Chronic Renal Failure

Question 1

What is the prevalence of CKD in the US?

Answer 1

10%

Question 2

Can you reverse CKD?

Answer 2

Nope - just slow the progression

Question 3

Do we screen for CKD?

Answer 3

Not the general population, but we do screen high risk groups (with history of DM, CVD, HTN, HL, obesity, metabolics yndrome, smoking, HIV, hep C, malignancy, family history, age over 60, on treatment with nephrotoxic drugs)

Question 4

How do we screen for CKD?

Answer 4

UA, check urine albumin or protein, urine creatinine, serum creatinine`

Question 5

What is CKD defined as?

Answer 5

kidney damage (any pathological abnormality in blood, urine tests or imagine studies)

or GFR less than 60 for greater than three months

Question 6

What are the number 1 and number 2 causes of CKD?

Answer 6

Diabetes and hypertension - cause 70% of all CKD

Question 7

What are the 5 stages of CKD in terms of GFR?

Answer 7

stage 1: kidney damage plus normal GFR (over 90% kidney function(

stage 2: kidney damage an dmild decrease in GFR (60-89%)

sage 3: moderate decrease in GFR (30-59%)

stage 4: severe decrease in GFR (15-29% of function)

stage 5: kidney failure (less than 15%)

Question 8

What is the easiest way to get an estimate of GFR? Is it accurate?

Answer 8

plasma creatinine - simple and inexpensive, but can be quite inaccurate

Question 9

What are some things that will throw off the plasma creatinine and make it a less than ideal measure of GFR?

Answer 9

reduced with low muscle mass
raised with high protein meal
affected by certain drugs

Question 10

What is considered the most accurate esimating molecule for GFR?

Answer 10

cystatin C - a low molecular weight protein produced by all nucleated cells (not affected by diet, gener, age or muscle mass, but it is affected by steroids)

Question 11

Does creatinine clearance overestime or underestimate the GFR?

Answer 11

overestimates if because there are tubular secretion of creatinine, making the urine creatinine concenration higher than what was actually filtered in the glomerulus.

Question 12

What is the Cockroft-Gault formula for estimated creatining clearance based on plasma creatinine?

Answer 12

140-age x weight (in Kg)
divided by
72 x Cr (x .85 if female)

Question 13

What’s the best approximation of the true GFR?

Answer 13

plasma clearance, but it’s invasive - have to do the 24 hr urine excretion or use radioisotopes

Question 14

What are the steps to managing chrnic kidney disease?

Answer 14

1. treatment of the reverislbe causes of renal dysfuction
2. prevent or slow progression
3. treat complications
4. eventually prepar for replacement therapy

Question 15

What are some reversible causes of renal dysfunction?

Answer 15

1. decreased renal perfusion - HTN meds too high? dehydrated?
2. Nephrotoxic drugs (stop NSAIDS!)
3. Urinary tract obstruction (kidney stones, prostatitis, etc)

Question 16

How do you slow the rate of progression of CKD?

Answer 16

ACE or ARBS
treat HTN
dietary protein restriction
treat HL
tight glycemia control in diabetics
avoid nephrotoxic agents

also weight control and smoking cessation

Question 17

What will happen to creatinine initially when you start someone on an ACE or ARB?

Answer 17

creatinine will increase in the first 4 weeks, but don’t take them off it! it will go back down

Question 18

What are some of the potential complications of CKD that will need to be addressed?

Answer 18

volume overload
hyperkalemia
metabolic acidosis
hyperphosphatemia
hyperparathyroidism
anemia

Question 19

You can also get a metabolic acidosis in CKD. How do you manae this and why should you?

Answer 19

put them on sodium bicarb supplements

should do this because bone buffering can occur with prolonged acidosis and this can worsen bone disease. Uremic acidosis also leads to skeletal muscle breakdown and dimisnishe albumin synthesis (edema)

Question 20

How do you deal with the hyperphosphatemia?

Answer 20

dietary phosphorus restriction - no dairy or nuts

phosphate binders (calcium carbonate or non calcium lanthanum carbonate)

Question 21

Why do you get secondary hyperparathyroidism?

Answer 21

the kidneys aren’t working, so you don’t get enough activation of vitamin D. without vitamin D you don’t get calcium reabosrtion. Without calcium reabosprtion you get low serum calcium which triggers secondary PTH release

Question 22

How do you treat the secondary hyperparathyroidism?

Answer 22

give activated vitamin C - calcitriol, doxecalciferol, paricalcitol

or a calcimimetic called cinacalcet

Question 23

Why do you get an anemia in CKD?

Answer 23

no erythropoietin - no RBC production

Question 24

WHen should you treat the anemia?

Answer 24

if the Hb goes below 10

Question 25

Once a patient reaches stage 4 or 5, what do you need to start discussing?

Answer 25

transplant or dialysis