Urinary Tract Infection, Nephrolithiasis, Chronic Renal Failure

Question 1

Which organs are affected in Urinary Tract Infection? What usually causes it? What are some risk factors?

Answer 1

Urethra, Bladder or Kidney. Most commonly arises due to ascending infection; increased incidence in females. Risk factors include sexual intercourse, urinary stasis and catheters.

Question 2

What is cystitis? How does it present? What are the laboratory findings?

Answer 2

Infection of the bladder. Presents as dysuria, urinary frequency, urgency an suprapubic pain; systemic signs are usually absent. Lab findings: Cloudy urine with > 10 WBCs/high power field 2. Dipstick sowhs positive leukocyte esterase (due to pyuria) and nitrites 3. Culture shows greater than 100,000 colony forming units (gold standard)

Question 3

What is the etiology of Urinary Tract Infection?

Answer 3

1. E coli (80%) 2. Staphylococcus saprophiticus - increased incidence in young sexually active women 3. Klebsiella pneumoniae 4. Proteus mirabilis (alkaline urine with ammonia scent) 5. Enterococcus faecalis

Question 4

You get a urine sample that has pyuria (>10WBCs/hpf and lekocyte esterae) with a negative urine culture. What does it suggest?

Answer 4

Urethritis due to Chlamidya trachomatis or Neisseria gonorrhoeae

Question 5

A patient presents with fever, flank pain, WBC casts and leukocytosis. He also has increased urinary frequency and painful urination. What does he have? What causes this/ What organisms are usualy implicated?

Answer 5

Pyelonephritis which is infection of the kidney. Usually due to ascending infection. Increased risk with vesicoureteral reflux. Most common pathogens are E coli (90%), Enterococcus faecalis, Klebsiella species

Question 6

What is chronic pyelonephritis? What is it caused by? What can it lead to? What is seen on histology?

Answer 6

Interstitial fibrosis and atrophy of tubules due to multiple bouts of acute pyelonephritis. Due to vesicouureteral reflux (Children) or obstruction. Leads to cortical scarring with blunted calyces. Scarring at upper and lower poles is characteristic of vesicoureteral reflux.

Question 7

You are examining a slide of atrophic tubules that contain eosiophilic proteinaceous material that resemle thyroid follicles. The patient’s chart is also indicative of waxy casts. What is this patient suffering from?

Answer 7

Chronic pyelonephritis

Question 8

What are the risk factors for nephrolithiasis? How does it present? Is it unilateral or bilateral? How long does it take for the stone to pass through?

Answer 8

Risk factors include high concentration of solute in the urinary filtrate and low urine volume. Presents as colicky pain with hematuria and unilateral flank tenderness. Stone is usually passed within hours.

Question 9

What are the most common causes of end stage renal failure? How is it treated? What risk is there during treatment?

Answer 9

Diabetes mellitus, HTN and glomerular disease. Treatment involves dialysis or renal transplant. Cysts often develop with shrunken end-stage kidneys during dialysis, increasing risk for renal cell carcinoma.

Question 10

What are the clinical features of chronic renal failure?

Answer 10

1. Uremia
2. Salt and Water retention with resultant HTN
3. Hyperkalemia with metabolic acidosis
4. Anemia due to decreased EPO production by renal peritubular intersitital cells
5. Hypocalcemia and hyperphosphatemia
6. Renal osteodystrophy due to osteitis fibrosa cystica, ostemalacia and osteoporosis