Nephrology: Challenging Cases COPYRIGHT UPDATE IN INTERNAL MEDICINE Robert S. Brown, M.D.

Transcription

1 Nephrology: Challenging Cases UPDATE IN INTERNAL MEDICINE Robert S. Brown, M.D.

2 Conflict of Interest Disclosure I disclose the following relevant financial relationship: Börm Bruckmeier Publishing LLC Author Nephrology Pocket and Acid Base Electrolytes Pocket book & apps

3 Renal Disorders

4 1) A 66 yo man with Type 2 diabetes is started on empaglifloxin (Jardiance ), an SGLT-2 inhibitor. He starts a weight loss diet, skipping meals. Over the next month, he notes polyuria and a 3 Kg weight loss. He comes now complaining of malaise, nausea, vomiting and abdominal pain.

5 Lab: Na 132; K 5.2; Cl 100; HCO 3 14 mmol/l; glucose 163 mg/dl (9.0 mmol/l) At this time, you suspect he has: A. Ketoacidosis B. Type 2 proximal RTA C. Type 4 RTA D. Primary hyperventilation E. Bacterial or fungal urinary tract infection

6 2) A 48 yo woman returns from 2 months in Brazil with muscle twitching, cramps, weakness and polyuria. PMHx: Hypertension on HCTZ; GERD on omeprazole.

7 She had received numerous mosquito bites and testing for zika virus is positive. Evaluation is also notable for hypokalemia, hypocalcemia, and widening of her QRS on ECG.

8 At this time, you suspect that her new symptoms have been caused by: A. Hypokalemia B. Hypoparathyroidism C. Hypomagnesemia D. Guillain Barre syndrome E. Anxiety about zika virus & pregnancy

9 3) A previously healthy 26-year-old man becomes ill with fever, malaise, back pain, and sore throat. One day later he notices gross hematuria. Urinalysis shows 2+ protein, 3+ blood, RBC/hpf with acanthocytes. The serum creatinine is 0.9.

10 The most likely cause of the urine findings is: A. Acute post-streptococcal glomerulonephritis B. Nephrolithiasis C. IgA nephropathy D. Lupus nephritis E. Granulomatosis with polyangiitis (formerly Wegener s granulomatosis)

11 4) A 21-year-old man presents to the emergency room after a lacrosse game with abrupt onset of fever to 103ºF (39.4ºC) and cough. Urinalysis shows 3+ protein without red blood cells. Three weeks later, he comes for followup feeling well. The exam is normal. A repeat urinalysis reveals 1+ protein and a negative sediment. The creatinine is 1.0 mg/dl (88 µmol/l).

12 The best plan now would be to: A. send the urine for microalbuminuria B. collect supine and upright timed urine specimens for protein determination C. obtain serum complement levels, ASO & protein electrophoresis of blood & urine D. obtain a renal ultrasound E. reassure the patient that this is "functional" proteinuria & recheck next year

13 5) A 45 year old man who is HIV positive has had headache, weakness, generalized aching, nausea and vomiting for one week. He has a history of hypertension for 3 years and has been on hydrochlorothiazide for 3 months. He drinks 3-5 alcoholic beverages a day and admits to past use of intravenous cocaine and heroin.

14 On exam, he appears lethargic with a BP of 170/115 mmhg, P of 100/min and T 98 0 ( ). Fundi show arteriolar narrowing. There is mild jugular venous distension and basilar crackles. There is 3+ pitting edema of the legs and generalized tenderness. Neurologic exam shows weakness, more marked proximally than distally.

15 Laboratory tests: BUN 60 mg/dl (21.4 mmol/l) Creatinine 9 mg/dl (796 µmol/l) Sodium 136 meq/l Potassium 6.8 meq/l Chloride Bicarbonate 100 meq/l 14 meq/l Calcium 6.4 mg/dl (1.6 mmol/l) Phosphorus 12.5 mg/dl (4.0 mmol/l) Uric acid 21 mg/dl (1249 µmol/l) Bilirubin 0.6 mg/dl (10 µmol/l) Hematocrit 35 % WBC 14,000/cu mm Platelets 125,000/cu mm

16 Peripheral blood smear shows normal differential and morphology Urinalysis: 1+ protein, 4+ heme by dipstick. Sediment: 3-5 RBC/hpf, 1-3 WBC/hpf; several coarse granular casts/lpf. Renal ultrasound: normal kidney size without evidence for obstruction

17 Evaluation of the renal failure would most likely reveal: A. hypertensive nephrosclerosis B. allergic interstitial nephritis secondary to thiazide therapy C. systemic vasculitis with a crescentic glomerulonephritis D. acute tubular necrosis E. focal glomerular sclerosis with collapsing glomerulopathy F. urate nephropathy

18 6) A 26 year old woman is admitted to the hospital following a one to two week diarrheal illness. She has been febrile and confused at home. On exam, she is delirious with a BP 140/90, P 110/min, T 103ºF (39.4ºC). There is no clear source of fever. Stool is green and bloody.

19 Laboratory studies show a hematocrit of 24%, WBC of 8,200 without band forms and platelet count of 62,000. The peripheral blood smear reveals numerous schistocytes. The BUN is 78 mg/dl (27.8 mmol/l). The creatinine is 4.2 mg/dl (371 µmol/l). The urinalysis reveals 2+ protein, RBC/hpf and granular casts.

20 You would start : A. Treatment only after special tests return B. Antibiotics targeted against Gram-negative organisms C. Supportive care D. Corticosteroids and cyclophosphamide E. Plasma exchange therapy + FFP

21 7) A 69 year old man complains of 2 weeks of cough. Exam is normal as are blood tests except the creatinine is 1.7 mg/dl (150 µmol/l). He is treated with 5 days of levofloxacin. He returns 2 weeks later (bad followup!!), now with hemoptysis and a petechial rash on the lower extremities.

