35: AKI, CKD

Question 1

creatinine

Answer 1

metabolite of creatine phosphate from muscle

Question 2

what is creatinine used or?

Answer 2

estimating GFR

Question 3

two main methods/calculators for estimated GFR (eGFR)

Answer 3

1. CKD-EPI

2. MDRD

Question 4

relationship between GFR and serum creatinine

Answer 4

higher GFR = exponentially less serum creatinine

Question 5

anuria

Answer 5

urine <100 mL/day

Question 6

oliguria

Answer 6

urine <500 mL/day

Question 7

azotemia vs pre-renal azotemia vs uremia

Answer 7

1. azotemia: elevated BUN
2. pre-renal azotemia: elevated BUN out of proportion to serum Cr due to poor renal perfusion
3. uremia: elevated BUN WITH symptoms

Question 8

symptoms of uremia

Answer 8

N/V, confusion, fatigue, metallic taste in mouth, anorexia

Question 9

four toxins that can cause acute tubular necrosis

Answer 9

1. myoglobin (rhabdomyolysis)
2. uric acid
3. myeloma light chains
4. IV contrast

Question 10

two groups of drugs that can cause decreased renal blood flow -> pre-renal AKI

Answer 10

NSAIDs, ACEIs/ARBs

Question 11

if pre-renal AKI is present long enough, what will develop (not CKD lol)

Answer 11

ATN (acute tubular necrosis)

Question 12

two types of obstruction that will cause post-renal AKI

Answer 12

1. bladder obstruction

2. bilateral ureteral obstruction

Question 13

what do renal tubular epithelial cells and granular casts suggest?

Answer 13

ATN

Question 14

what do WBC casts or urine eosinophils suggest?

Answer 14

AIN: acute interstitial nephritis

Question 15

what does proteinuria, hematuria, and dysmorphic RBC casts suggest?

Answer 15

nephritic syndrome

Question 16

what does heavy proteinuria, fatty casts, oval fat bodies, and minimal hematuria suggest?

Answer 16

nephrotic syndrome

Question 17

FENA (fractional excretion of Na) formula**

Answer 17

Na excreted / Na filtered

Question 18

FENa < 1% vs FENa > 2% suggests what?**

Answer 18

<1% -> pre-renal AKI

>2% -> ATN

Question 19

in which pts is FENa less accurate, and FEUrea should be used?

Answer 19

pts on diuretics

Question 20

what does FEUrea <35% vs >50% suggest?

Answer 20

<35% -> pre-renal AKI

>50% -> ATN

Question 21

what happens if after 3 months of AKI, pts kidney function is not back to baseline?

Answer 21

Dxed with CKD

Question 22

specific GFR and Cr cutoff to intiate dialysis

Answer 22

there is none

Question 23

indications for dialysis

Answer 23

A: acidosis
E: electrolyte imbalance
I: intoxication with toxins
O: overload (volume overload)
U: Uremia (if encephalopathy or pericarditis)

Question 24

six signs of kidney damage that can qualify as CKD criteria

Answer 24

1. albuminuria
2. urine sediment abnormalities
3. electrolyte abnormalities
4. histologic abnormalities
5. structural abnormalities on imaging
6. Hx kidney transplant

Question 25

what does the amount of albuminuria signify in CKD?

Answer 25

prognosis

Question 26

what causes anemia in CKD?

Answer 26

when kidneys produce less EPO

Question 27

what causes bone pain and fragility in CKD?

Answer 27

kidneys not regulating Ca and Phosphorus -> secondary hyperparathyroidism

Question 28

two ways CKD can lead to iron deficiency

Answer 28

1. chronic blood loss from dialysis | 2. decrease in GI Fe absorbtion

Question 29

pathology of osteitis fibrosis cystica

Answer 29

CKD -> excess PTH -> osteoclast activation -> bone breakdown

Question 30

findings of osteitis fibrosis cystica

Answer 30

subperiosteal bony reabsorption, bone cysts, "brown tumors" from microhemorrhages in bone