A 59-year-old postmenopausal woman with a past medical history of Billroth II gastric bypass surgery 15 years before for bariatric purposes, Barrett esophagus, pericarditis secondary to suspected rheumatologic disease status treated with a pericardial window 3 years before, rheumatoid arthritis with negative rheumatoid factor, paroxysmal atrial fibrillation, amiodarone-induced hypothyroidism, and osteoporosis treated with denosumab 3 months before was referred to the emergency department by her endocrinologist after outpatient labs revealed profound hypocalcemia, hypophosphatemia, and hypomagnesemia. The patient had recently returned from vacation, where she experienced 2-3 episodes of diarrhea. She reported compliance to her medications, which included 50,000 IU ergocalciferol daily and 630 mg calcium citrate 2-3 times daily, apart from taking a decreased dose of calcium for the last 4 days of her vacation since she was running low on pills. She noted fatigue and intermittent tingling in her hands, feet, and perioral region for 2-3 days prior to admission. She denied weight loss, fever, muscle cramping, seizures, loss of consciousness, or lightheadedness.\nOn presentation, the patient was afebrile with a temperature of 98.2ºF, blood pressure of 136/74 mmHg, heart rate of 71 beats/min, and respiratory rate of 15 breaths/min. Her oxygen saturation was 100% on room air. Physical examination revealed a well-appearing woman with a body mass index (BMI) of 30 kg/m2 in no acute distress. Neck was supple with no thyromegaly. There were no abnormalities on cardiac or pulmonary exam. Abdomen was soft, nontender, and nondistended with normal bowel sounds. Patient had a positive Chvostek's sign. No muscle twitches or spasms were appreciated. Strength, sensation, reflexes, and cranial nerves were intact. The patient had no signs of confusion or psychosis.\nBlood tests from the emergency department revealed a calcium of 5.8 mg/dL, phosphorus of <1 mg/dL, and magnesium of 1.7 mg/dL. Albumin was 3.8 g/dL, so the corrected calcium was 6.0 mg/dL. Ionized calcium was 0.8 mg/dL. Parathyroid hormone was 136 ng/L. 25-Hydroxy vitamin D was normal at 46 ng/mL, and 1-25-hydroxy vitamin D was normal at 30 pg/mL. Urinalysis was within normal limits, and urine calcium was <2 mg/dL. Creatinine was 0.61 mg/dL, and blood urea nitrogen was 11 mg/dL. TSH was normal at 0.78 μU/mL. An electrocardiogram performed in the emergency department showed normal sinus rhythm with a corrected QT interval of 493 ms.\nIn the emergency department, the patient was given 2 g of IV magnesium sulfate, 30 mmol of IV sodium phosphate, and 1 g of IV calcium gluconate. During her 4-day hospital stay, the patient continued to receive IV calcium, as well as oral calcitriol, phosphate, and magnesium. When she was able to consistently maintain serum calcium of at least 8.0 mg/dL on oral calcium citrate supplementation, she was discharged with a calcium level of 8.0 mg/dL, magnesium of 1.9 mg/dL, and phosphorus of 2.3 mg/dL. She was instructed to take calcium citrate of 1260 mg 4 times daily, calcitriol of 0.25 mcg 2 times daily, phosphorus of 250 mg 3 times daily, and magnesium oxide of 400 mg 2 times daily and to be followed up closely with her endocrinologist. Since discharge, the patient has been able to maintain adequate calcium levels on a low dose of calcium supplementation, and she is interested in considering further doses of denosumab.
A 74-year-old male with a past medical history of severe osteoporosis, chronic obstructive pulmonary disease (COPD), marginal gastric ulcers status-post sleeve gastrectomy, and Crohn’s disease status-post small bowel resection presented to the emergency department due to an acute onset of right shoulder pain. Vital signs revealed a temperature of 37.2°C, blood pressure of 112/61 mmHg, heart rate of 78, respiratory rate of 16 and oxygen saturation of 92% on 1.5 L by nasal cannula, which he used at baseline. Initial laboratory workup revealed severe hypocalcemia at 4.8 mg/dL and hypophosphatemia at 0.8 mg/dL. Upon further history taking, the patient stated that he receives denosumab injections for his severe osteoporosis. The patient denied muscle cramps, spasms, weakness, seizures, facial twitching, lightheadedness, and psychiatric changes. Of note, he had a history of chronic hypocalcemia with a baseline of 7 mg/dL and reported taking daily calcium and vitamin D supplements. His physical examination was unremarkable except for shoulder pain on passive range of motion. Chvostek and Trousseau signs were both negative. Additional laboratory workup (Table ) was significant for hyperparathyroidism and normal levels of magnesium, albumin, and vitamin D. His arterial blood gas results (Table ) revealed respiratory acidosis presumed to be due to COPD.\nThe patient was admitted to the intensive care unit, monitored on cardiac telemetry, and started on IV calcium carbonate in addition to his home calcium and vitamin D oral supplements. Endocrinology was consulted and calcium levels were trended until normalization. The patient was ultimately discharged on calcium carbonate 1,250 mg by mouth three times per day, calcium-vitamin D gummies by mouth three times per day, cholecalciferol 1,000 international units by mouth two times per day, and calcitriol 0.5 mcg oral capsule four times per day. His serum calcium level at eight months post-discharge has been maintained at roughly 9.5 mg/dL on this regimen and he has remained asymptomatic throughout.