Bladder Emptying: Complete Emptying

Abstract

Along with urinary storage, the emptying of urine is a key function of the bladder. Although this seems simple on the surface, the ability to completely empty the bladder safely and efficiently requires the intimate coordination of numerous organs, supporting structures, and neurotransmitters. While a low post-void residual (PVR) is often considered a surrogate for complete emptying, this value may not be consistent from void to void and may be affected by numerous factors. The PVR value should be evaluated as a single puzzle piece, in the scope of the patient’s history, findings on physical examination, and measures of actual emptying, such as uroflowmetry and/or pressure-flow studies. The goal of this chapter will be to focus on the emptying phase and what steps constitute complete emptying. The chapter will also illustrate examples of incomplete emptying, their pathophysiology, urodynamic and radiographic findings, and implications for the patient.