Detroit Medical Center, Michigan State University College of Osteopathic Medicine, Harper Professional Building, Detroit, Michigan, USA Scott Salmon
Received date: August 14, 2013; Accepted date: August 26, 2013; Published date: August 28, 2013
Citation: Salmon S, Odom BD, Santucci RA (2013) A Hospital Policy of Automatic Urine Cultures Performed on Suspicious Urinalysis Increases Speed of Transition from Empiric to Culture-Specific Antimicrobials. J Community Med Health Educ 3:232. doi: 10.4172/2161-0711.1000232
Copyright: © 2013 Salmon S, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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Recent guidelines from Medicare dictate how hospitals are to provide patient care in diseases such as congestive heart failure and chronic obstructive pulmonary disease starting at their admission from the emergency department . One area lacking national standard of care criteria is hospital admissions for urinary tract infections (UTI), although expenses surrounding so called “catheter associated UTI” are no longer reimbursed. This is important as UTI are the most frequent cause of bacteremia/sepsis in the elderly population . In the USA there is a general increase in UTI morbidity and greater antimicrobial resistance among uropathogens . To lower the severity of illness and death from UTI, it is critical to give patients culture sensitive antibiotics as soon as possible . To determine the feasibility, cost, and potential benefits, our hospital implemented a lab protocol change that automatically triggered a urine culture on any suspicious urine analysis that met preset lab criteria for an infection. We hypothesized this lab implementation would result in urine cultures being available for >90% of patients admitted for urinary tract infections. We also hypothesized that this microbiology lab protocol change would shorten the time to appropriate antimicrobial selection.
After Institutional Review Board approval, a retrospective chart review was performed from 2008 on patients that were admitted to Garden City Hospital with a diagnosis of urinary tract infections. Variables reviewed were gender, age, length of stay, day urine culture was obtained, length of culture incubation, number of days empiric antibiotics were used, type of empiric antibiotics used, total days of IV/PO antibiotics, pathogen cultured, and pathogen sensitivities. Colonization from chronic Foley catheter use can also appear similar to a urine infection but catheter prevalence prior to hospitalization was not factored into the study.
The study included all patients with urinary tract infection as a primary diagnosis from the hospital’s admission database from June to December 2008. Urine cultures obtained before antibiotics were administered were reviewed retrospectively and the sensitivities were compared to the antibiotic treatment of choice. The initial antibiotic selection was presumed to be empiric and was recorded as such.
The lab protocol that triggered an automatic urine culture from the patient’s urine analysis included any nitrates, +1 or greater bacteria, 5 or greater White Blood Cell (WBC). Culture sensitivities were compared to the empiric antibiotic given. Empiric antibiotics were considered appropriate if they covered the cultured pathogen based on sensitivities. Urine cultures were performed on hospital day #1 if the patient’s urine analysis was sent to microbiology before 5 pm; those admitted for UTI after 5 P.M had their urine culture started the next day.
Hospital charges were estimated for urine culture and average daily cost of hospitalization at an academic medical center. The cost of hospitalization was based on total cost of hospitalization for every person admitted for UTI divided by the number of total days in the hospital.
A total of 74 patients were admitted with a diagnosis of UTI between June 6, 2008 and December 31, 2008. Initial cultures were obtained from 72 patients (97%) between hospital day #1 or #2. The two remaining patients did not have urine cultures because one was a direct admit from another facility for UTI and was already being treated. The second patient had a secondary admitting diagnosis of “recent UTI” but her UA was negative and did not trigger a urine culture. Of the 74 patients, 22 (30%) were male and 52 (70%) were female. Median age was 81 (IQR 71-85) years. Median length of stay was 5 (IQR 4-8) days.
Of 72 patients, 69 (96%) had urine cultures performed within the first 24 hours. The remaining 3/72 patients (4%) had urine cultures started within 48 hours. A pathogen was cultured in 67/72 (93%) of urine specimens obtained. The remaining 5 cultures (7%) with no identified pathogen had 3 (60%) with “no growth” and 2 (40%) with “multiple organisms probable contaminant.” Median length of culture incubation was 3 (IQR 3-4) days. Pathogens isolated included 31 Escherichia coli (45%), 11 Enterococcus species (16%), 7 Klebsiella pneumoniae (10%), 5 Proteus mirabilis (7%), 4 Pseudomonas aeruginosa (6%), 4 Morganella morganii (6%), 2 Providencia stuartii (3%) 1 Candida (1.4%), 1 Streptococcus species (1.4%), 1 Staphylococcus aureus (1.4%), 1 Staphylococcus species (1.4%), 1 Citrobacter freundii (1.4%).
