Internal Medicine Board Review: Nephrology

Internal Medicine Board Review:
Steven Wagner M.D.
July 16, 2014
Purpose of board review
Pass the boards
Not intended as a complete review
“Boards correct” ≠ “real life correct”
Pick the right answer and move on
And the point is……
• Most questions have a specific teaching point
• If you miss the point, you will probably miss
the question
• Getting the point will not guarantee that you
get the correct answer
– Still have to understand the rest of the question
Inter-nephrologist agreement
• Put 10 nephrologists in a room with a patient,
and you will receive at least 11 diagnoses
• Some might disagree with question format
and/or the answers
With that in mind,
Question 1
A 41-year-old female is seen for follow-up of high blood
pressure. She follows a healthy, active lifestyle and does not
smoke. She is on no medications or birth control.
BP 173/112, BMI 23, other vitals WNL
Labs are normal, including renal panel, UA, glucose, and lipids
What is the most appropriate NEXT STEP in management of her
a) Lisinopril / Hydrochlorothiazide
b) Diet and exercise
c) Norvasc
d) See her back in 2 weeks for a blood pressure recheck
Key point: manage hypertension
• Hypertension is divided into stages
• Our patient has stage II hypertension
• Will need drug therapy
Why the other choices are wrong
Lisinopril / Hydrochlorothiazide
Diet and exercise
See her back in 2 weeks for a blood pressure recheck
• Had a BMI of 23 and a healthy diet
• Norvasc is unlikely to be effective alone
• She is already “following up” at the current
visit. Time to do something.
Question 2
A 23-year-old white female is evaluated for 2 months of fatigue,
polyarthritis, oral ulcers, and edema. She has no significant
medical history and takes no medications.
Blood pressure 165/100, other vitals WNL. Ulcers on hard palate
and buccal mucose. Erythema and tenderness of the MCP and
PIP joints. 2+ LE edema bilaterally.
Hb 11, WBC 2.1, PLT 110K, Albumin 3.4, Creat 1.4
UA shows 25-50 RBC, 25 WBC, and erythrocyte casts
24-hour urine protein is 2.5 grams
Which of the following is the most likely diagnosis?
a) Focal segmental glomerulosclerosis
b) IgA nephropathy
c) Post-infectious glomeulonephritis
d) Proliferative lupus nephritis
Key point: diagnose lupus nephritis
• Lupus nephritis is characterized by hematuria and
proteinuria in the setting of clinical findings of
• Diagnosed with:
>500 mg protein in 24 hour sample
>10 RBC per HPF
RBC or WBC casts in sterile urine (active sediment)
OR by kidney biopsy
• Remember that lupus is a syndrome
• RBC casts indicate GLOMERULAR hematuria
Why the other choices are wrong
Focal segmental glomerulosclerosis
IgA nephropathy
Post-infectious glomeulonephritis
Proliferative lupus nephritis
• FSGS generally presents with more proteinuria
(nephrotic syndrome)
• IgA nephropathy is unlikely in the setting of
clinical findings of lupus
• The answer can’t be post-infectious without
evidence of recent infection (at least on the
• NONE of the incorrect answers explain her
cytopenias etc
Question 3
A 75-year-old man with known alcoholic cirrhosis has 3 weeks of
worsening ascites. He still drinks and is not a transplant candidate.
Don’t even ask. His only medication is propranolol.
He is alert and oriented. BP 109/68, pulse 58, other vitals WNL
No neurologic findings, no asterixes
Abdominal exam nontender with significant ascites. 1+ LE edema
Labs: Albumin 2, BUN 8, Creat 1.6, Na 119, K 3.6, OSM 250
Urine: OSM 156, Na <5
Paracentesis: transudative ascites with WBC 50/uL
What is the appropriate management of this patients
a) 3% saline with a goal of correcting Na by 10 in the next 24 hrs
b) Conivaptan
c) Demeclocycline
d) Fluid and sodium restriction
Key point: Manage asymptomatic
• Management of hyponatremia depends on
the symptoms
– Increased urgency in the setting of seizures,
unresponsiveness, etc
• Remember to correct slowly
Why the other choices are wrong
3% saline with a goal of correcting Na by 10 in the next 24 hrs
Fluid and sodium restriction
• 3% saline is too aggressive in this setting
• Conivaptan decreases BP and is
– Tolvaptan also relatively contraindicated now
• Demeclocycline is effective in SIADH
– This patient has appropriately high levels of ADH
Question 4
A 71-year-old female has a 3-year history of hypertension. She
feels well. She is compliant with a low-sodium diet and does not
smoke. She takes maximal doses of Chlorthalidone, enalapril,
amlodipine, and carvedilol.
