Ambulatory monitoring and conventional cystometry in asymptomatic female volunteers.

OBJECTIVES

Ambulatory monitoring continues to gain acceptance and increasing clinical application. There remains, however, a sparsity of published data asymptomatic volunteers, particulary women. Our aim was, by study of such a group, to establish normal ranges for cystometric variables on ambulatory monitoring.

PARTICIPANTS

We recruited 22 women from staff and gynaecological inpatients. A standard questionnaire of urinary complaints was administered and any woman with significant symptoms was excluded. Conventional cystometry and ambulatory monitoring were undertaken in all volunteers in random order. Volunteers were asked to go about everyday activities and to keep a detailed event diary whilst undergoing ambulatory monitoring.

RESULTS

Using standard International Continence Society terminology, detrusor instability was found in 18% of volunteers on conventional cystometry and in 68% on ambulatory monitoring. Significant differences were found between ambulatory monitoring and conventional cystometry with respect to the detrusor pressure rise on filling (P < 0.001) and voided volumes (P < 0.001). A significant difference was also present with respect to voiding pressures (P < 0.001), although the absence of simultaneous flow rate measurement makes absolute separation of voiding pressure from post-voiding after contractions difficult.

CONCLUSIONS

Ambulatory monitoring detects a greater number of abnormalities based on conventional cystometric criteria of normality. Before we can usefully apply the method to symptomatic patients we must first define normal ranges for filling and voiding cystometry for the technique. This study moves towards this goal. (The addition of flow rate data will permit accurate identification and measurement of voiding pressures.)