Leaving an indwelling needle unsealed may result in blood reflux and may also cause catheter blockage. The purpose of an indwelling needle closure is to flush residual irritating medication into the bloodstream to avoid irritation of local blood vessels and to maintain venous access. It also prevents blood from coagulating at the tip of the tubing when it is next connected to an infusion, which could result in a blockage. An indwelling needle that is not sealed may bleed back, and blood or medication may form an embolus in the IV catheter and cause a blockage. Therefore, positive pressure tubing sealing with dilute heparin solution, isotonic saline, etc. is usually required after infusion. In addition, if the skin around the needle becomes red, swollen, itchy and other discomforts, it needs to be removed promptly and the IV puncture needle needs to be re-punctured. In daily life, attention should be paid to the care of the indwelling needle, such as the indwelling limb needs to avoid excessive movement, and should avoid immersion in water. When dressing and undressing, put on the needle-side limb first, and take off the needle-side limb first. Once the indwelling needle catheter blockage, should consult the health care personnel, if necessary, to give the removal of the needle treatment, the patient should not unauthorized removal of the needle.