Case study using simultaneous bladder pressure and urine loss measurements.

Using an "electronic nappy" of improved design and a miniature pressure manometer of the strain-gauge type mounted at the tip of a catheter, the case of a patient with spina bifida and a large lipoma has been investigated. Some retention exists, but areas on the lipoma surface can be touched lightly, causing an increase in bladder pressure with subsequent voiding as measured by the nappy. Investigations of the same area by electrical stimulation produced rises in bladder pressure sustained for only a few seconds, as in the case of manual stimulation. Local anaesthetic in the "trigger" area prevented bladder pressure changes and urine loss, but triggering returned as the anaesthetic wore off.