Abstract: Objective To investigate the accuracy of measurement and localization of the depth of internal jugular vein catheterization under the guidance of ultrasound. 
Methods A total of 96 patients who underwent surgery for congenital heart disease (CHD) under general anesthesia were selected. They were divided into a research group (n=48) and a control group (n=48) according to random number table method. The patients in the research group were guided by ultrasound to locate the placement of the tip of the internal jugular vein catheter and measure the placement depth of the catheter. In the control group, the body surface landmark positioning method was used to measure the placement depth of the internal jugular vein catheter, and the differences in the placement depth of the internal jugular vein catheter were compared between two groups. After surgery, chest X-ray was used to determine whether the catheter tip located by ultrasound was within the T4 segment. The Bland-Altman method was used to analyze the consistency between two methods and the postoperative chest X-ray localization method. 
Results The catheters were successfully placed in both groups without complications. The depth of catheter placement measured in the research group was smaller than that in the control group ［(6.17±0.90) cm vs. (6.59±0.94 ) cm, P＜0.05］. The coincidence rate between the correct detection of the position of the deep venous catheter tip and the chest X-ray was 81.25% in the control group and 97.91% in the research group, and there was a statistical difference between two methods (P＜0.05). Bland-Altman consistency analysis showed that the research group had a high consistency between the depth of positioning the internal jugular vein catheter and the distance from the puncture point to the tracheal carina. 
Conclusion Ultrasound-guided  depth positioning of internal jugular vein catheterization in infants and young children can dynamically and directly guide and locate the puncture and placement position, which is more intuitive and accurate than body surface landmark positioning. 

Key words: heart disease, ultrasonography, infants and young children