Attending Version

Urinary Tract Infections & Pyelonephritis

created by Dr. Jernigan

Objectives:

1.  Recognize clinical presentation/definition of pyelonephritis

2.  Identify reasons to hospitalize

3.  Identify common organisms

4.  Be able to choose appropriate initial antibiotics

5.  Recognize underlying risk factors, and differences between men and women

6.  Understand indications for imaging & additional work-up

7.  Understand etiology of catheter related infections

References:

1. Guidelines for Antimicrobial Treatment of Uncomplicated Acute Bacterial Cystitis and Acute Pyelonephritis in Women (guidelines from the IDSA) Clinical Infectious Disease 1999;29:745-58

2. Diagnosis and Management of Acute Pyelonephritis in Adults. American Family Physician 2005;71:933-42

3. Risk Factors for a Poor Outcome After Therapy for Acute Pyelonephritis. BJU 2006; 98:141-7

4. Urinary Tract Infections in Men. Annals of Internal Medicine 1989 Jan 15;110(2) 138-50

5. UpToDate

Acute pyelonephritis: symptoms; diagnosis; and treatment

Indications for radiologic evaluation in acute pyelonephritis

Urinary tract infection associated with indwelling bladder catheters

6. Nosocomial Urinary Tract Infections. Mandell, Douglas, and Bennett’s Principles and Practices of Infectious Diseases, 6th edition, Volume 2.
Case

HPI: 48 yo woman presents to the ER c/o N/V & back pain. On further questioning, she reports initially feeling ill w/ dysuria, frequency, urgency and low back pain 5-7 days ago. 2 days ago she developed fevers & chills. Over the past day she has worsened with the development of severe right flank pain 9/10, rigors & nausea & vomiting.

PMHx: HTN

Meds: lisinopril 10 mg daily

Allergies: NKDA

Social: married school-teacher

Physical: T 39.8, bp 95/55, HR 120: RR26: sat 92%RA

Gen: appears ill & uncomfortable, A&O

HEENT: oral mucosa dry

Lungs: CTA
CV: tachycardic, RR, no m/r/g

Back: + right CVAT

Abd: suprapubic tenderness

Ext: no c/c/e

Labs: wbc 10k, 90% neutrophils, hct and platelets wnl

Electrolytes wnl, bun 24, creatinine 1.0

UA: ++LE, TNTC WBCs with clumps, many bacteria

1.  Should she be managed as an outpatient or an inpatient?

Inpatient (or at least ER observation). She does not have any risk factors for a complicated course, but has clinical signs and symptoms which make it likely she would be unable to tolerate oral medications (N/V, severe pain, high fever & dehydration). In addition, she needs fluid resuscitation.

2.  Which antibiotic regimen would you choose?

A.  Cefotaxime 1 g IV q 12 hours

B.  Ciprofloxacin 400 mg IV q 12 hours

C.  Ampicillin IV & Gentamicin IV

D.  Any of the above

Correct answer is D. All have appropriate coverage for GNRs, which are the most likely organisms.

3.  What further testing do you want?

A.  Blood cultures

B.  Abd CT- stone protocol

C.  Renal US

D.  None of the above

Correct answer D. Blood cultures are positive in 20% of patients, & do not correlate with worse prognosis/course. Initial imaging is not indicated in women with typical presentations. In women without all of the classic symptoms, should generally perform a pelvic exam.

4.  Would your management change if she were a man?

Some would recommend imaging, but this recommendation is not evidence based. Most men have a functional or anatomic abnormality, but generally they respond well to 14 days of antibiotics.

5.  48 hours later, her symptoms have improved: pain now 2/10, N/V resolved but her T max is 38.7. Urine culture grew E. coli sensitive to all antibiotics. What do you want to do?

Fevers may take 72 hours to resolve. Since she is improving, further work up or change in treatment is not needed. If she were worsening, or still febrile >72 hours after starting antibiotics, would recommend imaging to look for kidney stones, obstruction, or abscess.

Other questions (not related to case)

True or false:

1. Suprapubic catheters reduce risk of urinary tract infections compared to foley catheters.

False. Suprapubic catheterization postpones, but does not reduce, risk over time for acute pyelonephritis, bladder stones, and upper tract stones. It does reduce risk of urethral strictures, epididymitis, and periurethral abscesses.

2. UTIs are the most common source of bacteremias in nursing homes.

True. Indwelling catheters are the leading risk factor for bacteremia in nursing home patients. Patients are 59 times more likely to be bacteremic over a 1 year period if indwelling catheter is present. E. coli is the most common organism isolated in these cases.

3. Trimethoprim-sulfamethoxazole is acceptable empiric antibiotic coverage for treatment of UTIs.

False. Over 20% of E. coli are now resistant to bactrim, making it unacceptable for empiric coverage. Flouroquinolones are the accepted initial coverage.

