Acute Renal Failure

Question 1

what is the definition of acute renal failure

Answer 1

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

Question 2

what is the RIFLE classification in acute kidney injury (AKI)

Answer 2

1. Rising Creatinine
2. Injury
3. Failure
4. Loss
5. ESRD

Question 3

What should you know about the RIFLE classification?

Answer 3

The severity increases from R to E

This is correlated with a rise in serum creatinine level and decrease in urinary output

Question 4

What is different in non-oliguric renal failure?

Answer 4

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

Question 5

Post renal dysfunction is caused by and what will you see

Answer 5

obstructive uropathy (any level of the GU tract: renal pelvis, any part of collecting system)
you will see hydronephrosis and enlargement of the kidneys

Question 6

what are the tests used for post renal dysfunction

Answer 6

ultrasound, CT scan, IVP(intravenous urogram- obselete to CT) and cytoscopy and reterograde pyelo-gram is the gold standard

Question 7

what are the two types of intra-renal obstruction

Answer 7

(microscopic salts and obstruction) intratubular crystals from uric acid, acyclovair, sufadiazene, methotrexate, and indanivir

Intratubular protein deposition with multiple myeloma

Question 8

what are the potential damages with obstruction in post renal dysfunction?

Answer 8

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

Question 9

what are some causes of pre-renal ARF

Answer 9

• 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

Question 10

what is the difference between azotemia and uremia?

Answer 10

azotemia refers only to blood test increase in BUN, Cr, and other nitrogenous waste. Uremia is a clinical syndrome in the presence of azotemia

Question 11

what are some other causes of pre-renal ARF?

Answer 11

other causes

• gastrointestinal bleeding
• administration of corticosteroids
• high protein diet
• administration of tetracylcines
• hypercatabolism

Question 12

how do you use the measurements of BUN and Creatinine to make your analysis?

Answer 12

If the BUN is proportionally greater than the creatinine then you know that this is a pre-renal dysfunction

Question 13

what is the most common and potentially reversible intrinsic renal disease?

Answer 13

Acute tubular necrosis

Question 14

what are the common clinical settings for ischemic acute tubular necrosis?

Answer 14

shock, sepsis, severe volume depletion/hemorrhage,

Question 15

red blood cell casts means the patient has

Answer 15

glomerulonephritis

Question 16

if it is white cell casts

Answer 16

pylonephritis or interstitial nephritis

Question 17

the pathogenesis of acute tubular necrosis is

Answer 17

• 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

Question 18

what are the histologic findings in acute tubular necrosis

Answer 18

vacuolization and denuding of epithelial brush border

Question 19

what are the distinguishing features between pre-renal azotemia from acute tubular necrosis

Answer 19

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

Question 20

what are the biomarkers used to aid in distinguishing renal damage from pre-renal damage

Answer 20

KIM- kidney injury markers
NGAL- neutral gelatinase associated lipocalin
CYASTATIN C
Interleukin 8

Question 21

what are the metabolic complications of acute renal failure and uremic syndrome

Answer 21

• hyponatremia
• hyperkalemia
• hypocalcemia and hyperphosphate
• hypermagnesemia (pregnant women)(serious electrolyte abnormality)
• hyperuricemia
• Metabolic acidosis

Question 22

what are the cardiac complications of ARF

Answer 22

• 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

Question 23

what are the neurological complications of acute kidney injury

Answer 23

• metabolic encephalopathy known as asteristics (because of uremia)
• neuromuscular irritability (dialysis best treatment)
• seizures
• coma

Question 24

what are the hematologic complication

Answer 24

• anemia
• bleeding tendency secondary to defective platelet function
• impaired white cell function leading to decreased immune response
• REVERSED BY DIALYSIS

Question 25

WHAT ARE the GI complications?

Answer 25

due to submucosal hemorrhages

• uremic gastritis, enteritis, and colitis
• NVD and bleeding

Question 26

what are the infection complications

Answer 26

• pnuemonia
• UTIs
• Line sepsis
• Bacteremia
• Wound infections

Question 27

dialytic therapy is good for what conditions?

Answer 27

• uremic syndrome
• metabolic acidosis
• CHF and fluid overload
• refractory hyperkalemia

Question 28

the ARF is most seen in

Answer 28

hospitalized patients with significant mortality