Abstract

Introduction and hypothesis "Dropped p(abd) at void" occurs when p(abd) decreases below the previous resting pressure during voiding time. We sought clinical factors associated with this phenomenon and evaluated whether its correction modifies the urodynamic diagnosis. Methods Retrospective cross-sectional study of non-neurological consecutive symptomatic women. The following definitions were used: "dropped p(abd) at void": decrease in p(abd) at Q(max) >= 5 cmH(2)O; bladder outflow obstruction (BOO) (p(detQmax) >= 25 cmH(2)O + Q(max) <= 12 ml/s and female BOO index (p(detQmax) - 2.2*Q(max)) > 18; "low detrusor contraction strength": PIP1 (p(detQmax) + Q(max)) < 30. In patients with "dropped p(abd) at void", p(detQmax) was corrected. Results A total of 360 women were analyzed. Ninety-five percent of the women had a variation in p(abd) at Q(max) between -13 and 53 cmH(2)O. "Dropped p(abd) at void" was found in 100 women (27.8%). History of stress urinary incontinence (SUI) surgery was significantly higher (p = 0.016) and symptoms of mixed urinary incontinence were significantly lower (p = 0.030) in patients with "dropped p(abd) at void". On multivariate analysis only the history of SUI surgery maintained its significance (OR = 1.787 [95% CI: 1.058, 3.017], p = 0.030). When correcting p(detQmax) in women with "dropped p(abd) at void", 2 or 5 patients lost BOO diagnosis (depending on how it was diagnosed) and 7 patients gained a "low detrusor contraction strength" diagnosis. Conclusions Approximately one-quarter of women had "dropped p(abd) at void", which was associated with a history of SUI surgery. Correction of p(detQmax) would lead to a 2.5% to 3.33% diagnostic modification.