Pathoma UTI, Nephrolithiasis, and Chronic Renal Failure

Question 1

What is cystitis and how does it present?

Answer 1

Infection of the bladder. Presents as dysuria, urinary frequency, urgency, and suprapubic pain.

Systemic signs usually absent

Question 2

Labs for Cystitis

Answer 2

Cloudy urine with > 10WBCs/hpf

Dipstick: Positive leukocyte esterase due to pyuria and nitrites

Culture > 100,000 colony forming units

Question 3

2 most common bacteria with cystitis

Answer 3

E. Coli = 80%
Staph saprophyticus = increased incidence in young sexually active women

Interesting note, Proteus mirabilis cystitis gives you alkaline urine

Question 4

If patient presents with sterile pyurian what does that mean and what does it suggest? What bacteria are we working with?

Answer 4

Pyuria (infection of the urine) but negative culture

Suggests urethritis, not cystitis, due to Chlamydia rachomatis or Neissera gonorrhea

Question 5

Pyelonephritis

Answer 5

Infection of the kidney usually due to ascending infection.

resents with fever, flank pain, WBC casts, and leukocytosis in addition to symptoms of cystitis

Question 6

Most common pathogens for pyelo?

Answer 6

90% E Coli

Can also be Klebsiella and Enterococcus

Question 7

Chronic pyelo?

Answer 7

Leads to interstitial fibrosis and atrophy of tubules.

Due to vesicoureteral reflux in children or an obstruction

Question 8

Scarring from chronic pyelo

Answer 8

Cortical scarring with blunted calyces

Scarring at upper and lower poles is characteristic of VUR

Question 9

Chronic Pyelo leads to what process histologically?

Answer 9

Thyroidization of the kidney.

Atrophic tubules contain eosinophilic proteinaceous material reminiscent of thyroid follicles

Waxy casts in the urine

Question 10

Most common type of kidney stone and how we treat it

Answer 10

Calcium oxalate/phosphate.

HCTZ to treat

Question 11

Second most common stone and how we treat it?

Answer 11

Ammonium magnesium phosphate. Surgery required because it results in a staghorn calculi in renal calyces which act as a node for UTIs.

Question 12

What causes an ammonium magnesium phosphate stone?

Answer 12

Infection with a urease-positive organism like Vulgaris or Klebsiella, which cause the urine to become alkaline, forming the stone

Question 13

This stone has a special radiology that instantly tells you what it is

Answer 13

Uric acid stone, third most common, shows a radiolucent stone instead of an opaque one

Question 14

Treatment for uric acid stone?

Answer 14

Hydration and alkalization of urine (potassium bicarb)

Allopurinol can also be given if the patient has gout

Question 15

Unlike ammonium magnesium stones, uric acid stones usually result from:

Answer 15

Acidic pH

Question 16

Rarest type of stone and how it is treated

Answer 16

Cysteine, most commonly seen in kids. May form staghorn calculi. Treatment involves hydration and alkalinization of urine

Question 17

Staghorn cell I’m thinking what and how do I distinguish?

Answer 17

Ammonium phosphate since it is more common, but if it is a kid, it may be a cysteine stone

Question 18

Most common causes of Renal failure

Answer 18

DM, HTN, glomerular disease

Question 19

Common effect of end stage renal failure is uremia. What is it and what does it lead to?

Answer 19

Increased nitrogenous waste products in the blood (azotemia)

Leads to nausea, anorexia, pericarditis, platelet dysfunction, encephalopathy with asterixis, and deposition of urea crystals on the skin

Question 20

How do we get anemia with CRF?

Answer 20

Erythropoietin is down because it is made by the renal peritubular insterstitial cells

Question 21

2 causes of hypocalcemia in CRF

Answer 21

1. Can’t convert Vitamin D

2. Can’t excrete phosphate = high phosphate, which binds up free Ca

Question 22

CRF can cause renal osteodystrophy. What is it?

Answer 22

Damage to the bone because of renal failure

It has three parts
1. osteitis fibrosa cystica - Low Ca = High PTH which resorbs bone, which causes fibrosis and cysts

2. osteomalacia = can’t mineralize the osteoid made by osteobasts because your Ca levels are low
3. Osteoporosis = Obviously. From acidosis, we start using the bone to help reduce the acidity, and this eats the bone away

Question 23

Why do cysts develop on the kidneys of CRF patients?

Answer 23

Shrunken kidney put on dialysis will develop cysts

Dialysis on an end stage small kidney leads to renal cell carcinoma