Reducing Use of Indwelling Urinary Catheters and Associated Urinary Tract Infections

Methods

Approval from the appropriate institutional review board was obtained before the study began. Informed consent was not required.

The research was done at Rush University Medical Center, a 613-bed, nonprofit, inner city academic medical center. The MICU was a 21-bed unit that provided critical and intermediate care to adults with primarily medical illnesses. Most common diagnoses included pneumonia, severe sepsis, neutropenic fever, gastrointestinal bleeding, and multi-organ failure. Mean length of stay was 5.2 days. The nurse to patient ratio was typically 1 to 2. On this unit, urinary catheters are inserted at the discretion of the physician or critical care nurse. Catheters are discontinued on order of a physician. The unit’s nosocomial infection rates, including rates for CAUTIs, are compiled and posted monthly.

Before the intervention, a team of MICU clinicians reviewed current catheter practices, analyzed relevant publications, and developed criteria for use of indwelling urinary catheters (Table 1 ⇓). This team consisted of 3 senior staff nurses, 2 advanced practice nurses, and the unit’s medical director. Once criteria were defined, educational sessions on the study objectives, rationale, methods, and expectations were provided by the investigators to MICU nurses and physicians. Appropriate indications for insertion or continuation of indwelling urinary catheters were emphasized.

The study population consisted of all consecutive patients admitted to the MICU from December 1, 2007, to May 31, 2008, who had an indwelling urinary catheter during their unit stay. During this time, all patients in the unit who had indwelling urinary catheters were identified each day by one of the nurse coinvestigators at nursing shift report. Patients with urinary catheters were evaluated by one of the study investigators on the day of MICU admission and daily thereafter by using the criteria for appropriate use of the catheters. Nurses assigned to patients with an indwelling catheter were consulted about the principal reason for catheter placement or continuation. Daily evaluations by the nurse investigators continued until a patient’s catheter was removed or the patient was discharged from the unit. Results of daily screenings were presented by a nurse investigator during multidisciplinary morning rounds. Recommendations were made to discontinue indwelling urinary catheters in patients who were judged not to meet the defined criteria.

Data collected during the intervention phase included duration of catheterization, appropriateness of urinary catheterization, and reasons for inappropriate catheter use. Surveillance for CAUTIs was performed by nurse epidemiologists from the medical center’s infection control department. Monthly summaries of total days of use of urinary catheters and CAUTIs were prepared by the nurse epidemiologist assigned to the MICU.

The hypothesis was that days of use of urinary catheters and number of CAUTIs would decrease during the intervention months compared with the 11 months before the intervention. Total days of use of catheters and monthly CAUTI rates before and during the intervention were compared by using unpaired t tests. Significance was set at P < .05.

Definitions

A CAUTI was defined as an infection in a patient with a urinary catheter who met the NHSN definition of a urinary tract infection ¹⁰ (Table 2 ⇓).

Urinary catheter device days were the total number of days of use of an indwelling urinary catheter. Condom catheters, suprapubic catheters, and nephrostomy tubes were excluded from counts, as were patients receiving intermittent catheterizations. Patients with urinary catheters were identified each morning from the charge nurses’ unit nursing report sheet. Each patient with a catheter at that time was counted as 1 device day. Monthly catheter device days were the sum of the daily counts.

CAUTI rates were defined as the number of CAUTIs divided by the number of urinary catheter device days multiplied by 1000. CAUTI rates were computed monthly.

Inappropriate catheter days were the total number of days urinary catheters remained in place without acceptable indications according to study criteria listed in Table 1 ⇑.

Results

During the 6-month intervention, 337 patients had indwelling urinary catheters for a total of 1432 days. Of the patients, 58% were women. The age range was 18 to 99 years, with a mean of 61 years.

Overall, 456 of the 1432 device days (32%) were considered inappropriate. Inappropriate days included 108 days in which urinary catheters placed in the emergency department or at an outside facility were removed on the first day of MICU admission because catheter continuation was judged inappropriate according to study criteria. If analysis was restricted to patients with catheters in place for 24 hours or more, 119 of 1095 device days (11%) were judged inappropriate. Reasons offered most commonly by nurses for catheter continuation against recommendation were incontinence, particularly in women, and concern for skin integrity. Other reasons included obesity, diuresis, and perceived patient discomfort. Three patients requested that the catheter be continued for their comfort or convenience.

Table 3 ⇓ and Figures 1 ⇓ and 2 ⇓ summarize the outcomes before and after the intervention. Before the intervention, the mean number of urinary catheter days was 311.7 d/mo. In comparison, mean catheter days during the intervention declined to 238.6 d/mo, a reduction of 73.1 d/mo. In the 11 months before the intervention, 15 CAUTIs occurred during 3429 device days or 4.7 per 1000 days. In the intervention phase, 0 CAUTIs occurred in 1432 device days. These differences were statistically significant.

Discussion

Nosocomial infections, including CAUTIs, are considered a clinical indicator of quality of care. Catheter-associated urinary tract infections were included in the list of largely preventable harms due to medical care developed by the Centers for Medicare and Medicaid Services. ¹¹ CAUTIs were selected by the centers as a high-volume, high-cost health care problem with acceptable prevention strategies. CAUTIs were considered an avoidable complication, and unless patients had the infections at the time of hospital admission, secondary costs for CAUTIs would not be reimbursed by the centers.