BP 168/112, pulse 68, BMI 26, other vitals WNL
Systolic crescendo-decrescendo murmur at the RUSB
Normal carotid upstroke, normal JVP
Renal panel, UA, CBC, glucose, and lipids are normal.
What is the most appropriate next step?
a) Ambulatory blood pressure monitoring
b) Echocardiogram
c) Addition of a vasodilator such as hydralazine
d) Urine metanephrine measurement
Key point: Diagnose resistant
• You have to diagnose something before you
can treat it
• She has hypertension in clinic but will need
documentation of hypertension outside the
office before proceeding
Why the other choices are wrong
Ambulatory blood pressure monitoring
Addition of a vasodilator such as hydralazine
Urine metanephrine measurement
• Echo would be appropriate to evaluate her
murmur, but is not needed for the workup of
her hypertension
• Hydralazine might be helpful, but first we
need a diagnosis
• Metanephrines might be helpful once a
diagnosis of resistant hypertension is made
Question 5
A 38-year-old black female has 6 months of LE edema and
weight gain of 10 kg. Her urine is frothy but no hematuria. She
takes no medications and has no significant history.
BP 155/105, other vitals WNL. BMI is 30
3+ LE edema, otherwise has a normal exam
Labs: Albumin 2.4, creat 1.6, LDL 170, SPEP WNL, RF negative,
ANA negative, Hepatitis panel negative
24-Urine protein = 7.8 grams
Which of the following is the most likely diagnosis?
a) IgA nephropathy
b) Focal segmental glomerulosclerosis
c) Lupus nephritis
d) Post-infectious glomerulonephritis
Key point: FSGS is pure nephrotic
• FSGS is a common adult diagnosis
• Usually not subtle, with heavy proteinuria and
nephrotic syndrome
– Low albumin
– Hyperlipidemia
– Edema
Why the other choices are wrong
IgA nephropathy
Focal segmental glomerulosclerosis
Lupus nephritis
Post-infectious glomerulonephritis
• IgA nephropathy is generally less proteinuria
and also usually has glomerular hematuria
• Lupus nephritis usually has glomerular
hematuria. Could be class V lupus, but ANA
was negative
• Post-infectious glomerulonephritis is wrong
because there is no mention of an infection
Question 6
A 23-year-old female is seen in the ER with 2 months of
progressive weakness. She is no longer ambulatory. No diarrhea
or weight loss. She has a history of Sjogren syndrome and takes
no medications.
Vital sign WNL. BMI 22.
Diffuse weakness on exam , no atrophy or tenderness
Labs: Albumin 4.5, BUN 13, creat 1.1, Na 141, K 1.9, Cl 117, HCO3
14, Phos 3.5.
UA benign, no glucose, no WBC, Anion gap = positive
Renal ultrasound: nephrocalcinosis bilaterally
Which of the following is the most likely diagnosis?
a) Gitelman syndrome
b) Distal (type I) renal tubular acidosis
c) Laxative abuse
d) Proximal (type II) renal tubular acidosis
Key point: Diagnose distal RTA
• Associated with rheumoatologic diagnoses
– Sjogrens, lupus, RA
• Ability to excrete H+ ions is impaired
– Inappropriately alkaline urine pH
• Increased pH leads to kidney stones
• pH >6 in the setting of hypokalemic acidosis,
Sjogrens, and nephrocalcinosis is HIGHLY
– This one is not subtle
Why the other choices are wrong
Gitelman syndrome
Distal (type I) renal tubular acidosis
Laxative abuse
Proximal (type II) renal tubular acidosis
• Gitelman syndrome would be hypotensive and
lytes would look like HCTZ use
• Laxative abuse would have a negative urine anion
– Compensatory increase in ammonium excretion
• Proximal RTA would be expected to have a
normal urine pH
– Distal acidification still intact
• Proximal also often associated with glucosuria,
Fanconi syndrome
Question 7
A 45-year-old female with a history of frequent UTI’s presents with
foul smelling urine, dysuria, and urgency. Her last UTI was
Morganella morganii. She has a known history of kidney stones.
Vitals are WNL
Exam is benign
Labs: Creat 1.2, Albumin 4.2, Calcium 9.3, PTH 12
UA: pH 7.2, WBC 2+, leukocyte esterase, no hematuria, no protein
Due to frequent infections in the setting of kidney stones, a CT scan
is performed, which confirms the presence of bilateral staghorn
calculi. She proceeds to Urology.
