Catheterization and urinary tract infections: microbiology

Enhancing quality practice for prevention and diagnosis of urinary tract infection during inpatient spinal cord rehabilitation

OBJECTIVES

To reduce the incidence of Urinary Tract Infection (UTI) in subacute SCI individuals admitted for tertiary inpatient rehabilitation.

DESIGN

A quality improvement team was assembled to improve UTI prevention/diagnosis. To plan data collection, UTI-related factors were mapped in an Ishikawa (fishbone) driver diagram. Data including patient demographics, presence and frequency of signs and/or symptoms of UTI and antibiotic initiation from August to December 2015 were recorded. Sensitivity, Specificity, Positive and Negative Predictive Values (PPV, NPV), and Likelihood Ratios (LR) were calculated for each sign and symptom.

SETTING

Tertiary SCI Rehabilitation Results: Among 55 inpatients with subacute SCI who had signs/symptoms prompting urine culture and sensitivity (C&S), 32 (58.18%) were diagnosed with a UTI. The most frequent symptoms were foul smelling urine (41%), change in urine color (31%), and incontinence (25%), and the most common sign was fever (34%). Most UTIs (81%) occurred among individuals using Clean Intermittent Catheterization (CIC), with 46% of catheterizations performed by nurses. Foul smelling urine had the highest sensitivity (0.50, 95% CI: 0.31-0.69), and new incontinence had the highest specificity (0.88, 95% CI: 0.69-0.97) for UTI diagnosis. The highest PPV belonged to the cloudy urine (0.71, 95% CI: 0.42-0.92). The combination of cloudy and foul smelling urine increased the PPV to 78% (95% CI: (0.40-0.97).

CONCLUSIONS

The concurrent presence of cloudy and foul smelling urine is predicted of UTI diagnosis inpatients tertiary setting. SCI inpatients are susceptible to UTI when learning CIC technique from nurses.

Anatomy and physiology of urinary elimination. Part 1

Elimination of urine is an essential bodily function, but independence in this activity may be affected by physical and mental disability. Part 1 of this article discusses the anatomy and physiology of the renal and urinary tract and the production of urine. Urinalysis is a vital nursing assessment and the collection of specimens and the range of tests undertaken are outlined. Assisting patients to use the toilet, commode or bedpan is an essential nursing skill. The importance of sensitivity, empathy and moving and handling risk assessment is discussed, and the assessment and management of urinary tract infection and urinary tract stones are addressed. The importance of prevention of cross infection for nurses and patients is highlighted throughout the article.

Preventing and managing catheter-associated urinary tract infections

Since the Foley catheter was introduced in the 1930s it has become one of the primary sources of hospital acquired infections and long term urinary catheters used in community based patients account for some 4% of community nurses' time. This burden is likely to increase given the projected rise in life expectancy and size of the ageing population. This article considers the current literature around indwelling urinary catheterization and its management with a focus on long term catheterization in the community. The authors discuss contemporary strategies to manage or prevent CAUTI that are based on best practice guidelines. However, it is clear from the dearth of empirical evidence that there is an urgent need to establish well constructed research studies to investigate the prevalence of long term urinary catheterization in the community and the prevention and management of CAUTI.

Fundamental principles of indwelling urinary catheter selection

Catheter selection is a skilled element of continence care, particularly when the catheter is intended to remain in situ for prolonged periods. It is important to choose carefully, referring to catheter length, material, Charrière size and balloon infill volume, any of which may--if not attended to correctly--cause problems. This article gives some advice on catheter selection and outlines what may occur if certain issues are dealt with incorrectly.

pH testing in catheter maintenance: the clinical debate

The pH of urine is widely recognized as being a major contributory factor in urinary catheter encrustation. What is less widely appreciated is the range of factors that affect the pH of urine, and which therefore affect the reliability and validity of urine pH testing. This article examines the validity of various urinary pH testing methods and discusses the theoretical and practical implications of the uncertainty surrounding their practical value.

