Home Urodynamic Pressures and Volume Measurement for the Neurogenic Bladder: Initial Validation Study.

PURPOSE

We evaluated the ability of a bladder pressure/volume diary to identify patients at risk for increased intravesical pressures.

MATERIALS AND METHODS

Patients dependent on clean intermittent catheterization used ruler based manometry to measure intravesical pressures before leakage or scheduled drainage at home. We prospectively collected clinical, urodynamic and bladder pressure/volume diary data in patients with spina bifida who were optimized on anticholinergic therapy and clean intermittent catheterization. Measurements were taken with patients in the supine position with relaxed abdominal muscles. We defined increased pressure as detrusor pressure greater than 30 cm water as measured by urodynamics. ROCs were plotted to correlate bladder pressure/volume diary variables with abnormal intravesical pressures, and the most sensitive variable in determining abnormal intravesical pressures was sought as the end point.

RESULTS

A total of 30 patients with a mean age of 10 years (range 1 to 20) were included. Home pressures measured at maximal clean intermittent catheterization volume and mean bladder pressure/volume diary pressures were most reliable in predicting urodynamic pressures greater than 30 cm water (AUC 0.93 and 0.87, respectively). Home pressures measured at maximal clean intermittent catheterization volumes less than 20 cm water were associated with normal bladder pressures (less than 30 cm water) on urodynamics, with a sensitivity of 100% and a specificity of 80%.

CONCLUSIONS

Home manometry less than 20 cm water provides a reliable measurement of safe pressures. A bladder pressure/volume diary is feasible and can aid in monitoring pressures at home without the additional cost and morbidity of urodynamics. A bladder pressure/volume diary may be a useful tool to help identify patients who would benefit from urodynamic testing.