What is the most likely composition of her kidney stones?
a) Calcium oxalate
b) Uric acid
c) Ammonium magnesium phosphate
d) Cystine
Key point: Diagnose struvite stones in
the setting of Urease-splitting bacteria
• Common urease splitting bacteria are Proteus
and Morganella
• The boards will not always give you Proteus in
these questions
• Urine pH is key:
– High pH with mention of infection is almost always
struvite stones
Why the other choices are wrong
Calcium oxalate
Uric acid
Ammonium magnesium phosphate
• Calcium oxalate stones are the most common
stone (90%) but not with a high pH
• Uric acid stones are almost never seen with
alkaline urine. Alkalinization is a TREATMENT
for uric acid stones
• Cystine stones are seen in Cystinuria, a genetic
disorder. Think 6-sided crystals
Question 8
A 47-year-old female is seen for diabetes followup. She has CKD,
HTN, retinopathy, and neuropathy. She is active and follows a
diabetic diet. She is on glyburide, amlodipine, and gabapentin.
Vitals: BP 124/80, otherwise WNL
Exam: Trace edema, otherwise WNL
Labs: Creat 3.1, HCO3 17, BUN 88, K 4.8
Which of the following is the most appropriate addition to her
current medical regimen?
a) Allopurinol
b) Phosphate binder
c) Sodium bicarbonate
d) Sodium polystyrene
Key point: Treat metabolic acidosis in
CKD with bicarbonate
• Non-gap acidosis with chronic kidney disease
• Can have a gap with severe renal failure
• Treatment with bicarbonate may reduce bone
loss and possibly CV morbidity, and seems to
slow CKD progression
Why the other choices are wrong
Phosphate binder
Sodium bicarbonate
Sodium polystyrene
• High uric acid is associated with renal disease
progression, but multiple studies have failed to
show benefit from allopurinol
• Phosphate binder is not needed in the setting of
normal phosphorus
• Sodium polystyrene is not needed in this patient
with a normal serum phosphorus, and has a role
ONLY in acute hyperkalemia (if even then)
Question 9
A 54-year-old female is seen for followup of diabetes and
hypertension. She is overweight and noncompliant with all
lifestyle interventions. She is on metformin, glipizide, irbesartan,
HCTA, and simvastatin.
BP 154/82, BMI 38, other vitals WNL
Exam: No LE edema
Labs: creat 1.2, K 5.1, Phos 3.8, 24-hour urine protein 200 mg
In addition to lifestyle modification, which of the following is
the most appropriate next step in management?
a) Diltiazem
b) Furosemide
c) Lisinopril
d) Spironolactone
Key point: Manage hypertension in a
diabetic patient
• Diltiazem is the best choice in this patient
• She is well above the guideline of 130 systolic
in a diabetic patient
Why the other choices are wrong
• Furosemide is not needed as she has no
evidence of volume overload
• Lisinopril is not indicated. Studies show no
benefit with dual RAS blockade, and there is
an increased risk of hyperkalemia
• Spironolactone might be effective, but is
relatively contraindicated in the setting of
borderline hyperkalemia
Question 10
A 54-year-old male is seen for a history of frequent
nephrolithiasis. At least 2 of his stones were analyzed and found
to be uric acid. After his third stone, potassium citrate was
initiated. He also has diabetes, HTN, and hyperlipidemia. No
known history of gout. His diet consists of red meat with most
meals, and he has inconsistent fluid intake. He is on metformin,
metoprolol, atorvastatin, and aspirin.
Vitals and exam WNL. BMI 32.
Labs: BUN 15, creat 1.1, Uric acid 7.8
24-hour urine (mg): Ca 220, Citrate 400, Oxalate 26, uric acid 710
Urine volume: 1600 mg in 24 hours. Urine pH 6.2
Which of the following is the most appropriate treatment?
a) Acetazolamide
b) Allopurinol
c) Calcium carbonate
d) Chlorthalidone
Key point: Manage uric acid stones
with Allopurinol
• Patient has uric acid stones in spite of urinary
• Serum uric acid is elevated
• Other risk factors:
– High meat intake
– Low urine volume
• Dietary modification and increased fluid intake
would be helpful as well
Why the other choices are wrong
Calcium carbonate
• Acetazolamide would alkalinize the urine but
would cause metabolic acidosis
• Calcium carbonate is used for oxalate stones
• Chlorthalidone is a thiazide diuretic, which will
increase serum uric acid levels and might lead
to the development of gout
Question 11
A 75-year-old female is seen for escalating hypertension. She
quit smoking 5 years ago after a TIA. She takes metoprolol,
amlodipine, and HCTZ. Six months ago her BP was 148/82, three
months ago it was 158/90. Today it is 174/96.
