The PCI procedure is actually a percutaneous coronary intervention. The preoperative preparation for this procedure is somewhat elaborate. Most patients use the radial artery from the right upper extremity as the puncture access, so the nurse will be asked to rehydrate the left upper extremity and prepare the skin on the right upper extremity. Once the puncture is performed in the femoral artery approach, the skin preparation of the groin is required, and skin preparation is the most common preoperative preparation. As the patient also has preoperative preparation, the bladder must be emptied before surgery, because many patients will habitually urinate after stress. Because the sterilized laying towel patients are in the awake state, there is no way to urinate, and some patients are not used to lying down to urinate, so there will be an embarrassing situation when the doctor is operating and the patient wants to go to urinate. So it is better to exercise to relieve urine lying down before the intervention. Some patients think that it is a surgical procedure and prepare for fasting, but in fact, when performing vascular puncture, it is easy to cause certain adverse reactions and cause the occurrence of vasovagal reflex. Patients should also be reminded of the need for reasonable fluid supplementation before surgery. Adequate hydration can help the body excrete contrast agent because contrast agent is a potion that cannot be absorbed by the body, but is necessary for use during coronary interventions, so adequate hydration preparation 12 hours before surgery can reduce the occurrence of contrast nephropathy.