The postvoid residual (PVR) is one of the most widely used noninvasive, noncomplex studies of the bladder and holds great relevance within urology and primary care. The volume that a patient leaves within the bladder after the end of voiding provides a plethora of information about not only the bladder’s ability to contract, but may give information on obstruction and incontinence. The amount of urine left within the bladder after voiding may be measured with two common techniques; ultrasound and bladder catheterization. Bladder ultrasonography provides a rapid noninvasive method to estimate the amount of urine left. This carries with it a low risk of invasive complications such as infection and injury to the urethra [12]. Disadvantages of this technique as compared to direct measurement with catheterization include the concern about inaccuracy of the volume estimated. The equipment needed to perform ultrasonography may be complex and require special techniques to use. However, with the implementation of ultrasonography across many subspecialty fields including emergency rooms, outpatient clinics and the inpatient care wards this technology is becoming increasingly available. In addition to this, purpose specific scanners are now available commercially that are designed specifically to determine the postvoid residual. These are available for use by clinicians and nurses with minimal training and experience.

Interpretation of the post void residual and the clinical relevance of this is discussed elsewhere in the book and the reader is encouraged to visit those chapters for details (See chapter “Noninvasive Urodynamics”).

The more invasive component of bedside urodynamics is the cystometrogram and one would not need to do this study if they’ve already decided to move forward with invasive multichannel/fluorourodynamics. Therefore the indications for this pertain to those patients with simple straightforward questions. Patients with an unsuccessful prior surgical intervention, those who fail medical therapy or those with a neurologic complaint typically would not be good candidates for the bedside urodynamics as they typically would be scheduled for formal more complex urodynamics [7]. While the data garnered from a bedside urodynamics cystometrogram are limited, the study may be very helpful in assessing three key components; bladder capacity, sensation and presence of detrusor over activity. This can be an invaluable study in those patients with straightforward symptoms of stress and urgency incontinence as well as bladder over activity.