Transcript Nephrology Board Review

Nephrology
Board Review
Emily Chang
June 18, 2010
14. A 23 yo man with HIV comes for a f/u exam. He was hospitalized a week ago with Pneumocystis jiroveci
pneumonia, which is being treated with trimethoprim-sulfamethoxazole and a prednisone taper. During his
hospitalization, he was diagnosed with hyponatremia. He feels well, and his condition has significantly
improved since his discharge 3 days ago.
On physical exam, T 36.6, P 84, R 12, BP 110/60. He appears thin and in no apparent distress. Cardiac
examination is normal. The lungs are clear to auscultation. There is no peripheral edema.
CD4 87, Glu 182, BUN 12, Cr 0.7, Na 111, K 3.6, Cl 96, Bicarb 22, Alb 3.3, Phos 2.6
Serum osm 246, UNa 117, UK 24, Uosm 453
Which of the following is the most likely cause of his hyponatremia?
A. Syndrome of inappropriate antidiuretic hormone secretion
B. Volume depletion
C. Adrenal insufficiency
D. Pseudohyponatremia
E. Psychogenic polydipsia
Hyponatremia
Free water intake + underlying impairment of free water excretion.
1. Check serum osm. If >280, then hyperglycemia or mannitol.
Hyperglycemia correction is 1.6 for every 100 of glu over 100.
2. Check urine osm. If <100, then psychogenic, water intoxication or reset osmostat
because the kidneys are functionally able to dilute urine.
3. Check volume status.
If hypovolemic, check UNa. <25, then extrarenal fluid loss. >25, then renal fluid
losses.
If normovolemic, causes are many: renal failure, hypothyroid, adrenal insufficiency,
pain/stress/trauma, positive-pressure ventilation, exogenous desmopressin, post-op.
If all absent, then check UNa. >25 = SIADH.
If hypervolemic, heart failure, cirrhosis or nephrotic syndrome.
34. A 61 year old woman is hospitalized for a 5-day history of nausea and vomiting and a 2-day
history of postural lightheadedness. Her Cr is 7mg/dL (baseline Cr 1 month ago was 1 mg/dL).
She has a h/o HTN and type 2 DM. Medications include aspirin, atenolol, glipizide, enalapril
and chlorthalidone.
On physical examination, P 68, BP 85/60. She is not in distress. Skin turgor is decreased.
Cardiac and pulmonary examinations are normal. There is no peripheral edema. On
neurological examination, she is alert and oriented.
Glu 56, BUN 85, Cr 8, Na 120, K 3.7, Cl 86, Bicarb 26
UA several hyaline casts/hpf
UCr 40, UNa 40
Which of the following is the next best step in this patient’s management?
A.
B.
C.
D.
E.
IV 3% NaCl, 100 mL
Bolus therapy with 1000mL of NS (0.9%)
Dialysis
Fluid restriction
Dopamine titrated to maintain a MAP of >60 mmHg
Why is her UNa so high if she is volume depleted?
- Use of diuretics
- May represent a transitional state between pre-renal renal failure to ischemic
tubular injury
- In early ischemic tubular injury, urine sediment may be bland
39. A 34-year old woman who underwent elective laparoscopic bilateral tubal ligation 1 day ago
develops severe HA and nausea the next morning. During the surgery, 5% dextrose in 1/4 strength
normal saline therapy is initiated and maintained at 125 mL/h. She remains in recovery until late in
the afternoon because she is too sedated to be discharged. IV meperidine is administered with
adequate relief of her pain.
Glu 115, BUN 12, Cr 1.0, Na 126, K 3.9, Cl 96, Bicarb 22
Which of the following is the most appropriate next step in the management of this patient?
A.
B.
C.
D.
E.
D/c 5% dextrose in 1/4 strength NS; begin 3% saline via infusion pump
D/c 5% dextrose in 1/4 strength NS; begin IV 0.9% saline at 200mL/h
Emergent CT scan of the head
Administer naloxone
Switch meperidine to fentanyl
48. A 73-year old woman is brought to the ED after falling at home. Her family states that she
has been very confused and disoriented over the past 2 days and that she began therapy with a
new medication 1 week ago. She also has type 2 DM.
On physical exam, T 37C, P 68, R 12, BP 115/65. She is confused and unable to appropriately
answer questions. Cardiac examination is normal. The lungs are clear to auscultation. There
is no edema.
Glu 94, BUN 17, Cr 1.1, Na 107, K 2.9, Cl 76, Bicarb 21.
Therapy with which of the following agents was most likely recently started in this
patient?
A.
B.
C.
D.
E.
