray group ( P<0.05). For ELBWI, the above five indexes in the ultrasound group were better than the X-ray subgroup ( P<0.05). For VLBWI, only the catheterization procedure duration and first-time success rate were better in the ultrasound group than the X-ray group ( P<0.05). Conclusion:Ultrasound-guided PICC catheterization in VLBWI/ELBWI is convenient and accurate, which can improve success rate, reduce radiation exposure and repeated catheterization injury. Timely tracking and adjustment of the catheter under ultrasound can reduce complications after catheterization. This technique is worth popularizing among VLBWI/ELBWI.