12 Pyelonephritis. Urinary tract infections Flashcards
what is pyelonephritis ?
inflammation of the parenchyma and lining of the renal pelvis
what are the risk factors for pyelonephritis ?
hematogenous route :
septicemia
infective endocarditis
ureteral obstruction
ascending infection :
female - shorter urethera
catheterisation
obstruction of urine flow / incomplete bladder emptying
- prostatic hypertrophy
- renal calculi
- tumor
loss of neurological control of bladder and sphincter - paraplegia and multiple sclerosis
vesicoureteral reflux
diabetes mellitus
not regular sanitisation / frequent sexual intercourse
what are the etiological agents of pyelonephritis ?
usually enteric gram negative rods ecoli proteus mirabilis citrobacter klebsiella eneterobacter pseudomonad aeruginosa
gram positive
staph saprophytic
staph epidermidis enterococcus
corynebacteria
fungi - candida
protozoa - tichomonas vaginalis
what are the clinical features of pyelonephritis ?
acute
acute onset of pain
dysuria
Costovertebral angle tenderness: pain upon percussion of the flank (usually unilateral)
high fever - picket fence of 72hr
nausea
vomiting
cloudy urine , foul smelling
cystitis : increased frequency and urgency to pee
suprapubic pain
hematurea
======
chronic
perisitant flank or abdominal pain
=====
XG
recurrent fevers
painful kidney mass
loss of function of the affected kidney
what is the classification of pyelonephritis ?
acute
emphysematous pyelonephritis
complication
chronic = more often in children
- chronic reflux associated - posterior urethras valve abnormality - and reflux
- chronic obstructive - calculi or tumors
xanthogranulomatous pyelonephritis
diagnosis of pyelonephritis ?
non specific findings of the UTI
pyuria - positive esterase on dipstick test
leukocytouria
bacteria
positive nitrites on dipstick test = such as coli
hematurea
=======
urine ph more than 7 = urea splitting organism
WBC casts
======
urine culture
intravenous pyelogram - enlarged kidneys with poor flow of dye thriught the kidneys
====
blood culture - 2 sets
====
abc
leukocytosis
inflammatory markers
======
us not usually doe in patients with suspected acute uncomplicated pyelonephritis
US - abcess ,
edemtaous renal parenchyma
loss of corticomeduallry differentiation
ct
complication of acute pyelonephritis ?
papillary necrosis - DM , UT obstruction
pyonephrosis
perinephric abcess - extension through renal capsule
septics shock
where does acute pyelonephritis usually affect ?
exudative purulent localised inflammation of the renal pelvis
can go to the renal
the cortex - spares the glomerulus and vessels
purulent inflammation of the interstitialum and the the renal tubules
can cause tubular necrosis
what is the characteristic feature of chronic pyleoneprhits ?
chronic pyelonephritis by obstructive uropathy :
dilated pelvis
thin cortex
dilated calyces
thickened capsule
diffuse asymmetric scaring and fibrosis of the corticomedually junction
vesicouriteral reflex - irregular scarring on poles and thickened capsule there and thin cortex
blunted and dilated calyces - from recurrent urinary reflux
cortex is normal
histology - interstitial fibrosis
tubular atrophy
sclerosis of glomeruli
eosinophilic casts in tubules resembling thyroid tissue thyrioidisation of the kidney
what causes xanthogranulomatous pyelonephritis ?
chronic pyelonephritis characterized by chronic destructive granuloma formation, with lipid laden macrophages
Associated with Proteus mirabilis and Escherichia coli infections with chronic urinary obstruction
what are the causes for emphysematous pyelonephritis ?
exclusively in poorly controlled diabetic patients
production of gas in renal and perinephritisc tissue
bilateral papillary necrosis
rise in serum creatinin levels
Typically caused by E. coli or K. pneumoniae
Treatment includes IV antibiotics, percutaneous drainage, and, in some cases, nephrectomy.
complication of chronic pyelonephritis ?
