BackgroundPoint-of-care ultrasound (POCUS) can guide umbilical vein catheter placement in real time and monitor catheter tip position, allowing avoidance of severe complications due to catheter malposition. This study aims to explore the effectiveness of POCUS in guiding venous catheter insertion and monitoring complications.MethodsSixty-eight neonates with ultrasound-guided venous catheter insertion at the Neonatal Department of Dongguan Children's Hospital between December 2020 and February 2022 were included. POCUS was applied to monitor catheter tip location daily until catheter removal. A displacement range exceeding the intersection of the inferior vena cava and right atrium by ±0.5 cm was considered misalignment.ResultsSixty-four neonates had a displaced catheter tip (94.1%, 64/68), with a median displacement distance of 0.4 cm (minimum −0.2 cm, maximum 1.2 cm). Ten neonates had a misalignment (14.7%, 10/68) caused by displacement. Displacement usually occurs within 2–4 days after placement, with displacement rates of 94.1% (64/68), 90.6% (58/64), and 98.3% (59/60) on days 2, 3, and 4, respectively, and could still occur on day 9 post-placement. In addition, misalignment mainly occurs on the second day after placement. During the monitoring process, 58 neonates had catheter tip displacement ≥2 times, resulting in 252 displacement and 22 misalignment incidents. Among them, the catheter tip migrated outward from the inferior vena cava seven times, all of which were removed in time. Ultrasound was used for positioning 486 times, and x-ray was indirectly avoided 486 times.ConclusionThe catheter tip is prone to displacement and misalignment after umbilical vein catheterization, which most commonly occurs on days 2–4. POCUS is recommended for daily monitoring of the tip location during umbilical vein catheterization until catheter removal.