In 73 of 74 patients (99%), empiric antibiotics were initiated. Median length of empiric antibiotic use was 4 (IQR 4-5) days. 5/ 72 (7%) of patients had negative cultures and empiric antibiotics were terminated. Of 73 patients, 30 (45%) were started on only one empiric antibiotic, while 40 patients (55%) were started on empiric mult-agent antibiotic therapy. The pathogen was not sensitive to the chosen single agent in 13/30 patients (43%). The pathogen was not sensitive to the chosen multi-agent antimicrobials in 9/40 patients (23%). Overall empiric antibiotics were ineffective in 22/70 patients (31%).
A microbiology laboratory protocol is a very effective way to obtain urine cultures automatically based on urine analyses suspicious for infection. This protocol helps negate human error in the physician ordering a urine culture, and insures that the urine is collected prior to antibiotic initialization. This study showed that a simple lab protocol effectively obtained urine cultures on patients admitted for a urinary tract infection 97% of the time. The protocol was essentially 100% successful when you account for the fact that the two patients without a culture performed did not have a urine analysis that would trigger a urine culture.
In our study, approximately 33% of the patient population had resistant organisms not sensitive to the empiric antibiotics initially chosen by their physicians, and thus directly benefited from this protocol. Antimicrobial resistance even properly chosen empiric antibiotics is common. In the USA, 45% of patients admitted for UTI have multi-drug resistant organisms . Due to increased drug resistance, it is imperative to identify the pathogen in a timely manner to ensure proper treatment and reduce the morbidity, mortality, and increased hospital charges associated with these pathogens [2,4].
There are 6 reasons to consider this lab protocol change. One, it shortens the time to starting a urine culture in the population most likely to benefit from timely urine culture information. In our study, the protocol resulted in early cultures in 97% of patients. Two, early culture shows if the pathogen is sensitive to empiric antibiotics, and allows earliest opportunity to switch to appropriate antimicrobials when necessary. In our study, 33% of patients were started on an antimicrobial regimen to which their infections were not susceptible. Three, multi-drug resistant organisms are increasing and early identification of their presence allows the most effective treatments. Four, protocols such as this can limit the overuse of antibiotics because empiric antibiotics will be stopped if a urine culture is negative. For example, in our study 5/72 patients (7%) had negative cultures that resulted in the stoppage of their empiric antibiotics. Five, urine cultures are a standard of care for proper treatment of urinary tract infections, and automatic protocols such as this ensure they are obtained without fail. Lastly, catheter acquired UTIs are not reimbursed by Medicare . Due to this, it is imperative to identify UTIs that are present upon admission before they result in payment cuts to the hospital.
At $13.25 per urine culture, the cost of this lab protocol change is relatively small. Over an entire year at a university hospital, 181 patients were admitted for a urinary tract infection. If this protocol had been initiated, it would have cost that hospital $2,398.25, roughly the cost of 1/3 the day ($6,700) for a single patient admitted for UTI. Initiating our laboratory protocol change can not only decrease the time it takes to obtain a urine culture, but also potentially save lives. The 28-day survival rate is almost 6-fold higher when patients with bacteremia, for example, are given culture-appropriate antimicrobials. [(12.5% vs. 2.3%) (p=0.02)] .
We recognize there are several limitations to this study. These include its retrospective nature, and potential institution-to-institution variability in UTI patient length of stay and hospital costs. However, due to relatively consistent reimbursement from Medicare, the costs should be very similar across the United States.
A laboratory protocols for obtaining automatic urine cultures on urinalysis that are suspicious for UTI is easy to implement and has the potential to speed appropriate antimicrobial therapy while it saves hospitals money. Especially in our age of multi-drug resistant organisms, this protocol will ensure timely institution of appropriate antibiotics, with the potential to speed recovery and save lives.
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