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After completing this case study, the reader should be able to:

  • Analyze a patient case history and identify potential causes of electrolyte disorders.

  • Select the appropriate route of administration and dose of electrolyte replacement therapy specific for a patient.

  • Develop a monitoring plan for efficacy and toxicity in patients receiving electrolyte replacement therapy.

  • Outline a patient education plan for a patient receiving electrolyte replacement supplements.


Chief Complaint

“I’m short of breath.”


Dorothy Snow is a 45-year-old woman with a history of nonischemic cardiomyopathy who presents to the ED with a 3-day history of shortness of breath with mild-to-moderate exertion. She reports three-pillow orthopnea × 2 days and cough during sleep. Denies chest pain; occasional palpitations. Reports a 10-lb weight gain in the last week and an increase in her lower extremity edema.

Two months ago, Mrs Snow was hospitalized briefly with atypical chest pain and had persistent hypokalemia for which her metolazone 5 mg daily was discontinued. Approximately one month ago, she subsequently developed significant fluid retention and her PCP restarted metolazone 5 mg PO MWF. About 2 weeks ago, she had an ED visit and her potassium was 7.2 mEq/L (hemolyzed sample). The potassium level was repeated with a result of 5.5 mEq/L. At that time, her potassium supplement dose was reduced from 80 mEq PO QID to 80 mEq PO BID.

PMH (Per Patient Report and Medical Records)

  • Nonischemic cardiomyopathy—echo LVEF 25% (11 months ago)

  • ICD placement (3 weeks ago)

  • Pulmonary hypertension—secondary to left heart disease

  • HTN

  • Asthma

  • Sleep apnea

  • Type 2 DM with peripheral neuropathy

  • Obesity

  • Chronic sinusitis

  • Anxiety disorder

  • Hypothyroidism


Both parents are deceased


Lives with husband. No alcohol use. Former smoker—quit 8 years ago. No illicit drugs.


  • Valsartan 160 mg PO BID

  • Omeprazole 20 mg PO daily

  • Carvedilol 25 mg PO BID

  • Digoxin 0.25 mg PO daily

  • Spironolactone 25 mg PO daily

  • Furosemide 80 mg PO BID

  • Citalopram 20 mg PO daily

  • Atorvastatin 20 mg PO daily

  • Insulin glargine 30 units SC Q 12 H

  • Insulin aspart 20 units SC TID with meals

  • Pregabalin 50 mg PO BID

  • Metolazone 5 mg PO MWF

  • Loratadine 10 mg PO daily

  • Tiotropium one puff daily

  • Fluticasone/salmeterol 500/50 one puff BID

  • Mometasone one spray each nostril daily

  • Meclizine 12.5 mg PO BID

  • Magnesium oxide 400 mg PO TID

  • Potassium chloride 80 mEq PO BID

  • Levothyroxine 75 mcg PO daily

  • Lorazepam 0.5 mg PO TID

  • Folic acid 1 mg PO daily

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