Cystometry: H2O or CO2 as filling medium? A literature survey of the influence of the filling medium on the qualitative and the quantitative cystometric parameters

A literature survey is presented on the influence of the filling medium on qualitative and quantitative cystometric parameters. Only ten relevant reports comparing H2O and CO2 cystometry were found. From the reports the following parameters were extracted: size and description of study population, randomisation of sequence of the cystometries (H2O/CO2), patient position, filling rates, catheters used, and qualitative and quantitative cystometric parameters. The conclusions that can be drawn from the ten studies analysed are that the qualitative classification is independent of the used filling medium (CO2 or H2O). However, the quantitative parameters (first sensation and maximal cystometric capacity) decrease statistically significantly when CO2 is used as the infusion medium. However, we found it difficult to compare the studies, since investigative modalities known to influence the obtained cystometric data differed significantly from study to study.