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Research project: Dissolution profiles for urinary catheter encrustation - Dormant - Dormant

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Recurrent catheter encrustation leading to blockage occurs in up to 50% of long-term catheterised patients.


The major components of encrusting material are struvite (magnesium, ammonium phosphate) and calcium phosphate, which are precipitated from the urine in alkaline conditions caused by infection with urease-producing micro-organisms. There is evidence from laboratory studies using models of the catheterised bladder that these mineral deposits can be dissolved by acidic 'catheter maintenance' solutions (eg. Suby G, Solution R and mandelic acid) and this is supported by clinical experience (Getliffe, 1996). However, there is little research evidence on which to base decisions on the optimum volume and frequency of bladder washouts.

A catheter lumen holds little more than 4ml and the use of a larger volume than necessary means that more of the bladder tissue will be in contact with a potentially irritant chemical which could cause tissue damage. Similarly if solutions are left in contact with tissue for longer than necessary there is increased risk of tissue damage.

Recent studies by the research team indicate that 50ml solution is as effective as 100ml in dissolving mineral deposits and that two sequential applications of 50ml are significantly more effective than a single solution (Getliffe et al. 2000). The current study is designed to refine a model for the production of encrusting material and to investigate the dissolution profile of encrusting material under varying conditions of time and pH. Outcomes will provide guidance on optimum conditions for clinical application of catheter maintenance solutions and will inform subsequent clinical studies.

Project team

Kathryn Getliffe 

Related research groups

Active Living and Rehabilitation
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