ESRD
papillary necrosis
focal glomerulosclerosis
treatment of pyelonephritis ?
Empiric antibiotic therapy for uncomplicated pyelonephritis
Most patients can be treated with an oral fluoroquinolone (e.g., ciprofloxacin, levofloxacin ) for 5–7 days
Alternatives
Amoxicillin-clavulanate for 10–14 days
or
Cefpodoxime for 10–14 days
Consider a single dose of a broad-spectrum parenteral antibiotic prior to the administration of oral antibiotics, especially when the local rates of drug-resistant E. coli are unknown or known to be > 10%.
Ceftriaxone
OR gentamicin
Supportive care
Encourage the patient to drink adequate amounts of fluids.
Analgesics as needed (see pain management)
Antiemetics as
=============
Patients with complicated acute pyelonephritis should be admitted to the hospital and started on parenteral empiric antibiotic therapy
Not severely ill and no risk factors for multidrug-resistant bacterial infection
A fluoroquinolone Ciprofloxacin or An extended-spectrum cephalosporin Ceftriaxone
Consider adding an aminoglycoside until culture results are available.
Gentamicin
============
Severely ill (i.e., septic) and/or with risk factor(s) for multidrug-resistant gram-negative bacterial infection
A carbapenem Meropenem or An extended-spectrum penicillin with a β-lactamase inhibitor (e.g., piperacillin-tazobactam ) or An extended-spectrum cephalosporin Ceftriaxone
==========
Enterococcus or MRSA suspected
vancomycin
Daptomycin
Linezolid
If recurrence is caused by the same organism despite adequate treatment, then prolong the course of antibiotics for 6 weeks.
treatment for chronic pyelonephritis ?
Long-term antibiotics (e.g., oral trimethoprim-sulfamethoxazole or nitrofurantoin) may be necessary.
what are the main pathogens causing urinary tract infections ?
Infection ascends from the urethra to the bladder
Can ascend further to the ureters
Escherichia coli: leading cause of UTI (approx. 80%)
Staphylococcus saprophyticus: 2nd leading cause of UTI in sexually active women
Klebsiella pneumoniae: 3rd leading cause of UTI
Proteus mirabilis
(all of the above Produces ammonia, giving the urine a pungent or irritating smell
Associated with struvite stone formation)
candida - for immune compromised
what are the risk factors for urinary tract infections ?
SAME FOR PYELONEPHRITIS
Prevent bladder emptying and/or result in urinary stasis
Examples include:
Benign prostatic hyperplasia
Congenital malformations causing vesicoureteral reflux
Urinary bladder diverticulum
Neurogenic bladder
Urinary tract calculi
female:
urethra is shorter and the anal and genital regions are in close proximity
male - higher for uncirmbscribed
Pregnancy: hormonal changes during pregnancy → urinary stasis and vesicoureteral reflux → increased risk of UTIs
post menopause
Postmenopause: ↓ estrogen → ↓ vaginal lactobacilli → ↑ vaginal pH → ↑ colonization by E. coli
catheterisation
spermicide and diaphragm use
sexual intercourse
diabetes mellitus
what i the classification of urinart tract infections ?
Upper UTI: upper urinary tract comprises kidneys and the ureters (pyelonephritis)
Lower UTI: lower urinary tract comprises the bladder (cystitis, the most common location of UTI), urethra (urethritis), and prostate in males (prostatitis)
UTI and pylenephritis is divided into complicated and uncomplicated through what ?
Uncomplicated UTI: UTI in immunocompetent, premenopausal, nonpregnant women without conditions predisposing them to infection or therapy failure
Complicated UTI: UTIs in men, pregnant or postmenopausal women, children, and individuals with factors predisposing them to infection or therapy failure. Such factors include:
functional or anatomical abnormalities (e.g., BPH, obstruction, stricture)
UTI that spreads beyond the bladder (e.g., sepsis, prostatitis)
History of urological pathologies (e.g., neurogenic bladder, kidney cysts, stones)
History of impaired renal function or renal transplantation
Diabetes mellitus or other metabolic disorders
Immunocompromise (e.g., transplant recipients, HIV/AIDS)
Recent history of instrumentation (e.g., cystoscopy
what is the definition of recurrent UTI ?
