As patients with chemotherapy for malignant tumors often need frequent and large amount of infusion, vascular elasticity becomes poor, and some chemotherapeutic drugs are vascularly toxic and easily cause phlebitis, routine peripheral intravenous injection is difficult, especially for obese, edematous patients, pediatric patients or cachectic patients, superficial veins are difficult to find, and the establishment of reliable deep venous access is extremely important. 1, implantable intravenous infusion port Also known as implantable central venous catheter system, CVPAS), referred to as infusion port, is a closed intravenous infusion system that can be completely implanted in the body, which can be used for various highly concentrated chemotherapy drugs, complete parenteral nutrition infusion and blood transfusion, blood sample collection, etc.; it can reduce the pain and difficulty of repeated venipuncture, prevent damage to peripheral veins from irritating drugs, and patients daily life is not restricted, no need to change medication and can bathe, which greatly improves their quality of life. Infusion port is the latest technology of clinical intravenous infusion system in recent years, which has been used clinically in foreign countries since 1980s, but has not been widely carried out in China. 2.The structure and application principle of infusion port At present, domestic mostly adopts Bard infusion port, which is composed of two parts: silicone catheter and infusion seat. The silicone catheter is 30~40 cm long, with a lateral hole at the head end and a three-way valve design, which can ensure that when the catheter is connected to a syringe to pump back pressure, the valve opens inside the guide tube and can extract venous blood; and when infusion or pushing with a syringe, the pressure is >10.67kPa, the valve opens outside the catheter and can inject drugs into the vessel; when the catheter is not used, the valve is in a closed state, which can effectively prevent blood When the catheter is not used, the valve is closed, which can effectively prevent blood from backflowing into the catheter or injection seat, and can also prevent gas from entering the blood circulation and forming air embolism. The infusion seat is in the shape of a flat circular cap with a bottom diameter of about 3 cm and a top diameter of 2 cm, with a silicone catheter attached to the side opening and a puncture septum of silicone material with an automatic healing function at its top. The method of implantation of the infusion port is performed by the surgeon in the operating room, choosing the healthy side with the head deviated to the opposite side, entering the subclavian vein with a puncture needle from the external 1/3 of the subclavian margin under local anesthesia, and placing the catheter into the vein from the puncture sheath under the guidance of a guide wire, with the best position of the head end of the catheter being the junction of the superior vena cava and the atrium, while bluntly separating the skin and subcutaneous tissue 0.5-1.0 cm below the skin of the subclavian fossa A skin pocket and tunnel were made to fix the injection seat of the infusion port. 72 h later, the infusion port could be used and radiological examination was performed to confirm the position of the catheter and to check the implantation site for swelling, infection, hematoma, and twisting and loss of the device. 3. Health education before and after infusion port implantation Health education can help people form correct concepts and behaviors and promote physical and mental health. The infusion port is a new type of infusion device, which is not yet popularly used in China, and there are few sources of relevant information for patients. The implantation requires an external jugular vein incision under local anesthesia, and the removal also requires local anesthesia, which makes patients fearful of implantation failure. Therefore, nurses patiently explain to patients and their families about this technique, such as indications, contraindications (confirmed or suspected infection, bacteraemia or sepsis, allergic reaction to infusion port materials), complications, advantages, etc. We also helped the patients to master the self-care skills of the infusion port, as well as the possible reactions and preventive measures during the placement process, and also demonstrated on site to eliminate the patients’ doubts. Analgesics can be given to those with more obvious pain at the implanted injection seat within 3 d after the operation to ensure patients’ comfort and good sleep and to relieve anxiety. 4. Post-implantation application and care Puncture method Strictly abide by the aseptic technique operation routine. Explain the operation procedure to the patient before operation, wear sterile gloves, sterilize the infusion port as the center with a radius of 10~12 cm, find the position of the infusion port with the left hand, form a triangle with the thumb, index finger and middle finger of the left hand, arch the infusion port, determine the center of these three fingers as the puncture point, use a non-damaging needle (its tip is a specially designed surface that is not easy to damage the silicone puncture membrane of the infusion port) to insert the puncture septum vertically from the center. It is forbidden to tilt or shake the needle and reach the bottom of the reservoir, with gentle movements, stopping at the slightest feeling of resistance. (1) Infusion care After puncture, blood was drawn back to confirm that the needle position was correct before infusion, and the infusion pressure was not higher than 25 kPa, and the tube was flushed with 10 ml of 0.9% sodium chloride injection before infusion [10]. When parenteral nutrition was infused for a long time, the tube was pulsed with 0.9% sodium chloride injection 10 ml once every 4 hours to prevent drug deposition in the infusion port. In addition, when multiple incompatible drugs are administered to a patient, the next drug must be administered after a pulsatile flush with 0.9% sodium chloride injection 10 ml in between to prevent drug deposition or even blockage of the catheter due to contraindication of compatibility, which may endanger the patient’s life. Due to the three-way valve design of the silicone catheter, the tube can be sealed with 0.9% NaCl injection 10 ml positive pressure pulsatile after routine infusion, and 0.9% NaCl injection 20 ml after blood and TPN transfusion. When the infusion port is not used for a long time, use 0.9% sodium chloride injection to flush the tube at least every 4 weeks to avoid blockage. Take care to avoid strenuous chest and shoulder exercises, such as playing ball, swimming, etc. (2) Blood collection care It is generally not recommended to collect blood using infusion port to avoid blockage of catheter or injection seat. When blood must be collected, flush the tube with 10 ml of 0.9% sodium chloride injection, first draw out at least 5 ml of blood and discard it, then draw out the required amount of blood with a 20 ml syringe and seal the tube with 20 ml of 0.9% sodium chloride injection by positive pressure pulse.