Furosemide
Acetazolamide
Spironolactone
Hydrochlorathiazide
Amiloride
HCTZ can cause severe hyponatremia. How?
It works at level of cortical collecting duct by blocking Na/Cl co-transporter.
Therefore it impairs kidneys diluting capacity but not concentrating ability.
Relative volume depletion can be induced, leading to stimulation of ADH,
which leads to urinary concentration, water retention and hyponatremia.
28. A 64 yo man is admitted to the ICU with pneumonia and septic shock. Over the past 4 days, he
has had increasing SOB and fever. He has HTN. Surgical history is significant for a previous
cholecystectomy. Medications are amlodipine and hctz.
On physical examination, T 38.8C, P 110, R 22, BP 85/50. Cardiac exam reveals a greade 2/6 systolic
murmur. On pulmonary exam, there are crackles over the entire right lung field. There is trace pedal
edema.
Glu 115, BUN 22, Cr 1.4, Na 135, K 4.8, Cl 103, Bicarb 10, Alb 3.8
pH 6.94, pCO2 48, pO2 51
Which of the following conditions is most likely present in this patient?
A.
B.
C.
D.
E.
Anion gap metabolic acidosis
Mixed non-anion gap metabolic acidosis and respiratory acidosis
Mixed anion gap metabolic acidosis and respiratory alkalosis
Mixed anion gap metabolic acidosis and respiratory acidosis
Mixed non-anion gap metabolic acidosis and respiratory alkalosis
Acid/Base





Look at ABG for pH and pCO2 to determine if respiratory
Look at Bicarb for metabolic component
Calculate AG (remember to correct for Alb)
Calculate Delta-Delta to determine if non-gap component
Determine if respiratory compensation is adequate:
 Winter’s
formula: Expected pCO2 = 1.5 (HCO3) + 8 +/- 2
62. A 44 yo woman with cirrhosis 2/2 autoimmune hepatitis is hospitalized for a progressively
worsening 2-day h/o fever and abdominal pain. She is currently on the orthotopic liver transplant list
and has been clinically stable for the past month. She has previously undergone transjugular
intrahepatic portosystemic shunt placement and a cholecystectomy. Medications are oral
spironolactone 100mg BID, furosemide 80mg BID and oral lactulose 30 mL BID.
On physical exam, T 38.2C, P 72, R 24, BP 74/55. She appears cachectic. Cardiac and pulmonary
exams are normal. The abdomen is distended, and there is diffuse tenderness. There is 1+ pitting
edema in the lower extremities. SBP is suspected, and she is admitted to the hospital.
Glu 84, BUN 20, Cr 1.3, Na 128, K 5.1, Cl 104, Bicarb 12, Alb 1.4
pH 7.25, pCO2 28, pO2 78
Which of the following is the most likely diagnosis in this clinical scenario?
A.
B.
C.
D.
E.
Mixed anion gap metabolic acidosis and respiratory alkalosis
Mixed anion gap metabolic acidosis and respiratory acidosis
Mixed non-anion gap metabolic acidosis and respiratory acidosis
Anion gap metabolic acidosis
Non-anion gap metabolic acidosis
65. A 21 yo man is evaluated in the ED for severely diminished mental status. He has a 3-day h/o
nausea and has been unable to eat well. This morning, he vomited several times.
On physical exam, T 37.4, P 105, R 28, BP 122/57, He is thin and appears in moderate distress.
Cardiac and pulmonary examinations are normal. The abdomen is soft and nontender. A stool
specimen is negative for occult blood. During the examination, he begins to vomit large amounts,
aspirates a significant amount of his stomach contents, and develops respiratory failure. He is
intubated and started on mechanical ventilation.
Labs 1 hour after initiation of mechanical ventilation:
Glu 980, BUN 11, Cr 1.7, Na 138, K 3.7, Cl 91, Bicarb 16
ABG on O2 pH 7.53, pCO2 19, pO2 67
Which of the following is the most likely acid-base disturbance present in this patient?
A.
B.
C.
D.
Mixed anion gap metabolic acidosis/non-anion gap metabolic acidosis/respiratory acidosis
Mixed anion gap metabolic acidosis/metabolic alkalosis/respiratory alkalosis
Mixed anion gap metabolic acidosis with respiratory alkalosis
Mixed metabolic alkalosis with respiratory acidosis
Compensation




Metabolic Acidosis
 Every 1 mmol/L decrease in HCO3 -> 1 mm Hg decrease in pCO2
 pCO2 should approach last two digits of pH (ex: pCO2 of 24 should correspond to pH of
7.24)
Metabolic Alkalosis
 Every 1 mmol/L increase in HCO3 -> 0.7 mm Hg increase in pCO2.
