RESUMO
OBJECTIVES: To compare the initial resting intravesical pressure (pves ) and abdominal pressure (pabd ) in the sitting position with the typical range of values, to assess the correlation between such pressures and patient xipho-pubic distance, body weight, height and body mass index (BMI), and to estimate if xipho-pubic distance can be a guide to interpret initial resting pressures in urodynamic testing. METHODS: Women with lower urinary tract symptomatology referred for urodynamic testing were consecutively enrolled in a prospective study. Conventional cystometry was done following "good urodynamic practices". The correlation between initial resting pves and pabd and xipho-pubic distance, body weight, height and BMI were studied using simple and multiple linear regression analysis. Statistical significance was defined as P < 0.05. RESULTS: One hundred women aged (mean ± SD) 59.2 ± 13.3 were studied. There was a significant correlation between both pves and pabd , and xipho-pubic distance, body weight and BMI and no correlation with height. Over the multiple analysis, xipho-pubic distance and body weight correlated independently with pves ; body weight correlated independently with pabd . Three patients had pves and/or pabd out of typical range, with BMIs values of 18.48, 18.72 and 35.81 kg/m2 . There was a wide range of difference between xipho-pubic distance and initial resting pressures. CONCLUSIONS: Out of range initial resting pressures occur in underweight (or close to) or severely obese patients. Xipho-pubic distance and body weight correlated independently with pves . Body weight correlated independently with pabd . Xipho-pubic distance cannot be a guide to interpret the initial resting pressures.