Uroflowmetry

With a urodynamic Uroflowmetry the patient empties his bladder into a funnel. A connected device determines the amount of urine released per unit of time and thus allows conclusions to be drawn about any existing micturition disorders. The procedure takes place on an outpatient basis and is not associated with any risks or side effects.

What is uroflowmetry?

With urodynamic uroflowmetry, the patient empties his bladder into a funnel. A connected device determines the amount of urine released per unit of time and thus allows conclusions to be drawn about any existing micturition disorders.

Bladder emptying disorders are micturition disorders and, as a group of diseases, include a variety of diseases with conduction symptoms after, before or during urination.

Urology deals with disorders of micturition and includes a large number of specific diagnostic procedures for researching the causes of impaired urination. A subgroup of urological examination procedures is the group of urodynamic examination procedures. Uroflowmetry belongs to this group of methods. With this method, the amount of urine released per unit of time is determined. Micturition disorders often manifest themselves in this examination as lowered values.

Rarely, elevated values ​​above a certain level indicate a micturition disorder. To perform a uroflowmetry, a patient with an urge to urinate empties into a funnel. A sensor unit on the funnel records the amount of urine released per unit of time. The urine flow rate should ideally be around 20 milliliters per second. Decreased values ​​are associated with obstruction of the flow of urine from the bladder or are associated with a weakness of the bladder muscle.

Function, effect & goals

The patient's bladder is ideally well filled to perform uroflowmetry. There must be sufficient urge to urinate at the time of the examination. The patient withdraws and directs his urine stream into a funnel provided by the urologist.

The funnel is connected to an examination device that carries a unit of sensitive sensors. For this reason, when the patient directs the urine stream into the funnel, the device can determine the amount of urine per unit of time. Overall, this determination is used by the device to calculate different values. In addition to the urine flow rate Q, the most important of these values ​​are the urine flow time t, the maximum urine flow Qmax and the mean urine flow Qave. The micturition volume V and the micturition duration or urination time are also recorded by the device.

In the majority of cases, uroflowmetry is followed by a sonographic examination. This imaging using an ultrasound device detects the residual urine that has remained in the bladder. For the evaluation of urflowmetry, the urologist uses the standard values ​​and their reference ranges. The reference range for the value of the maximum urine flow for an adult patient is between 15 and 50 milliliters per second. When the maximum urine flow is below ten milliliters per second, the urethral obstruction is usually the cause of the urination disorder.

If, on the other hand, the values ​​are between ten and 15 milliliters per second, this is a gray area. In this case, the urologist must refer to further investigative procedures for diagnosis. Various phenomena and symptoms indicate an indication of uroflowmetry. For example, uroflowmetry can be used to clarify symptoms such as a subjectively perceived weakening of micturition. If the patient has a history of prolonged micturition, the procedure is also indicated. The same is true for symptoms such as intermittent micturition that stops unexpectedly from time to time.

A disturbed beginning to urinate, an imperative to urinate or a recurring infection of the urinary tract can also be an indication for the examination. Uroflowmetry can also be used to clarify these symptoms if patients experience urination with small amounts of urine at a significantly increased frequency or if they have abnormally frequent urination during the night.

Risks, side effects & dangers

Uroflowmetry is an extremely gentle examination method that is not perceived as unpleasant by the patient. Risks and side effects do not occur. The patient also benefits from the short time required for the procedure.

Inpatient admission to a hospital is not required to perform uroflowmetry. Usually, the examination takes place on an outpatient basis at a resident urologist. The patient receives the results on the same day. Since the examination does not put any further strain on the patient and his organism, uroflowmetry should, for example, take precedence over diagnostic imaging for diagnosing a micturition disorder. Imaging diagnostics are usually associated with radiation exposure and the associated risks and side effects. In most cases, contrast media is also used, which can make the patient feel headaches or similar complaints and stress his organism.

Such risks and side effects are spared the patient with uroflowmetry. In this context, the diagnostic method is ideally suited for diagnostic pre-sensing. The diagnostic method needs to be combined with additional procedures only under certain circumstances and after certain uroflowmetry findings. In most cases, the method cannot adequately determine whether a micturition disorder is present. For this reason, after an abnormal uroflowmetry, additional procedures for diagnostic work-up are usually carried out.

If the uroflowmetry is normal, the urologist will only order additional diagnostic steps in rare cases. Under certain circumstances, uroflowmetry cannot provide any meaningful results. A prerequisite for meaningful results is a need to urinate. In addition, the bladder must be well filled. A meaningful result can only be given if the amount of urine released exceeds 150 milliliters.