22 Physical examination shows an ill-appearing man with blood pressure of 150/98 mmhg. The lungs reveal bilateral crackles. The rest of the physical exam is unremarkable except for raised, non-blanching papules over the lower extremities.

23 Urinalysis reveals 3+ protein, 3+ hemoglobin with numerous RBC s, 5-10 WBC s, and RBC and WBC casts. Serum creatinine is 6.4 mg/dl (566 µmol/l). Complement levels are normal. Chest X-ray reveals bilateral pulmonary infiltrates.

24 The procedure most likely to yield a useful diagnosis is: A. Renal biopsy B. Bronchoscopy C. Thoracoscopic lung biopsy D. Renal arteriogram E. Serum tests for anti-glomerular basement antibody (anti-gbm) and anti-neutrophil cytoplasmic antibodies (ANCA)

25 8) The most likely diagnosis in the foregoing patient is: A. Cryoglobulinemic vasculitis B. Goodpasture's syndrome C. Systemic vasculitis associated with an anti-neutrophil cytoplasmic antibody D. Henoch-Schonlein purpura E. Systemic lupus erythematosus

26 9) A 52-year-old woman with known polycystic kidney disease develops low grade fever and mild left flank pain. Urinalysis reveals numerous white blood cells, red blood cells and bacteria. The urine gram stain reveals gram-negative rods.

27 The best treatment option for this patient is: A. Intravenous gentamicin for presumed Gram-negative bacterial urinary tract infection B. Begin both gentamicin and cephalothin therapy to achieve synergy of two antibiotics in the urine and fluid of an infected cyst C. Begin either oral ciprofloxacin or sulfa-trimethoprim D. Obtain an US or CT to look for an infected cyst E. Both C and D

28 Kidney Stones

29 10) An otherwise healthy 44-year-old man has recurrent calcium oxalate stones. He is on no medications and has no history of gastrointestinal or urinary tract disease. Serum electrolytes are normal. Serum calcium and phosphate are repeatedly normal. Urinalysis is normal with ph of 5.5.

30 Urinary evaluation (24 hr) reveals: Calcium Oxalate Citrate 350 mg/day (8.73 mmol) 47 mg/day ( 520 µmol) 200 mg/day (1041 µmol) Urate 860 mg/day (5116 µmol) Sodium Volume 237 meq/day 1,900 ml/day

31 All of the following therapies could be useful except: A. Hydrochlorothiazide B. Potassium citrate C. Low sodium diet D. Low calcium diet E. Allopurinol

32 11) The previous patient has developed colicky flank pain and is noted to have a 5 mm stone in the distal left ureter. At this time, you advise: A. Tamsulosin B. Nifedipine C. Shock wave lithotripsy D. Ureteroscopy with stent placement E. More sex

33 Acid Base & Electrolyte Disorders

34 12) Hyperkalemia may be exacerbated by all of the following drugs except: A. ACE inhibitors B. Heparin C. Amphotericin B D. Trimethoprim E. Succinylcholine

35 13) A patient brought to the ER with a high anion gap metabolic acidosis might have any of the following toxicities except: A. Methanol or ethylene glycol B. Ethanol C. Isopropyl rubbing alcohol D. Acetaminophen E. Metformin

36 14) A 68 year old woman has noted leg edema and fatigue. Laboratory studies reveal: Hgb 9.9 Na 138 BUN 37 K 4.2 Creatinine 1.7 Cl 116 Glucose 96 CO 2 17 Calcium 10.1 ph 7.34 Phosphate 1.8 Albumin 2.6 Urinalysis: ph 7.0, 1+ protein, 1+ glucose, 5-15 RBC/hpf, 5-10 WBC/hpf, rare waxy cast Urine protein/ urine creatinine: 2.7

37 The most likely diagnosis is: A. Nephrocalcinosis due to RTA B. Sjogren s syndrome with nephropathy C. Membranous nephropathy associated with a carcinoma D. HIV nephropathy E. Light chain deposition nephropathy

38 Extra Credit Questions

39 15) A 26 yo woman enters the ED with confusion. Lab values reveal: Blood electrolytes Na K Cl HCO Arterial blood gas ph pco 2 po

40 These values most likely indicate: A. With ph of 7.43, normal acid-base status B. With HCO 3 of 16, metabolic acidosis C. With pco 2 of 25, respiratory alkalosis D. Either the HCO 3 or pco 2 is compensatory but it isn t clear which is primary E. It must be both metabolic acidosis with respiratory alkalosis

41 16) Your diagnostic concern(s) in this patient might be: A. Hyperventilation syndrome B. Salicylate toxicity C. Renal tubular acidosis D. Sepsis E. B or D

42 17) A 75 year-old man with hypertension, claudication and anginal chest pain undergoes a cardiac catheterization and percutaneous coronary angioplasty using 360 ml of low osmolar radiocontrast. The pre-catheterization creatinine was 1.4 mg/dl (124 µmol/l). Three days later, the creatinine was 1.6 mg/dl (141 µmol/l), but when seen one week later with abdominal pain, the creatinine had increased to 3.2 mg/dl (283 µmol/l).

43 Physical examination shows BP 180/105 and a decreased left femoral pulse with cyanotic splotches of both feet. Urinalysis showed 1+ protein, trace blood with 4-8 RBC/hpf, 5-10 WBC/hpf and occasional granular casts.

44 Your thinking at this point would be: A. Radiocontrast nephrotoxicity is most likely B. A renal sonogram with Doppler flow is likely to show no perfusion to one of the kidneys C. There may be eosinophilia and an elevated serum amylase D. A CT scan of the abdomen is likely to show aortic dissection E. Obtain a renal biopsy