The dissolution of urinary catheter encrustation

Abstract

Objectives To identify the optimum volume of acidic bladder washout solution to dissolve catheter encrustations and to compare the effectiveness of different bladder washout delivery devices. Materials and methods Urinary catheter encrustation was generated in vitro using a model of the catheterized bladder adapted from previous work. An acidic bladder washout solution (Suby G) was applied via the catheter in the model and retained for 15 min. The amount of encrusting material dissolved was measured by colorimetric analysis of the magnesium and calcium content of the solution returned after the washout procedure. The relative effectiveness of different volumes of washout solution and different washout delivery devices (Optiflow, Bard Ltd, Crawley; UroTainer, B/Braun Medical Ltd, Aylesbury; and a bladder syringe) in dissolving catheter encrustations was compared to the ‘standardized’ conditions commonly used in practice. Results There was no statistically significant difference between washouts with 100 mL and washouts with 50 mL for any of the delivery devices tested. Gentle agitation with 50 mL Suby G did not significantly improve the dissolution of encrustation but the total amount of material dissolved when two washouts with 50 mL Suby G were used sequentially was significantly better than a single washout with either 100 mL or 50 mL. Conclusions Under controlled laboratory conditions, smaller volumes of acidic bladder washout solution (50 mL) are as effective as the 100 mL commonly used in practice, but two sequential washouts with 50 mL are more effective than a single washout. The newly designed Optiflow delivery device is at least as effective as the other devices tested. This study provides new evidence which may contribute to decision‐making by practitioners in relation to cath‐eter care.

epic2: National Evidence-Based Guidelines for Preventing Healthcare-Associated Infections in NHS Hospitals in England

“…1,140,[190][191][192][193][194][195][196][197][198][199] Three studies, however, suggest that an acid washout solution (Suby G) is effective in reducing catheter encrustation. 196,198,200 Evidence from best practice supports the findings in respect of bladder irrigation, instillation and washout and indicates that the introduction of such agents may have local toxic effects and contribute to the development of resistant microorganisms. However, continuous or intermittent bladder irrigation may be indicated during urological surgery or to manage catheter obstruction.…”

Validation of the CDC biofilm reactor as a dynamic model for assessment of encrustation formation on urological device materials

“…Encrustation of medical devices implanted within the lower urinary tract is virtually ubiquitous when devices remain in situ for 30 days, although only approximately 23% of urinary stents will become encrusted 2. Any model system developed may ultimately only provide a representation of the encrustation process because high degrees of interpatient variation occur in the degree of encrustation observed 45. However, where urine and a urease‐positive bacterial strain are present, the formation of encrustation is assured 25…”

“…2 Any model system developed may ultimately only provide a representation of the encrustation process because high degrees of interpatient variation occur in the degree of encrustation observed. 45 However, where urine and a urease-positive bacterial strain are present, the formation of encrustation is assured. 25 The model system described herein has been demonstrated to produce encrusted deposits similar to those observed in a blockage-prone patient.…”

Urethral catheterisation (male and female)

“…• Knowledge of appropriate anatomy and physiology. [16][17][18] Patient preparation 8,9 • Ethical issues.…”