PSAT179 Hypercalcemia Associated with Antibiotic-Impregnated Calcium Sulfate Beads

INTRODUCTION: Hypercalcemia is an electrolyte disturbance with a wide spectrum of symptoms ranging from asymptomatic, to coma and arrhythmia. Primary hyperparathyroidism and malignancy are the most common causes of hypercalcemia, accounting for up to 90% of cases. Here we discuss transient hypercalcemia associated with Stimulan antibiotic-impregnated calcium sulfate (AICS) beads implanted after an orthopedic procedure. CASE: A 63 year old female with a past medical history of hypertension and type 2 diabetes mellitus presented to the hospital with signs and symptoms of infection of her left prosthetic hip which had been inserted a few weeks earlier. She was admitted for an orthopedic procedure to replace the prosthetic joint and insert antibiotic-impregnated calcium sulfate beads. The procedure was successful and the patient was admitted to the Medicine Floor for monitoring. The day after the procedure the patient was noted to be lethargic. CT head was unrevealing and after de-escalation of narcotics, the patient remained alert but difficult to arouse. Further workup revealed a Calcium of 14.5 (15.1 corrected for Albumin of 3.3). She reported bone pain, constipation, and abdominal discomfort. The patient was immediately treated with intravenous hydration as well as Calcitonin 300 mg within the first 48 hours. Initial workup revealed non-PTH-mediated hypercalcemia. Parathyroid Hormone Related Peptide, Vitamin D, Serum Protein Electrophoresis, and Angiotensin-Converting Enzyme were all normal. Sarcoidosis, Multiple Myeloma, and malignancy were ruled out. Given an unrevealing workup, this transient hypercalcemia was determined to be caused by AICS beads. Over the course of 6 days, following IV fluid resuscitation and calcitonin the patient's mental status and calcium level and her symptoms resolved. DISCUSSION: AICS beads are a well-accepted adjuvant therapy in preventing and treating prosthetic joint infections. There are few reported cases of transient hypercalcemia due to AICS beads, more commonly seen with a higher number of beads used. While hypercalcemia seems to be a rare side effect, if severe it has the potential to be life-threatening. Severe cases of hypercalcemia may lead to cardiovascular compromise, altered mental status, encephalopathy, and pancreatitis. Patients with calcium levels greater than 14 or greater than 12 with symptoms should be treated aggressively to avoid serious complications. Initial management is aimed at elimination of calcium, decreased absorption of calcium, and repletion of intravascular volume.Awareness of the risk of hypercalcemia associated with AICS bead use and careful post-operative monitoring can assist in early identification and management of this potentially fatal adverse effect. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.