Respiratory Acidosis
 Acute: 10 mm Hg increase in pCO2 -> 1 mmol/L increase in HCO3
 Chronic: 10 mm Hg increase in pCO2 -> 4 mmol/L increase in HCO3
Respiratory Alkalosis
 Acute: Every 10 mm Hg increase in pCO2 ->
2 mmol/L decrease in HCO3
 Chronic: Every 10 mm Hg increase in pCO2 ->
4 mmol/L decrease in HCO3
77. A 56 yo man with a h/o alcoholism is found lying on the street with impaired consciousness.
On arrival at the ED, he is unresponsive and intubated.
On physical exam, T 36.1, P 70, BP 126/80. Fundoscopic exam shows no papilledema. Cardiac,
pulmonary, and abdominal exams are normal. There is no peripheral edema.
Glu 86, BUN 45, Cr 2.8, Na 138, K 5.4, Cl 94, Bicarb 14
ABG on O2 15 min after intubation: pH 7.28, pCO2 29, pO2 108
Plasma osm 316
UA calcium oxalate crystals
Renal ultrasound reveals normal sized kidneys with no obstruction or hydronephrosis.
Which of the following is the most appropriate treatment for this patient?
A.
B.
C.
D.
E.
Fomepizole and HD
Bicarbonate supplementation
Ethanol drip
HD
Fomepizole and ethanol drip
Calculating osmolal gap:
Can be useful if you are suspecting ethylene glycol or methanol intoxication.
Measured serum osm - Calculated serum osm
Calculated serum osm = 2 x Na + BUN/2.8 + Glu/18
If >10, suggest presence of unmeasured osmole.
11. A 55 yo man with HTN and diabetic nephropathy comes for a f/u visit. He was diagnosed with
type 2 DM 10 years ago. He has no SOB or edema. Medications are glipizide 5mg BID,
pioglitazone 30mg daily, metoprolol 100mg daily, fosinopril 80mg daily, hctz 25mg daily, atorvastatin
40mg daily, and asa 81mg daily.
On physical exam, P 55, BP 145/85. He is obese. Retinal microaneurysms are present. On
cardiac exam, there is a regular sinus rhythm with no murmurs. The lungs are clear to auscultation.
There is trace pedal edema.
Cr 1.0, Na 140, K 4.0, Cl 106, Bicarb 24
24-Hour urine protein excretion 6g/24 h
UA 4+ protein, 1-2 erythrocytes and 8 leukocytes/hpf
On abdominal ultrasounds, the right kidney is 12cm and the left is 12.2cm. There is normal
echogenicity and no hydronephrosis, masses or stones.
Which of the following is the most appropriate next step in this patient’s management?
A.
B.
C.
D.
E.
Increase hctz dose to 50mg daily
Add amlodipine
Add prazosin
Increase metoprolol dose to 150mg/day
Add losartan
66. A 45 yo woman is evaluated for newly diagnosed HTN. She has a FH of essential HTN, and both
her parents have type 2 DM.
On physical exam, BP 150/95. BMI is 32. The remainder of the exam is normal.
BUN, Cr, electrolytes normal
glu (fasting) 90
Total cholesterol 220, HDL 35, LDL 140, TG (fasting) 250
In addition to repeating BP measurement to confirm the diagnosis of HTN and counseling
regarding lifestyle modification, therapy with which of the following agents is indicated for this
patient?
A.
B.
C.
D.
HCTZ
Doxazosin
Atenolol
Irbesartan
13. A 45 yo woman is referred for evaluation for a blood pressure measurement of 150/94. Her
husband is a nurse and regularly measures her BP at home. Her usual home BP measurement is
between 110/76 and 120/80. She does not smoke cigarettes. Her mother has HTN.
On physical exam, her average BP is 148/98. Results of lab studies, including the Cr, are normal.
In addition to counseling regarding lifestyle modifications, which of the following is the most
appropriate management for this patient?
A.
B.
C.
D.
Begin hctz
Begin enalapril
Perform ambulatory BP monitoring
Continue home BP measurement
30. A 65 yo woman is evaluated for resistant HTN. Despite use of antihypertensive therapy for over
20 years, her BP usually is approximately 160/90. For several years she has been taking amlodipine
10, metoprolol 100mg daily. However, her regimen recently was changed to lisinopril 20mg daily and
SR verapamil 180mg daily.
On physical exam, P 68, BP 178/100. On cardiac exam, PMI is prominent and displaced laterally.
Lungs are clear to auscultation. Remainder of the exam is normal.
