2.3. Control Group
STERILE
The patient lay on their back, with their upper limbs hanging down on both sides of the body. Slightly abducted the right upper lamb and turned the head to the opposite side, and the neck, chest and right upper arm was completely exposed. A distance of 1 cm below the middle point of the right clavicle was taken as the puncture entry point, and the needle was inserted at an angle of 15°–20°, with the needle body close to the lower edge of the clavicle. The needle was pumped while entering, the guide wire was passed through the puncture needle, and the catheter was sent to the preinserted vein along the guide wire. After establishing the length, the guide wire was withdrawn slowly to ensure the correct positioning of the catheter tip. After successful catheterization, the skin was sutured to fix the catheter in place. The catheterization site was covered with a sterile dressing, which was changed twice a week, and the catheter was regularly checked or replaced.