Acute Kidney Injury

Question 1

What is the clinical criteria for Risk?

Answer 1

Increase in serum creatinine to 1.5-2 from baseline

Uop less than 0.5 ml/kg/hr for 6 hours

Question 2

What is the clinical criteria for injury?

Answer 2

Increase in serum creatinine to 2-3 x baseline

UOP less than 0.5 ml/kg/hr for 12 hours

Question 3

What is the clinical criteria for failure?

Answer 3

Increase in serum creatinine greater than 3 X baseline
UOP less than 0.3ml/kg/hr for 24 hours
Anuria for 12 hours

Question 4

What is the criteria for Loss?

Answer 4

Loss of kidney function for more than 4 weeks

Question 5

What is the criteria for ESRD?

Answer 5

Loss of kidney function for more than 3 months

Question 6

What is the AKIN criteria?

Answer 6

Diagnostic scale for AKI that came out after RIFLE

Question 7

What is AKIN stage 1 criteria

Answer 7

Increase in serum creatinine of greater than 0.3 mg/dl or 1.5-2 X baseline
UOP less tha 0.5 ml/kg/hr for greater than 8 hours

Question 8

What is AKIN stage 2 criteria?

Answer 8

Increase in serum creatinine to greater than 2-3 X baseline

UOP less tha 0.5 ml/kg/hr for over 12 hours

Question 9

What is the AKIN stage 3 criteria?

Answer 9

Increase in serum creatinine to 3 X baseline
Increase in serum creatinine greater than 4 mg/dl with an acute increase of greater than 0.5 mg/dl
UOP less than 0.5 ml/kg/hr for 24 hours
Anuria for 12 hours

Question 10

What is the insult in pre renal disorders?

Answer 10

A decrease in renal blood flow

Usually from heart failure, hypovolemia, shock

Question 11

What causes ATN?

Answer 11

Septic shock
Contrast dye
Nephrotoxic drugs
Rhabdo

Question 12

What is the pathological process in ATN?

Answer 12

Oxidative injury causes the epithelial lining of the renal tubule to die. They slough into the lumen and create obstruction and back pressure, thereby lowering the GFR via the tubuloglomelular feed back system

Question 13

What is the most common cause of AKI?

Answer 13

ATN

Question 14

What is the most cause of AKI.

Answer 14

Sepsis

Question 15

What does a spot urine sodium less than 20 mean?

Answer 15

The process is pre renal

Question 16

What does a spot urine of greater than 40 mean?

Answer 16

This process is intrinsic

Question 17

What are the exceptions to the spot urine sodium of over 40?

Answer 17

It can be prerenal if you have ongoing dieresis, or if they have CKD

Question 18

What does it mean if the FeNa is less than 1%?

Answer 18

Prerenal

Question 19

What does it mean if FeUrea is greater than 50%?

Answer 19

It is intrinsic

Question 20

What are the exception to FeNa.

Answer 20

Diuretics
CKD
Can be false low in ARF with sepsis, contrast, rhabdo

Question 21

What is the advantage of using FeUrea?

Answer 21

It is not influenced by diuretics

Question 22

How long do you continue a fluid challenge?

Answer 22

Until you get response or are worried about volume overload

Question 23

What is the rifle criteria?

Answer 23

Risk
Injury
Failure
Loss
Esrd

Question 24

What is the mechanism of AKI with contrast?

Answer 24

Direct renal tubule injury
Renal vasoconstriction
Generation of toxic oxygen metabolites

Question 25

When does AKI from contrast usually appear?

Answer 25

Within 72 hours

Question 26

How long does it take contrast nephropathy to resolve?

Answer 26

2 weeks

Question 27

What is the most effective preventive measure against contrast nephropathy?

Answer 27

IV hydration : isotonic Aline 100-150 ml/hr started 3-12 hours before the procedure and continued 6-24 hours after

Question 28

How much fluid should you give if you must do a scan emergently in a patient at high risk for AKI?

Answer 28

300-500 ml

Question 29

What is the high dose NAC regimen for contrast nephropathy?

Answer 29

1,200 mg pro bid X 48 hours beginning the night before the procedure

Question 30

What is the NAC dosing for an emergency procedure?

Answer 30

1,200 mg prior

Question 31

What are the most common drugs to cause AIN?

Answer 31

Penicillins

Question 32

What are the signs of AIN?

Answer 32

Fever, rash, eosinophilia, sterile pyuria

Question 33

How do hemoglobin and myoglobin cause ATN?

Answer 33

The iron moiety makes free radicals

Question 34

What is the treatment of ATN.

Answer 34

Aggressive volume | Alkaline the urine

Question 35

What is the normal intra abdominal pressure?

Answer 35

5-7mm hg

Question 36

What is IAH (intra abdominal hypertension) defined as?

Answer 36

Sustained increase above 12 mm hg

Question 37

What is abdominal compartment syndrome defined as?

Answer 37

When IAP is above 20 mm hg and there is evidence of end organ damage

Question 38

What is the equation for abdominal perfusion pressure?

Answer 38

MAP-IAP

Question 39

What is the goal APP for renal perfusion to happen?

Answer 39

APP greater than 60

Question 40

What is renal perfusion pressure equivalent to in IAH?

Answer 40

The APP

Question 41

Why does IAP have made greater impact on GFR than an equivalent decrease in MAP?

Answer 41

Because it is the equivalent of proximal tubule pressure and because FG= MAP- IAP x2

Question 42

How should you try to reduce IAP?

Answer 42

Sedation to reduce abdominal muscle contraction Avoiding elevating the head of the bed more than 20 degrees Avoiding positive fluid balance

Question 43

How can you measure IAP.

Answer 43

Through a decompressed bladder by injecting 25-50 ml of saline thru a special catheter

Question 44

What are the indication for RRT?

Answer 44

Volume overload Life threatening hyperkalemia or metabolic acidosis Removal of toxins

Question 45

How does hemodialysis work?

Answer 45

By diffusion which is driven by concentration gradient

Question 46

What is the counter current exchange?

Answer 46

Blood and dialysis fluid are run in opposite directions to maintain the concentration gradient

Question 47

What is the benefit of dialysis?

Answer 47

Rapid clearance of small solutes

Question 48

What is the disadvantage of dialysis?

Answer 48

Limited removal of large molecules The need to maintain blood flow at 200-300ml/min which creates risk of hypotension

Question 49

How does hemo filtration work?

Answer 49

Removes solutes by convection, where a hydrostatic pressure gradient is used to move a solute containing fluid across a semipermeable membrane (solvent drag method)

Question 50

What are the advantages of hemo Filtration?

Answer 50

Gradual removals of fluid without hemodynamics compromise Large amount of fluid removal Removes larger molecules (better for removing toxins)

Question 51

What are the disadvantages of hemofiltration?

Answer 51

Slow Continuous need IV fluid replacement for filtration loss since it is basically washed away with water