Vitals: BP 174/96, pulse 61, otherwise WNL
Exam: Carotid bruits, epigastric bruits, s4 gallop, 1+ LE edema
Lab: Creat 1.7, Na 14, UA normal
Which of the following is the most appropriate next step in
a) Add an ACE inhibitor
b) Increase the metoprolol dose
c) Obtain doppler ultrasound of the renal arteries
d) Obtain renal angiography
Key point: Manage revovascular
• This patient has accelerating hypertension
• Severe PVD on exam, including epigastric
• Treat renal artery stenosis medically unless
there is a hemodynamically significant lesion
on imaging
• Currently much debate on stent vs medical
Why the other choices are wrong
Add an ACE inhibitor
Increase the metoprolol dose
Obtain doppler ultrasound of the renal
Obtain renal angiography
• An ACE inhibitor might cause significant acute
renal failure, especially if she has bilateral
• Metoprolol would slow her pulse further
• Renal angiogram is relatively contraindicated
with her GFR of about 30
Question 12
A 25-year-old male has dark urine and oliguria. He has 5 days of a
URI with rhinitis, sore throat, and fever. Has mild myalgia and
bilateral flank pain but no dysuria. He is taking ibuprofen for pain
Vitals: BP 135/88, remainder WNL
Exam: Erythematous pharynx without exudate, neck
lymphadenopathy, 1+ LE edema
Labs: Hb 9.8, WBC 9.9, PLT 258K, C3+C4 WNL, CK 95, Creat 2.3, ASO
UA: >100 RBC, 2-5 WBC, no bacteria
Renal US: Essentially normal
Which of the following is the most likely cause of acute renal
a) Analgesic nephropathy
b) IgA nephropathy
c) Post-infectious glomerulonephritis
d) Rhabdomyolysis
Key point: IgA nephropathy causes
renal failure concurrent with URI
• Gross hematuria with URI can be the first
presentation of IgA nephropathy
• Mucosal infection causes production of IgA,
with abnormally formed IgA antibodies
causing nephropathy
• Macroscopic hematuria is a favorable
prognostic finding
• Worrisome findings include severe AKI, age >
50, crescents or fibrosis on renal biopsy
Why the other choices are wrong
Analgesic nephropathy
IgA nephropathy
Post-infectious glomerulonephritis
• Hematuria is not a feature of analgesic
• Post-infectious is similar but generally
presents after a latency period
• Rhabdomyolysis may lead to AKI, but CK was
normal and there was no myoglobin on UA.
Question 13
A 54-year-old female has a 4-week history of LE edema and 5 kg
weight gain. No hematuria or dysuria. She has a 14-year history
of well controlled HTM and DM. She is on lisinopril, metformin,
and simvastatin.
Vitals: BP 135/85. Otherwise WNL.
Exam: Retinal exam WNL. Bilateral 3+ LE edema
Labs: Albumin 2.3, BUN 21, Creat 0.7. The following are normal:
Complement, cryoglobulin, SPEP, PF, ANA, Hepatitis panel
Urine: 24-hour protein 12 grams
Kidney biopsy shows subepithelial deposits with foot process
Which of the following is the most likely diagnosis?
a) Diabetic nephropathy
b) Membranous lupus nephritis
c) Minimal change glomerulopathy
d) Primary membranous glomerulopathy
Key point: Patients are allowed to have
2 diseases
• She has a long history of well-controlled
diabetes and suddenly presents with
nephrotic syndrome
• Unusual progression for diabetic nephropathy
• Membranous nephropathy is common in this
age group
• Secondary membranous associated with
medications, malignancies, and infections.
Why the other choices are wrong
Diabetic nephropathy
Membranous lupus nephritis
Minimal change glomerulopathy
Primary membranous glomerulopathy
• This is an unusual progression for diabetic
nephropathy, which generally progresses much
• Membranous lupus is generally seen in the
setting of systemic lupus
• Minimal change disease might present similarly
but would not have deposits on biopsy
Question 14
A 65-year-old male is hospitalized following emergent surgery for
perforated bowel. He has stage 4 CKD at baseline. He has HTN
treated with amlodipine.
Vitals: Temp 38.1, BP 150/95, pulse 102
Exam: Bowel sounds present, colostomy well perfused
Serum K increases from 4.8 to 6.9, creatinine increases from 5.4
to 6.4. Bicarbonate is 17. Urine output has fallen to 50 mL over
8 hours and does not improve with fluids.
