Urinary Tract Infections & Pyelonephritis

Attending Version
Urinary Tract Infections & Pyelonephritis
created by Dr. Jernigan
Recognize clinical presentation/definition of pyelonephritis
Identify reasons to hospitalize
Identify common organisms
Be able to choose appropriate initial antibiotics
Recognize underlying risk factors, and differences between men and women
Understand indications for imaging & additional work-up
Understand etiology of catheter related infections
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.
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.
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
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
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
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.
1. 3rd generation cephalosporins
2. Flouroquinolones
3. Aminoglycoside (if normal kidney function and not high risk for renal
4. If enterococcus suspected: ampicillin plus aminoglycoside (be aware of
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
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).
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