Pyelonephritis

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Definition
• It is Bacterial infection of the renal pelvis,
tubules and interstitial tissue of one or both
kidneys
• potentially organ- and/or life-threatening infection that
characteristically causes some scarring of the kidney
with each infection and may lead to significant
damage to the kidney
Pathophysiology and aetiology
• Infection usually ascends from the urethra most
bacterial causes bowel organisms eg Ecoli (70
-80%)
• Hospital-acquired infections may be due to
coliforms and enterococci.
• Haematogenous spread is rare eg Staph aureus
• Frequently due to ureterovesical reflux
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 5 3 -7 2 1 8 -5 7

Causes of UTI's Outpatients Inpatients

(%) (%)
Escherichia coli 53-72 18-57

Coagulase negative 2-8 2-13

Staphylococcus

Klebsiella 6-12 6-15

Proteus 4-6 4-8
Morganella 3-4 5-6
Enterococcus 2-12 7-16
Staphylococcus 2 2-4
aureus
Staphylococcus 0-2 0.4
saprophyticus

Pseudomonas 0-4 1-11

Candida 3-8 2-26
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Complicated UTI Etiology (%)
• Escherichia coli 21 – 54
• Klebsiella pneumoniae 1.9 – 17
• Enterobacter species 1.9 – 9.6
• Citrobacter species 4.7 – 6.1
• Proteus mirabilis 0.9 – 9.6
• Providencia species 18
• Pseudomonas 2 – 19
aeruginosa 6.1 – 23
• Enterococci species

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 Microbiology of Community-Acquired
Urinary Tract Infection
Dysuria-Pyuria Sydrome in Females
Children Adults
More frequent . Escherichia coli . Escherichia coli
. Staphylococus
saprophyticus (young,
sexually active patient)
Less Frequent . Other Enterobacteriaceae . Other Enterobacteriaceae
. Enterococci . Enterococci
. Streptococcus agalactiae

Other Community-Acquired Infection

Children Adults
More frequent . Escherichia coli . Escherichia coli
Less Frequent . Other Enterobacteriaceae . Other Enterobacteriaceae
. Enterococci . Enterococci
Microbiology of Nosocomial Acquired
Urinary Tract Infection in Children or Adult

Catheter-Associated Short-Term (< 30 –d) Catheterization

More frequent . Escherichia coli
Less Frequent . Other Enterobacteriaceae
. Pseudomonas Spp.
. Staphylococcus epidermidis

Catheter-Associated Long-Term (> 30 –d) Catheterization

More frequent . Providencia stuartii

. Pseudomonas Spp.
. Escherichia coli
. Other Enterobacteriaceae
Less Frequent . Staphylococcus epidermidis
 Pyelonephritis may be acute or chronic
Pathology
• Kidneys enlarge
• Interstitial infiltration of inflammatory cells
• Abscesses on the capsule and at
corticomedullary junction
• Result in destruction of tubules and the
glomeruli
• When chronic, kidneys become scarred,
contracted and nonfunctioning

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 Pathogenesis
• Rectal and/or vaginal reservoirs
• Colonization of perianal area
• Bacterial migration to
perivaginal area
• Bacteria ascend through
urethra to bladder
• Intercourse may contribute
urethral colonization
and ascending infection
• ASB in 1st trimester of
pregnancy may cause
pyelonephritis in 3rd trimester

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 Clinical Manifestations of acute
pyelonephritis
• Symptoms develop rapidly (<24 hours) and may include:
• Acutely ill
• Chills
• Fever >38°C
• Flank pain and
• Nausea/vomiting
• Renal angle tenderness
• Confusion in elderly
• Leukocytosis
• Pyuria
• Bacteriuria
In addition symptoms of lower tract involvement
• Dysuria
• Frequency 9
 Risk factors
• Mechanical:
– Structural abnormalities to the kidneys and the urinary tract
• vesicoureteral reflux (VUR) especially in young children,
• calculi
• urinary tract catheterisation
• nephrostomy
• pregnancy
• neurogenic bladder (e.g. due to spinal cord damage, spina bifida
or multiple sclerosis) and
• prostate disease (e.g. benign prostatic hyperplasia) in men
• bladder tumours
• urethral strictures
• Constitutional:
– diabetes mellitus, immunocompromised states
 Diagnosis
• Is not always straightforward
• A number of studies using immunochemical
markers have shown that many women, who
initially present with lower tract symptoms,
actually have pyelonephritis
• The extremes of age, the presentation may be so
atypical (feeding difficulty or fever)
• In the elderly presentation may be mental status
change or fever

