<p>Pain Score of TTE.</p>

Background ECG-guided tip localization of central venous access has been clinically proven to be highly accurate and safe. However, real-time tip localization in patients with atrial fibrillation remains a challenge. Transthoracic ultrasound catheter tip localization is noninvasive and real-time. However, no methodological or accuracy studies of its localization have been reported in the literature. Objective To explore the accuracy of the TTE technique in localizing the tip position of central venous access devices (CVADs) and to establish a standardized TTE-guided catheter tip positioning procedure. Methods This was an self-controlled trial. A total of 35 patients requiring PORT or PICC implantation participated in this study from April 2023 to March 2024. First, catheter positioning was performed under TTE guidance, and after determining the position of the catheter tip, the insertion depth and relative data were recorded. Subsequently, ECG-guided positioning was performed. The final position of the catheter was standardized by ECG. Results A total of 35 patients successfully underwent CVAD insertion under the guidance of IC-ECG. Five patients were excluded from the per-protocol (PP) analysis because the catheter tip could not be visualized in the Apical Four Chamber View. Statistical analysis showed no significant difference between ECG-measured depth and TTE-measured depth (t = −1.405, p = 0.17). In the PP Bland–Altman analysis, the mean bias was −0.13 with 95% limits of agreement (LOA) from −1.10 to 0.83, indicating good agreement between the two methods. An additional intention-to-diagnose (ITD) analysis with extreme value imputation for the five missing cases yielded a mean bias of −0.34 and 95% LOA from −1.70 to 1.00, further confirming the robustness of the findings. The pain intensity score did not exceed 4 points for 34 patients, with only one patient reaching 5 points. The TTE operation time did not exceed 8 minutes for each patient. Conclusion This study suggests that non-contrast TTE shows reasonable consistency with IC-ECG, with short operation time and acceptable patient discomfort. TTE may serve as a feasible, real-time, non-invasive alternative for patients in whom IC-ECG cannot be used.背景 经心电图（ECG，Electrocardiogram）引导的中心静脉置管尖端定位已被临床证实具备极高的准确性与安全性。然而，针对心房颤动患者的实时置管尖端定位仍是一项临床难题。经胸超声导管尖端定位具有无创、实时的优势，但目前国内外文献尚未见其定位方法学与准确性相关的研究报道。 研究目的 探讨经胸超声心动图（TTE，Transthoracic Echocardiography）技术定位中心静脉通路装置（CVADs，Central Venous Access Devices）尖端位置的准确性，并建立标准化的TTE引导导管尖端定位流程。 研究方法 本研究为一项自身对照试验。2023年4月至2024年3月，共纳入35例需行植入式静脉输液港（PORT，Port-a-Cath）或经外周置入中心静脉导管（PICC，Peripherally Inserted Central Catheter）植入的患者参与本研究。首先在TTE引导下完成导管定位，确认导管尖端位置后记录置入深度及相关数据；随后采用ECG引导定位，最终以ECG结果作为导管位置的标准化判定依据。 研究结果 共35例患者在IC-ECG引导下成功完成CVAD植入。其中5例患者因心尖四腔切面无法显示导管尖端，被排除出符合方案集（PP）分析。统计学分析显示，ECG测量的置入深度与TTE测量的置入深度无显著统计学差异（t=-1.405，P=0.17）。在PP集的布兰德-奥特曼（Bland-Altman）分析中，平均偏倚为-0.13，95%一致性界限（LOA）为-1.10至0.83，表明两种定位方法具有良好的一致性。针对5例缺失数据的病例采用极值插补法进行补充意向诊断（ITD）分析后，平均偏倚为-0.34，95% LOA为-1.70至1.00，进一步证实了研究结果的稳健性。34例患者的疼痛强度评分未超过4分，仅1例患者评分为5分；所有患者的TTE操作时长均未超过8分钟。 研究结论 本研究表明，无对比剂增强的TTE与IC-ECG定位结果具有较好的一致性，且操作耗时短、患者耐受度良好。对于无法采用IC-ECG引导定位的患者，TTE可作为一种可行、实时且无创的替代定位方案。