Chronic Renal Failure Flashcards
What is the prevalence of CKD in the US?
10%
Can you reverse CKD?
Nope - just slow the progression
Do we screen for CKD?
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)
How do we screen for CKD?
UA, check urine albumin or protein, urine creatinine, serum creatinine`
What is CKD defined as?
kidney damage (any pathological abnormality in blood, urine tests or imagine studies)
or GFR less than 60 for greater than three months
What are the number 1 and number 2 causes of CKD?
Diabetes and hypertension - cause 70% of all CKD
What are the 5 stages of CKD in terms of GFR?
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%)
What is the easiest way to get an estimate of GFR? Is it accurate?
plasma creatinine - simple and inexpensive, but can be quite inaccurate
What are some things that will throw off the plasma creatinine and make it a less than ideal measure of GFR?
reduced with low muscle mass
raised with high protein meal
affected by certain drugs
What is considered the most accurate esimating molecule for GFR?
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)
Does creatinine clearance overestime or underestimate the GFR?
overestimates if because there are tubular secretion of creatinine, making the urine creatinine concenration higher than what was actually filtered in the glomerulus.
What is the Cockroft-Gault formula for estimated creatining clearance based on plasma creatinine?
140-age x weight (in Kg)
divided by
72 x Cr (x .85 if female)
What’s the best approximation of the true GFR?
plasma clearance, but it’s invasive - have to do the 24 hr urine excretion or use radioisotopes
What are the steps to managing chrnic kidney disease?
- treatment of the reverislbe causes of renal dysfuction
- prevent or slow progression
- treat complications
- eventually prepar for replacement therapy
What are some reversible causes of renal dysfunction?
- decreased renal perfusion - HTN meds too high? dehydrated?
- Nephrotoxic drugs (stop NSAIDS!)
- Urinary tract obstruction (kidney stones, prostatitis, etc)
How do you slow the rate of progression of CKD?
ACE or ARBS treat HTN dietary protein restriction treat HL tight glycemia control in diabetics avoid nephrotoxic agents
also weight control and smoking cessation
What will happen to creatinine initially when you start someone on an ACE or ARB?
creatinine will increase in the first 4 weeks, but don’t take them off it! it will go back down
What are some of the potential complications of CKD that will need to be addressed?
volume overload hyperkalemia metabolic acidosis hyperphosphatemia hyperparathyroidism anemia
You can also get a metabolic acidosis in CKD. How do you manae this and why should you?
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)
How do you deal with the hyperphosphatemia?
dietary phosphorus restriction - no dairy or nuts
phosphate binders (calcium carbonate or non calcium lanthanum carbonate)
Why do you get secondary hyperparathyroidism?
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
How do you treat the secondary hyperparathyroidism?
give activated vitamin C - calcitriol, doxecalciferol, paricalcitol
or a calcimimetic called cinacalcet
Why do you get an anemia in CKD?
no erythropoietin - no RBC production
WHen should you treat the anemia?
if the Hb goes below 10
Once a patient reaches stage 4 or 5, what do you need to start discussing?
transplant or dialysis
