The significance of natural bladder filling by the production of urine during cystometry.
OBJECTIVE
Natural bladder filling by the production of urine could potentially influence the outcome of urodynamic investigations. In this prospective study, we determined the natural bladder filling rate during cystometry.


METHODS
Between October 2005 and March 2006, we performed conventional urodynamic studies in 101 consecutive patients. We measured the exact volume infused during artificial filling, the volume voided and post-void residual urine (PVR) after a pressure flow study to examine the difference between the measured bladder volume (voided volume plus PVR) and the infused volume. We also measured the exact time required for the urodynamic investigation. Finally, we analyzed the natural filling rates in 34 patients after excluding inadequate cases.


RESULTS
The mean volume of artificial filling was 304.4 ml (SD +/- 100.5 ml) and the mean measured volume consisting of the voided volume plus PVR was 337.2 ml (SD +/- 106.5 ml). The mean total time was 24.2 min (range: 15.0-41.5 min) and the mean time for artificial filling was 7.2 min. The mean volume of natural filling and the mean rate of natural bladder filling were 32.8 ml (12.1% of artificial filling) and 1.4 ml/min, respectively.


CONCLUSIONS
Natural filling by the production of urine can affect the results of cystometry considerably, and should be considered when performing urodynamic investigations and interpreting the results. Because the effects can increase with the time required to conduct the investigation, effort should be made to decrease the total duration of urodynamic investigations.
Lee
Sang Wook
SW
Department of Urology, Kangwon National University College of Medicine, Kangwon National University Hospital, Chunchon, South Korea. paulee@kangwon.ac.kr
Kim
Jeong Hyun
JH
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011312:Pressure; D011446:Prospective Studies; D011470:Prostatic Hyperplasia / Q000503:physiopathology*; D015203:Reproducibility of Results; D013997:Time Factors; D001743:Urinary Bladder / Q000503:physiopathology*; D001750:Urinary Bladder, Neurogenic / Q000503:physiopathology*; D014546:Urinary Catheterization; D014563:Urodynamics