BUN 18, Cr 0.9, Na 147, K 3.3, Cl 100, Bicarb 28
An echocardiogram reveals increased left ventricular mass.
Which of the following is the most appropriate next step in this patient’s management?
A.
B.
C.
D.
MRA
hctz 25mg daily
Aldosterone-Renin ratio
CT scanning
Hypertension
•
•
•
•
•
The target BP for the general population is <140/90 and is <130/80 for patients with DM or
renal disease.
HTN and proteinuria are important risk factors for progression of diabetic nephropathy to
ESRD. First line treatment in patients with diabetic nephropathy should be with ACE-I and
ARBs. Combination therapy MAY be more effective than max ACE-I doses alone.
Based on ALLHAT trial, initiation of therapy with a drug that has been associated with
improved insulin resistance (ACE-I and ARBs), especially in someone with risk factors for type
2 DM, have been associated with lower incidence of new-onset diabetes compared to
diuretics and beta-blockers.
White coat hypertension cannot be proven with home BP monitoring, needs ambulatory BP
monitoring
In early onset, severe or resistant HTN, especially with hypokalemia and hypernatremia
(although these not always seen), screening for hyperaldo is indicated. ARR is preferred
screening test. Levels best measured after BB, ACE-I and diuretics have been d/c’d. These
patients will benefit from aldosterone blockade.
72. An 80 yo woman is evaluated for resistant HTN and fatigue. Home BP measurements are
typically approximately 180/70. Medications are metoprolol 50mg daily, lisinopril 20mg daily and
hctz 12.5mg daily.
On physical exam, P 72, BP 180/70.
BUN 12, Cr 0.9, Na 132, K 3.3, Cl 99, Bicarb 26
Plasma renin activity 0.36 ng/mL
Which of the following is the most appropriate next step in this patient’s management?
A.
B.
C.
D.
Double the dose of hctz
Double the dose of metoprolol
Double the dose of lisinopril
Discontinue the hctz; add spironolactone 25mg daily
81. A 35 yo woman who is 15 weeks pregnant is referred for evaluation of HTN. She discontinued
her antihypertensive regimen when she learned that she was pregnant.
On physical exam, P 90, BP 160/98. Cardiac and pulmonary exams are normal. There is trace
ankle edema.
BUN 6, Cr 0.6, Na 136, K 3.7, Bicarb 23
Treatment with which of the following agents is most appropriate for this patient?
A.
B.
C.
D.
E.
HCTZ
Lisinopril
Losartan
Labetalol
Atenolol
9. A 51 yo man with h/o chronic lymphocytic leukemia with transformation to prolymphocytic
leukemia is hospitalized for chemotherapy with R-CHOP (cyclophosphamide doxorubicin
vincristine prednisone rituximab). Before initation of chemo, he receives allopurinol and NS
@250 mL/hr. One day later, his Cr is 2.3 (baseline 0.8) and his UOP over the past 12 hours is
200 mL despite continued saline hydration.
On physical exam, he is afebrile, pulse 98, R 16, BP 134/78. There is lymphadenopathy involving
the cervical and submental chains and supraclavicular areas bilaterally, as well as bulky axillary
and inguinal lymphadenopathy. Cardiac and pulmonary exams are normal. The spleen is
palpable approximately 3-4 cm below the left costal margin, and there is no hepatomegaly. There
is no edema, cyanosis or clubbing of the extremities.
Hct 22, Leukocyte 72, Plt 19
BUN 63, Uric Acid 19, Cr 2.3, K 5.5, Bicarb 17, Alb 4.2, Ca 7.5, Phos 11
UA pH 5, numerous finely granular casts/hpf, no uric acid crystals
Which of the following is the most appropriate next step in this patient’s management?
A. Switch IV hydration to sodium bicarbonate
B. Start furosemide
C Start rasburicase
D. Start HD
E. Start probenecid.
63. A 83-year-old male nursing home resident w/ a hx of dementia is evaluated in the ED for
abdominal pain. According to the nursing home staff, he had become increasingly agitated over
the past day.
On PE, T 36.7 C, P 96, and BP 150/92. The patient appears frail and confused and is clutching his
abdomen and writhing in pain. He is unable to answer questions. Pulmonary exam reveals
crackles at both lung bases. Skin turgor is normal. There is suprapubic tenderness. The
prostate is smooth, enlarged, and has an estimated mass of 40 g. There is trace ankle edema
bilaterally.
Na 137, K 6.2, Cl 107, HCO3 18, BUN 63, Cr 3.6
U/A: SG 1.014, Trace protein, 2-3 leukocytes/hpf, 3-5 erythrocytes/hpf
Which of the following is most likely to establish a diagnosis?
