In addition to the amount of urine, various delivery characteristics during urination are also investigated. In the case of bladder emptying disorders, urologists perform uroflowmetry, i.e. urine flow measurement.
Delivery characteristics
All information on the subject of dispensing characteristics
At a glance
With the help of a so-called uroflowmeter, the outflow of urine during bladder emptying (micturition) is recorded and graphically displayed in a so-called urine flow curve.
Further information
Based on the height and course of this urinary flow curve, the urologist can draw conclusions about certain diseases such as urethral narrowing or prostate enlargement after the examination. As the most important measured value, it records the amount of urine per unit of time (s) during a micturition.
The following values are recorded or calculated, among others:
- Urine flow rate (Q) [ml/s]
- Urine flow time (t) [s]
- Maximum urine flow (Qmax) [ml/s]
- Mean urine flow (Qave) [ml/s]
- Micturition volume (V) [ml]
- Micturition duration (bladder emptying time) [s]
Urologists usually perform uroflowmetry for the following complaints:
- Incontinence – a patient is not able to retain urine
- Reflux – here urine flows from the bladder back into the ureter and possibly even back into the renal pelvis
- Attenuation of the urine stream
- Temporary suspension during urination (intermittent micturition)
- Disturbances at the beginning of urination (micturition start disturbances)
- painful urge to urinate with difficulty of urination – dysuria
- Increased nocturnal urination – nocturia
- Prolonged urination
- Urge to urinate frequently without increased excretion – pollakiuria
- Residual urine feeling
- Urinary congestion with suspected bladder emptying disorder
- Therapy control after operations on the urethra, prostate or drug treatment of a bladder emptying disorder
- Imperative urge to urinate with or without urge incontinence – sudden, uncontrollable urge to urinate with or without involuntary loss of urine
After the uroflowmetry, the urologist checks by means of ultrasound examination whether there is residual urine in the bladder. If this is the case, it is determined exactly how much urine has remained in the bladder. Residual urine can lead to infections in the bladder by multiplying germs and, in the case of an ascending infection, also to urinary tract or kidney inflammation.
Sources
- Clement, K. D., et al. (2015): Invasive urodynamic studies for the management of lower urinary tract symptoms (LUTS) in men with voiding dysfunction. Cochrane Database Syst Rev.
- Abrams, P.; Cardozo, L.; Fall, M.; Griffiths, D.; Rosier, P.; Ulmsten, U.; van Kerrebroeck, P.; Victor, A.; Wein, A. & of the International Continence Society, S. S. (2002): The standardisation of terminology of lower urinary tract function: report from the Standardisation Sub-committee of the International Continence Society. Neurourol Urodyn, 21, 167–178
- Abrams et al. (1987): Urodynamik für Klinik und Praxis. Berlin Heidelberg New York : Springer
- Geirsson, G. et al. (1999): The bladder cooling reflex and the use of cooling as stimulus to the lower urinary tract. In: J Urol 162, Nr. 6, S. 1890–6
- Medical info: Reabsorption of water and concentration of urine, URL: http://www.medizinfo.de/nieren/anatomie/rueckresorption.shtml
- Urology Guide: Urinary Tract – Urinary Drainage System, URL: https://www.urology-guide.com/anatomie/harnwege/
- Urologist Portal (2016): Urological Functional Diagnostics, URL: https://www.urologenportal.de/fachbesucher/wirueberuns/dgu/dgu-die-organe/arbeitskreise/arbeitskreis-funktionsdiagnostik/kompetenzen/urologische-funktionsdiagnostik.html
