A prospective case-control observation study method was adopted. The investigators of each center included patients who met the inclusion and exclusion criteria and were fully informed about the content of the study, possible benefits, and risks. After obtaining informed consent, the patients were included in the method of continuous sampling and convenient sampling. According to the method of random control, the patients were grouped. In the control group, the length of catheter insertion is measured from the pre-puncture point to the shoulder or armpit. In experimental group 1, the catheter insertion length is measured from the pre-puncture point to the midpoint of the clavicle, and in the experimental group, 2 catheter insertion length is measured from the pre-puncture point to the sternoclavicular joint. With a single-blind design, patients do not know the enrollment situation. The catheter was inserted by a full-time specialist nurse of intravenous therapy under ultrasound guidance combined with the modified Seedinger technique. The catheter was inserted according to the length of different measurement methods in different groups. After the catheter was inserted, an X-ray examination was performed to determine the catheter tip position again. Data collection and follow-up observation will be conducted by researchers who have been uniformly trained. Record the baseline data of the patients in the group before catheterization, record the insertion status during catheterization, record the patient's catheter use and catheter sealing frequency every day during catheter placement, and evaluate catheter function and complications until extubation daily.
The research protocol was based on assigning patients to three different catheter tip groups and then observing the relationship between the tip and catheter-related complications when infusing antimicrobial agents.