How to determine residual urine volume of bladder

There are two main methods for bladder residual urine volume in clinical practice. The first method is B-ultrasound examination. This is the most commonly used method, which will not cause urinary tract infection and is relatively safe. The patient first holds urine and does ultrasound, and then tries to drain urine clean, and then goes to review ultrasound. The amount of residual urine is measured directly by the instrument. The second method is catheterization. After the patient urinates, a catheter is inserted to drain urine. Therefore, the residual urine volume is determined. This method is accurate and reliable, but it may cause discomfort to the patient and may not be accepted by the patient. It may also cause urinary tract infection. Excessive residual urine volume in the bladder indicates that the urinary function of the bladder is not fully compensated. The amount of urine produced is directly proportional to the degree of lower urinary tract obstruction. Generally, the residual urine volume of the bladder should be less than 5 ml.