Clinical utility of a portable ultrasound scanner in the measurement of residual urine volume.

BACKGROUND

Post-voiding residual urine volume is an important investigation in the management of voiding dysfunction. Catheterisation is widely regarded as the "gold" standard method of measurement. We investigated the performance of a portable ultrasound scanner (Bladder Scan BVI-2500), as an alternative method of measurement.

METHODS

This study was prospective in nature. One hundred measurements of post-voiding residual urine volume by ultrasound were compared with measurements by catheterisation.

RESULTS

The mean absolute error of the scanner was 52 mL. For volumes below 200 mL and 100 mL, this was 36 mL and 24 mL respectively. A decision regarding whether to decompress the bladder by catheterisation would have also been correct in 86% to 89% of instances, depending on the cut-off value of the residual volume used. In other words, the ultrasound measurement would have been correct in 9 out of 10 clinical cases.

CONCLUSION

We recommend the routine use of portable ultrasound scanners of similar accuracy in the measurement of post-voiding residual urine volume.