Katherine Walton

Antimicrobial catheters for reduction of symptomatic urinary tract infection in adults requiring short-term catheterisation in hospital: a multicentre randomised controlled trial

BACKGROUND Catheter-associated urinary tract infection (CAUTI) is a major preventable cause of harm for patients in hospital. We aimed to establish whether short-term routine use of antimicrobial catheters reduced risk of CAUTI compared with standard polytetrafluoroethylene (PTFE) catheterisation. METHODS In our parallel, three group, multicentre, randomised controlled superiority trial, we enrolled adults (aged ≥16 years) requiring short-term (≤14 days) catheterisation at 24 hospitals in the UK. Participants were randomly allocated 1:1:1 with a remote computer allocation to receive a silver alloy-coated catheter, a nitrofural-impregnated catheter, or a PTFE-coated catheter (control group). Patients undergoing unplanned catheterisation were also included and consent for participation was obtained retrospectively. Participants and trial staff were unmasked to treatment assignment. Data were collected by trial staff and by patient-reported questionnaires for 6 weeks after randomisation. The primary outcome was incidence of symptomatic urinary tract infection for which an antibiotic was prescribed by 6 weeks. We postulated that a 3·3% absolute reduction in CAUTI would represent sufficient benefit to recommend routine use of antimicrobial catheters. This study is registered, number ISRCTN75198618. FINDINGS 708 (10%) of 7102 randomly allocated participants were not catheterised, did not confirm consent, or withdrew, and were not included in the primary analyses. Compared with 271 (12·6%) of 2144 participants in the control group, 263 (12·5%) of 2097 participants allocated a silver alloy catheter had the primary outcome (difference -0·1% [95% CI -2·4 to 2·2]), as did 228 (10·6%) of 2153 participants allocated a nitrofural catheter (-2·1% [-4·2 to 0·1]). Rates of catheter-related discomfort were higher in the nitrofural group than they were in the other groups. INTERPRETATION Silver alloy-coated catheters were not effective for reduction of incidence of symptomatic CAUTI. The reduction we noted in CAUTI associated with nitrofural-impregnated catheters was less than that regarded as clinically important. Routine use of antimicrobial-impregnated catheters is not supported by this trial. FUNDING UK National Institute for Health Research Health Technology Assessment Programme.

Types of urethral catheter for reducing symptomatic urinary tract infections in hospitalised adults requiring short-term catheterisation: multicentre randomised controlled trial and economic evaluation of antimicrobial- and antiseptic-impregnated urethral catheters (the CATHETER trial)