•
•
•
•
Response to normal saline
Blood urea nitrogen-creatinine ratio
Fractional excretion of sodium
Placement of a urinary bladder catheter
51. A 66 yo man with h/o CAD and HTN is evaluated for abd pain, low-grade fever, myalgias,
nausea and generalized weakness. Cr is 6 (baseline 1.4). Two weeks ago, he was hospitalized for
anginal chest pain. Cardiac catheterization at that time showed a 30% LAD stenosis and a 90%
RCA lesion. A RCA stent was placed.
On physical exam today, T 37.8C, BP 140/96. On cardiac exam, a right carotid bruit and S4 gallop
are present. On pulmonary exam, the lungs are clear. Abd exam is unremarkable. There is trace
pretibial edema bilaterally, and the distal pulses are not palpable. A netlike violaceous rash is
visible over the legs, and the right great toe is cool and cyanotic.
Hgb 8.3, leukocyte 6.7, Plt 434
C3 low, C4 normal
UA 1+ blood, 1+ protein, 3-5 leukocytes/hpf, 5-10 erythrocytes/hpf
Which of the following is the most likely diagnosis?
A.
B.
C.
D.
E.
Radiocontrast nephropathy
Prerenal acute renal failure
Acute interstitial nephritis
Microscopic polyangiitis
Atheroembolic disease
68. A 66 yo woman is evaluated for fatigue, decreased exercise tolerance of 1 month’s duration,
and new-onset DOE. Therapy with OTC ibuprofen was unsuccessful, and she d/c’d its use. She
has a h/o HTN and was diagnosed with type 2 DM that is controlled by diet 2 years ago.
Medications are lisinopril 20mg daily and hctz 25mg daily.
On exam, P 74, BP 148/86. The conjunctivae are pale. Cardiac exam reveals a grade 2/6 systolic
ejection murmur. There is 1+ LE edema.
Hgb 7.2, leukocyte count 7.1, Plt 125
BUN 64, Cr 5.2, Na 133, K 4.1, Cl 110, Bicarb 19, Glu 142, Alb 4.0, Ca 11.0, Phos 5.4
UA pH 5.0, SG 1.015, no blood, 1+ protein, 5-10 leukocytes/hpf
UPC ratio 2.5 mg/g
Which of the following is the most likely cause of this patient’s renal failure?
A.
B.
C.
D.
E.
Chronic interstitial nephritis
Hypertensive nephrosclerosis
Acute interstitial nephritis
Myeloma kidney
Diabetic nephropathy
AKI
1.
2.
3.
4.
5.
Pre-renal, post-renal, intrinsic
CLINICAL clues!!!
FeNa <1% suggests pre-renal, >2% c/w tubular injury, but interpret carefully in clinical context
Urine sediment
Renal Ultrasound
Pre-renal causes:
GI losses
Hemorrhage
HF
Renal Artery Stenosis
Drug-induced
Sepsis
HRS
Compartment Syndrome
Intrinsic causes:
Ischemic
Nephrotoxic
AIN
GNs
TMAs
Atheroembolic disease
Post-renal causes:
Prostate enlargement
Pelvic tumor
Ureteral tumor, stones
or stricture
Crystals
Drugs
Proteins (cast
nephropathy)
8. A 52 yo woman with type 2 DM and HTN comes for a routine office visit. She has a 30 packyear h/o cigarette smoking. Her mother had DM and was on HD. Medications are insulin,
metoprolol 100mg daily, fosinopril 40mg daily, hctz 50mg daily, atorvastatin 40mg daily, and asa
81mg daily.
On exam, BP 165/95. There are retinal microaneurysms. Cardiac exam reveals a regular rhythm
with an S4. The lungs are clear to auscultation. There is no JVD. There is 1+ pedal edema. The
distal pulses are absent in both feet.
HgbA1c 7.2%
Glu 180
Cr 1.2
24-hour urinary protein excretion 1.8g/24 h
Which of the following factors is most likely to cause this patient’s CKD to rapidly progress
to ESRD?
A.
B.
C.
D.
E.
Poorly controlled DM
Family history
Poorly controlled HTN
Proteinuria
Cigarette smoking
19. A 50 yo woman with type 2 DM and progressive CKD comes for a f/u visit. She has had leg
swelling but does not have nausea, vomiting, chest pain, SOB, orthopnea, PND or dysuria. She
follows a 0.8mg/kg/d dietary protein restriction and takes lisinopril 80mg daily.
On exam, BP 130/70. There are retinal microaneurysms. Cardiac exam reveals a regular sinus
rhythm with an S4 and a grade 2/6 systolic murmur at the base. The lungs are clear. There is JVD.
