Continuous monitoring of bladder pressure in dogs in a completely physiological state

Bladder pressure changes in the completely physiological state of dogs were recorded on voiding, coughing, defaecating, vomiting, etc, by a pressure transducer embedded in the submucosal layer of the anterior bladder wall. The static pressures in the standing and lying positions were almost the same at about 10 cm H2O and in the sitting position the pressures were about 30 cm H2O. The voiding pressure was recorded 28 times and ranged from 44 to 257 cm H2O (average 141). These data were higher than expected and we recommend further studies on the maximum voiding pressure. On voiding, various patterns of pressure curve were observed and in the monophasic pressure curve, which probably shows normal urination, there was a time difference between urine flow and voiding pressure curve. Our new method may be useful not only as a sensory device for neurogenic bladder patients but also as an experimental system to study the effect of drugs on autonomic nerves.