Bedside ultrasound diagnosis of residual urine volume.

A hand-held real-time ultrasound scanner was used for the estimation of bladder volume in the hope of eliminating unnecessary postoperative catheterizations. In 11 women, the bladder was filled stepwise and scans were done at volumes of 0, 50, 100, 150, and 200 ml, 50 ml being chosen as the minimum volume for clinically significant residual urine. The method was then used in 43 examinations on 26 patients, 24 of whom had had a gynecological operation. There were only three mistakes: once a residual urine volume of more than 50 ml was missed, and twice the scan wrongly suggested a residual urine volume of more than 50 ml.