1. A 30 year old man presents to your outpatient clinic with 3 months of progressive fatigue. He thinks there was blood in his urine on two occasions after strenuous exercise. He gives no other history and he does not smoke. Physical examination is unrevealing. The blood urea nitrogen (BUN) is 15mg/dL and the creatinine is 1.1mg/dL. A urinalysis is notable for trace protein. The most likely cause of his "bloody" urine is [1]:

   A. Post-infectious Glomerulonephritis
   B. Myoglobinuria due to rhabdomyolysis
   C. Paroxysmal nocturnal hemoglobinuria
   D. Benign Tubular Proteinuria
   E. Goodpasteure's Syndrome

2. A 35 year old woman develops increasing confusion 1 weeks after getting over a severe sore throat which was relieved with acetaminophen (Tylenol®) and over the counter cough medicine. Examination reveals a blood pressure of 145/95mmHg, pulse 105, respirations 28, and temperature 99.8°F orally. There is mild asterixis and a mild pericardial rub at the apex; otherwise the exam is normal. Urinalysis is notable for 3+ blood, 50-100 red blood cells without casts, 2-3 white blood cells, 3+ albumin. Routine screening laboratory tests are sent. The most likely diagnosis is [2]:

   A. Focal Segmental Glomerulosclerosis (FSGS)
   B. Wegener's Granulomatosis
   C. Cryoglobulinemia
   D. Post-streptococcal Glomerulonephritis
   E. Systemic Lupus Erythematosus

3. The creatinine returns at 4.5mg/dL, BUN 70mg/dL. The patient reports good urine output. Which test is likely to confirm the diagnosis [3] ?

   A. Renal Biopsy
   B. Anti-neutrophil cytoplasmic antibody test
   C. DNAse and anti-streptolysin O titers
   D. Hepatitis B and C titers
   E. Antinuclear antibody test

4. The patient suddenly develops hemoptysis. A glomerular basement membrane antibody test is found to be positive at high titer. The creatinine rises to 5.5mg/dL and urine output begins to decline. The most appropriate treatment is [4]:

   A. Plasmapheresis
   B. Cyclophosphamide intravenously
   C. High dose glucocorticoids intravenously
   D. Dialysis
   E. Cyclosporine 5mg/kg intravenously

5. A 45 year old woman is transferred to the medical intensive care unit when her respiratory status declined. She smoked 2 packs per day for 20 years and took no medications. She was well until 1 week earlier when she developed a cough, yellow-green sputum production, and pain on the right side of her chest. She was seen as an outpatient and a diagnosis of bronchitis was made. She was given erythromycin. Two days later her fevers increased to 102.5°F orally and she came to the emergency room. She appeared acutely ill. Her blood pressure was 150/100 mm in both arms, pulse 130 and regular, respirations 32, and her temperature was 101.9°F orally. She had right lower and middle lung zone crackles and pain worse on inspiration. A sputum specimen showed gram-negative coccobaccili and many neutrophils. Her white blood count was 16.5K/µl with 80% mature neutrophils and 10% immature (band) forms. The sodium was 130mM, potassium 3.2mM, chloride 100mM, bicarbonate 16mM, BUN 28mg/dL, creatinine 1.3mg/dL. A chest radiograph showed a consolidation in the right lower lobe. with possible right middle lobe involvement. There was a small right pleural effusion. An arterial blood gas drawn while the patient was breathing room air showed a pH 7.32, pO2 72mm, pCO2 25mm, and a calculated bicarbonate of 17mM. She was admitted to the hospital and treated with intravenous cefuroxime and normal saline.
6. The acid-base disturbance in this patient is [5]:

   A. Repiratory acidosis and metabolic acidosis
   B. Respiratory alkalosis and metabolic acidosis
   C. Respiratory acidosis and metabolic alkalosis
   D. Metabolic acidosis alone
   E. Respiratory acidosis alone

