①Evaluation: The puncture site was determined by senior nurses based on group assignment before placement. The depth and diameter of the pre-punctured vein were measured using ultrasound assessment, and the intima of the pre-punctured vein was examined without applying a tourniquet. ②Catheterization: A 3 Fr, 8 cm tip-opened long PIVC was used. Catheters were placed according to the designated sites for each group using ultrasound-guided and accelerated Seidinger techniques. After confirming catheter placement, needleless connectors and extension were attached, and the catheter was secured without tension using a sterile transparent dressing. ③Maintenance: Specialized nurses were trained to monitor and evaluate catheter function daily. Clinical nurses conducted routine maintenance until the study completion. Daily data were recorded and updated in computerized records.

①Evaluation: The puncture site was determined by senior nurses based on group assignment before placement. The depth and diameter of the pre-punctured vein were measured using ultrasound assessment, and the intima of the pre-punctured vein was examined without applying a tourniquet. ②Catheterization: A 3 Fr, 8 cm tip-opened long PIVC was used. Catheters were placed according to the designated sites for each group using ultrasound-guided and accelerated Seidinger techniques. After confirming catheter placement, needleless connectors and extension were attached, and the catheter was secured without tension using a sterile transparent dressing. ③Maintenance: Specialized nurses were trained to monitor and evaluate catheter function daily. Clinical nurses conducted routine maintenance until the study completion. Daily data were recorded and updated in computerized records.

A fixed routine for pre-insertion cleaning and equipment was followed, including hand washing, placing the patient in a recumbent position, skin antisepsis, and preparation of the sterile field. Catheter insertion was performed by senior specialized nurses in the intravenous treatment room, which was a standardized setting for venipuncture.

Catheter-related complications were assessed including thrombophlebitis, other phlebitis, catheter occlusion, bleeding, catheter-related infections, and weeping.

The puncture success rate with one-attempt refers to the instance where the puncture needle successfully enters the target vein on the first attempt without needing to change the puncture site.