Catheter Associated Urinary Tract Infections ( CAUTI ) in adults ( ≥ 16 years of age ) - Guideline for the management of in secondary care

Publication: 22/10/2013  --
Last review: 25/10/2019  
Next review: 25/10/2022  
Clinical Guideline
CURRENT 
ID: 3504 
Approved By: Improving Antimicrobial Prescribing Group 
Copyright© Leeds Teaching Hospitals NHS Trust 2019  

 

This Clinical Guideline is intended for use by healthcare professionals within Leeds unless otherwise stated.
For healthcare professionals in other trusts, please ensure that you consult relevant local and national guidance.

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Guideline for management of Catheter Associated Urinary Tract Infections (CAUTI) in Adults (≥ 16 years of age)

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Summary
Catheter Associated Urinary Tract Infections ( CAUTI ) in adults ( ≥ 16 years of age )

Diagnosis

  • Catheter Associated Urinary Tract Infections (CAUTIs) symptoms include fever (≥ 37.7ºC), suprapubic tenderness, or otherwise unexplained systemic symptoms such as altered mental status.
  • If there are symptoms of upper UTI in patients with a urinary catheter please see the upper UTI guideline. Upper UTI symptoms include costovertebral angle tenderness, back pain or where the severity of infection is not in keeping with a lower urinary tract infection e.g. hypotension or evidence of a Systemic Inflammatory Response Syndrome (SIRS).
  • Patients who are no longer catheterised but had indwelling urinary catheters within the past 48 hours are also considered to have catheter-associated UTI if they have CAUTI symptoms. These patients may also have dysuria and/or urinary frequency in addition to the symptoms listed above.
  • CAUTI is a clinical diagnosis not a laboratory diagnosis as Catheter Specimen Urine (CSU) samples invariably grow bacteria.
  • CSU samples should be sent when CAUTI is clinically suspected; the results of these will direct antimicrobial therapy when a clinical diagnosis of CAUTI has been made.
  • CSU sample should NOT be tested with urine dipsticks.
  • CSU sample should not be sent in the absence of clinical evidence of a UTI. A change in urine colour or turbidity alone is not an indication to send a CSU for microbiological analysis.

Non anti-microbial management

  • Catheterised patients with asymptomatic bacteriuria should not receive antibiotic treatment.
  • Patients with an indwelling catheter and symptomatic urinary tract infection should have their catheter removed if it is no longer indicated or have their catheter changed in addition to appropriate antibiotic treatment for infection.

Antimicrobial management
Before commencing an empirical regimen please check the results server to see if previous results are available to allow immediate initiation of directed antimicrobial therapy e.g. GP CSU sample. If result available see directed therapy: Table 3

Table 1. Empirical antimicrobial regimens for the treatment of CAUTI - Oral

 

Recommended Treatments

Notes

1st Line

Nitrofurantoin capsules PO 50mg 6-hourly

No evidence of Upper UTI

(liquid should not be used due to costs - please use fosfomycin sachets where appropriate)

Avoid Nitrofurantoin in patients with an estimated glomerular filtration rate (eGFR) of less than 45 ml/min.

Please ensure CrCl is used as eGFR overestimates renal function in the elderly. In these patients, move to second line choice.

Avoid if Upper UTI is suspected

Liquid should not be used due to costs - please use fosfomycin sachets where appropriate.

Avoid in patients with suspected or known glucose-6-phosphate dehydrogenase (G-6-PD) deficiency.

Avoid at term in pregnancy.

2nd Line

Pivmecillinam electronic Medicines Compendium information on Pivmecillinam PO 400mg stat dose then 200mg 8-hourly

Penicillin antibiotic: Avoid in penicillin allergy

No evidence to support use in Upper UTI

3rd Line

Fosfomycin PO 3g stat and repeated at 72 hours

Creatinine clearance <10mL/minute: Not recommended.

No evidence to support use in Upper UTI

See also - Duration of treatment

Table 2. Empirical antimicrobial regimens for the treatment of CAUTI - Intravenous

Recommended Treatment

Penicillin allergy

Aztreonam Description: electronic Medicines Compendium information on Aztreonam IV
Creatinine clearance  >30mL/minute

  • 1g 12-hourly

Creatinine clearance  10–30 mL/minute

  • Initial dose 1g then 500mg 12 hourly

Creatinine clearance  <10mL/minute

Initial dose 1g then 250mg 12 hourly Avoid in pregnancy

Alternative Treatment

Note

Gentamicin

Consider risks of renal/auditory side effects

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Background

Urinary catheters are used for a variety of indications resulting from mechanical and physiological impairment to the urinary tract. They may be used long term or short term. This guideline relates to the use of urinary catheters in all adults with catheters except complex urological patients e.g. those with ureteric stents in addition to urinary catheters.

