SIM Renal Failure Flashcards
(29 cards)
How do you determine if someone has intrinsic vs. pre-renal vs. post-renal failure?
It is intrinsic if there is no evidence of the other two (pre or post)
What is pre-renal failure?
Reduced blood flow to kidneys
What is post-renal failure?
Obstruction of urine flow
What tells us the patient didn’t have chronic renal failure?
She had a normal Cr 1 month ago.
She has few risk factors for CKD (only age, HTN)
What tells us the patient likely has acute renal failure?
Normal HCT, absence of renal cortical thinning on CT, oliguria, timing
What is the DDX for intrinsic renal disease?
- Glomerulonephritis
- Interstitial nephritis
- Tubular disease
- Vascular disease
What findings are consistent with a tubulointersitial process?
- Proteinuria
- Pyuria
- Casts
What do patients with glomerulonephritis usually have in their urine?
- Red cells
- Red cell casts
What is interstitial nephritis characterized by?
Inflammation & scarring of tubules & interstitial spaces with sparing of glomeruli and vasculature
What are the three categories of interstitial nephritis?
- Immune-mediated
- Infection-mediated
- Idiopathic
What are examples of immune-mediated interstitial nephritis?
- Drug hypersensitiivity
- W/Glomerulonephritis
- W/out Glomerulonephritis
What immune-mediated interstitial nephritis includes glomerulonephritis?
Lupus
IgA nephropathy
What immune-mediated interstitial nephritis doesn’t include glomerulonephritis?
Sarcoid, Sjogren’s, Transplant rejection
What are examples of Infection-mediated interstitial nephritis?
- Pyelonephritis
- Post-infectious
- Granulomatous disease
What are examples of post-infection interstitial nephritis?
Streptococci, staphylococci, diphtheria, legionella, yersinia, leptospira, mycobacterium, mycoplasma, rickettsia, syphilis, toxoplasmosis, and numerous viruses (EBV, HIV, CMV)
What are examples of granulomatous disease interstitial nephritis?
TB, sarcoid
What types of drugs are associated with interstitial nephritis?
- Antibiotics
- Diuretics
- Nonsteriodal anti-inflammatory drugs (NSAIDS)
- Others
What antibiotics are associated with interstitial nephritis?
- Penicillins
- Cephalosporins
- Sulfonamides
- Fluoroquinolones
- Rifampin
- Trimethoprim
What Diuretics are associated with interstitial nephritis?
- Furosemide (lasix)
- Thiazide-type diuretics
What “other” drugs are associated with interstitial nephritis?
- Allopurinol (Zyloprim)
- Cimetidine (Tagamet)
- Phenytoin (Dilantin)
- Proton pump inhibitors (PPIs)
- 5-aminosalicylates
- Protease inhibitors
- Lithium
- Carbamazepine
What features of the SIM patient were consistent with interstitial nephritis associated with NSAID use?
- Addition of ibuprofen (recent)
- Pruritis (skin hypersensitivity)
- UA results
What makes NSAIDs a more likely cause than Thiazide?
Eosinophilia
-Can’t complete exclude thiazides though
What percentage of NSAID induced interstitial nephritis requires dialysis?
1/3 of cases
What are key features of NSAID induced interstitial nephritis?
- Rash
- Eosinophilia (40% of cases)
- Hematuria (40% of cases)
- Pyuria
- Eosinophiluria
- Proteinuria
- Renal failure (may require dialysis)
- Nephrotic syndrome (70% of cases - develops over time - protein spilling due to damage to kidneys)
