Approach to Kidney Pt

Question 1

Three Categories of Renal Syndromes

Answer 1

• Pre-Renal: Left heart -> afferent arteriole -> Volume/Perfusion problems
• Renal: Glomerular, tubulointerstitial, vascular
• Post-renal: obstruction f/ Renal pelvis to meatus

Question 2

What factors differentiate acute vs chronic kidney problem

Answer 2

• BUN + Creatinine
• Renal Size/symmetry (ultrasound)
• Clinical Hx

Question 3

Glomerular Syndromes

Answer 3

• Acute Nephritis
• Nephrotic Sx
• Asymptomatic Urinary abnormalities (Proteinuria, hematuria)
• Glomerulonephritis

Question 4

Tubulointerstitial Syndromes

Answer 4

• TI Nephritis/Nephropathy
• Tubular transport defects + Renal Tubular Acidosis (Bartter, Gittelman, Fanconi)
• ARF
• Asymptomatic abnormalities

Question 5

Creatinine Test

Answer 5

• Proportional to muscle mass; daily excretion normal;
• 24H Determines GFR;
• Normal 0.7 -> 1.4
• Ccr = Ucr X V/Pcr OR
• Cockcroft-Gault: (140-age) X Weight/ 72 X Pcr (X 0.85 for females)

Question 6

BUN Test

Answer 6

• Protein Metabolism

- BUN: Cr is 10-20:1

Question 7

Which of the following is the best way to assess renal function?
A. Creatinine clearance
B. Inulin clearance
C. Iothalamate clearance
D. Cockcroft-Gaultequation
E. MDRD equation

Answer 7

B. Inulin clearance

Question 8

Test for Bence-Jones Proteins in Urine

Answer 8

Sulfosalicylic Acid Test (SSA)

Question 9

pot urine protein to creatinine ratio

Answer 9

approximates 24 hour urine collection based on expected daily appearance of creatinine

Question 10

Oval fat bodies

Answer 10

lipid laden renal tubular cells associated with nephrotic syndrome

Question 11

Formation of Urinary Casts

Answer 11

• Intratubular precipitation of Uromodulin
  • Conditions of low flow, alkaline pH
  • Identified by trapped intratubular contents, e.g., cells, debris

Question 12

Types (6) of Urinary Casts

Answer 12

• Hyaline -> translucent; f/ Pre-renal Azotemia
• RBC Casts -> AGN
• WBC -> Nephritis
• Epithelial -> ARF w/ tubular necrosis; “Dirty” pigment
• Granular -> ARF w/ acute tubular necrosisl “Dirty;” cellular debris
• Waxy -> subacute/Chronic renal disease; Tubular atrophy

Question 13

Urine Sodium

Answer 13

• No normal value
• Una low when volume depleted
• Una high in impaired tubular functions

Question 14

FeNa

Answer 14

• Determines intrinsic Renal Failure vs Pre-renal Azotemia
• Na Clearance/Creatinine Clearance
• FeNa = (Una X Pcr)/(Pna X Ucr) X 100
• Normal is 1%

Question 15

Tubular Reabsorption of solutes

Answer 15

• TRx = 1 - Fex

- Eval of phosphate + AA loss in proximal tubul;ar disease (Fanconi Sx)

Question 16

Urine Anion Gap

Answer 16

• Una + Uk - Ucl
• UAG > 0 = Renal
• UAG < 0 = GI