≥ 3 infections in one year or ≥ 2 infections in 6 months
what are the clinical features of UTI ?
Lower urinary tract infection : Hematuria Increased urinary frequency Urinary urgency Suprapubic tenderness Dysuria
UUTI:
same as pyelonephritis
diagnosis of UTI ?
Pseudomonas aeruginosa: blue-green pigment
Urinalysis
Urinalysis collection method:
Clean-catch midstream : necessary to avoid contamination with vaginal or skin flora
Diagnostic criteria for UTI:
> Pyuria: ≥ 5–10 WBC/HPF
> Bacteriuria: abnormal number of bacteria present in urine sample
Findings indicative of UTI :
Positive leukocyte esterase: an enzyme produced by WBC that indicates pyuria
Positive nitrites: indicates presence of bacteria that convert nitrates to nitrites, which are most commonly gram-negative bacteria (e.g., E.coli)
Positive urease: indicates presence of urease-producing organisms (e.g., Proteus, Klebsiella, S. saprophyticus), which cause the urine to become more alkaline (pH > 7)
Other findings
Leukocyte casts will likely be absent with lower UTIs.
URINE CULTURE
Significant bacteriuria: defined as ≥ 10^5 CFU/mL; confirms the diagnosis
Typical colony findings
E. coli: intensely pink on MacConkey agar
Klebsiella pneumoniae: viscous colonies
Proteus mirabilis: target or branching appearance on agar
Diagnostic imaging
Indications
> Persistent symptoms (after > 48–72 hours of appropriate antibiotic therapy)
> Recurrent symptoms (within a few weeks of appropriate treatment)
> Suspected urinary tract obstruction
> Severe illness (e.g., septic shock)
CT scan without contrast
First choice
Assessment of urinary stones, obstruction, tumors, cysts, trauma
Ultrasound
potential urinary obstruction
Can help diagnose pyelonephritis
treatmnet of UTI ?
uncomplicated UTI
increased fluid intake
empiric treatmnet
LOCAL RESIATNCE PATTERN SHOULD GUIDE THE CHOICE OF EMPERIC THERAPY
Phenazopyridine, a urinary analgesic
First-line treatment
Fosfomycin (single dose): should be avoided in suspected pyelonephritis
Nitrofurantoin for 5–7 days: should be avoided in patients with renal insufficiency or in suspected pyelonephritis
Trimethoprim-
sulfamethoxazole (TMP-SMX) for 3 days: should be avoided in areas with high resistance (> 20%)
SECOND LINE Fluoroquinolones (e.g., ciprofloxacin, levofloxacin)
Oral cephalosporins (e.g., cefpodoxime, cefdinir)
Penicillins (e.g., amoxicillin-clavulanate)
what is the antibiotic therapy for complicated UTI?
Treatment is generally given for 7–14 days in complicated UTIs.
Antibiotics of choice
Fluoroquinolones (e.g., ciprofloxacin, levofloxacin)
TMP-SMX [34]
Considerations for treatment in men
Fosfomycin and nitrofurantoin are not treatment options, as they do not penetrate prostatic tissue and prostatitis is a common issue with UTI since its close to he bladder
antibiotic therapy for recurrent infections ?
restarted on the same treatment for 2 additional weeks and a urine culture should be obtained.
Chemoprophylaxis :
Postcoital prophylaxis
Nitrofurantoin or a single dose of TMP-SMX
esp in women trying to conceive
Continuous prophylaxis with low-dose TMP-SMX for up to 6 months
prevent UTI and pyelonephritis ?
Increased fluid intake
Timely bladder voiding
Postcoital voiding
Adequate genital hygiene
Intermittent straight catheterization
Indicated for individuals with neurogenic bladder