The abdomen is large with normal bowel sounds. There is no pedal edema. Pinprick and vibratory
sensation are absent in both feet.
Hct 35%, Hgb 11
Iron 45, iron binding capacity 290
Ferritin <12
Cr 2.0
Sodium 138, K 5.0, Cl 106, Bicarb 22, Alb 3.5
24-hour urinary protein excretion 3g/24 h
An EKF is normal.
Which of the following is the most appropriate next step in this patient’s management?
A.
B.
C.
D.
Refer for permanent vascular access
Restrict protein intake to 0.6 g/kg/d
Start erythropoietin treatment
Add diltiazem 120mg daily
2. A 60 yo woman with h/o type 1 DM and stage 4 CKD comes for a routine f/u exam. She asks about
modalities of RRT.
Which of the following is the best option for this patient?
A.
B.
C.
D.
E.
0-Ag mismatched deceased donor kidney transplantation
PD
HD
Living donor kidney transplantation after a course of dialysis
Preemptive living donor kidney transplantation
CKD
An alteration in kidney function or structure of 3months or greater and progressive loss of renal function
and/or complications due to decreased renal function.
Strategies to slow progression:
-ACE-I or ARB therapy
-BP control
-Tight glycemic control in diabetics
-Low protein diet (0.8-1 g/kg/d)
-Cholesterol lowering to <100
-Erythropoietin for goal Hgb >12
-Low sodium diet
-Smoking cessation
-Weight loss
-Reduce elevated Ca-Phos product
-Avoid nephrotoxic drugs
-Referral for vascular access and transplant eval when GFR reaches 30mL/min range
Preemptive transplant has improved mortality compared to transplant after dialysis.
Living donor transplants are equivalent to or better than well-matched deceased transplants.
71. A 70 yo woman with HTN and CKD comes for a f/u visit. On exam, P 80, BP 140/80. BMI is 21.
Cardiac exam reveals a regular sinus rhythm with no murmur. The lungs are clear. Bowel sounds
are normal. There is 1+ pedal edema.
BUN 30, Cr 2.5, Na 140, K 5, Cl 105, Bicarb 20, Phos 7, Ca 9, Alb 3.5
Which of the following is the most likely cause of this patient’s hyperphosphatemia?
A.
B.
C.
D.
E.
Primary hyperparathyroidism
High Phos intake
Vitamin D deficiency
GFR decrease
Hypocalcemia
Secondary
Hyperparathyroidism
•
•
•
•
In patients with CKD, Phos excretion goes down and retention occurs when GFR <60.
Increase in Phos causes decrease in ionized Ca which stimulates PTH secretion.
Serum levels normalize at expense of elevated PTH levels.
As kidney function worsens, 1,25-vit D deficiency contributes to hypocalcemia, further
stimulating PTH secretion. As GFR goes down further, phosphate excretion also decreases
leading to hyperphosphatemia.
18. A 49 yo man with h/o gouty arthritis comes for a f/u evaluation. One week ago, he was
evaluated in the ED for left-sided flank pain and hematuria. A plain abdominal X-ray is
unremarkable. After radiography is performed, the patient urinates debris and his pain is
immediately relieved.
Labs obtained in the ED:
BUN 12, uric acid 9.0, Cr 1.0, Na 138, K 4.6, Bicarb 26, Alb 4.0, Ca 10.1, Phos 2.1
UA pH 5, 3+ blood, 10-15 erythrocytes/hpf
He has had no further symptoms.
Which of the following is the most likely diagnosis?
A.
B.
C.
D.
E.
Calcium oxalate stones
Uric acid stones
Calcium phosphorous stones
Struvite calculi
Cystine stones
27. A 25 yo man with h/o active Crohn’s disease with several small-bowel resections is evluated for
recurrent calcium oxalate kidney stones. He typically passes 3-4 stones each year and he becomes
incapacitated during acute attacks. He requests further therapy for stone prevention.
A plain abdominal X-ray is obtained in the office and reveals no calcifications in the GU tract.
Uric acid 6.8, BUN 10, Cr 0.8, Na 139, K 4.3, Bicarb 25, Ca 9.9, Phos 2.2
UA pH 5.0, no blood or protein
In addition to increasing fluid intake, which of the following recommendations is warranted?
A.
B.
C.
D.
Ca intake >1g/d
A high sodium diet
A high protein diet
Furosemide 40mg daily
36. A 56 yo woman is evaluated for recurrent UTIs. Three weeks ago, she had a UTI with Klebsiella,
and she has had four previous Proteus UTIs over the past 6 months.
