Renal

Question 1

Which receptor changes the release of Renin from JG cells?

Answer 1

Stimulation of beta1 increases Renin release.

Question 2

Psychogenic Polydipsia

Answer 2

Pathologic excessive water drinking. Just rule out DM and DI with a glucose test and a water restriction test.

Question 3

What is N-acetyl cysteine used for?

Answer 3

It prevents renal damage from contrast or acetaminophen overdose.

Question 4

Which drug can prevent calcium stones? Both Calcium phosphate and calcium oxalate.

Answer 4

Potassium Citrate. Urine citrate binds divalent Ca and prevents it from precipitating.

Question 5

Acetazolamide has the greatest effect on which part of the nephron? What condition is commonly used for?

Answer 5

PCT because it is a Carbonic Anhydrase inhibitor. This is where most of the H+ is secreted as NH4. It is used in glaucoma to decrease aqueous humor production.

Question 6

How can the Renal Plasma Flow be calculated?

Answer 6

Using PAH, which is actively secreted almost entirely. RPF = [PAH in Urine] x [Urine flow] / [PAH in blood]

Question 7

What is winter’s formula? What is it used for?

Answer 7

PaCO2 = 1.5 x HCO3 + 8 +/- 2 It is used to estimate the appropriate respiratory compensation in metabolic acidosis.

Question 8

What are the K+ sparing diuretics? What is their mechanism of action?

Answer 8

Spironalactone and Eplerenone are aldosterone receptor antagonists. Triamterene and Amiloride are ENaC channel down-regulators.

Question 9

Which section of the urethra is most likely to be injured secondary to pelvic injury?

Answer 9

The membranous segment between the prostate and the bulbous segment.

Question 10

A patient with ESRD is at greatest risk for…

Answer 10

osteodystrophy (lack of 1,25 dihydroxy vitamin D and increase in phosphate)

Question 11

What is Von Hippel-Lippau disease?

Answer 11

Delation or mutation of the VHL gene on chromosome 3p that leads to Renal Cell Carcinoma.

Question 12

What are the side effects of Thiazide diuretics?

Answer 12

hypoK, hypoNa, hyperUrecemia, and hyperCa

Question 13

How is NSAID-associated chronic renal injury characterized?

Answer 13

Papillary Necrosis and Chronic Interstitial Nephritis.

Question 14

What is a good side effect of thiazide diuretics?

Answer 14

The increase Ca++ reabsorption in the DCT and thus can prevent osteoporosis and kidney stones. Wowow! Double whammy!

Question 15

What is the side effect of ACE inhibitors that happens immediately after the first dose? What are predisposing factors?

Answer 15

Reflex hypotension from low ATII. Can be predisposed by hyponatremia, hypovolemia, hypotension, high renin, or high aldosterone levels which themselves can be exacerbated by other diuretics. (Basically the more activated the RAAS the more severe.)

Question 16

What are the common findings in the serum of patients with PSGN?

Answer 16

Low C3
ASO titer
High anti-DNase B titer
Cryoglobulins

Question 17

Which bleeding disorders do dialysis patients develop? What is the etiology?

Answer 17

Uremic Platelet Dysfunction. PT, PTT and platelet count are normal. Bleeding time is significantly prolonged. It’s essentially a platelet dysfunction while everything else is normal.

Question 18

What should be your first suspicion on patient with a history of polycystic kidney disease presenting with a headache?

Answer 18

The same mechanism that leads to cyst causes berry aneurysms in the circle of willis and if they rapture they can lead to subarachnoid hemorrhage.

Question 19

What effect does angiotensin II have on the kidneys?

Answer 19

Constriction of efferent arteriole. This means that upon starting ACE inhibitors GFR decreases.

Question 20

Describe urine osmolality along the nephron. What is happening at each point?

Answer 20

PCT = 300 mOsm/L isotonic H2O and NaCl reabsorption.
DL= H2O absorption only so osmolality reaches 1200 mOsm/L.
AL = NaCl absorption only so the osmolality decreases to 200 or even 100 mOsm/L
DCT = Osmalility rises a little due to H2O permeability but not more 300mOsm/L
CD = Depending on ADH high H2O permeability that can concentrate urine to as much as 2000mOsm/L.

Question 21

What effect does ethylene glycol poisoning have on the kidneys?

Answer 21

Formation of Calcium Oxalate stones that cause damage to the tubular epithelium.

Question 22

Which kidney disease has been associated with anti-phospholipase A2 antibodies?

Answer 22

Membranous nephrOpathy.

Question 23

Which drugs can cause interstitial nephritis?

Answer 23

Methicillin, NSAIDs & Furosemide

Question 24

What is Mannitol? When is it used in trauma? What is the risk?

Answer 24

It is an osmotic substance that can be used to treat cerebral edema and reduce intracranial pressure. In the kidneys it causes diuresis. However it can also cause severe pulmonary edema that could lead to death.

Question 25

What is the volume status on a patient who has SIADH? Why?

Answer 25

Euvolemic Hyponatremia. The onset of the ADH is so slow that there is enough time for a compensatory decrease in aldosterone and increase in natriuretic peptide.

Question 26

What are the electrolyte abnormalities seen through the progression of Acute Tubular Necrosis?

Answer 26

1. Oliguria leads to Hyperkalemia (asymptomatic if <6)
2. Anion Gap Metabolic acidosis
3. In recovery polyuria Hypokalemia, Hypomagenesia and Hypocalcemia can develop.

Question 27

Which kidney stone grow in low pH? Which ones grow in high pH?

Answer 27

High: Calcium phosphate, Ammonium magnesium phosphate.
Low: Calcium oxalate, Uric acid and Cysteine.

Question 28

Which chemotherapeutic drug causes hemorrhagic cystitis? What other drug can prevent it?

Answer 28

Nitrogen mustard based drugs like Cyclophosphamide or Ifosfamide. his can be prevented with Mesna which binds and inactivates the metabolites in the urine.

Question 29

Which type of kidney stones are Nitroprusside test positive?

Answer 29

Cystine. Cyanide is first added to break S bonds and then the Nitroprusside binds the new free Sulfurs of Cysteine or Homocysteine.