Acute Renal Failure Flashcards
What is acute renal failure?
ARF refers to a syndrome of rapidly deteriorating GFR with the accumulation of nitrogenous wastes (urea and creatinine) refered to as azotemia. Serum creatinine acutely increases by more than 0.5 mg/dL or more than 50% over baseline levels.
What are the criteria for AKI?
RIFLE: Risk of renal dysfunction, Injury to the kidney, Failure of kidney function, Loss of kidney function, and ESRD.
What two diseases account for most of the cases of ARF?
reduced renal perfusion and acute tubular necrosis
What are the categories of ARF?
pre-renal, renal, and post-renal
What is a key element that can help distinguish the cause of ARF?
A thorough medical history
What are the general symptoms of ARF?
N/V, diarrhea, pruritis, drowsiness, dizziness, hiccups, SOB, anorexia and hematochezia.
What are the common physical findings for pre-renal ARF?
tachycardia and hypotension
What are the common physical findings for post-renal ARF?
a distended bladder, CVA tenderness, or enlarged prostate
What is the key parameter to measure renal function?
GFR
What is the UA for post-renal ARF? Pre-renal?
Both have generally normal UA, with only a few hyaline casts.
What is the UA for a renal ARF?
Granular casts, WBCs and casts, RBCs and casts, proteinuria and tubular epithelial cells indicate intrinsic renal causes
Low GFR, Low urine sodium, accompanied by elevated urine osmolality, BUN:Cr (> 20:1), and specific gravity would be characteristics of which type of ARF?
Pre-renal
Decreased BUN:Cr accompanied with increased FeNa and urine sodium would be characteristics of which type of ARF?
Intrinsic Renal
What can you do if the presentation is undistinguishable between acute and chronic kidney disease? What will you see?
Renal US, a smaller kidney will indicate chronic disease
How do we treat ARF?
Treatment involves correction of the underlying problem. Achieve normal hemodynamics if pre-renal, adjust and avoid nephrotoxic medications in intrinsic renal, relieve obstruction in post-renal.
What type of acid base disorder is usually accompanying ARF?
Anion gap or non-anion gap metabolic acidosis
What is the most common type of ARF?
Pre-renal
What is the diagnostic study of choice for identifying acute tubular necrosis?
FeNa, it will be the only kidney disease with a value greater than 1%, Urinary Na will also be > 20.
What is the etiology of acute interstitial nephritis?
allergic reaction, drug reaction, infection, or collagen vascular disease
What do we find on the UA of ATN and AIN?
ATN- granular (muddy brown) casts, renal tubular casts
AIN- WBCs and casts w/ or w/out eosinophils
