Clean catheterization: Definition: Clean catheterization is a method of catheterization without indwelling catheters that can be performed by non-medical personnel (patients, relatives or companions) to reduce the patient’s dependence on medical personnel and to improve the patient’s independence in daily life. Indications: Patients with spinal cord injury or other diseases who are unable to urinate on their own or have inadequate voluntary urination (residual urine over 80-100ml). Steps: 1. The operator washes the hands according to the “six-step washing technique” and locally cleans the patient’s perineum with soap or cleaning solution. 2.Hold the disposable catheter and insert it into the urethra, and push it in slowly until the urine is discharged from the catheter, and male patients should pay attention to the direction of the urethral opening towards the abdomen to avoid damage to the urethral isthmus, and apply lubricant (such as paraffin oil) to the outside of the catheter before insertion to reduce insertion resistance. 3. Remove the catheter immediately after the catheterization is completed and dispose of the catheter in the medical garbage bag. Frequency of use: If the patient is completely unable to urinate on his own, the frequency of use is 4-6 times/day, and the volume of urine per catheterization is about 400ml; if he can partially urinate, the frequency of use is 1-3 times/day; clean catheterization can be stopped when the residual urine is <80-100ml. Precautions: 1. Patients must have the regularity of drinking and urinating at regular intervals so that the timing of catheterization can be reasonably selected. 2.When completely unable to urinate, the amount of water should be controlled so that the volume of urine is about 800~1000 ml/d; after forming reflex urination, more water should be drunk to keep the volume of urine at 1500-2000 ml. 3.All operation movements must be gentle and no violence should be used to avoid urethral injury. 4. The whole process should be relaxed and the tube should be removed slowly to ensure that the urine is drained.