Various aspects on indwelling urinary catheter treatment and its relation to asymptomatic bacteriuria and urinary tract

Catheter-associated urinary tract infection (CAUTI) is one of the most common kinds of patient harm. One way of introducing bacteria into the urinary tract is by inserting a contaminated indwelling urinary catheter (IUC) due to non-aseptic handling during insertion or during maintenance of the IUC and/or the attached urine collection bag. Another way is to leave the IUC in place. The longer the dwell time the greater the risk of bacteriuria. In Sweden, the recommendations from The National Board of Health and Welfare on IUC-insertion procedure has shifted gradually from requiring sterile catheter to accepting non-sterile catheter over the years. In parallel, various denominations has been introduced for IUC-insertion, one of them called clean/nonsterile technique. In 2012 the European Association for Urology Nurses (EAUN) published a guideline on urethral catheterisation requiring sterile IUC and aseptic technique during procedure. The Swedish national Handbook for Healthcare was inspired by it and revised its recommendations. Though, different hospitals had differing requirements on sterility during IUC-insertion procedure. The overall aim with this thesis was to gain increased knowledge in various aspects on indwelling urinary catheter treatment and its relation to asymptomatic bacteriuria and urinary tract infection.

In Study I, a cross-sectional survey, we used a structured questionnaire to explore how registered nurses and assistant nurses from three departments at hospital A described their IUC-insertion procedure in relation to what they called their insertion technique, and whether they followed the hospital guideline for urethral catheterisation. Of 492 included in the study analyses at hospital A, 58% (n=287) said that they followed the hospital guideline. Irrespective of the origin of the denomination used, "clean/non-sterile technique" was used significantly more often by the registered nurses (244/308 vs 104/179, P<0.001) whereas the assistant nurses used the denomination "sterile technique" significantly more often (75/179 vs 64/308) (P<0.001). Overall, 82% considered the catheter should be kept sterile during procedure but only 16% described all the prerequisites to achieve this. Assistant nurses performed IUC-insertion at least twice a week significantly more often than registered nurses (22/179 vs 4/210, P<0.001). Though, this was not an everyday task.

In Study II the same questionnaire was used in a cross-sectional survey to compare how registered nurses and assistant nurses from three departments at hospital A and hospital B described their IUC-insertion procedure in relation to the denominations they used for the procedure. A total of 819 participants, 492 from hospital A and 327 from hospital B, were included in the study analyses. Most participants called their IUC-insertion technique "clean/non-sterile". The participants' conformity with all the sterility precautions in the EAUN-guidelines were associated with working at departments of Cardiology and Surgery (OR 2.35, 95% CI 1.69-3.27), use of sterile catheterisation set (OR 2.06, 95% CI 1.42- 2.97), use of sterile drapes for dressing on insertion area (OR 1.91, 95% CI 1.24- 2.96) and using the term "sterile technique" (OR 1.64, 95% CI 1.11-2.43).

In Study III, an observational study on asymptomatic bacteriuria (ABU) and first urinary tract infection (UTI) event during the remaining inpatient care, 196 asymptomatic geriatric inpatients from two hospitals were included in the analyses. Significantly more ABU was found in patients with a history of catheterisation compared to those without (38/104, 36,5% vs 19/92, 20,7%, P=0.018). History of catheterisation was significantly associated with ABU after adjustment for confounders (OR 2.79, 95% CI 1.31-5.91). Of 124 patients possible to follow up at one of the study sites, five patients received antibiotic treatment for UTI during the remaining hospital stay. All UTI-cases were women, all had had ABU and four of five had had an IUC on admission. Three of five women had diabetes mellitus.

In Study IV same geriatric inpatients and same questionnaire was used. The overall proportion of uropathogens >103 CFU/mL was significantly higher in patients with a history of catheterisation than without (P=0.006). The proportion of secondary uropathogens was also significantly higher in patients with a history of catheterisation compared to those without (P=0.028). Female sex (OR 3.58, 95% CI 1.76-7.29), history of catheterisation (OR 3.03, 95% CI 1.52-6.04) and diabetes mellitus (OR 2.23, 95% CI 1.11-4.47) were significantly associated with the overall detection of uropathogens. The most common uropathogen was E. coli. Overall, 34% of the E.coli isolates were antibiotic resistant to at least one antibiotic group assessed. Among the E. coli isolates assessed for biofilm formation, five were biofilm formers, of which all came from women with ABU detected in prior study urine samples. Four isolates originated from women with a history of catheterisation. Culture results of IUC-urine samples and voided urine samples from the same 73 patients with an IUC on admission were compared. The results were incongruent in 21% of the related urine samples.

Conclusions: Clean/non-sterile insertion technique counteracts asepsis and jeopardizes patient safety and efforts to prevent CAUTI. Harmonised and implemented national guidelines and skill training on a regular basis is a great concern for patient safety. Significant bacteriuria is increased in asymptomatic patients with a history of catheterisation up to four weeks prior to the IUC- removal. The proportion of E. coli resistant to cefadroxil and ciprofloxacin in geriatric inpatients is worrying. Biofilm forming E. coli is not common in inpatients catheterised for less than two weeks. To minimise unnecessary antibiotic treatment against secondary uropathogens, voided urine sampling is preferable to IUC-urine sampling, when possible, in patients who have been catheterised for less than two weeks.

List of scientific papers

I. Kulbay A, Tammelin A. Clean or sterile technique when inserting indwelling urinary catheter: An evaluation of nurses and assistant nurses' interpretations of a guideline at an acute-care hospital in Sweden. Nordic Journal of Nursing Research. 2019;39(2):92-97. https://doi.org/10.1177/2057158518800261

II. Kulbay A, Joelsson-Alm E, Tammelin A. The impact of guidelines on sterility precautions during indwelling urethral catheterization at two acute-care hospitals in Sweden - a descriptive survey. BMC Nursing. 2021;20(1):99. https://doi.org/10.1186/s12912-021-00619-x

III. Kulbay A, Joelsson-Alm E, Amilon K, Tammelin A. Asymptomatic bacteriuria and urinary tract infection in geriatric inpatients after indwelling urinary catheter removal: a descriptive two-centre study. Infect Prev Pract. 2024;6(4):100411. https://doi.org/10.1016/j.infpip.2024.100411

IV. Kulbay A, Amilon K, White J, Joelsson-Alm E, Tammelin A. Uropathogens, antibiotic resistance and biofilm producing Escherichia coli among inpatients with and without a history of urethral catheterization. [Manuscript]