• The most likely explanation for the failure of the sodium to correct is [6]:

  A. Hypovolemia
  B. Adrenal Insufficiency
  C. Thyroid Disease
  D. Underlying renal disease
  E. Syndrome of Inappropriate Antidiuretic Hormone (SIADH)

• A repeat chest radiograph showed continued consolidation of the right lower lobe with progression in the right middle lobe. The right pleural effusion was unchanged. On the next hospital day, the patient's fever was 103.2°F orally. Gentamicin was added and the cefuroxime changed to ceftazidime. A repeat creatinine 6 hours later was 1.9mg/dL with a BUN of 30mg/dL. The serum sodium was 131mM, urine sodium was 90mM. The most likely explanation for the creatinine rise was [7]:

  A. Gentamicin toxicity
  B. Gentamicin and Ceftazidime toxicity
  C. Renal Immune Complex Disease from infection
  D. Acute Tubular Necrosis due to hypotension
  E. SIADH

• Gentamicin was discountinued. The creatinine continued to rise 0.8mg/dL each day over the next three days. Urine output was 600cc the first day, 800cc the second day, and 1200cc the following day. The patient's fever was down to 99.4° with acetaminophen. She felt better. She was transferred out of the intensive care unit. The serum sodium was 134mM, potassium 3.8mM, chloride 105mM, bicarbonate 21mM, BUN 86mg/dL, and creatinine 4.6mg/dL. Urine output was 800-1200ml per day. What is the most likely prognosis concerning the patient's renal function [8] ?

  A. She will decline and require dialysis within 1 week
  B. She will progress to dialysis within 3 months
  C. Her renal function will improve to baseline or nearly baseline
  D. Her renal function will stabilize at the current level
  E. Her renal function will worsen slightly then stabilize

• A 45 year old man undergoes coronary angiography following a myocardial infarction and recurrent non-exertional chest pain. The right femoral vein is entered for the procedure, which shows two vessel coronary artery disease. A 95% stenosis of the left anterior descending artery is widened with a balloon angioplasty procedure. Three days after the procedure he develops painful purpuric lesions on two toes and his creatinine increases from 1.3mg/dL baseline to 2.4mg/dL. The white blood cell count is 12.5K/µl with 8% eosinophils. The most likely diagnosis is [9]:

  A. Cholesterol Emboli Syndrome
  B. Systemic Vasculitis
  C. Allergic Reaction to Radiocontrast Material
  D. Radiocontrast Nephropathy
  E. Acute post-infectious glomerulonephritis

• A 70 year old man is brought from his home to the emergency room. He was found unconscious on his floor with urine near him. He has a history of hypertension treated with combination diuretic therapy (hydrochlorthiazine with triampterene). The blood pressure is 95/65 mmHg, pulse 84, respirations 12, temperature 96.2°. He is groans in response to deep pain only, and he moves all four extremities with painful stimuli. His mucus membranes are dry. Examination is notable for a soft S4 gallop and a II/VI crescendo-decrescendo murmer at the base with radiation to the carotids. The carotid pulses are not delayed, but they are weak. Serum sodium is 125mM, potassium 4.6mM, chloride 92mM, bicarbonate 28mM, BUN 46mg/dL, and creatinine 2.1mg/dL. The urine sodium is 110mM, urine potassium is 12mM. The most likely explanation for the electrolyte disturbances is [10]:
A. Dehydration
B. Diuretic Effect
C. Hemorrhage
D. Syndrome of Inappropriate Antidiuretic Hormone (SIADH)
E. Renal Insufficiency

Answers

1. B
2. D
3. C
4. A (Only plasmapheresis works quickly enough to prevent progressive renal failure.)
5. B
6. E (SIADH is often seen with pneumonia.)
7. D
8. C (Acute tubular necrosis is almost always reversible, often back to baseline.)
9. A
10. B (Combination of high urine sodium and hyponatremia)