Uroflow measurements: their information yield in a long-term investigation of pre- and postoperative measurements.

This investigation shows that the reproducibility of uroflow measurements is limited. For their evaluation, anamnesis and the measured results have to be taken into account equally. We found correspondence of both parameters in about 50% only. One single measurement cannot provide precise information, as psychogenic, social, and other factors influence the measurement. In our study 3 subjects had their micturitions registered over a period of 2 months. We found an increase of the maximum flow with increasing bladder volume. The maximum bladder volume was reached in only four micturitions. Normal values range at about 25% of the maximum bladder volume. Analyzing the micturitions in regard to the time of day, we found maximum flow rates in the morning hours. Under clinical conditions the altered surroundings lead to a measured result which is psychogenically influenced and can only be balanced after repeated measurements. The curves of all 3 patients were equal and inconspicuous. In cases of infravesical obstruction, surgical success could be documented by comparing the pre- and postoperative uroflows. In all cases of neurogenic bladder disorders and unclear findings, uroflow measurements are, however, not sufficient, and diagnosis is accomplished by a complete urodynamic examination. In spite of certain restrictions, uroflowmetry yields a high level of information, besides being a simple, at any time reproducible, and noninvasive procedure. Due to its low costs, it should be the primary step in diagnostics in the clinic as well as for practitioners.