BACKGROUND Catheter-associated urinary tract infection (CAUTI) is a major preventable cause of harm for patients in hospital and incurs significant costs for health-care providers such as the UK NHS. Many preventative strategies and measures have been introduced to minimise CAUTI risk, including the use of antimicrobial catheters. However, there is considerable uncertainty regarding their usefulness in terms of reducing symptomatic CAUTI, and whether or not they are cost-effective. OBJECTIVES Do antimicrobial catheters reduce the rate of symptomatic urinary tract infection (UTI) during short-term hospital use and is their use cost-effective for the UK NHS? DESIGN A pragmatic multicentre UK randomised controlled trial comparing three catheters as they would be used in the UK NHS: antimicrobial-impregnated (nitrofurazone) and antiseptic-coated (silver alloy) catheters with the standard polytetrafluoroethylene (PTFE)-coated catheters. Economic evaluation used a decision model populated with data from the trial. Sensitivity analysis was used to explore uncertainty. SETTING Relevant clinical departments in 24 NHS hospitals throughout the UK. PARTICIPANTS Adults requiring temporary urethral catheterisation for a period of between 1 and 14 days as part of their care, predominantly as a result of elective surgery. INTERVENTIONS Eligible participants were randomised 1 : 1 : 1 to one of three types of urethral catheter in order to make the following pragmatic comparisons: nitrofurazone-impregnated silicone catheter compared with standard PTFE-coated latex catheter; and silver alloy-coated hydrogel latex catheter compared with standard PTFE-coated latex catheter. MAIN OUTCOME MEASURES The primary outcome for clinical effectiveness was the incidence of UTI at any time up to 6 weeks post randomisation. This was defined as any symptom reported during catheterisation, up to 3 days or 1 or 2 weeks post catheter removal or 6 weeks post randomisation combined with a prescription of antibiotics, at any of these times, for presumed symptomatic UTI. The primary economic outcome was incremental cost per quality-adjusted life-year (QALY). Health-care costs were estimated from NHS sources with QALYs calculated from participant completion of the European Quality of Life-5 Dimensions (EQ-5D). RESULTS Outcome analyses encompassed 6394 (90%) of 7102 participants randomised. The rate of symptomatic UTI within 6 weeks of randomisation was 10.6% in the nitrofurazone group (n = 2153; -2.1% absolute risk difference), 12.5% in the silver alloy group (n = 2097; -0.1% absolute risk difference) and 12.6% in the PTFE group (n = 2144). The effect size {odds ratio (OR) [97.5% confidence interval (CI)]} was 0.82 (97.5% CI 0.66 to 1.01) for nitrofurazone (p = 0.037) and 0.99 (97.5% CI 0.81 to 1.22) for silver alloy (p = 0.92) catheters. The nitrofurazone catheters were more likely to cause discomfort during use and on removal. The primary economic analysis suggested that nitrofurazone-impregnated catheters would be, on average, the least costly (> £7 less than PTFE) and most effective option at current NHS prices. There was a 73% chance that nitrofurazone would be cost saving and an 84% chance that the incremental cost per QALY would be < £30,000. At the trial price (£6.46), silver alloy catheters were very unlikely to be cost-effective. These results were unchanged in sensitivity analyses, although when the length of stay cost was excluded the incremental cost per QALY for nitrofurazone against PTFE was £28,602. CONCLUSIONS The trial estimate of clinical effectiveness for nitrofurazone-impregnated catheters was less than the pre-specified minimum absolute risk difference that we considered important (-3.3%), and the surrounding CI included zero, indicating that any reduction in catheter-associated UTI was uncertain. Economic analysis, although associated with uncertainty, suggested that nitrofurazone-impregnated catheters may be cost-effective for the NHS. The trial ruled out the possibility that silver alloy-coated catheters might reach the pre-set degree of clinical effectiveness and that their use was unlikely to be cost-effective. These findings should be considered by patients, clinicians and health-care policy-makers to determine whether or not a change in practice is worthwhile. Future research should be aimed at determining the minimum clinically important difference in terms of CAUTI prevention in comparative trials, and to identify reliable methods which can detect the impact of the intervention on quality of life and other drivers of cost, when the intervention is a subsidiary part of overall treatment plans.

Types of urethral catheter for reducing symptomatic urinary tract infections in hospitalised adults requiring short-term catheterisation