CAUTI is one of the most common healthcare associated infections1.

Approximately 15-25% of hospitalised patients have urinary catheters.

Most catheters in hospital are short term (2-4 days).

Urinary catheters become colonised with bacteria after insertion. This occurs at a rate of approximately 5% a day. This colonisation results in urine samples being contaminated with bacteria. This is called catheter-associated bacteruria (CA-bacteruria) 2.

CA-bacteruria in most patients is not associated with disease, i.e. it is not associated with symptomatic urinary tract infection.

In a study of newly inserted urinary catheters there was no difference in rates of dysuria, frequency, fever or loin pain in those with and without CA-bacteruria. This suggests symptoms referable to the urinary tract in those with a urinary catheter are not predictive of CA-UTI3.

Patients with urinary catheters can develop symptomatic Catheter Associated-UTI (CAUTI).

Approximately 20 % of hospital-acquired bacteraemias arise from the urinary tract, and the mortality associated with this condition is about 10 % 4.
[Evidence Level B]

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Clinical Diagnosis

Recommendation: CAUTI is normally diagnosed clinically.

Catheter Associated Urinary Tract Infections (CAUTIs) symptoms include fever >38ºC, suprapubic tenderness, or otherwise unexplained systemic symptoms such as altered mental status.

If there are symptoms of upper UTI in patients with a urinary catheter please see the upper UTI guideline. Upper UTI symptoms include fever, costovertebral angle tenderness, back pain or where the severity of infection is not in keeping with a lower urinary tract infection e.g. hypotension or evidence of a Systemic Inflammatory Response Syndrome (SIRS). 1

Patients who are no longer catheterised but had indwelling urinary catheters within the past 48 hours are also considered to have catheter-associated UTI if they have these symptoms. These patients may also have dysuria and/or urinary frequency in addition to the symptoms listed above.1

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Severity Assessment

Recommendation: If CAUTI is associated with severe sepsis, please manage according to the upper UTI guideline.

Recommendation: If CAUTI is associated with systemic inflammatory response syndrome (SIRS) please consider if the patient should be managed according to the upper UTI guideline.

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Investigation

Recommendations:1/5/6/7

  • Urine dipstick test should NOT be used on urine samples collected from indwelling catheters because bacteria colonising the catheter and the inflammation caused by the catheter will give falsely positive nitrite and leucocyte esterase results respectively. [Evidence level B]
  • All in-patients with suspected CAUTI should have a catheter specimen of urine sample sent for microbiological analysis.
  • The method of urine collection (CSU) should always be stated on the request form.
  • Patients with a systemic inflammatory response or signs of severe sepsis should have a blood culture taken before antibiotics are started.
  • In patients with recurrent CAUTIs (≥3 per annum or ≥2 per 6 months) or upper UTI renal ultrasound is recommended.
  • CSU samples should not be sent in the absence of clinical evidence of a UTI. A change in urine colour or turbidity alone is not an indication to send a CSU for microbiological analysis.

Evidence review/justification for recommendations5/6

Interpretation of microbiology results

The interpretation of microbiology investigations for UTIs is heavily dependent upon the pre-test probability i.e. the probability of infection based on the clinical examination and history. For example, where there is a high probability of infection based on the clinical history negative microbiology results do not exclude a diagnosis of urinary tract infection. . A guide to when to use urine dipstick and MSU/CSU testing in the diagnosis of lower UTI is provided in Figure 1, see below.

Urine dipstick testing [Evidence level B]

Urine dipstick testing should NOT be used on urine samples collected from indwelling catheters because bacteria colonising the catheter and the inflammation caused by the catheter will give falsely positive nitrite and leucocyte esterase results respectively. [Evidence level B]

Laboratory urinary analysis (including culture) [Evidence level B]

The interpretation of urine samples is heavily dependent upon the clinical details and the method of urine collection. For example, in the absence of urinary symptoms any growth of bacteria is likely to represent urinary catheter colonisation only.  CA-bacteruria is not a disease and requires no treatment.

Urinary catheters inevitably become colonised with bacteria so the growth of bacteria from urine collected via an indwelling catheter cannot be used alone as evidence of a urinary tract infection.