Physical exam is unremarkable. UA is significant for LE and 2+ blood, and pH is 7.5. Abdominal CT
reveals a 5-cm staghorn calculus in the left kidney.
In addition to increasing fluid intake, which of the following is the most appropriate therapy in
this setting?
A.
B.
C.
D.
Potassium citrate
Allopurinol
Antibiotics
Low-calcium diet
44. A 44 yo man with h/o nephrolithiasis requests nonpharmaceutical interventions for stone
prevention. His last symptomatic kidney stone was 2 years ago. He does not recall the exact type of
stone that he formed but believes that it contained calcium. Previous labs have showed normal renal
function and normal levels of Ca, Phos and uric acid. A plain abdominal X-ray performed 1 year ago
revealed no GU calcifications. He does not have a FH of nephrolithiasis but wishes to reduce his
chances of developing further kidney stones.
In addition to increasing fluid intake to >2L/d, which of the following is the best initial therapy
for this patient?
A.
B.
C.
D.
Increase dietary calcium intake
Decrease dietary sources of citrate
Increase dietary animal protein intake
Increase dietary sodium intake
Nephrolithiasis
•
•
•
Predominantly calcium, but also uric acid, struvite and cystine.
Fluid intake is key.
Risk factors:
•
•
•
•
high sodium and protein intake and low calcium intake, low fluid intake
Hypercalciuria, hypocitraturia, hyperuricosuria, hyperoxaluria
Gout, obesity, RTA, sarcoidosis, primary hyperPTH, medullary sponge kidney, horseshoe
kidney, HIV/AIDs with protease inhibitors, type 2 DM
PCKD, Dent’s disease, cystinuria, primary hyperoxaluria
•
•
•
•
•
•
Hypercalciuria most common abnormality, usually related to increased Ca absorption in gut.
Excess Ca from bone and renal tubular defects in Ca absorption can also contribute.
People with gout have increased levels of uric acid in their urine. These stones are
radiolucent (can’t be seen on x-ray – need CT or U/S).
Calcium oxalate stones are most prevalent, but elevated urinary oxalate levels only account
for 8% of metabolic abnormalities in nephrolithiasis. Associated with low Ca diet (lack of
intestinal Ca available for oxalate binding) and malabsorption syndromes that increase oxalate
absorption in the gut and prolonged use of Abx that alter enteric flora that degrade oxalate.
High affinity for oxalate to bind Ca in urine leads to insoluble precipitates and Ca oxalate
stones.
Oxalate rich foods are nuts, chocolate, rhubarb, spinach.
Citrate inhibits crystal formation and binds to urinary Ca.
Staghorn calculi most commonly struvite magnesium, ammonium phosphate, and /or Ca
carbonate. Chronic infections from Proteus and Klebsiella which convert urea to ammonia,
causing alkaline urine and struvite crystallization. Do NOT further alkalinize with potassium
citrate.
41. A 29 yo black man with HIV infection comes for a routine exam. He has a h/o numerous OIs and
was reently treated with a course of IV acyclovir. He also is positive for Hep C.
On exam, there is 2+ pitting edema to the knees. The remainder of the exam is normal.
BUN 30, Cr 1.8, Alb 2.8
UA no hematuria, 4+ proteinuria, abundant oval fat bodies, no other formed cellular elements, no
glycosuria, no amino aciduria, no granular casts
C3 110, C4 35
CD4 180
HIV RNA VL 5,000 copies
Renal U/s reveals echogenic kidneys
Which of the following is the most likely cause of this patient’s renal dysfunction?
A.
B.
C.
D.
Trimethoprim-sulfamethoxazole
Pentamidine
Collapsing FSGS
Postinfectious membranoproliferative glomerulonephritis
24. A 34 yo asymptomatic black man is evaluated for peripheral edema of several months’ duration.
Medical hx is unremarkable.
On exam, P 79, BP 140/90. He is in excellent health and appears muscular. There is 2+ lower
extremity edema. The remainder of the exam in normal.
BUN 5.1, Cr 1.8, Alb 3.0
UA 3+ proteinuria, several oval fat bodies/hpf
UPC ratio 3mg/g
Which of the following is the most likely diagnosis?
A.
B.
C.
D.
E.
Membranous nephropathy
FSGS
MCD
MPGN
Focal proliferative lupus nephritis
16. A 65-year-old man is evaluated for hypoalbuminemia, hyperlipidemia, and slowly progressive
proteinuria that have developed over 1 year. One year ago, he underwent squamous cell lung
cancer resection.
On PE, BP is 150/90. Cardiac exam reveals a normal S1 and S2 w/o rubs or gallops. Pulmonary
exam shows decreased breath sounds in the right lower lobe consistent with his previous surgery.
