Renal Flashcards
RBC casts seen in?
Glomerulonephritis (nephritic syndrome), ischemia, or malignant hypertension
WBC casts seen in?
tubulointerstitial inflammation, acte pyelonephritis, transplant rejection
Fatty casts “oval fat bodies” seen in?
nephrotic syndrome
Granular “muddy brown” casts seen in?
Acute tubular necrosis
Waxy casts seen in?
Advanced renal disease/chronic renal failure, chronic glomerulonephritis/chronic pyelonephritis
Hyaline casts seen in?
nonsepcific, can be a normal finding, often seen in concentrated urine samples
Dysplastic Kidney?
non-inherited congenintal malformation where renal parenchyma has cysts and cartilage
What are common complications of ADPKD?
berry aneurysms, hepatic cysts, and mitral valve prolapse
What do the kidneys look like in Medullary cystic kidney disease?
cysts in teh medullary collecting ducts and parenchymal fibrosis results in shrunken kidneys and worsening renal failure
What are the different type of acute renal failure?
prerenal azotemia, postrenal azotemia, acute tubular necrosis, acute interstitial nephritis, and renal papillary necrosis
What is a common cause of prerenal azotemia?
Decreased renal blood flow (cardiac failure)
What are the lab findings in prerenal azotemia?
dec GFR, azotemia, oliguria, serum BUN:Cr ratio >15, FeNA 500mOsm/kg because there is no damage to the renal tubules
Expalin the BUN:Cr ratio in prerenal azotemia?
BUN and Cr are freely filtered, BUN is reabsorbed but Cr is not. In prerenal azotemia, low blood flow leads to inc aldosterone so increase Na and H2O reabsorption and BUN follows and gets reabsorbed
What is a common cause of postrenal azotemia?
obstruction of urinary tract downstream from kidney, ureters blocked.
Lab findings in postrenal azotemia?
Ureter blockage leads to increased hydrostatic pressure in the tubules, therefore dec GFR, azotemia and oliguria.
Early Stage: inc hydrostatic pressure pushed BUN to get reabsorbed, BUN:Cr > 15. Renal epithelium still intact so FeNa 500
Late Stage: tubular damage due to longstanding obstruction, cannot reabosrb BUN so BUN:Cr <15, FeNa>2%, urine osm <500
What is the most common cause of acute renal failure?
acute tubular necrosis aka intrarenal azotemia
Presentation of ATN?
brown granular casts in urine due to necrotic cells sloughing off and plugging the tubules. BUN:Cr<15, FENa>2%, urine osm <500
What are the two etiologies of ATN?
ischemia or nephrotoxic
Which segments of kidney are most susceptible to ischemic damage?
PCT and TAL (medullary portion)
Which segments of the kidney are most suseptible to nephrotoxic damage?
PCT (the drugs hit here first!)
What are common toxic agents to the kidney?
aminoglycosides (gentamycin), heavy metals (lead), myoglobinuria (crush injury), ethylene glycol (kids accidentally ingest and get oxalate crystals in urine), radiocontrast dye, and urate (tumor lysis syndrome in leukemia getting chemo)
How do you prevent tumor lysis syndrome?
hydration and allopurinol prior to initiation of chemo
How do you treat ATN?
dialysis until the tubular epithelium regenerates
What causes acute interstitial nephritis?
NSAIDs, penicillin, diuretics
What are defining characteristics of acute interstitial nephritis?
eosinophils in urine, oliguria, fever, rash. drug-induced hypersensitivity reaction involving intersition and tubules (infilatration of the CT between the tubules)
Common causes of renal papillary necrosis?
chronic analgesic abuse, diabetes mellitus, sickle cell trait or disease, severe acute pyelomephritis
When not idiopathic, what disease is associated with Minimal Change Disease?
Hodgkin Lymphoma
What are the common characteristics of nephrotic syndromes?
Hypoalbuminemia (pitting edema), hypogammaglobulinemia (inc risk of infection), hypercoagulable state (loss of ATIII), hyperlipidemia and hypercholesterolemia (fatty casts in the urine)
What risk factors are commonly associated with Focal Segmental Glomerulosclerosis?
HIV, heroin use, and sickle cell disease
What are the comon risk factors of Membranous Nephropathy?
Caucasian adults, assocatied with HBV or HCV, solid tumors, SLE, or drugs like NSAIDs and penicillamine
Which nephrotic syndrome has granular IF with subepithelial immune complex desposits?
Membranoue nephropathy (glomerulonephritis)
What nephritic and nephrotic syndromes is SLE associated with?
nephritic (most common): diffuse proliferative GN
nephrotic: memranous glomerulonephritis