Exam 3: AKI Flashcards

1
Q

The term Acute renal failure (ARF) is now reserve for severe ** and implies the need for **.

A

AKI

Dialysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is it called when you have abrupt loss of kidney function resulting in retention of urea and other nitrogenous waste products, as well has dysregulation of volume status and electrolytes?

A

AKI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the diagnosis of AKI based on?

A

Based on serum creatinine levels or a decrease in patients urine output

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the potential problems of diagnosing AKI using creatinine?

A
  • in early AKI, serum creatinine may be low even low GFR is markedly reduced
  • Creatinine is removed by dialysis so it is not possible to assess kidney function using creatinine when on dialysis
  • There is no consensus on what creatinine level actually indicated AKI
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the diagnostic levels used to confirm AKI?

A
  • Increase in serum creatinine by >0.3 within 48 hours
  • Increase in serum creatinine to >1.5 times baseline
  • Urine volume < 0.5ml/kg/hr for six hours
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

If patient has creatinine around 1.9 x their baseline, what stage of AKI are they?

A

Stage 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

If patient has anuria for <12hrs, what kind of AKI stage are they?

A

Stage 3, needs dialysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

AKI develops in up to *** of ICU patients?

A

60%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the 3 etiologies of AKI?

A
  • prerenal (decreased renal perfusion)
  • Intrinsic renal ( pathology of vessels, glomeruli, or tubules)
  • postrenal (obstructive)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

AKI in the hospital is most often from ** disease or **.

A

Prerenal or acute tubular necrosis (ATN)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the most commo cause of AKI?

A

ATN with prerenal being next

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the least common cause of AKI?

A

Obstructive (10%)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the 5 causes of prerenal disease?

A
  • True volume depletion (GI loss, burns, respiratory loss)
  • Hypotension (shock)
  • Edematous states (HF, cirrhosis)
  • Selective renal ischemia (bilateral renal artery stenosis)
  • Drugs affecting GDR (NSAIDS and ACE inhibitors)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the causes of intrinsic renal disease?

A
  • Renal ischemia
  • Sepsis
  • Nephrotoxins (IV CONTRAST)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How does IV contrast cause Intrinsic renal disease?

A

It causes renal tubular epithelial cell toxicity and renal medullary ischemia from vasoconstriction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the risk factors for Contrast induced ATN?

A
  • Preexisting renal disease
  • volume depletion
  • repeated doses of contrast
  • DM, CHF, and age
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the prevention of contrast induced ATN?

A
  • Hydration
  • Low osmolal agents at low dose
  • avoid repetitive doses
  • Avoid nephrotoxic drugs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the cause of post renal disease and what are common examples?

A
  • Obstruction of the flow of urine
  • prostatic disease (cancer or hyperplasia), metastatic cancer, and neurologic disease (neurogenic bladder and urinary retention)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

If patient has a reduction in GFR and no intrinsic renal disease, what does this mean?

A

There needs to be BILATERAL obstruction. One kidney stone wont decrease GFR because the other kidney will take over

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is considered nonoliguric?

A

> 400ml/24hrs usually 1-2 L/day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is considered oliguric?

A

<400mL/24hrs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is considered anuric?

A

<50 to 100ml/24 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What labs do you want to order in a patient with AKI?

A
  • Urinalysis

- Serum metabolic panel (creatinine, GFR, and fractional excretion of Na+ (FENa)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What imaging is commonly helpful in AKI?

A

Renal US

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are the 3 components of urinalysis?

A
  • Gross eval
  • Dipstick analysis
  • Microscopric examination
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are pathognomonic for ATN?

A

Muddy brown casts on urinalysis

27
Q

What is the normal range of creatinine in males?

A

0.6-1.2

28
Q

What is the normal range of creatinine for females?

A

0.5-1.1

29
Q

In a oliguric patient, what can FENa help distinguish?

A

Prerenal AKI from ATN

30
Q

If FENa is <1, what does it suggest?

A

Prerenal

31
Q

If FENa is >2, what does this suggest?

A

Intrarenal (ATN)

32
Q

When is FENa not helpful?

A
  • Its unreliable in patients on diuretics

- Serum creatinine is not stable in AKI

33
Q

What is the major reason to get imaging in AKI?

A

Assess for urinary tract obstruction

34
Q

Why is a renal US most commonly used in AKI?

A
  • Safe
  • easy
  • sensitive to obstruction
35
Q

What are the risks associated with urinary tract obstruction?

