PRESSURE-FLOW STUDIES IN ELDERLY MEN WITHOUT VOIDING PROBLEMS - ESTIMATION OF THE URETHRAL PRESSURE-FLOW RELATION AND URETHRAL ELASTICITY
1990 (English)In: Neurourology and Urodynamics, ISSN 0733-2467, E-ISSN 1520-6777, Vol. 9, no 2, 123-138 p.Article in journal (Refereed) Published
The flow in the urethra is controlled by an elastic constriction, the flow-controlling zone. The distensibility of this zone is described by the pressure/area relation, which gives the static pressure as a function of the cross-sectional area at the flow-controlling zone. The pressure/area relation can be calculated from the pressure/flow relation, which is estimated from the pressure/flow plot obtained at a urodynamic examination. In this study the urethral pressure/flow and pressure/area relations were estimated for 21 randomly selected men (62–75 years old) without voiding problems.
Nineteen of 21 persons in this group had pressure/flow relations with a low slope. This corresponds to a low slope in the pressure/area relation indicating high distensibility of the flow-controlling zone, which for 18 persons was estimated to be distended to areas larger than 10 mm2 during micturition. Twenty persons had a minimal urethral opening pressure below 55 cm H2O. The estimated pressure/area relation was linear in 59% of the micturitions, indicating that the flow-controlling zone could have been distended to a larger cross-sectional area, if the bladder had achieved a higher pressure. The 10th–90th percentiles for maximum flow and detrusor pressure at maximum flow were 7.2–24.3 ml/s and 24–76 cm H2O, respectively. Four persons had low flow and low pressure, indicating diminished detrusor contractility with age. Twenty-four percent of the persons had unstable bladder contractions with a pressure rise < 15cm H2O and 19% with a pressure rise < 15cm H2O.
Place, publisher, year, edition, pages
1990. Vol. 9, no 2, 123-138 p.
Fluid Mechanics and Acoustics
IdentifiersURN: urn:nbn:se:liu:diva-117008DOI: 10.1002/nau.1930090205OAI: oai:DiVA.org:liu-117008DiVA: diva2:802001