Abdominal exam is normal. There is 3+ edema of the lower extremities.
Lab studies:
BUN 17, Cr 1.0
U/A: Sp Grav 1.020, numerous granular casts and oval fat bodies/hpf
24-hour urinary protein excretion: 15 g/24 h
CXR reveals a new 1-cm nodule in the left upper lobe.
Which of the following is the most likely cause of this patient’s renal symptoms?
•
•
•
•
•
Minimal change glomerulopathy
Focal segmental glomerulosclerosis
Membranous nephropathy
IgA glomerulonephritis
ANCA associated vasculitis
3. A 21-year-old woman is evaluated for facial and lower-extremity edema of 1 week’s duration.
For the past 3 weeks, she has had fatigue. She has no history of diabetes mellitus, cigarette
smoking, or illicit drug use.
On PE, blood pressure is 90/55. Cardiac and pulmonary exams are normal. There is periorbital
edema. The abdomen is soft and without masses. There is 2+ lower extremity edema.
Cr 0.7
Total cholesterol 325
Albumin 2.9
C3 and C4 normal
Urinalysis: Sp Grav 1.026, 3+ protein, 0-1 erythrocytes/hpf, numerous oval fat bodies/hpf
24-hour urinary protein excretion 15 g/24 hr
Which of the following is the most likely diagnosis?
•
•
•
•
•
Minimal change glomerulopathy
Membranous nephropathy
Focal segmental glomerulosclerosis
Membranoproliferative glomerulonephritis
Systemic lupus erythematosis nephritis
Nephrotic Syndrome
•
•
•
•
•
FSGS (most common, younger age)
Membranous (older, assoc with infections – HBV, HCV, syphilis, autoimmune, carcinomas,
drugs)
MCD (primarily seen in children, edema, hypoalbuminemia, hypercholesterol, oval fat bodies)
MPGN (usually associated with infections, immunocompromised diseases like SLE, cryo)
Secondary causes:
•
•
•
•
•
Diabetic nephropathy
Amyloidosis
HIVAN (typically collapsing FSGS variety, will see proteinuria)
SLE type V
Obesity
49. A 42-year-old man is evaluated for a 2-month history of rash on his lower extremities and a 6month history of cold-induced acral cyanosis and discomfort. He also has a 2-month history of
alcohol abuse.
On PE, pulse is 78 and BP is 150/90. Cardiac and pulmonary exams are unremarkable. On
abdominal exam, the liver is 3 cm below the right costal margin. A spleen tip is not felt. There is
1+ lower-extremity edema. A purpuric rash also is present on the lower extremities.
Hg 11.4, Platelet count 120,000
Cr 1.7
C3 86, C4 5
AST 57, ALT 5
UA 3+ hematuria, 1+ protein, 7-10 dysmorphic erythrocytes/hpf
Which of the following is most likely causing this patient’s renal abnormalities?
•
•
•
•
•
Systemic lupus erythematosus glomerulonephritis
Henoch-Schonlein purpura glomerulonephritis
Cryoglobulinemic glomerulonephritis
Antineutrophil cytoplasmic antibody-associated small-vessel vasculitis
Anti-glomerular basement membrane glomerulonephritis
6. A 17-year-old man is evaluated for the abrupt onset of a lower-extremity rash and intermittent
episodes of mild abdominal pain. He is otherwise asymptomatic.
On PE, respiratory rate is 18, pulse is 78, and BP is 140/90. Cardiac, pulmonary, and abdominal
exams are normal. There are lesions resembling palpable purpura on the extremities.
BUN 16, Cr 0.9
C3 100, C4 31
UA 1+ protein, 12 dysmorphic erythrocytes and 1 erythrocyte cast/hpf
Which of the following is the most likely diagnosis?
•
•
•
•
•
Systemic lupus erythematosis glomerulonephritis
Antineutrophil cytoplasmic autoantibody-associated small-vessel vasculitis
Cryoglobulinomic vasculitis
Henoch-Schonlein purpura
Postinfectious glomerulonephritis
Nephritic Syndrome
•
•
•
•
•
•
•
•
•
IgA nephropathy (most common, normal C3)
Post-strep GN (ASO, low C3)
Lupus nephritis (+ANA, anti-ds DNA, low C3)
Anti-GBM Ab disease (anti-GBM)
HSP (IgA nephropathy, systemic vasculitis, normal C3)
MPGN (low C3)
Cryoglobulin (low C3, HCV Ab)
Endocarditis (fever, + blood cx, low C3)
Small- and Medium-Vessel Vasculitis
(Questions from MKSAP 14)
WooHoo!