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An investigation of the basic physics of irrigation in urology and the role of automated pump irrigation in cystoscopy.

Chang D, Manecksha RP, Syrrakos K, Lawrentschuk N - ScientificWorldJournal (2012)

Bottom Line: In Experiment 2, saline bags were placed under external pressures to evaluate the effect on flow rate.Increase in external pressure on saline bags elevated flow rates, but inconsistently.A fuller bladder led to a decrease in flow rates.

View Article: PubMed Central - PubMed

Affiliation: Urology Unit, Department of Surgery, University of Melbourne, Austin Health, Melbourne, VIC, Australia.

ABSTRACT

Objective: To investigate the effects of height, external pressure, and bladder fullness on the flow rate in continuous, non-continuous cystoscopy and the automated irrigation fluid pumping system (AIFPS).

Materials: Each experiment had two 2-litre 0.9% saline bags connected to a continuous, non-continuous cystoscope or AIFPS via irrigation tubing. Other equipment included height-adjustable drip poles, uroflowmetry devices, and model bladders.

Methods: In Experiment 1, saline bags were elevated to measure the increment in flow rate. In Experiment 2, saline bags were placed under external pressures to evaluate the effect on flow rate. In Experiment 3, flow rate changes in response to variable bladder fullness were measured.

Results: Elevating saline bags caused an increase in flow rates, however the increment slowed down beyond a height of 80 cm. Increase in external pressure on saline bags elevated flow rates, but inconsistently. A fuller bladder led to a decrease in flow rates. In all experiments, the AIFPS posted consistent flow rates.

Conclusions: Traditional irrigation systems were susceptible to changes in height of irrigation solution, external pressure application, and bladder fullness thus creating inconsistent flow rates. The AIFPS produced consistent flow rates and was not affected by any of the factors investigated in the study.

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The physics of flow in a tube.
© Copyright Policy - open-access
Related In: Results  -  Collection


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figbox1: The physics of flow in a tube.

Mentions: Governing the flow of fluids through any closed system is determined by physics (Box 1) whereby the flow will increase if there is ((3)) an increase in the pressure difference and radius of the tube or ((5)) a decrease in the length of the tube and viscosity of the fluid [4]. Although an increase in the height of the irrigation fluid logically results in a higher pressure difference and thus an increase in flow, the question to be considered is whether there is a reduction in the rate of increase in flow rate after a certain height, thereby decreasing the effect of further increases in the height of irrigation fluid. Furthermore, what is poorly understood and studied is the effect of pressure generated in the bladder when irrigation is used in a closed system or in a continuous flow system, with or without automated pumping systems.


An investigation of the basic physics of irrigation in urology and the role of automated pump irrigation in cystoscopy.

Chang D, Manecksha RP, Syrrakos K, Lawrentschuk N - ScientificWorldJournal (2012)

The physics of flow in a tube.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3362017&req=5

figbox1: The physics of flow in a tube.
Mentions: Governing the flow of fluids through any closed system is determined by physics (Box 1) whereby the flow will increase if there is ((3)) an increase in the pressure difference and radius of the tube or ((5)) a decrease in the length of the tube and viscosity of the fluid [4]. Although an increase in the height of the irrigation fluid logically results in a higher pressure difference and thus an increase in flow, the question to be considered is whether there is a reduction in the rate of increase in flow rate after a certain height, thereby decreasing the effect of further increases in the height of irrigation fluid. Furthermore, what is poorly understood and studied is the effect of pressure generated in the bladder when irrigation is used in a closed system or in a continuous flow system, with or without automated pumping systems.

Bottom Line: In Experiment 2, saline bags were placed under external pressures to evaluate the effect on flow rate.Increase in external pressure on saline bags elevated flow rates, but inconsistently.A fuller bladder led to a decrease in flow rates.

View Article: PubMed Central - PubMed

Affiliation: Urology Unit, Department of Surgery, University of Melbourne, Austin Health, Melbourne, VIC, Australia.

ABSTRACT

Objective: To investigate the effects of height, external pressure, and bladder fullness on the flow rate in continuous, non-continuous cystoscopy and the automated irrigation fluid pumping system (AIFPS).

Materials: Each experiment had two 2-litre 0.9% saline bags connected to a continuous, non-continuous cystoscope or AIFPS via irrigation tubing. Other equipment included height-adjustable drip poles, uroflowmetry devices, and model bladders.

Methods: In Experiment 1, saline bags were elevated to measure the increment in flow rate. In Experiment 2, saline bags were placed under external pressures to evaluate the effect on flow rate. In Experiment 3, flow rate changes in response to variable bladder fullness were measured.

Results: Elevating saline bags caused an increase in flow rates, however the increment slowed down beyond a height of 80 cm. Increase in external pressure on saline bags elevated flow rates, but inconsistently. A fuller bladder led to a decrease in flow rates. In all experiments, the AIFPS posted consistent flow rates.

Conclusions: Traditional irrigation systems were susceptible to changes in height of irrigation solution, external pressure application, and bladder fullness thus creating inconsistent flow rates. The AIFPS produced consistent flow rates and was not affected by any of the factors investigated in the study.

Show MeSH