In the microbiology laboratory urine samples may undergo the following tests:

  • White cell count
  • Red cell count
  • Epithelial cell count
  • Bacterial culture and identification
  • Antibiotic susceptibility testing

White cell count

  • A raised white cell count in urine is called a pyuria.
  • At LTHT we define pyuria as ≥ 104 leukocytes/mL of urine (>40 leukocytes/microlitre).
  • Causes of pyuria include the presence of a foreign body (e.g. catheter).
  • The urinary white cell count is therefore not useful in diagnosing a CAUTI.

Red cell count

  • A raised red cell count is called haematuria
  • At LTHT we define haematuria as >140 red cells/microlitre.
  • There are many causes of haematuria including infection and catheterisation.
  • Haematuria is a poor indicator of bacterial infection.

Epithelial cells

  • Epithelial cells are found on the surface of internal and external body surfaces.
  • Types of epithelial cells found in urine samples include vaginal epithelial cells, urethral epithelial cells and bladder epithelial cells.
  • Epithelial cells from these different sites have different physical appearances. When microscopy of urine sample was performed manually it was possible to report the cell type. If vaginal epithelial cells are seen it would suggest urine is contaminated by vaginal contents and that the urine quality was poor. Microscopy is now automated and this distinction cannot be made unless manual microscopy is completed.
  • In CSUs only bladder epithelial cells should be seen and these are not an indication of the quality of the urine sample.  

Bacterial count and culture

  • An estimate of the quantity of bacteria is made based on the number of bacteria growing on urine culture.
  • At LTHT we define a significant growth of bacteria as ≥105 colony forming units of pure growth/mL mid-stream specimen of urine (MSU). Urinary tract infections, principally lower UTIs, may be associated with lower bacterial counts.
  • Mixed growth from a urine sample can occur e.g. E. coli and Enterococcus spp. This increases the probability that the sample is contaminated.
  • Patients with urinary catheters often have a significant growth of bacteria. The growth in bacteria in a CSU does not in itself suggest CAUTI.
  • Rapid transport and culture, or special measures to assure preservation of the sample are essential for reliable laboratory diagnosis.
  • Delays and storage at room temperature allow organisms to multiply which generates results that do not reflect the true clinical situation.  Where delays in processing are unavoidable, refrigeration at 4°C or the use of a boric acid preservative is essential.

Antibacterial susceptibility testing

Routine susceptibility testing of urines is standardised i.e. it is not different depending upon if a patient has upper or lower tract infection. Therefore not all antibiotics reported on urine culture results are suitable for the treatment of upper UTI. For example, Nitrofurantoin is suitable for the treatment of lower UTI but not upper UTI. The susceptibility testing completed and reported may be modified if clinical details provided by the requester indicate upper tract infection.

Collecting urine sample(s) for Microbiology

  • Urine cultures are positive in around 90% of cases of lower UTI
  • Therefore for all suspected UTIs, if possible, a urine sample should be collected prior to starting empiric antimicrobial therapy.
  • For catheterised patients, the specimen should be obtained aseptically from a sample port in the catheter tubing. The specimen should not be taken from the collection bag.    
  • The urine sample for Microbiology should normally be sent in a red-topped (boric acid containing) sterile universal container.  Boric acid inhibits bacterial growth in the container post sample collection. The container should ideally be filled to the line as directed – a false negative culture result can occur with a small urine volume. 

Blood cultures [Evidence level B]

Where patients have sepsis blood cultures should be taken.

Non microbiological investigation

  • Blood tests.
    • Inflammatory markers e.g. neutrophils/CRP are not well correlated with a diagnosis of lower UTI or response to treatment. Their use is not routinely recommended.
  • Radiological imaging of the urinary tract is not normally indicated in patients with lower UTI. In patients with recurrent CAUTIs (≥3 per annum or ≥2 per 6 months) or upper UTI, renal ultrasound is recommended.

Urine appearance: Production of turbid urine is reported to have a sensitivity of 90% and a specificity of 66% for the presence of symptomatic bacteriuria. This means if a patient has clear urine it is unlikely they have a UTI, but does not exclude it. It also means many patients with turbid urine do not have a UTI. Turbid urine should not in itself be used to diagnose a UTI. 5/6[Evidence level B]

Figure 1: A summary of the process to be followed when considering if a patient has a lower urinary tract infection.

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Treatment
Non-Antimicrobial Treatment

Recommendation: In patients with catheter associated UTI (CAUTI) if the urinary catheter is no longer indicated, remove the catheter at the earliest possible opportunity [Evidence level D].