Developing alternative devices to the long-term urinary catheter for draining urine from the bladder

The self-retaining urinary catheter is used for long-term drainage of urine from the bladder only as a last resort because of serious associated complications, yet it remains a routine method for managing older and disabled patients with loss of bladder control. Blockage of the catheter from calcified deposits within its lumen is a common occurrence, obstructing the passage of urine and causing an urgent, unpredictable problem for patients, carers and the nursing staff. The need for further research on the subject has been recognized for many years. The SuPort Project aimed to develop an alternative suprapubic urine collection system. This report outlines the approach adopted towards the design and selection of the novel device, the production problems that ensued and the small clinical trial of a modified prototype.

Catheter-associated urinary tract infections: prevalence of uropathogens and pattern of antimicrobial resistance in a UK hospital (1996-2001)

OBJECTIVE

To assess the change in the bacterial profile and pattern of antibiotic resistance of catheter-associated urinary tract infections (CAUTIs, the most prevalent form of nosocomial infections) between 1996 and 2001.

MATERIALS AND METHODS

Catheter samples of urine (CSUs) submitted in 1996, 1998 and 2001 (2451, 2460 and 3349 specimens, respectively) were analysed. The distribution of different uropathogens in bacterial CAUTIs and their in vitro antimicrobial resistance was evaluated over the study interval. The likelihood ratio test was used to assess whether there was a linear trend according to calendar year.

RESULTS

Escherichia coli was the most frequently isolated pathogen in all years, but its frequency declined over time (35.6%, 32.5% and 26.6%, respectively). Enterococcus was the second most frequent overall, with a significant increase in frequency with time (11.8%, 15.3% and 22.0%, respectively). There was also a considerable change in resistance patterns to antibiotics. As a result, in 1996, CAUTIs were least often resistant to ciprofloxacin (8.0%) followed by co-amoxiclav (18.5%) and cephalexin (25.4%). In 2001, CAUTIs were least often resistant to co-amoxiclav (22.5%), followed by ciprofloxacin (27.2%) and nitrofurantoin (28.8%).

CONCLUSION

The types of organisms associated with CAUTI have changed over the last 5 years in a UK institution, as have the patterns of antibiotic resistance. Currently, the most appropriate agents for the empirical management of CAUTIs seem to be co-amoxiclav, ciprofloxacin and nitrofurantoin.

Flexible cystoscopy: outpatients or domiciliary?

The cost of caring for people in the community with long-term indwelling catheters varies widely but represents a significant amount of NHS spending. A rapid access catheter clinic was established at a Bristol hospital, for people experiencing difficulties with their long-term catheters, to facilitate prompt assessment and treatment. Many patients were found to be severely disabled with mobility problems and relied on hospital transport to attend the clinic for flexible cystoscopy. As a consequence the concept of undertaking this procedure on a domiciliary basis was introduced with a view to cutting costs, improving time management and offering a more reliable service to patients. A prototype battery-powered flexible cystoscope was developed to facilitate this service and five visits were undertaken. Feedback from patients indicated a preference for the domiciliary service and cost benefits were identified. As a result of these initial experiences, we are now planning a pilot study to establish the feasibility and costs of providing a domiciliary service on a permanent basis and gather qualitative data from patients on quality-of-life issues.

Optimization of debris removal during bladder irrigation

Debris build-up within the bladder is one of the main problems encountered by patients undergoing long term catheterization. One of the methods of ameliorating this is to wash out the bladder at regular intervals. In this paper, an alternative method of bladder irrigation is investigated experimentally. The effectiveness of several possible catheter designs has been examined, together with other relevant variables such as the proximity and alignment of the tube tip to the debris and the irrigation flow rate. Results show that debris removal is very sensitive to tube design, with best designs achieving almost complete removal and the worst practically none. The proprietary continuous irrigation catheter used was particularly poor for the type of debris used. Removal is insensitive to the distance of the tube tip from the bladder base up to a limiting value, above which it reduces rapidly. Where misalignment causes the inlet jet to miss the debris, removal rates are very low. Increasing flow rate increases removal up to a limiting value, above which it remains constant. Although the results show the general trends, to optimize the system requires further understanding of the detailed flow patterns within the bladder. A theoretical study using computational fluid dynamics is thus being undertaken.