Met 2: Nephro; Lec 9, Ckd

Front 1

What constitutes chronic kidney disease?

Back 1

i) GFR <60 ml/min
or
ii) Kidney disease on imaging tests
or
iii) Evidence of kidney damage from urinalysis (i.e. proteinuria +/- hematuria

Front 2

What are common casuses of CKD?

Back 2

1. Diabetes
2. HTN
3. Glomerulonephritis
4. Cystic kidneys

Front 3

What is the GFR and what is a normal rate (in a 20 yo male)?

Back 3

Amount of water filtered across glomerular basement membrane per unit time.
Normal: 120 ml/min (20 yo male--GFR decreases ~1ml/min each year)

Front 4

What are some methods to assess GFR?

Back 4

1. Creatine based (serum creatine, creatinine clearance in timed urine collection, claculated GFR)

2. inulin, serum urea

3. Nuclear medicine methods

Front 5

Which of the following is false?
a) Creatinine is filtered at glomerulus, secreted in tubules, excreted in urine
b) serum creatinine levels similar for everyone
c) creatinine is a metabolite of creatinine-phosphate
d) Comes from myocytes of skeletal muscles

Back 5

b) (obvi). Serum creatinine levels very with the amount of skeletal muscle someone has

53-113 umol/L in adult males
37-96 umol/L in adult females and newborns

Front 6

If serum creatinine increased, the GFR would:
a) stay the same

b) decrease because they are inversely proportional to each other

c) increase because they are proportional to each other

Back 6

b) Decrease, because they areInversely proportional to each other.
Rise in sCr=decrease GFR

Front 7

What is the sCreatinine rule of thumb?

Back 7

As sCr doubles, GFR drops by 50%

Front 8

What are some of the problems with serum creatinine measurements to keep in mind when looking at test results?

Back 8

-Normal range measures variable
- daily production variations
-overestimates clearance
-drugs can increase sCr

Front 9

Why can serum creatinine be a poor indicator of early kidney disease?

Back 9

Wide range of normal. A large drop in GFR can still present in the normal range.

Front 10

2 important creatitine based calculations are?
What are some assumptions with these formulas?

Back 10

1. Cockcroft-Gault equation (Cr clearance)
CrCl (ml/min) =(140-age)*wt (kg)*1.2 (if male)/ srCr (mmol/L)

2. modification of diet in renal disease (MDRD) (for GFR)

Assumptions: steady state creatitine and average size persons

Front 11

Which of the following is incorrect regarding the formula estimated GFR?
a) GFR overestimated with high muscle mass
b) GFR overestimated when someone is sick
c) GFR overstimated with someone with an amputation
d) GFR underestimated with a high muscle mass

Back 11

a) GFR overestimated with high muscle mass

Not a "standard sized" person, so formula off. Consider 24 hr urine collection.

Front 12

In what population is the MDRD formula formula for eGMR most accurate?

Back 12

Those with chronic kidney disease. 
Not as accurate in a healthy-kidney population (normal GFR), pregnant, children, elderly, certain ethnicities, unusual muscle masses.

Front 13

What is the gold standard for measuring GFR?

Back 13

Nuclear medicine methods. 

Might be used for a live donor in a kidney transplant.

Front 14

Why might serum urea be increased?

Back 14

Increased protein metabolism
decreased GFR
Slow flow state CHF, obstruction

Front 15

Why might serum urea be decreased?

Back 15

Increased GFR
Decreased protein metabolism

Front 16

Urine protein losses can be assessed by:

Back 16

Urine dipsticks (affected by hydration status)
24 hr urines (can be collected improperly)
Random urine to quantify protein excretion (Albumin to creatinine ratio and protein-creatinine ratio)

(Should be done in addition to GFR tests when trying to establish CKD) (>3 months for Dx)

Front 17

When doing a 24 hour urine collection what is the most important instruction? What level of protein excretion would cause concern?

Back 17

PEE IN THE TOILET THE FIRST MORNING!!!!!

>200 mg/day begin to cause concern

Front 18

True or false:
According to the National Kidney Foundation Staging of CKD, you need to have a eGFR < 60 ml/min to have CKD.

Back 18

False. You can have chronic kidney disease with a GFR between 60-90 ml/min if you have proteinuria or structural disease.
However, if you have a GFR <60 you are automatically at Stage 3, whether or not you have structural disease or proteinuria.

Front 19

Who should be tested for CKD?

Back 19

Patients with: HTN, DM, HF, vascular disease (CAD, PVD)
Unexplained anemia
First Nations 
Fam hx ESRD
Inflammatory RA

Front 20

What should you expect to see on imaging on a patient with CKD

Back 20

Increased echogenicity (hallmark sign of CKD)
small kidneys
cystic kidneys
missing kidneys
scarred kidneys
nephrocalcinosis

Front 21

What are some risks of progressing to the need for dialysis in those with CKD?

Back 21

5 year risk for dialysis increased if:
Younger age (<65)
Proteinuria
Pronounced anemia (<100)
Early decline (>4 ml/min/year)
Lower GFR <20

Front 22

What are ways to prevent CKD progression?

Back 22

BP <130/80 (number 1)
A1C <7%
Modify CV risk factors (hyperlipidemia, smoking)
Avoid nephrotoxins (NSAIDs)

Front 23

What are some metabolic consequences to be aware of with CKD? What eGFR has the highest risk for metabolic abnormalities and should be referred to a nephrologist?

Back 23

-Electrolyte/mineral abnormalities: Na+, HCO3-, K+, Phosp & Ca2+
-Anemia

eGFR <30 - high risk of above abnormalities. Refer to nephrology

Front 24

What does a renal diet look like?

Back 24

Low Na+
Low P
Low K+
Low protein (1g/kg/day)

Front 25

Increased muscle catabolism, decline of GFR and bone demineralization (osteopenia) are associated with what metabolic abnormality?

Back 25

Metabolic acidosis (low HCO3-)

Tx: oral sodium bicarb, 1-4g/day in divided doses

Front 26

How does CKD cause anemia? How Hb <100 g/L treated?

Back 26

When eGFR is less than 50% of normal, erythropoietin production is decreased so less hemoglobin.

Treat anemia of <100 g/L with erythropoietin SC injection to get to target of 100-110g/L. Need rx from nephrologist.

Front 27

How are calcium and phosphorous abnormal in CKD and what are some of the consequences?

Back 27

Serum phosphorus too high (decreased excretion)
Serum calcium too low (from reduced VitD activity--activated to highly active form in kidney)

Consequences:
Blood vessel calcification
Metabolic bone disease (secondary hyperparathyroidism)

Front 28

What are some ways to prevent/treat metabolic bone disease?

Back 28

Normalize serum Ca
Normalize serum P (take a TUMS with meals to bind dietary phosphate)
Low P diet
Vitamin D