Nephrology ABIM Exam 140 Questions with Verified
Answers
Creatinine limitations include? - CORRECT ANSWER - age, gender, race, diet, and
metabolism
- Low muscle mass → disproportionately low serum
creatinine and overestimation of GFR
−GFR may be <50% normal before serum creatinine ↑
Newer marker of GFR - CORRECT ANSWER Cystatin C
CKD-EPI equation→ most accurate when - CORRECT ANSWER GFR is
normal/mildly reduced
* performs better at higher (normal) values of glomerular filtration rate.
Cockroft-Gault and MDRD equations → most
accurate with ? - CORRECT ANSWER stages 3 to 5 chronic kidney disease
Urine pH >7.0 - CORRECT ANSWER −Distal RTA (type I RTA)
−Infection with Proteus, Klebsiella or Pseudomonas species
Renal Glycosuria - CORRECT ANSWER - Think proximal RTA (type II RTA) when
glucose is normal
- Can be "physiologic" in pregnanc
when dipstick is positive for blood in absence of RBCs think about? - CORRECT
ANSWER Rhabdomyolysis
Leukocyte esterase and nitrates - CORRECT ANSWER When both tests are
concordant (either both
positive or both negative) → high positive and negative predictive values for UTI
• False negative nitrates → gram-positive infection (e.g., Enterococcus)
RBC Casts indicate? - CORRECT ANSWER Glomerulonephritis
,WBC Cast indicate? - CORRECT ANSWER Pyelonephritis
Granular or Muddy brown or dirty brown casts on UA indicate? - CORRECT
ANSWER ATN
Eosinophils indicate? - CORRECT ANSWER acute interstitial nephritis,
atheroembolic disease, infection
Increased Anion Gap Acidosis - CORRECT ANSWER • Ketosis: DKA, AKA, Starvation
• Type B Lactic acidosis (metformin, nucleoside reverse transcriptase inhibitors,
Linezolid, acetaminophen, propofol, and salicylates)
• Chronic kidney disease
• Toxicities: Methanol, ethylene glycol, salicylate
•D-lactic acidosis
•Propylene glycol (lorazepam infusion)
•Propofol
•Pyroglutamic acid (chronic acetominophen)
Osmolal Gap - How is it calculated?
If elevated, consider? - CORRECT ANSWER measured osmolality - calculated
osmolality
measured osmolality - (2x Na + Glu/18 + Bun/2.8)
alcohol poisoning
• Ethanol most common cause
• Methanol, ethylene glycol, isopropyl alcohol
↑ anion gap metabolic acidosis, blurred vision, scotomata, and blindness caused
by? - CORRECT ANSWER Methanol poisoning
Treatment is Fomepizole, ? Hemodiaylysis, Folic Acid
↑ anion gap metabolic acidosis -flank pain, hematuria,
and urinary calcium oxalate crystals caused by? - CORRECT ANSWER Ethylene
glycol poisoning
Treatment is Fomepizole, ? Hemodiaylysis, Folic Acid
, What causes an ↑ anion gap and no metabolic acidosis with + ketones? -
CORRECT ANSWER Isopropyl alcohol
Rx: Supportive
Non-Anion Gap Metabolic Acidosis Kidney HCO3-loss caused by? - CORRECT
ANSWER −Renal Tubular Acidosis
−Ileal conduit
−Drugs: Carbonic anhydrase inhibitor, amphotericin
−Exogenous acids: TPN
Urine Anion Gap or UAG =? - CORRECT ANSWER UAG = (urine [Na+] + urine [K+])-
urine [Cl-]
In non-anion gap acidosis, always calculate UAG
Urine Anion Gap Interpretation
1) Negative UAG → ?
2) Positive UAG → ? - CORRECT ANSWER • Negative UAG → Diarrhea/ laxative
abuse: kidney generates NH4, urine Cl increases
• Positive UAG → Likely to be RTA, NH4 production is impaired
Distal RTA's - CORRECT ANSWER • Type 1→ K is low and urine pH always >5.5
−Associated with stones, nephrocalinosis, HPTH
Therapy for Type 1 (distal) → HCO3
• Type 4 → K is high and urine pH variable, usu < 5.5−Usually
hyporenin, hypoaldo−Associated with diabetes, obstructive
uropathy
Therapy for Type 4 → goal is treatment of hyperkalemia
• Give Furosemide, HCO3
- therapy, mineralocorticoid
•Avoid ACE inhibitors, ARBS, aldosterone antagonists
(spironolactone), NSAIDs
Proximal RTA - CORRECT ANSWER • Type II RTA → low or normal serum
potassium and urine pH initially high, eventually<5.5
−Associated with Fanconi Syndrome: glycosuria, phosphaturia,
uricosuria, aminoaciduria, and low - grade proteinuria
Answers
Creatinine limitations include? - CORRECT ANSWER - age, gender, race, diet, and
metabolism
- Low muscle mass → disproportionately low serum
creatinine and overestimation of GFR
−GFR may be <50% normal before serum creatinine ↑
Newer marker of GFR - CORRECT ANSWER Cystatin C
CKD-EPI equation→ most accurate when - CORRECT ANSWER GFR is
normal/mildly reduced
* performs better at higher (normal) values of glomerular filtration rate.
