NS-AUA 2024 Annual Meeting Abstracts – Infertility, Impotence, General Urology

Introduction:We investigated whether absence of detrusor contraction in a urodynamic chair was observed when patients assumed a more normal voiding position and surface.We hypothesized that patients without demonstrable bladder contractions during urodynamics (UDS) or on UDS chair after permission to void may be able to mount a bladder contraction after changing to a more normal voiding position.Methods: We conducted a retrospective cohort study analyzing UDS over two years.UDS reads were screened for positional changes from UDS chair to either commode or standing when patients were unable to void.Studies with positional changes after permission to void were re-analyzed by two masked neurourologists.Data collected included: time spent attempting to void in UDS chair, whether bladder contraction was present, pdet/Qmax, Qmax when voiding occurred, time spent attempting to void after moving, presence of bladder contraction in new position, and new pdet/Qmax and Qmax.Results: Ninety-four of 503 patients were identified to have moved to the commode or a standing position due to unsatisfactory or absent void on the UDS chair.Of these, 81/94 (86.2%) studies were interpretable.Average time spent attempting to void on the UDS chair was 8.41 minutes +/-4.1.In the new position, the patients averaged 2.29+/-1.9minutes to void.Of the 81 patients identified with unsatisfactory or absent void on the UDS chair, 69 (85.2%) demonstrated bladder contraction in the new position.Agreement between providers on presence of bladder contraction in the UDS chair showed that 91.4% were congruent (k=0.78).For presence of bladder contraction on the commode/standing, 88.9% were congruent (k=0.42).Of those that were congruent (N=44/55), 80% of the patients unable to demonstrate a bladder contraction on the UDS chair were then able to demonstrate bladder contraction in the new position.If contraction was present, we compared the pdet/Qmax and Qmax on the UDS chair to the pdet/ Qmax and Qmax in the new position.The average pdet/Qmax on the UDS chair was 6.86+/-11.8cm H2O vs. the average pdet/Qmax in the new position, which was 25.9+/-17.9cm H2O (p=<0.001).The mean Bladder Outlet Obstruction Index (BOOI) on the chair was 13.3+/-14.4.The mean BOOI on the commode/ standing was 38.3+/-28.6.The mean Bladder Cancer Index (BCI) on the chair was 13.6+/-15.1,and 61.7+/-31.6 on the commode/standing (p<0.001).Conclusions: Atonic bladder/hypotonic bladder can be misdiagnosed based on measuring voiding only in a UDS chair.Moving to a more natural seating such as a commode or standing can improve measurement of detrusor function.