what is the definition of acute renal failure
rise in creatinine of 0.3 mg%
abrupt decline in the glomerular filtration rate over hours, or days as measured by the creatinine clearance or more commonly as estimated by a rise in the serum blood urea nitrogen (BUN) and serum creatinine; defined as a rise in creatinine of .3 mg
what is the RIFLE classification in acute kidney injury (AKI)
- Rising Creatinine
- Injury
- Failure
- Loss
- ESRD
What should you know about the RIFLE classification?
The severity increases from R to E
This is correlated with a rise in serum creatinine level and decrease in urinary output
What is different in non-oliguric renal failure?
urine output usually decreased but not necessarily. BUN may be high with low GFR, but patient may remain non-oliguric 15-20% of the time
Post renal dysfunction is caused by and what will you see
obstructive uropathy (any level of the GU tract: renal pelvis, any part of collecting system) you will see hydronephrosis and enlargement of the kidneys
what are the tests used for post renal dysfunction
ultrasound, CT scan, IVP(intravenous urogram- obselete to CT) and cytoscopy and reterograde pyelo-gram is the gold standard
what are the two types of intra-renal obstruction
(microscopic salts and obstruction) intratubular crystals from uric acid, acyclovair, sufadiazene, methotrexate, and indanivir
Intratubular protein deposition with multiple myeloma
what are the potential damages with obstruction in post renal dysfunction?
if the obstruction is proximal there is more of a problem with irreversible damage and kidney destruction (obstruction at the UP junction)
Less threatening if it is distal
the duration is also important to prevent the irreversible kidney damage
what are some causes of pre-renal ARF
- decrease in effective circulating plasma volume
- decrease in cardiac output
- decrease peripheral resistance (vasodilation)
- severe renal vasoconstriction
- mechanical occlusion of renal arteries
other causes
- gastrointestinal bleeding
- administration of corticosteroids
- high protein diet
- administration of tetracylcines
- hypercatabolism
what is the difference between azotemia and uremia?
azotemia refers only to blood test increase in BUN, Cr, and other nitrogenous waste. Uremia is a clinical syndrome in the presence of azotemia
what are some other causes of pre-renal ARF?
other causes
- gastrointestinal bleeding
- administration of corticosteroids
- high protein diet
- administration of tetracylcines
- hypercatabolism
how do you use the measurements of BUN and Creatinine to make your analysis?
If the BUN is proportionally greater than the creatinine then you know that this is a pre-renal dysfunction
what is the most common and potentially reversible intrinsic renal disease?
Acute tubular necrosis
what are the common clinical settings for ischemic acute tubular necrosis?
shock, sepsis, severe volume depletion/hemorrhage,
red blood cell casts means the patient has
glomerulonephritis
if it is white cell casts
pylonephritis or interstitial nephritis
the pathogenesis of acute tubular necrosis is
- whether it is nephrotic or ischemic there is necrosis at the proximal tubule and the GFR is decreased.
- diagnosis is almost always clinical
- has the ability to regenerate with recovery of renal function
what are the histologic findings in acute tubular necrosis
vacuolization and denuding of epithelial brush border
what are the distinguishing features between pre-renal azotemia from acute tubular necrosis
In pre-renal azotemia you have a problem with perfusion and volume depletion so
- BUN/creatinine ratio is high due to nitrogen and urea reabsorption
- Urinary Na excretion and Fractional excretion of Na(determines kidney functionality) will be low because bodies compensation to build back the volume it reabsorbs sodium
- urinary osmolarity will be high in response to taking back up so much water
what are the biomarkers used to aid in distinguishing renal damage from pre-renal damage
KIM- kidney injury markers
NGAL- neutral gelatinase associated lipocalin
CYASTATIN C
Interleukin 8
what are the metabolic complications of acute renal failure and uremic syndrome
- hyponatremia
- hyperkalemia
- hypocalcemia and hyperphosphate
- hypermagnesemia (pregnant women)(serious electrolyte abnormality)
- hyperuricemia
- Metabolic acidosis
what are the cardiac complications of ARF
- increase in total body sodium
- expansion of ECF volume with
- pulmonary and peripheral edema
- congestive heart failure
- cardiac arrhythmias (potassium abnormality inc)
- uremia causes pericarditis
what are the neurological complications of acute kidney injury
- metabolic encephalopathy known as asteristics (because of uremia)
- neuromuscular irritability (dialysis best treatment)
- seizures
- coma
what are the hematologic complication
- anemia
- bleeding tendency secondary to defective platelet function
- impaired white cell function leading to decreased immune response
- REVERSED BY DIALYSIS
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Nephrotic and Nephritic Syndrome47
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Renal Syndromes and Urinalysis50
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Renal Syndromes and Urinalysis Pt Deux25
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Acid and Bases20
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Acute Renal Failure28
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Fluids and Electrolytes27
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chronic kidney disease39
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Nephrolithiasis31
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Nutrition and Renal Disease5
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Tubulointerstitial infections54
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Male Genitalia24
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Renal Neoplasms16
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Anti-anxiety drugs1