ECG reveals peaked T-waves
In addition to calcium and insulin-dextrose, which of the
following is the most appropriate treatment?
a) Furosemide
b) Hemodialysis
c) Sodium bicarbonate
d) Sodium polystyrene sulfonate
Key point: Manage hyperkalemia
• Patient has hyperkalemia due to tissue
• Will need to have potassium removed from his
• Options are limited without urine output.
• After stabilization, hemodialysis is the best
option to quickly remove large amounts of
Why the other choices are wrong
Sodium bicarbonate
Sodium polystyrene sulfonate
• Lasix is unlikely to be effective in the setting of
oligo-anuria unresponsive to fluids
• Sodium bicarbonate is seldom effective in
acidosis of chronic kidney disease for lowering
• Sodium polystyrene sulfonate is contraindicated
in the setting of recent bowel surgery. The risk is
increased with solutions containing sorbitol.
Never give a kayexelate enema.
Question 15
A 27-year-old female is evaluated for 4 months of hypertension.
She feels well. History is otherwise unremarkable.
BP 166/108, other vitals WNL
Exam: Bruit in the right epigastric region. Otherwise WNL
Labs: Renal panel and UA are unremarkable
Renal angiogram shown at right
Which of the following is the most
appropriate next step?
a) ACE inhibitor
b) Calcium channel blocker
d) Surgical revascularization
Key point: PTCA is effective for
fibromuscular dysplasia
• Medial fibroplasia of the renal artery
• Generally in young patients with sudden onset
of hypertension
• Angiography is the best way to diagnose FMD
Why the other choices are wrong
ACE inhibitor
Calcium channel blocker
Surgical revascularization
• Drug therapy should not be attempted until
after the results of PTCA are apparent.
• Surgical revascularization is not first-line
therapy but might be needed for difficult
anatomy or those who do not respond to
Question 16
A 59-year old man is evaluated for worsening kidney function. He
was hospitalized since yesterday with a diabetic foot ulcer, which
has been progressing for 4 weeks. He has CKD, HTN, and diabetes.
He is on metformin, insulin glargine, lisinopril, and cefipime.
Vitals: BP 160/100, otherwise WNL. BP 3 months ago was 130/78
Exam: Erythematous foot ulcer, 2+ LE edema
Labs: Albumin 2.3, C3 and C4 decreased, creatinine 4.1 (BL=1.4)
Urine: 25 RBC, erythrocyte casts. 24-hour protein 1.5 grams
Which of the following is the most likely cause of AKI?
a) Diabetic nephropathy
b) IgA nephropathy
c) Post-infectious glomerulonephritis
d) Primary membranous glomerulopathy
Key point: Diagnose post-infectious GN
• Question stem notes a chronic infection
• Low complement
• Skin flora are common causes of postinfectious GN
• Can manifest as a rapidly progressive
glomerulonephritis (RPGN) or a more indolent
• Often progresses to advanced CKD, especially
in adults
Why the other choices are wrong
Diabetic nephropathy
IgA nephropathy
Post-infectious glomerulonephritis
Primary membranous glomerulopathy
• Diabetic nephropathy progresses slower and is
not associated with hematuria
• IgA nephropathy is generally seen in
association with a mucosal infection
• Membranous nephropathy generally presents
with more than 1.5 grams of protein and
generally has minimal hematuria
Question 17
A 51-year-old male is evaluated for 1 year of uncontrolled
hypertension. There is no family history of HTN. He never
smoked and has no other medical problems. He is on max doses
of chlorthalidone, lisinopril, and amlodipine.
Vitals: BP 160/94, pulse 76, remainder WNL
Exam: Unremarkable.
Lab: Creat 1.1, K 4.1, urianlysis WNL
Which of the following is the most appropriate next step in
a) Switch chlorthalidone to furosemide
b) Switch lisinopril to aliskiren
c) Obtain renal ultrasound with dopplers
d) Obtain a plasma renin aldosterone activity ratio
Key point: Hyperaldosteronism is a
common cause of secondary HTN
• This patient has resistant hypertension
– BP remains elevated on 3 medications, one of which is
a diuretic.
• Hypokalemia is not consistently seen with
• High aldosteronism in the setting of relatively low
renin suggests primary hyperaldosteronism
• Confirm with a 24-hour aldosterone collection
– High salt diet
Why the other choices are wrong
Switch chlorthalidone to furosemide
Switch lisinopril to aliskiren
Obtain renal ultrasound with dopplers
Obtain a plasma renal aldosterone activity
• Switch to a loop diuretic can be helpful in
patients with decreased renal function
• Aliskerin is not more effective than lisinopril
for blood pressure control
• While RAS could also cause the patient’s
symptoms, he has no other evidence of
vascular disease
Question 18
A 62-year-old male is hospitalized after being found down. He is
confused but thinks he was in a fight a few days ago. He has HTN
and hyperlipidemia, as well as alcohol abuse.