Outline for discussion

Clinical Presentation of UTIs/pyelonephritis:

1.  Fever >38 degrees Celsius

2.  Flank/CVA pain

3.  Pyuria

4.  Symptoms of lower UTI may or may not be present (dysuria, frequency, urgency, etc)

5.  Urine culture at least 10,000 CFU (consider diagnosis with lower counts in men & pregnant women). Urine culture positive in 90 % patients.

Risk Factors for developing Pyelonephritis (in women):

1.  frequency of sexual intercourse >= 3 per week in past 30 days

2.  recent UTI

3.  diabetes

4.  recent incontinence

5.  new sexual partner in past 1 year

6.  recent spermicide use

7.  UTI history in mother

Pyelonephritis/UTI in Men:

1.  50-80 % of men with UTI have genitourinary abnormalities.

2.  Signs & symptoms of UTI are similar to women

3.  As in women, E. coli most common organism

4.  Most will resolve without relapse with 7-10 days antibiotics for UTI; 14 days for pyelonephritis.

5.  If underlying prostatitis suspected, recommend 6 wks antibiotics.

6.  Some experts interpret high incidence of GU abnormalities as indication for imaging in all men, although others recommend only imaging those with recurrent infection, since majority respond to treatment and do not relapse.

Indications for Hospitalization:

1.  Inability to take oral medications (nausea/vomiting)

2.  Severe illness (i.e. high fever- T>39, dehydration, severe pain)

3.  Concerns about compliance

4.  Complicating medical problems

Organisms:

1.  Escherichia coli 70-95% of cases; increasing TMP/SMX resistance seen

2.  Klebsiella pneumoniae

3.  Enterobacter aerogenes

4.  Proteus mirabilis

5.  Enterococcus faecalis

6.  Staphylococcus saprophyticus

7.  Staphylococcus aureus - look for other source, usually a marker of disseminated infection.

Antibiotics:

1.  3rd generation cephalosporins

2.  Flouroquinolones

3.  Aminoglycoside (if normal kidney function and not high risk for renal insufficiency)

4.  If enterococcus suspected: ampicillin plus aminoglycoside (be aware of creatinine).

Duration of Antibiotics:

1. 10-14 days for pyelonephritis

2. Studies comparing 6 weeks to 2 weeks found no improvement in outcomes.

3. One study comparing 1 week to 3 weeks found higher relapse, although others found 7 days comparable to 14 days. 3 days of therapy had higher relapse rates.

Risk Factors for Complicated Course:

1.  Need for Hospitalization

2.  Diabetes

3.  Resistant Organisms

4.  Nephrolithiasis

5.  Indwelling catheter

6.  Obstruction

7.  Neurogenic Bladder

8.  Vesicoureteral Reflux

9.  Renal Failure

10.  Renal Transplant

11.  Immunosuppression

12.  Hospital Acquired Infection

13.  Age >65

14.  Sepsis

Pyelonephritis/UTIs associated with indwelling catheters:

1. UTIs from catheters is the most common nosocomial infection.

2. Almost 100% of foley catheters will be colonized after 30 days.

3. With time, presence of bacteria illicit inflammatory response, causing cystitis, pyelonephritis, bacteremia.

4. Majority of organisms responsible are from the patient’s colonic flora.

5. Risk factors for catheter related infection: duration of use (most important risk factor), diabetes, elevated creatinine, female, errors in catheter care, absence of antibiotics.

6. Most studies have required 100, 000 CFU on urine culture for diagnosis (in association with fever, urgency, urethral/pelvic pain).

7. Asymptomatic catheter-associated bacteriuria should not be treated.

8. Treatment of symptomatic infection: change catheter, treat for 7-10 days with appropriate antibiotics (oral if clinically able and organism susceptible). May need longer duration if complications occur or very resistant organism present.

9. S. aureus in the urine, even in catheterized patients, should prompt investigation for other sources (bacteremia, endocarditis, and/or abscess).

10. Candida albicans is increasingly common in nosocomial catheter infections. Most cases are asymptomatic, and do not need treatment other than changing catheter (would treat if patient symptomatic, or neutropenic, transplant patient, etc…).

11. Prevention: do not use catheters unless absolutely necessary, remove as soon as possible, condom catheter/intermittent catheterization are other options.

Post Module Evaluation

Please place completed evaluation in an interdepartmental mail envelope and address to Dr. Wendy Gerstein, Department of Medicine, VAMC (111).

1) Topic of module:______

2) On a scale of 1-5, how effective was this module for learning this topic? ______

(1= not effective at all, 5 = extremely effective)

3) Were there any obvious errors, confusing data, or omissions? Please list/comment below:

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5) Please provide any further comments/feedback about this module, or the inpatient curriculum in general:

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Attending Resident (R2/R3) Intern Medical student