UTIs & Nephrolithiasis Flashcards
What are some clinical signs of cystitis? What type of symptoms are usually absent?
Present: dysuria, urgency, frequency, suprapubic pain
Absent: systemic signs - fever, chills, etc.
In cystitis, describe lab findings on:
- Urinalysis
- Dipstick
- Culture
- Cloudy urine with > 10 WBCS/hpf
- Positive leukocyte esterase & nitrites
- > 100,000 CFU
What are the top 5 most common microorganisms causing cystitis?
- E coli
- Staph saprophyticus
- Klebsiella pneumoniae
- Proteus mirabilis
- Enterococcus faecalis
What is sterile pyuria?
Pyuria ( > 10 WBCs/hpf + leukocyte esterase positive) but negative urine culture
What are some causes of sterile pyuria?
- Urethritis due to Chlamydia or Neisseria gonorhoeae
- Stones
- Cancer
- TB
What do people with pyelonephritis present with?
Systemic signs: fever, etc + flank pain
Lab findings: WBC casts, leukocytosis
+ Symptoms of cystitis
What are the three most common pathogens causing pyelonephritis?
- E coli (90%)
- Klebsiella
- Enterococcus faecalis
What are the consequences of multiple incidences of acute pyelonephritis?
Interstitial fibrosis & atrophy of tubules
What effects does chronic pyelonephritis have on the kidney?
- Scarring in cortex (scarring specifically in upper and lower poles characteristic of VUR)
- Blunted calyces
- Waxy casts in urine
What is seen in the kidney tubules of an individual with chronic pyelonephritis? What does this resemble?
Contains eosinophilic proteinaceous material –> resembles thyroid follicles
Name two risk factors for the development of kidney stones.
- Increased concentration of solute in urinary filtrate
2. Low urine volume
What do individuals with a kidney stone present with?
- Colicky pain
- Hematuria
- Unilateral flank tenderness
What does one do about a kidney stone?
Wait. Usually passes within hours. If it doesn’t, surgery!
What is the most common type of kidney stone?
Calcium oxalate and/or calcium phosphate
How do you treat someone with recurrent calcium stones?
HCTZ –> Ca sparing diuretic (increased Ca absorption via enhanced Na Ca exchanger)
Or citrate
Calcium oxalate crystals are associated with what?`
- Ethylene glycol
- Vitamin C abuse
- Crohn disease
What is the most common cause of ammonium magnesium phosphate stones?
Infection with urease-positive organisms (Proteus, Klebsiella)
What type of stones do ammonium magnesium phosphate stones form?
Staghorn calculi in renal calyces –> increase risk of UTIs
How are ammonium magnesium phosphate stones treated?
Surgical removal & eradication of pathogen to prevent recurrence
What is the only type of stone that is radiolucent?
Uric acid stones
What are risk factors for developing uric acid stones?
- Hot, arid climates
- Low urine volume
- Acidic pH
What type of stones are commonly seen in gout patients?
Uric acid stones
How do you treat someone with uric acid stones?
- Hydration
- Alkalinization of urine –> potassium bicarbonate
- Allopurinol in gout patients
Which type of stone is commonly seen in children?
Cysteine stones
What are cysteine stones associated with?
Cystinuria (decreased cysteine reabsorption because of tubular defects)
What type of stones are cystein stones generally?
Staghorn calculi
How do you treat someone with cysteine stones?
Hydration and alkalinization of urine
What types of diseases can increase the risk for uric acid stones?
Diseases with increased turnover of cells –> hyperuricemia
- Leukemia, myeloproliferative disorders