Vitals: BP 165/85, pulse 102, temp 37.3
Exam: Multiple bruises, confused, orients to self only, membranes
are dry, abdomen soft, no edema
Labs: Hb 9.3, WBC 6.5, PLT 113K, BUN 85, Creat 4.5, K 5.1, HCO3
21, Phos 5.8, CK 15K
Urine: FENA 5.7%, 3+ blood, 3-5 RBC, 5-10 WBC, few granular casts
Which of the following is the most likely diagnosis?
a) Acute interstitial nephritis
b) Hepatorenal syndrome
c) Abdominal compartment syndrome
d) Pigment nephropathy
Key point: Recognize pigment
nephropathy as a cause of AKI
• Commonly presents with a history of muscle
– Fight
– Found down
• Also with myotoxic drugs, exertion
– Statins
• Exacerbated by volume depletion
• UA with positive heme but no RBC on micro
Why the other choices are wrong
Acute interstitial nephritis
Hepatorenal syndrome
Abdominal compartment syndrome
Pigment nephropathy
• Interstitial nephritis generally needs to have a
history of an offending agent
• There is no evidence of liver disease to
suspect hepatorenal syndrome, and he is not
• Abdomen is soft on exam, making
compartment syndrome unlikely
Question 19
A 30-year-old female has 2 months of edema and weight gain.
She has no history and takes no medications.
Exam: BP 132/82. 3+ LE edema, otherwise unremarkable
Labs: Albumin 3.1, BUN 19, creat 0.7, cholesterol 237, LDL 147,
Hepatitis negative, ANA negative, RF negative, HIV negative
Urinalysis: 3+ protein, estimated proteinuria 4 grams/day
Kidney biopsy is consistent with membranous glomerulopathy.
No evidence of mesangial involvement, glomerulosclerosis, or
interstitial changes.
Which of the following is the most appropriate treatment?
a) ACE and statin
b) Calcineurin inhibitor such as tacrolimus
c) Corticosteroids
d) Cyclophosphamide
e) Mycophenolate mofetil
Key point: Treat membranous
• She has primary membranous nephropathy
• Risk factors for progression:
– Age > 50
– Elevated creatinine
– Glomerulosclerosis, interstitial changes
– Persistent proteinuria for 6 months
• ACE and statin can control her hypertension
and hyperlipidemia of nephrotic syndrome
Why the other choices are wrong
ACE and statin
Calcineurin inhibitor such as tacrolimus
Mycophenolate mofetil
• She has a low risk of progression to ESRD
• Immunosuppressive therapy should be reserved
for more aggressive cases
• She might need in the future if she worsens
• Remember to counsel young women regarding
fetal risks with ACE and all immune suppressants,
esp mycophenolate mofetil
Question 20
A 48-year-old female is seen in the ER for fatigue, weakness, and
dizziness. She was at an outdoor concert all day. She has a
history of lupus without nephritis, as well as HTN. She is on
hydroxychloroquine and HCTZ. She took ibuprofen several times
today for myalgias.
BP 97/52 lying, 90/45 standing. Pulse 108
Exam: No rashes or edema. Mucous membranes dry
Labs: BUN 32, creat 1.2 (BL=0.7), FENA 1.2%, urinalysis benign
Which of the following is the most likely diagnosis?
a) Acute interstitial nephritis
b) Acute tubular necrosis
c) Lupus nephritis
d) Prerenal azotemia
Key point: Recognize the clinical and
lab findings of prerenal azotemia
• History of volume depletion
• ACE and NSAIDs can reduce renal
– Increased risk for azotemia
• FENA is >1.2%, but she is on HCTZ
Why the other choices are wrong
Acute interstitial nephritis
Acute tubular necrosis
Lupus nephritis
Prerenal azotemia
• There are no other exposures to suspect AIN
– Also no WBC or eosinophils on UA
• ATN generally displays muddy casts on UA.
She is at risk for ATN if hypovolemia continues
• Lupus nephritis would have hematuria or
some other evidence of lupus activity.
Question 21
A 45-year-old female comes to establish care. She is a recent
immigrant from Romania. She has CKD and hypertension.
