In vitro Investigations into the Formation and Dissolution of Infection‐induced Catheter Encrustations

Abstract

Encrustations are the most frequent complications occurring with indwelling catheters and urine drainage systems. The conditions for bacterial infections, using synthetic urine and controlled contamination by Proteus vulgaris, were standardised by using an in vitro model. Crystal deposits on catheters were analysed by infra-red spectroscopy and scanning electron microscopy. The main components of deposits in all investigations were struvite (MgNH4PO4.6H2O) 60-70% and carbonate apatite (Ca10(PO4,CO3)6 (OH,CO3)2) 30-40%. Investigations as to the quality and quantity of encrustations confirmed the analysis. Irrigation treatment was carried out with physiological saline solution and citric acid solution (Suby G) to study and quantify the dissolution of crystal deposits. Regular irrigation with citric solution resulted in a 70% dissolution of encrustations and ensured free flow as ascertained by measuring flow rates.

Life with an Indwelling Urinary Catheter: The Dialectic of Stigma and Acceptance

“…I conducted a phenomenological study to understand what it is like to live with a long-term (more than 4 months) urinary catheter. and catheter-associated urinary tract infection (Burr & Nuseibeh, 1997;Hesse, Nolde, Klump, Marklein, & Tuschewitzki, 1992;Stickler, Ganderton, King, Nettleton, & Winters, 1993;Wilde, 1997). However, only one researcher has examined catheter-related concerns of patients (Roe & Brocklehurst, 1987).…”

Catheter washout solutions for long-term urinary catheterisation in adults: A Cochrane review summary

“…Blockage of an indwelling catheter is traumatic, causing pain and distress. The most commonly isolated bacteria in blockages is Proteus mirabilis (Stickler and Feneley 2010), which may cause crystalline deposits (such as calcium phosphate and magnesium ammonium phosphate (struvite) to build up through a rise in pH caused by the metabolism of urea to ammonia and bicarbonate (Hesse et al 1992;Wilks et al 2015). Current practice for the management of catheter encrustation and blockage lies largely with nursing staff and it is clear that this practice varies greatly but is largely dependent on the use of catheter maintenance ("washout") solutions, yet the evidence to support this practice is weak.…”

Encrustation of a Metal Alloy Urinary Stent: A Mechanistic Investigation

“…Despite extensive documentation on stents, encrustation consists mainly of calcium oxalate [9, 10]and apatitic deposits [5, 11, 12, 13]. To our knowledge, no modelling in vitro work has been presented allowing for the reliable evaluation of the biomaterials used for the preparation of catheters or for the treatment of blocked or narrowed ureters.…”