BACKGROUND Catheter-associated urinary tract infection (CAUTI) is a major preventable cause of harm for patients in hospital and incurs significant costs for health-care providers such as the UK NHS. Many preventative strategies and measures have been introduced to minimise CAUTI risk, including the use of antimicrobial catheters. However, there is considerable uncertainty regarding their usefulness in terms of reducing symptomatic CAUTI, and whether or not they are cost-effective. OBJECTIVES Do antimicrobial catheters reduce the rate of symptomatic urinary tract infection (UTI) during short-term hospital use and is their use cost-effective for the UK NHS? DESIGN A pragmatic multicentre UK randomised controlled trial comparing three catheters as they would be used in the UK NHS: antimicrobial-impregnated (nitrofurazone) and antiseptic-coated (silver alloy) catheters with the standard polytetrafluoroethylene (PTFE)-coated catheters. Economic evaluation used a decision model populated with data from the trial. Sensitivity analysis was used to explore uncertainty. SETTING Relevant clinical departments in 24 NHS hospitals throughout the UK. PARTICIPANTS Adults requiring temporary urethral catheterisation for a period of between 1 and 14 days as part of their care, predominantly as a result of elective surgery. INTERVENTIONS Eligible participants were randomised 1 : 1 : 1 to one of three types of urethral catheter in order to make the following pragmatic comparisons: nitrofurazone-impregnated silicone catheter compared with standard PTFE-coated latex catheter; and silver alloy-coated hydrogel latex catheter compared with standard PTFE-coated latex catheter. MAIN OUTCOME MEASURES The primary outcome for clinical effectiveness was the incidence of UTI at any time up to 6 weeks post randomisation. This was defined as any symptom reported during catheterisation, up to 3 days or 1 or 2 weeks post catheter removal or 6 weeks post randomisation combined with a prescription of antibiotics, at any of these times, for presumed symptomatic UTI. The primary economic outcome was incremental cost per quality-adjusted life-year (QALY). Health-care costs were estimated from NHS sources with QALYs calculated from participant completion of the European Quality of Life-5 Dimensions (EQ-5D). RESULTS Outcome analyses encompassed 6394 (90%) of 7102 participants randomised. The rate of symptomatic UTI within 6 weeks of randomisation was 10.6% in the nitrofurazone group (n = 2153; -2.1% absolute risk difference), 12.5% in the silver alloy group (n = 2097; -0.1% absolute risk difference) and 12.6% in the PTFE group (n = 2144). The effect size {odds ratio (OR) [97.5% confidence interval (CI)]} was 0.82 (97.5% CI 0.66 to 1.01) for nitrofurazone (p = 0.037) and 0.99 (97.5% CI 0.81 to 1.22) for silver alloy (p = 0.92) catheters. The nitrofurazone catheters were more likely to cause discomfort during use and on removal. The primary economic analysis suggested that nitrofurazone-impregnated catheters would be, on average, the least costly (> £7 less than PTFE) and most effective option at current NHS prices. There was a 73% chance that nitrofurazone would be cost saving and an 84% chance that the incremental cost per QALY would be < £30,000. At the trial price (£6.46), silver alloy catheters were very unlikely to be cost-effective. These results were unchanged in sensitivity analyses, although when the length of stay cost was excluded the incremental cost per QALY for nitrofurazone against PTFE was £28,602. CONCLUSIONS The trial estimate of clinical effectiveness for nitrofurazone-impregnated catheters was less than the pre-specified minimum absolute risk difference that we considered important (-3.3%), and the surrounding CI included zero, indicating that any reduction in catheter-associated UTI was uncertain. Economic analysis, although associated with uncertainty, suggested that nitrofurazone-impregnated catheters may be cost-effective for the NHS. The trial ruled out the possibility that silver alloy-coated catheters might reach the pre-set degree of clinical effectiveness and that their use was unlikely to be cost-effective. These findings should be considered by patients, clinicians and health-care policy-makers to determine whether or not a change in practice is worthwhile. Future research should be aimed at determining the minimum clinically important difference in terms of CAUTI prevention in comparative trials, and to identify reliable methods which can detect the impact of the intervention on quality of life and other drivers of cost, when the intervention is a subsidiary part of overall treatment plans.

Fluids for continuous renal replacement therapy - an evaluation of microbial integrity

Purpose We have previously demonstrated widespread microbial contamination in the dialysis and replacement fluid circuits of bicarbonate-buffered, continuous renal replacement therapies (CRRTs). It is not known whether different CRRT fluids have an impact on bacterial activity. Methods In this study the in vitro growth and biofilm formation associated with seven strains of bacteria (Burkholderia cepacia, Escherichia coli, Staphylococcus aureus, Stenotrophomonas maltophilia, Pseudomonas aeruginosa, Pseudomonas fluorescens, and Staphylococcus epidermidis) in five CRRT fluids (Prismocitrate, Monosol S, Accusol 35, tri-sodium citrate and Ci-Ca K2) were studied. The fluids were each inoculated with light and heavy concentrations of each of the bacterial strains and incubated at 22 or 37°C for up to 72 h with and without bacterial growth medium. Bacterial growth was assessed by spectrophotometry. Biofilm formation was assessed by a standard microtiter plate assay. Results Unsupplemented fluids did not support bacterial growth or biofilm formation after 72 h incubation. When supplemented with bacterial growth medium, some fluids, in particular Accusol 35, Ci-Ca K2, and tri-sodium citrate, had an inhibitory effect on bacterial growth, although none suppressed growths across the panel of tested organisms. Conclusions Different CRRT fluids have different impacts on bacterial growth and biofilm formation, but all remain susceptible to extrinsic contamination.

Hyperammonaemic encephalopathy secondary to an infected perinephric urinoma

previously healthy 31 year old vegan female eveloped lower back pain following a fall 4 weeks rior to presentation. A MRI scan demonstrated a arge complex left perinephric collection fistulating o the posterior-lateral abdominal wall with a comlex intra-peritoneal collection and large staghorn alculus (Fig. 1). Following admission an emergency adiological drainage of the perinephric collection as performed. Cultures from this aspirate grew scherichia coli. Within 72 h the patient became eptic again and a CT-scan confirmed a large uri-