A

Obstruction may lead to infection, which can lead to urosepsis, which can lead to kidney failure

36
Q

Renal function after relief of obstruction is dependent on what?

A

The severity and duration of obstruction

37
Q

When is a renal biopsy performed?

A

In patients who have no clear explanation for AKI or it is very severe and rapid
-If creatinine in markedly elevated or significantly worsened over a few days

38
Q

What are the benefits of a renal biopsy?

A

Provides a definitive diagnosis and may allow therapeutic intervention to prevent ESRD

39
Q

What are the contraindications to a renal biopsy?

A
  • Bleeding diathesis
  • Severe HTN
  • Pyelonephritis
  • Renal tumor
  • Solitary native kidney
40
Q

What is considered mild AKI?

A

Transient increase in serum creatinine or fall in urine output

41
Q

What are the life threatening complications of AKI?

A
  • Volume imbalance
  • Metabolic acidosis
  • Hyperkalemia
  • Hypocalcemia
  • hyperphosphatemia
  • urea
  • AMS
42
Q

When a patient has volume depletion (vomiting, diarrhea, hypotension, tachycardia, oliguria) what should you do?

A

Administer IV fluid

  • fluid challenge attempts to identify prerenal failure
  • Crystalloid isotonic fluids are preferred
43
Q

How much fluid replacement should you begin with?

A

1-3 liters, with careful and repeated clinical assessment

44
Q

If patients do no respond to fluids, what does this mean?

A

Patient is unlikely to have prerenal disease and more likely to have ATN or other forms of intrinsic AKI

45
Q

If you have a volume overloaded patient that is NOT anuric, what is recommended?

A

Diuretics, but this should not be prolonged.

-If urine output does not increase after diuretics are given, they should be stopped

46
Q

Why do patients with AKI have metabolic acidosis?

A

They are not excreted acid they way they should and they are not making bicarbonate the way they should.

47
Q

What is the treatment of metabolic acidosis?

A
  • Dialysis
  • Bicarbonate administration

** choice depends on presence/absence of volume overload, or underlying cause and severity of acidosis

48
Q

If a patient have oligo-anuric AKI who are volume overloaded and have severe metabolic acidosis, what should you do?

A

Dialysis

49
Q

Why is dialysis preferred over the administration of bicarbonate for patients who are volume overloaded?

A

Bicarbonate administration results in a large sodium load that may cause or contribute to volume overload

50
Q

In a patient with AKI who is not volume overloaded and have no other indication for acute dialysis, what should you do?

A

Bicarb instead of dialysis, especially if acidosis is related to diarrhea, or pH <7.1 and awaiting dialysis

51
Q

What cardiac effects does hyperkalemia have?

A

-impaired neuromuscular transmission and cardiac conduction abnormalities

52
Q

What is the treatment of hyperkalemia?

A

-antagonizing the membrane effects of potassium by driving extracellular K into the cells, or removing excess K from the body

53
Q

Hypocalcemia in AKI in related to what?

A

HYperphosphatemia

54
Q

What are the symptoms of hypocalcemia?

A

-paresthesias, tetany, confusion, seizures, trousseaus sign, Chvosteks sign, and QT prolongation

55
Q

What is the treatment for patients with symptomatic hypocalcemia?

A

IV calcium

56
Q

What is the treatment for asymptomatic patients with hypocalcemia and hyperphosphatemia?

A

Correction of hyperphosphatemia (dietary phosphate binders)

57
Q

Selection of a phosphate binder depends on what?

A

The level of serum ionized calcium concentration.

58
Q

If serum calcium is low, what phosphate binders should you use?

A

Calcium acetate or calcium carbonate

59
Q

If serum ionized calcium is high, what phosphate binders should you use?

A

Aluminum hydroxide or Ianthanum carbonate

60
Q

What should be initiated in patients with severe uremia? What can result from severe uremia?

A

Dialysis

-uremia can cause pericarditis, neuropathy, and unexplained decline in mental status

61
Q

What is uremia?

A

A clinical syndrome associated with fluid, electrolyte, hormone, and metabolic abnormalities which develop in parallel with deterioration of renal function

62
Q

What does dialysis do?

A

Removed metabolic wastes and excess body water and replenishes body buffers
-Diffusion of small molecules down their concentration gradient

63
Q

Patients who recover from AKI are at greater risk for what?

A

To develop CKD and ESRD

64
Q

What patients with AKI have the highest morality rate?

A

ICU patients