Recommendation: In patients with catheter associated UTI (CAUTI) consider catheter exchange when the urinary tract is considered to be sterile (>48 hours after treatment initiated) and the patient is still on antibiotics [Evidence level D].

Note: Urinary catheters do not need to be changed routinely in patients without clinical evidence of a urinary tract infection. This applies to patients with and without catheter associated bacteriuria.

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Empirical Antimicrobial Treatment

Recommendation: Catheterised patients with asymptomatic bacteriuria should not receive antibiotic treatment1 [Evidence level B].

Recommendation:  Patients with an indwelling catheter and symptomatic urinary tract infection should ideally have their catheter changed in addition to appropriate antibiotic treatment for infection [Evidence level C].

A dose of a suitable parenteral antimicrobial (e.g. Gentamicin) can be given immediately prior to the procedure but this is not necessary if the patient is already on appropriate therapy.

If upper UTI symptoms are present, the patients antimicrobial management should be as for acute pyelonephritis 1.

Before commencing an empirical regimen please check the results server to see if previous results are available to allow immediate initiation of directed antimicrobial therapy e.g. GP CSU sample.

Table 1: Empirical antimicrobial regimens for the treatment of CAUTI: Oral

Table 2: Empirical antimicrobial regimens for the treatment of CAUTI: Intravenous

These empirical regimes are suitable for most patients with suspected lower urinary tract infection. In some patients where the consequences of a lower urinary tract infection may be significant e.g. urological patients, alternative agents may be considered empirically e.g. Gentamicin IV. Consideration should be given to the risk benefit of alternative regimens e.g. renal impairment and ototoxicity.

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Directed Antimicrobial Treatment (when microbiology results are known)

When a bacterial pathogen is identified in a urine sample antibiotic susceptibility testing will be available to guide antibiotic therapy. The susceptibility results may have to be requested by phoning microbiology on extension 23962. Susceptibility results are not routinely released on CSU samples as it is not possible for microbiologists, without clinical information, to differentiate CAUTI from CA-bacteruria.

Table 3. Directed antimicrobial regimens- Oral [Evidence level B]

 

Treatment

Note

1st line

Trimethoprim 200mg 12-hourly1

 

2nd Line

Amoxicillin electronic Medicines Compendium information on Amoxicillin 500mg 8-hourly

Penicillin antibiotic: Avoid in penicillin allergy

3rd Line

Nitrofurantoin 50mg 6-hourly

Avoid in patients with suspected or known glucose-6-phosphate dehydrogenase (G-6-PD) deficiency.

Avoid Nitrofurantoin in patients with an estimated glomerular filtration rate (eGFR) of less than 45 ml/min. Please ensure CrCl is used as eGFR overestimates renal function in the elderly. In these patients, move to second line choice.

Avoid using liquid preparation due to costs.

Avoid at term in pregnancy

4th Line

Pivmecillinam electronic Medicines Compendium information on Pivmecillinam 400 mg stat dose then 200 mg 8-hourly

Penicillin antibiotic: Avoid in penicillin allergy

5th Line

Cefalexin electronic Medicines Compendium information on Cefalexin 500mg 8-hourly

Avoid in those with CDI risk including all patients over 65 years

6th Line

Fosfomycin PO 3g stat and repeated at 72 hours

Creatinine clearance <10mL/minute: Not recommended.

7th Line

Ciprofloxacin electronic Medicines Compendium information on Ciprofloxacin 500mg 12 hourly

C. difficile risk

8th Line

Co-amoxiclav electronic Medicines Compendium information on Co-amoxiclav 625mg 8-hourly

C. difficile risk

1-Trimethoprim can normally be replaced by PO Co-trimoxazole electronic Medicines Compendium information on Co-trimoxazole at 960mg 12-hourly.

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Duration of Treatment

Table 4. Treatment duration for CAUTI. [Evidence level B-D]

Table 4. Treatment duration

Recommended Treatments

Duration

All: Urinary catheter removed

If the urinary catheter has been removed antibiotics can be stopped when symptoms have resolved.

Catheter remains in-situ

7 days

Nitrofurantoin

Pivmecillinam electronic Medicines Compendium information on Pivmecillinam

Trimethoprim

Co-amoxiclav electronic Medicines Compendium information on Co-amoxiclav

Amoxicillin electronic Medicines Compendium information on Amoxicillin

Cefalexin electronic Medicines Compendium information on Cefalexin

Ciprofloxacin electronic Medicines Compendium information on Ciprofloxacin

5 days

Aztreonam electronic Medicines Compendium information on Aztreonam

Fosfomycin

3g repeated on day 3 (Day 0/3)

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Switch to oral agent(s)

Oral switch regimens should be based on the results of susceptibility testing results - Table 3.

