SIM- Renal Failure

Question 1

What are signs of acute renal failure?

Answer 1

Normal creatinine 1 month ago: few risk factors for CKD (only age, HTN)

Normal hematocrit, absence of renal cortical thinning on CT, oliguria

Question 2

What is seen in pre and post renal affects to the kidney occurring with acute renal failure?

Answer 2

prerenal= reduced blood flow to kidneys

postrenal- obstruction of urine flow

Question 3

What is the DDX for intrinsic renal disease?

Answer 3

Glomerulonephritis, interstitial nephritis, tubular disease, vascular disease

Question 4

What is commonly observed iwth tubulointerstitial process?

Answer 4

Proteinuria, pyuria, casts

Question 5

What is commonly observed in patients with glomerulonephritis?

Answer 5

usually have red cells & red cell casts in urine

Question 6

What characterizes interstitial nephritis?

Answer 6

inflammation & scarring of tubules & interstitial spaces with sparing of glomeruli and vasculature

Question 7

What are the 3 categories of interstitial nephritis?

Answer 7

1. immune mediated
2. infection mediated
3. idiopathic

Question 8

What are examples of immune mediated interstitial nephritis?

Answer 8

1. drug hypersensitivity
2. with glomerulonephritis: lupus, IgA nephropathy
3. without glomerulonephritis: sarcoid, sjogren’s, transplant rejection

Question 9

What are examples of infection mediated interstitial nephritis?

Answer 9

1. pyelonephritis
2. post-infectious: eg streptococci, staphylococci, diphtheria, Legionella, Yersinia, leptospira, mycobacterium, mycoplasma, rickettsia, syphilis, toxoplasmosis, and numerous viruses (including EBV, HIV, CMV)
3. Granulomatous disease: TB, sarcoid

Question 10

What antibiotics are associated with interstitial nephritis?

Answer 10

penicillins
cephalosporins
sulfonamides
fluoroquinolones
rifampin
trimethoprim

Question 11

What diuretics are associated with interstitial nephritis?

Answer 11

furosemide (Lasix)

thiazide-type diuretics

Question 12

What NSAIDS are associated wtih interstitial nephritis?

Answer 12

allopurinol (Zyloprim)
cimetidine (Tagamet)
phenytoin (Dilantin)
proton pump inhibitors
5-aminosalicylates
protease inhibitors
lithium
carbamazepine

Question 13

What symptoms are associated wtih interstitial nephritis associated with ibu use?

Answer 13

recent addition of ibuprofen, pruritis (skin hypersensitivity) and UA results (eosinophilia)

Question 14

What are key features of NSAID induced interstitial nephritis?

Answer 14

Rash, eosinophilia (40% of cases), hematuria (40% of cases), pyuria, eosinophiluria, proteinuria, renal failure (requiring dialysis in about 1/3 of cases), nephrotic syndrome (70% of cases; not seen in this sim case, but would likely develop if case could be longer!)

Question 15

How do NSAIDS induce hyponatremia?

Answer 15

nsaids inhibit prostaglandin synthesis!

Prostaglandins play a role in water balance. Antagonize ADH thus inhibiting chloride transport by the thick ascending limb of henle and regulating medullary blood flow.

Question 16

What drug can cause hypokalemia?

Answer 16

hydrochlorothiazide use

perhaps worse in our pt due to vomiting

Question 17

What is the mechanism for drug induced interstitial nephritis?

Answer 17

CD4+ T-cell mediated reactivity or CD8+ cytotoxic T-cell-mediated tubular damage. Antigen likely the drug or drug metabolite attached to autologous macromolecules. Less likely to be autoimmune as condition resolves when drug is stopped.

Question 18

How do you tx interstitial nephritis?

Answer 18

tx with dialysis x 3, corticosteroids> renal function improved and returned to normal over next 3 weeks>
prednisone stopped and kidney function remained normal