A report describes a case of a 50-year-old woman with a past medical history of chronic obstructive pulmonary disease, hypertension, hyperlipidemia, bipolar disorder, autoimmune hepatitis with cirrhosis, gastroesophageal reflux disease, hypothyroidism, and type 2 diabetes mellitus, who complained of headache, dizziness, nausea, and weakness for three days. She reported overheating in her home because of the failed air conditioner. She also reported eating pieces of ice and standing near the fridge door to beat the heat. Still, she was feeling heated and sweating profusely throughout the day. 

She was taking an albuterol inhaler, clonidine 0.2 mg twice a day, atorvastatin 40 mg nightly, quetiapine 300 mg nightly, fluoxetine 20 mg daily, benztropine 1 mg twice a day, prednisone 5 mg daily, pantoprazole 40 mg daily, furosemide 20 mg daily, levothyroxine 50 mcg daily, metformin 1000 mg twice a day, insulin degludec 16 units every morning, and exenatide 2 mg weekly. She reported not adhering to her prescription medication regimen and diabetic diet in the past; no recent changes in her prescription medications and non-consumption of over-the-counter medications, including antacids, calcium, and vitamin A supplements.

Her initial vital signs were as- 

• blood pressure= 150/90 mmHg,
• temperature= 37.4°C,
• heart rate= 105 beats per min,
• respiratory rate= 18 breaths per min,
• oxygen saturation= 99% on room air. 

Physical examination showed her to be lethargic with dry mucus membranes. Her laboratory test revealed hyperglycemia and severe hypercalcemia. Her hyperglycemia had a normal bicarbonate and anion gap, suggesting hyperglycemia without diabetic ketoacidosis; hence, blood gas was analysis not performed at the time of admission. 

The electrocardiogram showed a normal sinus rhythm without ST-segment changes. The patient received a 2-liter fluid bolus of normal saline and was then started on the continuous infusion of normal saline at 150 mL/h.

The patient′s calcium level gradually improved with intravenous (i.v.) hydration and normalized by the third day of hospitalization, following which it was stopped. Bisphosphonate therapy was not needed. She underwent an extensive laboratory workup (reports unremarkable), including parathyroid hormone (PTH), parathyroid hormone-related peptide, 25-hydroxy vitamin D, 1,25-dihydroxy vitamin D, thyroid-stimulation hormone, cortisol, serum protein electrophoresis, and serum-free light chain, to underline the etiology of hypercalcemia. The patient′s symptoms resolved, and she received discharged on the fourth day of hospitalization, with calcium levels in the reference range.

One week after discharge, she had a follow-up visit with her primary care physician, and all her examinations were normal.

Am J Case Rep. 2022 Jun 1;23:e936204. doi: 10.12659/AJCR.936204. PMID: 35642124; PMCID: PMC9169683.