Indicators and interpretation
The maximum rate for men is more than 15 ml/s, for women it is more than 20 ml/s with a volume of 150–400 ml. A flat stretched curve with a Qmax less than 10 ml/s is typical for obstruction (adenoma, stricture), an intermittent one for straining with a weak detrusor, a “chopped” one for a stricture. The urologist evaluates the result together with residual urine and a urination diary, and if the picture is unclear, he prescribes a comprehensive urodynamic study. Repeated uroflowmetry 1–3 months after TURBT, HoLEP or urethrotomy objectively confirms the effect of the operation.
What does uroflowmetry show?
Uroflowmetry objectively measures the flow: a maximum velocity (Qmax) of less than 10–15 ml/s indicates obstruction (adenoma, stricture, cervical sclerosis) or bladder muscle weakness; the shape of the curve differentiates these causes. The study is mandatory before operations on the prostate and urethra, to monitor the result of treatment and in case of complaints of a weak stream, straining, or a feeling of incomplete emptying. Supplemented by measurement of residual urine by ultrasound.
How it goes
The patient is left alone in the office and urinates into the funnel of the device in the usual position - it is important that the volume is at least 150 ml, otherwise the result is unreliable and the study is repeated. The device creates a graph, and the doctor evaluates the indicators. Artificial (artificial) uroflowmetry is an option with filling the bladder through a catheter, used when natural filling is impossible.