If no susceptibility results available see Table 1: Empirical antimicrobial regimens for the treatment of CAUTI.

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Treatment Failure

To investigate treatment failure consider

  • Repeat urine testing for microbiological culture and susceptibility testing.
  • Alternative diagnoses.

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Referral Criteria

Consider a urological referral in patients with

  • Persistent haematuria
  • Features of urinary obstruction
  • History of pyelonephritis or previous genito-urinary tract surgery.
  • Frequent urinary tract infections (≥3 per annum or ≥2 per 6 months).
  • Abnormality on renal imaging e.g. ultrasound.

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Provenance

Record: 3504
Objective:
  • To improve the diagnosis and management of Catheter Associated Urinary Tract Infections (CAUTI) in Adults (≥ 16 years of age)
  • To provide evidence-based recommendations for appropriate diagnosis and investigation of Catheter Associated Urinary Tract Infections (CAUTI) in Adults (≥ 16 years of age)
  • To provide evidence-based recommendations for appropriate non-antimicrobial management of Catheter Associated Urinary Tract Infections (CAUTI) in Adults (≥ 16 years of age)
  • To provide evidence-based recommendations for appropriate empirical and directed antimicrobial therapy of Catheter Associated Urinary Tract Infections (CAUTI) in Adults (≥ 16 years of age)
  • To recommend appropriate dose, route of administration and duration of antimicrobial agents.
  • To advise in the event of antimicrobial allergy.
  • To set-out criteria for referral to specialists.
Clinical condition:

Catheter Associated Urinary Tract Infections

Target patient group: Adults >16 years
Target professional group(s): Secondary Care Doctors
Pharmacists
Adapted from:

Evidence base

Evidence base

  1. Hooton TM, Bradley SF, Cardenas DD, Colgan R, Geerlings SE, Rice JC, Saint S, Schaeffer AJ, Tambayh PA, Tenke P, Nicolle LE. Diagnosis, prevention, and treatment of catheter-associated urinary tract infection in adults: 2009 International Clinical Practice Guidelines from the Infectious Diseases Society of America. Clin Infect Dis. 2010 Mar 1;50(5):625-63.
  2. Haley RW, Hooton TM, Culver DH, Stanley RC, Emori TG, Hardison CD, Quade D, Shachtman RH, Schaberg DR, Shah BV, Schatz GD. Nosocomial infections in U.S. hospitals, 1975-1976: estimated frequency by selected characteristics of patients. Am J Med. 1981;70(4):947.
  3. Kunin CM, Chin QF, Chambers S. Morbidity and mortality associated with indwelling urinary catheters in elderly patients in a nursing home—confounding due to the presence of associated diseases. J Am Geriatr Soc 1987; 35:1001–1006.
  4. Gould CV, Umscheid CA, Agarwal RK, Kuntz G, Pegues DA. Guideline for prevention of catheter-associated urinary tract infections 2009. Healthcare Infection Control Practices Advisory CommitteeSOInfect Control Hosp Epidemiol. 2010;31(4):319.
  5. http://www.hpa.org.uk/webc/HPAwebFile/HPAweb_C/1194947404720
  6. SIGN Management of suspected bacterial urinary tract infection in adults A national clinical guideline July 2006.
  7. Nicolle LE, Bradley S, Colgan R, Rice JC, Schaeffer A, Hooton TM. Infectious Diseases Society of America guidelines for the diagnosis and treatment of asymptomatic bacteriuria in adults. Clin Infect Dis. 2005 Mar 1;40(5):643-54.
  8. NICE: Multidrug resistant urinary tract infections: fosfomycin trometamol https://www.nice.org.uk/advice/esuom17/chapter/key-points-from-the-evidence
  9. PHE: Management of infection guidance for primary care for consultation and local adaptation

Evidence levels:
A. Meta-analyses, randomised controlled trials/systematic reviews of RCTs
B. Robust experimental or observational studies
C. Expert consensus.
D. Leeds consensus. (where no national guidance exists or there is wide disagreement with a level C recommendation or where national guidance documents contradict each other)

Approved By

Improving Antimicrobial Prescribing Group

Document history

LHP version 2.0

Related information

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