Global Approach to Renal Disease

Question 1

What are findings in the history that indicate pre-renal vs. intra-renal disease?

Answer 1

pre - vomiting, diarrhea, blood loss, increased thirst

intra - increased urination, dyspnea, edema, nocturia, hematuria, renal stones

Question 2

What are the physical exam findings that indicate pre-renal disease?

Answer 2

orthostatic hypotension
decreased skin turgor
dry mucous membranes
low JVP

Question 3

What are the physical exam findings that indicate intra-renal disease?

Answer 3

HTN
retinopathy
elevated JVP
Rales, S3, peripheral edema

Question 4

What are tools that can be used to assess duration of renal disease?

Answer 4

old medical records
kidney size - small means chronic
signs of renal osteodystrophy - supports chronic
kidney biopsy
anemia and hyperphosphatemia less useful

Question 5

Why is it important to determine between acute and chronic renal disease?

Answer 5

acute - more likely to be self limited and better prognosis

treatment may vary

Question 6

How is serum creatinine used to assess renal function?

Answer 6

varies inversely with GFR
but insensitive to mild to moderate reductions
also slow to reflect acute changes in function

Question 7

What can be used as an alternative to creatinine to assess renal function?

Answer 7

24 hr urine collection with creatinine clearance
freely filtered and not reabsorbed - excreted by filtration
CCr can overestimate GFR in patients with CKD
can estimate with an equation or the MDRD (GFR)

Question 8

How can you more directly measure GFR than using creatinine?

Answer 8

Inulin (or iothalamate) clearance - freely filtered and not reabsorbed or secreted
admin as continuous infusion, also expensive

Question 9

What can the dipstick urine test detect or not detect?

Answer 9

detects negatively charged protiens (albumin)
cationic proteins (light chain Ig) will be negative - use SSA to detect all proteins

Question 10

What does a negative dipstick with a positive SSA indicate?

Answer 10

multiple myeloma