Family history includes a cousin with CKD. She has no urinary
symptoms, and takes captopril as well as occasional Ibuprofen
BP 138/67, BMI 22, other vitals WNL
Exam: Trace ankle edema, otherwise nonfocal
Labs: creat 2.8, K 4.9, HCO3 21
Urinalysis: Rare granular casts, otherwise normal
Renal ultrasound: Small kidneys without hydronephrosis
Which of the following is the most likely diagnosis?
a) Analgesic nephropathy
b) Balkan nephropathy
c) Hypertensive nephropathy
d) IgA nephropathy
Key point: Recognize Balkan
• Thought to be caused by aristolochia spp that
grows with wheat
• Results in regional pattern
• Increased risk of urothelial cancers
– Specific DNA adducts
• Also can be caused by chinese herbal
Why the other choices are wrong
Analgesic nephropathy
Balkan nephropathy
Hypertensive nephropathy
IgA nephropathy
• Analgesic nephropathy is unlikely without a
history of heavy use. Also more likely to
present with proteinuria
• Hypertensive nephropathy unlikely with wellcontrolled hypertension
• IgA nephropathy is unlikely without hematuria
or proteinuria, and without a history of
hematuria with URI
Question 22
A 76-year-old female is seen in the ER with 1 day of nausea,
vomiting, weakness, and confusion. She has fallen several times.
BP 130/78, pulse 68, BMI 19
Exam: Frail appearing, no edema, JVP normal
Labs: Albumin 3.6, BUN 10, creat 0.9, Na 120, K 3.6, Cl 83, HCO3
27, glucose 105, OSM 255
Urine: OSM 408, urinalysis normal
Which of the following is the most appropriate treatment?
a) 0.9% saline infusion
b) 3% saline infusion
c) Furosemide
d) Tolvaptan
Key point: Rapid treatment of
symptomatic hyponatremia
• The patient has SIADH with CNS symptoms
and is in a state of rapid decline
• 3% saline infusion is indicated
• Aim to raise serum sodium by 4-6 in the first
24 hours
• Use D5W if over-correction occurs
Why the other choices are wrong
0.9% saline infusion
3% saline infusion
• 0.9% saline would worsen the situation
– Na 155 in 0.9% saline
– People are not beakers
• Lasix prevents concentration of urine and forces
water excretion, which would help in time
• Tolvaptan (V2 receptor antagonist) might be
helpful but not acutely. Also is difficult to control
the rate of correction with “vaptan” agents
Question 23
A 60-year-old male comes into clinic as a new patient. He was
diagnosed with DM 6 months ago at a health fair. No other
history. He is on metformin.
BP 145/94, BMI 29. Exam normal
Labs: HbA1c 6.8%, BUN 10, creat 0.9, glucose 126
Urine: No protein on UA
Echo: LVH
Which of the following is the most appropriate next step?
a) Add an ACE inhibitor
b) Add a b-blocker
c) Add a calcium channel blocker
d) Add a diuretic
e) Continue current regimen
Key point: Prevent diabetic renal
• He has hypertension in the setting of diabetes
• Goal blood pressure 130/70
• RAS blockade can help prevent the onset of
diabetic renal disease
• Independent of BP control
• Glomerular hyperfiltration in DM?
Why the other choices are wrong
Add an ACE inhibitor
Add a b-blocker
Add a calcium channel blocker
Add a diuretic
Continue current regimen
• All the other agents listed would control the
BP but would have no effect on long term
renal function
• Continuing with current care is not an option
Question 24
A 66 year old female has AKI 4 days after colectomy for perforation.
No intra-op hypotension but required 15 L of fluid. Urine output
has gradually diminished and she is now oliguric. She received a
single dose of tobramycin post-op (just for fun?) and now is on
Vancomycin and Imipenem.
Intubated and sedated. Temp 37.2, BP 91/52. BMI 35
Cardiopulmonary exam as expected, abdominal exam reveals a
tense and distended abdomen with abdominal wall and LE edema.
BUN 45, creat 2.9 (up from 0.9 post-op), FENA 1.5%
Urinalysis with granular casts, no hematuria or pyuria
Renal ultrasound: Normal kidneys without hydronephrosis
What is the most likely cause of renal failure?
a) Aminoglycoside nephrotoxicity
b) Abdominal compartment syndrome
c) Pre-renal azotemia
d) Urinary onstruction
Key point: Abdominal compartment
syndrome is an important problem in
the ICU
• Patient is intubated and on paralytics
• Tense abdomen likely from abdominal wall
edema as well as bowel edema, fluid
• Exact pathophysiology of abdominal
compartment syndrome causing renal failure
is unknown
Why the other choices are wrong
Aminoglycoside nephrotoxicity
Abdominal compartment syndrome
Pre-renal azotemia
Urinary onstruction
• Aminoglycoside nephrotoxicity is unlikely with
only a single dose
• Pre-renal azotemia should have responded to
• Urinary obstruction was effectively ruled out
with a normal renal ultrasound
Question 25
A 54-year-old female is seen for recurrent kidney stones. She
had gastric bypass 1 year ago and BMI has fallen from 38 to 33.