As part of a campaign to reduce CAUTIs, the Centers for Disease Control and Prevention recommended use of urinary catheters only when indicated and prompt removal of the catheters when use was no longer appropriate. Situations justifying medical necessity for catheter placement were defined as relief of urinary obstruction, neurogenic bladder dysfunction and urinary retention, urological surgeries, and a need to obtain accurate measurements of urinary output in critical illness. Catheter use solely for the convenience of personnel providing patient care or as a substitute for nursing care of an incontinent patient was specifically discouraged. ¹¹ Other prohibitions to placement and continuation of indwelling urinary catheters included incontinence without significant loss of skin integrity; frequent, but medically unnecessary, monitoring of urinary output; diuresis; and convenience of care. ICU patients may be exposed to risks for CAUTIs without sufficient justification. In particular, catheters are often maintained in the absence of any clear indication, leading to a recommendation to review and define daily a purpose for catheter continuation. ¹²

As noted in a recent Robert Wood Johnson Foundation summary, ¹³ nurses’ preferences and judgments weigh heavily in decisions on insertion and maintenance of urinary catheters. Physicians are often unaware that inpatients under their care are catheterized or do not know why their patients have urinary catheters. ¹⁴ Because urinary catheters are most often placed and maintained at the behest of nurses, nurses should be included in strategies to limit catheter use and CAUTIs. Successful strategies have included educating nursing staff to limit catheter use and providing monthly reports of CAUTI rates, ¹⁵ daily reminders to physicians and nurses to remove unnecessary catheters, ^{16– 18} implementation of criteria-based catheter guidelines and daily determination of whether or not patients meet the criteria, ^{19– 21} and introduction of nurse-promoted protocols for discontinuing catheters. ^{18, 19} All strategies have resulted in a reduction in the duration of catheterization or in the number of CAUTIs or both.

Our results indicate that duration of urinary catheterization and occurrence of CAUTIs can be reduced by daily determinations by nurses of patients’ need for the catheters. We selected our strategy for 2 reasons. First, it included recognition of the central role of nurses in decisions on placement and continued use of urinary catheters. In our unit, orders from physicians for catheter placement or removal usually formalize a decision already made by a nurse. Second, the strategy provided a daily reminder to nurses and physicians that a patient had a catheter and that this invasive device was associated with the potential for harm. We suspected that clinicians in the ICU, if not complacent about risks associated with urinary catheters, had been more invested in limiting use of devices with more publicized hazards such as central venous catheters and mechanical ventilators.

Although no CAUTIs were detected during the 6-month intervention, we do not consider elimination of CAUTIs a reasonable goal. Indwelling urinary catheters will have a role in the management of selected patients with critical illnesses, and despite strict adherence to indicators, some CAUTIs will inevitably occur. Reasonable goals are to avoid overuse of indwelling urinary catheters and reduce CAUTI rates.

We recognize that adapting a strategy such as ours to reduce CAUTIs will require a marked shift in practice for most ICU nurses. Urinary incontinence is a nursing challenge, particularly in female, immobile, and obese patients. During the study period, nurses often were hesitant to remove catheters because they feared incontinence-related compromise to a patient’s skin integrity. Less often, nurses thought that anticipated patient discomfort justified catheter use. During the study we emphasized the positive trends in reducing monthly unit device days and rates of CAUTIs. We thought that the reductions in infections provided an upside to catheter discontinuance that helped balance nurses’ worries about risks of skin breakdown and the additional work necessitated by more frequent hygiene interventions and linen changes for patients.

Our unit’s resource needs were affected by the changes in practice related to earlier removal of urinary catheters. Requirements for external catheters, linens, and bath and skin care products increased during the study period. We also required more frequent access to a bladder scanner to evaluate patients for urinary retention. We uncovered a need for a protocol to address urinary retention that included alternatives to simply reinserting an indwelling catheter.

Finally, we recommend further research in this area. In particular, we were constrained by a lack of evidence-based information on incontinence-associated risks and discomfort. Urinary incontinence is a component of assessments for the risk of pressure ulcers, although no valid and reliable measures are available for assessing urine-exposed skin, and analysis of existing evidence does not support a clear causative relationship between urinary incontinence and pressure ulcers. ^{22, 23} Patients’ catheter-associated comfort or discomfort has rarely been investigated. We found limited and conflicting data in comparisons between infection risks of condom catheters and indwelling urinary catheters. ²⁴ Investigations in these areas are sorely needed so relative risks and benefits of urinary catheters and alternatives to urinary catheters can be better assessed.

Our study has several limitations. Generalization of outcomes is limited by use of a single unit in a single institution and by restricting the study to indwelling urinary catheters only. Device days and infection rates were compared before and after the intervention rather than by using a concurrent control group, introducing the possibility that other factors influenced outcomes. We did not have accurate information in the period before intervention to calculate mean duration of catheterization, and we cannot make conclusions about any effect on duration of catheterization. The indications used to determine appropriateness of catheter use were consensus opinions and were not evidence based. Subjectivity was involved in the daily evaluation of the appropriateness of catheter use. When differences of opinion occurred, the evaluators gave the most weight to judgments of nurses who were providing direct patient care.

Conclusion

This study was a before-and-after evaluation of a low-technology intervention to reduce duration of urinary catheterization and occurrence of CAUTIs in an MICU. CAUTIs are among complications fundamentally linked to nursing care and most likely constitute a measure of the performance of nursing care. Our results indicate that reductions in CAUTIs can be realized through a nurse-based intervention to avoid unnecessary catheter placement and limit duration of catheter use.