Urodynamic studies aim to objectively assess the functions of the lower urinary tract and understand its clinical implications. Invasive urodynamics involves insertion of one or more catheters or any other transducers into the bladder and/ or other body cavities, The professional standards for invasive urodynamics have been defined repeatedly by the ICS. A good quality test can be defined as one which allows interpretation of the test trace by another urodynamicist that reaches the same conclusions regarding the diagnosis and subsequent management of patients. Lack of a good quality test can put patients through to repeated invasive procedures. In this study we have analysed the urodynamic traces and reports of patients referred to our tertiary unit for functional urologic problems and who had to undergo a repeat invasive urodynamic test due to inconclusive and/ or poorly informative previous tests.

Patients assessed at our Functional Urology Outpatient Clinic between July 2020 and March 2024 were included. All patients came with a report of an invasive urodynamics (first test) performed elsewhere. The traces and reports of these examinations were scored using the Bristol UTraQ tool. Patients were assessed for their history, physical exam and urodynamics tests and when failure to reach a clinical conclusion to guide the patients further management, a second invasive urodynamics test following the ICS good urodynamics practice guidelines was performed.  All patients had a videourodynamic test as a second invasive urodynamic test (second test).

A total of 27 urodynamic traces that belong to 27 patients were analysed. The median age was 39 (range: 14-78) years. Presenting complaints were difficulty in voiding 12 (44.4%), urinary incontinence 9 (33.3%), overactive bladder 2 (7.4%), recurrent UTIs 2 (7.4%) and bladder pain 2 (7.4%). The first urodynamic tests were assessed and scored by 2 independent researchers. Videourodynamics was performed in 2 (7.4%) of the patients when 9 (33.3%) patients had neurogenic bladder disfunction and/ or previous anti- incontinence surgery. Most of the urodynamic studies were conducted at an university or training hospital 19/ 27 (60.3%). Median time between the the first and second test was 10 months (range: 1-116).
Most commonly detected error in the traces of first tests was lack of zero pressure values  (21, 77.8%), lack of zeroing to the atmosphere (5, 18.5%),  and good quality cough testing (8, 29.6%),  in the pre- filling phase. In the filling phase, the traces lacked good quality cough tests in 13/27 (48.1%) and live pressure fluctuations in 23/27 (85.2%) of the traces. Patient position was denoted only in 3.7% of the traces.  Patient reported sensation were marked on the trace in 21/27 (77.8%) but only consisted of first desire, normal desire and maximum capacity, other sensations such as pain urgency, fullness was not noted in any of the traces. Four patients (4/ 27; 14.8%) did not have a voiding phase done and cough test before and after voiding was only available in 2/27 (7.4%) of the patients. Also Qmax was marked away from artefacts in only 1/27 (3.7%) of the traces.

Our results showed significant errors in urodynamics practice in the patients referred to our centre. Significant errors were visible in pre- filling, filling and voiding phases.  This highlights the importance of audits in the urodynamics units.

A good quality urodynamic test is crucial in proper assessment of the lower urinary tract function and for subsequent correct management of patient’ s conditions.  We hope the results of this study could be a basis for local/ national audit programmes in urodynamics units.

Gammie A, Hashim H, Abrams P. Bristol UTraQ: A proposed system for scoring the technical quality of urodynamic traces. Neurourol Urodyn. 2022 Feb;41(2):672-678. doi: 10.1002/nau.24872. Epub 2022 Jan 15. PMID: 35032349.
Gammie, Andrew, et al. "International Continence Society guidelines on urodynamic equipment performance." Neurourology and urodynamics 33.4 (2014): 370-379.
Drake, Marcus J., et al. "Fundamentals of urodynamic practice, based on International Continence Society good urodynamic practices recommendations." Neurourology and urodynamics 37.S6 (2018): S50-S60.