Comparative examination of female urethral pressure profiles measured by CO2 and H2O infusion techniques

The urethral closure pressure profile (UCPP) was recorded in 100 consecutive patients using both the water infusion and the carbon dioxide infusion methods. Ninety-one per cent of the patients complained of discomfort during CO2 infusion. Thirty-two of the CO2 profiles were distorted due to patient discomfort or shortcomings in the design of the measuring system, and in these no quantitative comparisons could be made. In 68 cases the profile measurements were compared: average maximum closure pressures and functional urethral lengths were slightly less with the CO2 but some individual variations were substantial. We concluded that unreliability and patient reaction make CO2 infusion less suitable than H2O for measuring UCPP.