Electrolyte Quiz

A 58-year-old woman with ischemic cardiomyopathy is admitted in pulmonary edema. Her medications include aspirin, metoprolol, furosemide, spironolactone, digoxin, isosorbide dinitrate, and lisinopril. On examination, the blood pressure is 97/54 mm Hg, pulse rate 85 per minute, jugular venous pressure 9 cm, moist mucous membranes, lungs with diffuse inspiratory crackles, heart with an S3 gallop, and cool, clammy extremities with 1+ peripheral edema.

Laboratory Studies

Serum sodium 126 mEq/L

Serum potassium 3.5 mEq/L

Serum chloride 88 mEq/L

Serum bicarbonate 33 mEq/L

Blood urea nitrogen 45 mg/dL

Serum creatinine 1.1 mg/dL

Arterial pH 7.46

Urine electrolytes (6 hrs after last diuretic dose):

Urine sodium 15 mEq/L

Urine chloride < 5 mEq/L

Urine osmolality 210 mOsm/kg

Which of the following would be appropriate in the management of the hyponatremia in this patient:

A. Intravenous isotonic (0.9%) saline

B. Restriction of free water intake

C. Hypertonic (3%) saline

D. Hydrochlorothiazide

E. Hydrocortisone

The answer to the Electrolyte Quiz of Feb 22 is sarcoidosis

The Question

A 38 year old black female presents with a 1-year history of fatigue, malaise, mild dyspnea and weight loss. Key laboratory data: BUN 48, Cr 4.4 (was 3.7 mg/dL two months ago), Alb 3.9, Ca 11.6, PO4 5.2, Mg 2.5, ALT 104, AST 88, Alk phos 554, Bili 0.9, ESR 136; Urine: Ca 17.4, Cr 47.7, Protein 95; U/A: 2+ protein, 2+ blood, 2+ leuk est;  USed:  18-22 WBC, 25-30 RBC, 3+ Ca oxalate crystals; Ultrasound: Rt kidney 10.4 cm with multiple calculi, Lt kidney 10.5 cm with 3 calcifications in the region of the pyramids; no hydronephrosis; iPTH 2.8 pg/ml (NL10-65), 25-vit D 11.8 ng/mL (NL 9-43) , 1,25-vit D, 109.4 pg/mL (NL 15-60); Chest CT: Increased diffuse lung parenchymal density, enlarged lymph nodes in axillary, mediastinal and hilar regions.

What’s the diagnosis?

Hypercalcaemia in association with sarcoidosis was first described by Harrel et al. in 1939 and since then an increased risk of hypercalcuria and reduced bone density has also been demonstrated. The cause of the hypercalcemia is cctopic 1a-hydroxylation of 25-hydroxyvitamin D by macrophages.

Other key clinical features:

• Diffuse interstitial lung disease
• Lymphadenopathy
• Liver Bx: Non-caseating granuloma
• Renal Bx: Chronic interstitial nephritis, isolated granulomata, microcalcifications.

More reading, here.

A hypercalcemia algorithm:

Cases provided by Dr, Alan Yu (University of Kansas)