She has passed 3 stones since surgery, none of which was sent
for analysis. She also has diabetes and HTN, and is on
metoprolol and glyburide.
BP 125/78, remainder of exam is unremarkable
Urinalysis: Many crystals (see below)
Urine calcium and citrate are normal
Which of the following is the most appropriate next step?
a) Calcium carbonate supplements
b) Chlorthalidone
c) Potassium citrate
d) Tamsulosin
Key point: Oxalate stones can be seen
after gastric bypass
• Much less frequent with newer procedures
• Fat malabsorbtion leads to decreased intestinal
calcium, leaving unbound oxalate to be absorbed
• Treatment is with supplemental calcium to
complex with oxalate and lead to fecal
• Also increase fluid intake and decrease oxalate in
• Also seen with crohn’s or any disease that results
in small bowel resection
• Cannot happen after colectomy
Why the other choices are wrong
Calcium carbonate supplements
Potassium citrate
• Thiazides are useful in other types of calcium
stones, by decreasing urine calcium
• Potassium citrate is helpful in patients with
low urine citrate
• Tamsulosin and other a-blockers can help
move stones through the ureter but will not
help prevent future stones
Question 26
A 71-year-old female is hospitalized for chest pain. She has DM,
HTN, hyperlipidemia, and CKD. She is on lisinopril, rosuvastatin,
furosemide, carvedilol, insulin, and aspirin.
BP 118/50, pulse 70, cardiac exam is normal. Trace edema
Labs: Hb 11, creat 3.1 (baseline), electrolytes normal
Nuclear study shows reversible ischemia. Patient is scheduled
for cardiac cath. Lisinopril is held prior to the procedure.
Which of the following interventions will decrease her risk for
contrast-induced nephropathy?
a) Isotonic saline
b) Isotonic saline with mannitol diuresis
c) Oral hydration
d) Prophylactic hemodialysis
Key point: Better to prevent contract
• Contrast nephropathy incidence increases in
those with pre-existing renal disease
• Volume repletion is beneficial for prevention
of nephropathy
• No clear consensus on whether bicarb is
better than normal saline
• Decreased dye load, low-osmolar dye, etc
• Don’t go squirting any dye into the renal
Why the other choices are wrong
Isotonic saline
Isotonic saline with mannitol diuresis
Oral hydration
Prophylactic hemodialysis
• Mannitol diuresis is used to treat physicians, not
patients. Best use of mannitol is in situations where
increased osmolality is needed (CNS bleeds, etc)
• Oral hydration is not more effective, and best to be
fasting for a cath
• Prophylactic hemodialysis will lower the creatinine but
will not prevent the nephropathy.
– Contrast dye dialyzes but we can’t remove it fast enough
to make any difference
Question 27
A 32-year-old male is seen for a new diagnosis of autosomal
dominant polycystic kidney disease (ADPKD). His mother had
ADPKD, HTN, ESRD on dialysis, and died of a stroke. The patient
has HTN and takes metoprolol and losartan.
BP 132/82, remainder normal
Exam: Kidneys palpable and not tender
Labs: Creat 1.2, estimated urine protein 150 mg/day
Urinalysis: 5-10 RBC’s
Which of the following in the most appropriate next step?
a) 24-hour urine collection for protein
b) Cerebral MR angiogram
c) Genotype testing for ADPKD
d) Noncontrast abdominal CT scan
Key point: Patients with ADPKD are at
risk of cerebral aneurysms
• 8% incidence
• More common in those with a family history
of aneurysm rupture
– Mother had a stroke
• Also screen if patient has symptoms such as
headache etc
• Role of screening in patients with no family
history of aneurysm is unknown
Why the other choices are wrong
24-hour urine collection for protein
Cerebral MR angiogram
Genotype testing for ADPKD
Noncontrast abdominal CT scan
• Random UA indicated minimal proteinuria, so
a 24-hour collection is not needed.
Proteinuria is not usually seen in ADPKD.
• Genotype testing is not needed. We know he
has ADPKD.
• Abdominal CT would be indicated if he had
complaints of cyst rupture or infection

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