Defining achievable standards in urodynamics—a prospective study of initial resting pressures

AIMS: Establishing accurate initial resting pressures is an important step in quality control at the start of a urodynamics test. We therefore carried out a prospective study to establish the initial resting pressures achievable with careful quality control. METHODS: Consecutive patients undergoing urodynamics were recruited. Initial resting pressures were recorded in lying, sitting, and standing positions for each patient. The detrusor pressure values obtained before filling were then compared with the pressures obtained during filling. RESULTS: Initial resting abdominal and intravesical pressures were similar and at least 95% lay in the following ranges: lying 0-18 cmH(2) O, sitting 15-40 cmH(2) O, standing 20-50 cmH(2) O: these data gave initial resting detrusor pressure readings between -5 and +5 cmH(2) O in 97%, 97%, and 96%, respectively. Comparison of initial resting pressure readings with those obtained during filling showed that the narrow range of pressures was maintained during the urodynamic test. CONCLUSIONS: This study provides detailed prospective data on achievable initial resting pressures in urodynamics. In this study, p(det) was normally at or close to zero, and distributed more or less evenly either side. This suggests a range that differs from existing ICS GUP guidelines, and could be incorporated in future ICS guidelines.