Urethral instability: Diagnosis based on variations of the maximum urethral pressure in normal climacteric women

Abstract

AbstractThe existence of urethral instability as a pathological entity is debated, and this discussion is hampered by the lack of rational guidelines for its diagnosis. The literature is not uniform, as different authors have chosen arbitrary values of urethral pressure fluctuations for characterizing the condition. To attempt to clarify the situation, 85 healthy climacteric women have been examined. They had normal flow rates and were found to be normal on videocystourethrography. Their urethral pressure profile traces (microtransducer technique) were examined for fluctuations in the maximum urethral pressure (MUP). Given that the MUP decreases with age and that in this data set fluctuation in the MUP (Δ MUP) is dependent upon the MUP, the ratio of Δ MUP divided by MUP has been examined. Statistical analysis of the derived distribution suggests that fluctuations of MUP that are greater than one‐third of the resting MUP fall outside the 99% confidence limit and so should be regarded as abnormal. If, when this occurs, the patient is regarded as having urethral instability, then the incidence of urethral instability in our normal climacteric women is 14 ± 4%. We suggest that this method of analysis should be employed to arrive at a rational statistical threshold for the diagnosis of urethral instability. Only then will it be possible to explore the clinical implications of this condition.