Routine enema before urodynamics has no impact on the quality of abdominal pressure curves: Results of a prospective controlled study

Summary Aims The presence of stools in the rectum might affect the quality of the abdominal pressure curve during filling cystometry, but, to date, no study has evaluated the impact of bowel preparation before urodynamics. We evaluated the influence of a sodium phosphate enema before urodynamics on the quality of the abdominal pressure curve. Methods A prospective, controlled, single-blind study was conducted in a single center from May to June 2013. The patients were divided into 2 consecutive groups: patients seen in outpatient clinics during the first 6 weeks (group A) who underwent urodynamics without bowel preparation and patients seen in outpatient clinics during the second 6 weeks (group B) who had a prescription of sodium phosphate enema before urodynamics. The primary endpoint was the quality of the abdominal pressure curve evaluated independently by three physicians who were blinded to the study group. The following data were also collected: age, gender, the presence of a neurological disorder, complicated nature of urodynamics and bother related to preparation for it, assessed using a Likert scale (0 to 10), and the equipment used. A per protocol analysis and an intent-to-treat analysis were conducted. Results One hundred and thirty-nine patients were included: 54 in group A and 85 in group B. One-third of patients had neurological conditions. 14 patients in group B did not perform their scheduled enema. Thus, 68 patients performed an enema before urodynamics and 71 did not. There was no difference between groups A and B regarding the complicated nature of urodynamics (Likert scale: 3.12 vs. 3.18; P = 0.91) or bother related to preparation for it (Likert scale: 3.46 vs. 2.97; P = 0.43). In the per protocol analysis, the abdominal pressure curve was considered perfectly interpretable (PI) in 69% of patients who did not receive an enema before urodynamics and in 65% of patients who did ( P = 0.61). The between-group difference was not statistically significant in intent-to-treat analysis ( P = 0.99). In patients who did not receive an enema before urodynamics, the only factors statistically associated with better quality of abdominal pressure curves were age P = 0.001) and the urodynamic equipment used (Dantec ® > Laborie ® ; P = 0.01). Conclusion In this prospective study, routine enema before urodynamics did not improve the quality of the abdominal pressure curve and did not increase the complicated nature of urodynamics or the bother of preparation for it. Level of evidence 3.