Kidney

Question 1

Pre-Renal AKI Labs

Answer 1

• Hyaline casts on urine sediment (bland)
• BUN/Cr >20:1 (b/c tubules still able to reabsorb nitrogen)
• FE Na < 1% (b/c tubules still able to reabsorb Na)
• Urine Osm > 500 mOsm (can still conc urine)
• Urine Na <20

Question 2

Intrarenal AKI Labs

Answer 2

• Muddy brown casts, granular casts in ATN
• Fatty casts of nephrotic
• RBC casts, dysmorphic RBCs in acute glomerulonephritis
• WBC casts, eosinophils in nephritis
• BUN/Cr < 20:1
• FE Na > 2-3%
• Urine Osm 250-300 mOsm
• Urine Na >40

Question 3

Steps in AKI Eval

Answer 3

• 1- r/o post-renal causes w/ H&P, renal US and catheterization
• 2- UA
  - Dipstick
  - Microscopic examination (casts)
  - Urine chemistry - Na, Cr, Osm, calc Fe NAa
• 3- Urine cx and sensitivities if suspect infection
• 4- If renal US showed hydronephrosis then do CT abdomen and pelvis
• 5- Renal biopsy if suspect acute GN or interstitial nephritis
• 6- Renal arteriography if suspect renal artery occlusion

Question 4

Uremia Sx

Answer 4

• Pericarditis
• Nausea, vomiting, anorexia
• Neuro - lethargy, somnolence, confusion, peripheral neuropathy, uremic sz
• Platelet dysfunction
• Pruritus
• Inhibition of cellular and humoral immunity - infections = major cause mortality

Question 5

Indications for Dialysis

Answer 5

• A - acidosis
• E - electrolytes (persistent hyperkalemia)
• I - intoxications (methanol, ethylene glycol, lithium, ASA)
• O - overload (fluid)
• U - uremia (severe symptoms - on clinical basis)

Question 6

Dialysis/ ESRD Diet

Answer 6

Low in …

• Na
• K
• Protein
• Phos
• Mg

Question 7

What other things can cause in BUN?

Answer 7

catabolic drugs (steroids)

GI/soft tissue bleeding

inc dietary protein

Question 8

Nephrotic v Nephritic Findings

Answer 8

NEPHROTIC

• Urine protein excretion > 3.5g / 24 hr
• Hypoalbuminemia - edema
• Hyperlipidemia - liver comp by making more LDL and VLDL
• Fatty casts in urine
• Hyper-coaguable - lose clotting factors in urine
• Inc infection - lose immunoglobulins in urine

NEPHRITIC

• Hematuria - RBC casts
• AKI - azotemia, oliguria
• More mild proteinuria

Question 9

What is the most common nephrotic syndrome in US and what things is it associated with?

Answer 9

Membranous

Hep B, Hep C, syphilis, malaria

Gold, captopril, penicillamin, SLE,

Neoplasms

Question 10

Minimal Change Disease

Answer 10

• most common in kids
• Also seen in Hodgkin and non-Hodgkin lymphoma
• Fused foot processes on EM (normal on H&E)
• Give steroids

Question 11

FSGN

Answer 11

Focal Segmental

blacks; poor prognosis; associated w/ HIV

Question 12

Berger Disease

Answer 12

IgA Nephropathy

gross hematuria after URI or exercise

mesangial deposition of IgA and C3

Question 13

What disorders is membranoproliferative GN associated with?

Answer 13

Hep B, syphilis, SLE

Question 14

Alport v Goodpastures

Answer 14

• Alport Syndrome (hereditary nephritis) - hearing loss

- Goodpasture - anti BM IgG; affects lungs too (hemoptysis); linear immunofluorescence

Question 15

Renal Tubular Acidoses

Answer 15

Type 1

Cannot excrete H+ in distal tubules

• Hypokalemia
• Metabolic acidosis
• Alkaline urine - phosphate and Ca stones

Type 2

Cannot reabsorb bicarb in proximal tubules (Fanconi, Wilsons, lead, multiple myeloma)

• Hypokalemia
• Metabolic acidosis
• NO stones

Type 4

Dec Na absorption and H/K secretion in distal tubules (dec aldosterone or aldosterone resistance)

• HYPERkalemia
• Acidic urine
• Metabolic acidosis