The correlation of voiding variables between non-instrumented uroflowmetery and pressure-flow studies in women with pelvic organ prolapse

Abstract

Aims To (1) correlate peak and maximum flow rates from non-instrumented flow (NIF) and pressure-flow studies (PFS) in women with pelvic organ prolapse (POP); (2) measure the impact of voided volume and degree of prolapse on correlations. Methods We compared four groups of women with stages II–IV POP. Groups 1 and 2 were symptomatically stress continent women participating in the colpopexy and urinary reduction efforts (CARE) trial; during prolapse reduction before sacrocolpopexy, Group 1 (n = 67) did not have and Group 2 (n = 84) had urodynamic stress incontinence (USI). Group 3 (n = 74) and Group 4 participants (n = 73), recruited specifically for this study, had stress urinary incontinence (SUI) symptoms. Group 3 planned sacrocolpopexy. Group 4 planned a different treatment option. Participants completed standardized uroflowmetry and pressure voiding studies. Results Subjects' median age was 61 years; median parity 3% and 80% had stage III or IV POP. Based on the Blaivas–Groutz nomogram, 49% of all women were obstructed. NIF and PFS peak and average flow rates had low correlations with one another (0.31, P < 0.001 and 0.35, P < 0.001, respectively). When NIF and PFS voided volumes were within 25% of each other, the peak and average flow rate correlations improved (0.52, P < 0.001 and 0.57, P < 0.001, respectively). As vaginal prolapse increased, correlations between NIF and PFS peak and average flow rates decreased. Conclusion Peak and average flow rates are highly dependent on voided volume in women with prolapse. As the prolapse stage increases, correlations between NIF and PFS variables decrease. Neurourol. Urodynam. 27:515–521, 2008. © 2008 Wiley-Liss, Inc.