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 Laboratory Diagnosis of
pyelonephritis
Urinalysis
 10 WBC/hpf is the usual upper limit of normal
 Positive result on leukocyte esterase dipstick
test correlates well for detecting >10 WBC/hpf,
with a specificity of 65%–95%, and sensitivity
of 75%–95%
 Positive nitrate dipstick test result for
bacteriuria is only moderately reliable;
false-negative results are common
 Urine culture and sensitivity
 Blood culture

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Radiological investigations
• CT scan
• IVP=intra venous pyelogram
• Radionucleotide imaging with gallium
citrate and indium-111-labeled WBCs

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 Micturiting
cystourethrogram
(MCW showing
bilateral VUR,
grade IV on right
and grade III on
left-side. There is
bilateral ureteral
and pelvic dilation
with blunting of
fornices in the
right kidney.

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 Bilateral reflux
extending into the
pelvicalyceal
systems of the
kidney without
dilatation of the
calyces or ureters.
(Note catheter in
bladder)

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Medical Management
• Treated as outpatients if there is no nausea,
vomiting or dehydration and other signs and
symptoms of sepsis
• Very ill patients and all pregnant women are
hospitalized at least for 2 to 3 days for parenteral
therapy
• 2 weeks course
• Bactrim
• Ciprofloxacin
• Gentamicin with or without amoxicillin

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Problem
• Chronic or recurring symptomless
infection persisting for months or years
• Another 6 weeks course if relapse
• Follow up urine culture 2 weeks after
completion of therapy

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 Chronic Pyelonephritis
Repeated bouts of acute pyelonephritis may lead
to chronic pyelonephritis
Clinical manifestations
• No symptoms of infection unless an acute
exacerbation occurs
• Fatigue
• Head ache
• Poor appetite
• Polyuria
• Excessive thirst
• Weight loss
Progressive scarring  renal failure
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Assessment and diagnostic findings
• IVP
• Serum creatinine
• Blood urea
• Culture and sensitivity
Complications
ESRD=end stage renal disease
Hypertension
Kidney stones
Medical management
• According to C&S result
• Drugs carefully titrated if renal function is impaired
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Nursing management
• Fluid balance – I / O chart
• Fluids encouraged unless contraindicated
• 4th hourly temp
• Antibiotics
• Bed rest
• Teach how to prevent recurrent infections :
adequate fluids, emptying the bladder regularly
and performing recommended perineal hygiene
taking antibiotics as prescribed

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 IDSA Treatment Guidelines:
Acute Uncomplicated Pyelonephritis
• Mild or moderate symptoms:
Outpatient treatment (total of 7–14 days)
oral treatment:
Fluoroquinolone
TMP/SMX, if uropathogen is known to
be susceptible
If Gram-positive pathogen: amoxicillin
or amoxicillin-clavulanate

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 Treatment of Pyelonephritis
• Eradicate pathogens in kidney and
urothelium, and treat/prevent bacteremia
Hospitalized patients:
• IV antibiotic first 48–72 hours followed by 7
days of oral antibiotic therapy
– Fluoroquinolone IV, then PO
– Aminoglycoside ± ampicillin IV, then TMP/SMX
PO
– Third-generation cephalosporin IV, then TMP/SMX PO
Ambulatory patients: 7–14 days of PO
therapy with one of the antimicrobials above
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Scarred and contorted kidneys

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Destruction of approximately 70% of the kidney. Numerous dilated calyces with
yellow-brown calculi. The central necrotic areas are surrounded by dense
fibrosis.

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