Flashcards in Renal Deck (115)
Differentiate cyst location in dysplastic kidney dz, PKD, Medullary cystic kidney dz
dysplastic => renal parenchyma & abnormal tissue
PKD=> bilateral enlarged kidneys w/ cysts in cortex & medulla
medullary => medullary collecting ducts w/ parenchymal fibrosis leading to shrunken kidneys
How does the ARPKD present?
baby w/ portal HTN due to congenital hepatic fibrosis
How does ADPKD present?
young adult w/ HTN, hematuria, progressive renal failure w/ FHx of death due to berry aneurysm rupture or chronic renal failure
What is the timeline & hallmark of acute renal failure?
azotemia (high BUN & Cr) w/in days often w/ oliguria
What is the cause of pre renal ARF? what are the assoc labs?
decreased Q to kidneys so decreased GFR;
BUN:Cr > 15
tubular fxn intact so FENa < 1% & urine osm > 500 mOsm/kg
What is cause of post renal azotemia?
obstruction of urinary tract downstream decreasing GFR (backup), azotemia & oliguria
Differentiate the timeline of early & long-standing post renal obstruction
early increase in pressure leads to BUN:Cr > 15
FENa < 1% & urine osm > 500mOsm
long term causes tubular damage causing BUN:Cr < 15
FENa > 2% & urine osm < 500mOsm
what is the MCC of acute renal failure?
intrarenal azotemia => injury & necrosis of tubular epithelial cells
What will be seen on urinalysis during ATN?
brown, granular casts in urine
serum BUN:Cr < 15
FENa > 2%
urine osm < 500 mOsm
What are the clinical features of ATN?
oliguria w/ brown granular casts
BUN:Cr < 15
Hyperkalemia (decresed renal fxn) w/ metabolic acidosis
Describe ATN if ischemia is the cause. What is the most susceptible part of kidney?
decreased Q so often preceded by pre renal azotemia =>
proximal tubule & medullary segment of thick ascending limb are most susceptible
What are nephrotoxic agents to the kidney that may lead to ATN?
MC is aminoglycosides;
heavy metals (lead);
myoglobinuria (crush injury to muscle);
radiocontrast dye (CT scan);
urate (tumor lysis syndrome or high gout)
How will you know if someone ingested ethylene glycol?
oxalate crystals in urine
What are ways to avoid tumor lysis syndrome causing ATN?
hydration & allopurinol prior to CTX
If ATN occurs, how is it treated and can the pt recover? what is the timeframe?
Reversible => supportive dialysis due to severe electrolyte imbalances
oliguria can present for 2-3wks before recovery due to tubular cells regenerating
Why does it take 2-3wks for oliguria to remit?
tubular cells are stable cells so takes time to re-enter the cell cycle & regenerate
What causes acute interstitial nephritis? How is it treated? What happens if it is not?
Drug induced HSR causing infrarenal azotemia typically from NSAIDs, penicillin & diuretics
Resolves w/ drug stoppage;
if Rx is not pulled then renal papillary necrosis may occur
How does acute interstitial nephritis present?
oliguria, fever & rash varying from days to weeks (any time) after using a Rx => eosinophils MAY be in urine
How does renal papillary necrosis present? What are the common causes?
gross hematuria w/ flank pain
Chronic analgesic pain (phenacetin or aspirin use);
Sickle cell disease OR trait;
Severe acute pyelonephritis
Define nephrotic syndrome & the 4 possible results
proteinuria > 3.5g/day
hypoalbuminemia - pitting edema;
hypogammaglobulinemia - increased infection risk;
hyper coagulable state - due to loss of AT-3;
hyperlipidemia & hypercholesterolemia - fatty casts in urine
How does the MCC of nephrotic syndrome in children present on H&E? EM? IF? urinalysis?
H&E: normal glomeruli;
EM: effacement of foot processes
IF: no IC deposits so negative IF
Urinalysis has selective proteinuria w/ loss of albumin but not Ig loss
What cancer is minimal change disease associated with? why?
Hodgkin lymphoma due to massive increase of cytokines from RS cells
What is the response to treatment of minimal change disease?
excellent response to steroids due to damage caused by cytokines from T cells
What is the MCC of nephrotic syndrome in Hispanics & AA?
Focal segmental glomerulosclerosis (FSGS)
What is FSGS associated with?
HIV; heroin use; sickle cell disease
How does FSGS appear on H&E? EM? IF?
HE: focal & segmental pink sclerosis
EM: effacement of foot processes
IF: no IC deposits = neg IF
What is the response to Tx in FSGS?
poor response to steroids leading to chronic renal failure
What is the MCC of nephrotic syndrome in caucasian adults?
What is membranous nephropathy assoc w/?
SLE (usually diffuse proliferative GN);
Rx (NSAIDs & penicillamine)