Cockroft-Gault and MDRD equations → most
accurate with ? - CORRECT ANSWER stages 3 to 5 chronic kidney disease
Urine pH >7.0 - CORRECT ANSWER −Distal RTA (type I RTA)
−Infection with Proteus, Klebsiella or Pseudomonas species
Renal Glycosuria - CORRECT ANSWER - Think proximal RTA (type II RTA) when
glucose is normal
- Can be "physiologic" in pregnanc
when dipstick is positive for blood in absence of RBCs think about? - CORRECT
ANSWER Rhabdomyolysis
Leukocyte esterase and nitrates - CORRECT ANSWER When both tests are
concordant (either both
positive or both negative) → high positive and negative predictive values for UTI
• False negative nitrates → gram-positive infection (e.g., Enterococcus)
RBC Casts indicate? - CORRECT ANSWER Glomerulonephritis
,WBC Cast indicate? - CORRECT ANSWER Pyelonephritis
Granular or Muddy brown or dirty brown casts on UA indicate? - CORRECT
ANSWER ATN
Eosinophils indicate? - CORRECT ANSWER acute interstitial nephritis,
atheroembolic disease, infection
Increased Anion Gap Acidosis - CORRECT ANSWER • Ketosis: DKA, AKA, Starvation
• Type B Lactic acidosis (metformin, nucleoside reverse transcriptase inhibitors,
Linezolid, acetaminophen, propofol, and salicylates)
• Chronic kidney disease
• Toxicities: Methanol, ethylene glycol, salicylate
•D-lactic acidosis
•Propylene glycol (lorazepam infusion)
•Propofol
•Pyroglutamic acid (chronic acetominophen)
Osmolal Gap - How is it calculated?
If elevated, consider? - CORRECT ANSWER measured osmolality - calculated
osmolality
measured osmolality - (2x Na + Glu/18 + Bun/2.8)
alcohol poisoning
• Ethanol most common cause
• Methanol, ethylene glycol, isopropyl alcohol
↑ anion gap metabolic acidosis, blurred vision, scotomata, and blindness caused
by? - CORRECT ANSWER Methanol poisoning
Treatment is Fomepizole, ? Hemodiaylysis, Folic Acid
↑ anion gap metabolic acidosis -flank pain, hematuria,
and urinary calcium oxalate crystals caused by? - CORRECT ANSWER Ethylene
glycol poisoning
Treatment is Fomepizole, ? Hemodiaylysis, Folic Acid
, What causes an ↑ anion gap and no metabolic acidosis with + ketones? -
CORRECT ANSWER Isopropyl alcohol
Rx: Supportive
Non-Anion Gap Metabolic Acidosis Kidney HCO3-loss caused by? - CORRECT
ANSWER −Renal Tubular Acidosis
−Ileal conduit
−Drugs: Carbonic anhydrase inhibitor, amphotericin
−Exogenous acids: TPN
Urine Anion Gap or UAG =? - CORRECT ANSWER UAG = (urine [Na+] + urine [K+])-
urine [Cl-]
In non-anion gap acidosis, always calculate UAG
Urine Anion Gap Interpretation
1) Negative UAG → ?
2) Positive UAG → ? - CORRECT ANSWER • Negative UAG → Diarrhea/ laxative
abuse: kidney generates NH4, urine Cl increases
• Positive UAG → Likely to be RTA, NH4 production is impaired
Distal RTA's - CORRECT ANSWER • Type 1→ K is low and urine pH always >5.5
−Associated with stones, nephrocalinosis, HPTH
Therapy for Type 1 (distal) → HCO3
• Type 4 → K is high and urine pH variable, usu < 5.5−Usually
hyporenin, hypoaldo−Associated with diabetes, obstructive
uropathy
Therapy for Type 4 → goal is treatment of hyperkalemia
• Give Furosemide, HCO3
- therapy, mineralocorticoid
•Avoid ACE inhibitors, ARBS, aldosterone antagonists
(spironolactone), NSAIDs
Proximal RTA - CORRECT ANSWER • Type II RTA → low or normal serum
potassium and urine pH initially high, eventually<5.5
−Associated with Fanconi Syndrome: glycosuria, phosphaturia,
uricosuria, aminoaciduria, and low - grade proteinuria
