Internal Medicine Board Review: Nephrology

1. Internal Medicine Board Review:Nephrology Steven Wagner M.D. July 16, 2014

2. 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

3. 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

4. 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

5. With that in mind,

6. Question 1

7. 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 hypertension? • Lisinopril / Hydrochlorothiazide • Diet and exercise • Norvasc • See her back in 2 weeks for a blood pressure recheck

8. Key point: manage hypertension • Hypertension is divided into stages • Our patient has stage II hypertension • Will need drug therapy

9. Why the other choices are wrong • Lisinopril / Hydrochlorothiazide • Diet and exercise • Norvasc • 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.

10. Question 2

11. 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? • Focal segmental glomerulosclerosis • IgA nephropathy • Post-infectious glomeulonephritis • Proliferative lupus nephritis

12. Key point: diagnose lupus nephritis • Lupus nephritis is characterized by hematuria and proteinuria in the setting of clinical findings of lupus • 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

13. 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 boards) • NONE of the incorrect answers explain her cytopenias etc

14. Question 3

15. 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 hyponatremia? • 3% saline with a goal of correcting Na by 10 in the next 24 hrs • Conivaptan • Demeclocycline • Fluid and sodium restriction

16. Key point: Manage asymptomatic hyponatremia • Management of hyponatremia depends on the symptoms • Increased urgency in the setting of seizures, unresponsiveness, etc • Remember to correct slowly

17. Why the other choices are wrong 3% saline with a goal of correcting Na by 10 in the next 24 hrs Conivaptan Demeclocycline Fluid and sodium restriction • 3% saline is too aggressive in this setting • Conivaptan decreases BP and is contraindicated • Tolvaptan also relatively contraindicated now • Demeclocycline is effective in SIADH • This patient has appropriately high levels of ADH

18. Question 4

19. 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? • Ambulatory blood pressure monitoring • Echocardiogram • Addition of a vasodilator such as hydralazine • Urine metanephrine measurement

20. Key point: Diagnose resistant hypertension • 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

21. Why the other choices are wrong Ambulatory blood pressure monitoring Echocardiogram 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

22. Question 5

23. 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? • IgA nephropathy • Focal segmental glomerulosclerosis • Lupus nephritis • Post-infectious glomerulonephritis

24. Key point: FSGS is pure nephrotic syndrome • FSGS is a common adult diagnosis • Usually not subtle, with heavy proteinuria and nephrotic syndrome • Low albumin • Hyperlipidemia • Edema

25. 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

26. Question 6

27. 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? • Gitelman syndrome • Distal (type I) renal tubular acidosis • Laxative abuse • Proximal (type II) renal tubular acidosis

28. 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 SUGGESTIVE of distal RTA • This one is not subtle

29. 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 gap • 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

30. Question 7

31. A 45-year-old female with a history of frequent UTI’s presents with foul smelling urine, dysuria, and urgency. Her last UTI was Morganellamorganii. 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? • Calcium oxalate • Uric acid • Ammonium magnesium phosphate • Cystine

32. 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

33. Why the other choices are wrong Calcium oxalate Uric acid Ammonium magnesium phosphate Cystine • 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

34. Question 8

35. 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? • Allopurinol • Phosphate binder • Sodium bicarbonate • Sodium polystyrene

36. 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

37. Why the other choices are wrong Allopurinol 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)

38. Question 9

39. 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? • Diltiazem • Furosemide • Lisinopril • Spironolactone

40. 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

41. Why the other choices are wrong Diltiazem Furosemide Lisinopril Spironolactone • 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

42. Question 10

43. 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? • Acetazolamide • Allopurinol • Calcium carbonate • Chlorthalidone

44. Key point: Manage uric acid stones with Allopurinol • Patient has uric acid stones in spite of urinary alkalinization • 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

45. Why the other choices are wrong Acetazolamide Allopurinol Calcium carbonate Chlorthalidone • 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

46. Question 11

47. 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 management? • Add an ACE inhibitor • Increase the metoprolol dose • Obtain doppler ultrasound of the renal arteries • Obtain renal angiography

48. Key point: Manage revovascular hypertension • This patient has accelerating hypertension • Severe PVD on exam, including epigastric bruits • Treat renal artery stenosis medically unless there is a hemodynamically significant lesion on imaging • Currently much debate on stent vs medical management

49. Why the other choices are wrong Add an ACE inhibitor Increase the metoprolol dose Obtain doppler ultrasound of the renal arteries Obtain renal angiography • An ACE inhibitor might cause significant acute renal failure, especially if she has bilateral disease • Metoprolol would slow her pulse further • Renal angiogram is relatively contraindicated with her GFR of about 30

50. Question 12