Acute Refractory Hypocalcemia in a 51-Year-Old Male With a History of 1,1-Difluoroethane Inhalation

Hypocalcemia is a common electrolyte derangement that is most associated with parathryoid hormone or vitamin D abnormalities. Less common causes that most providers are aware of include hyperphosphatemia, acute pancreatitis, chronic kidney disease, and sepsis. However, certain populations are at risk for less common, but no less dangerous, causes. One such cause is 1,1-difluoroethane, an organofluorine that is used as a propellant in aerosol sprays and is commonly abused. 1,1-Difluoroethane has been noted to cause severe hypocalcemia by accumulation of the metabolite fluorocitrate in tissues. Here, we present the case of a 51-year-old male with severe hypocalcemia and multiple rib fractures following a fall, with recent history of tibial fracture. The patient had a medical history of osteoporosis with numerous fractures and chronic steroid use. He admitted to using keyboard cleaner as an inhalant for the previous month, which was found to contain 1,1-difluoroethane. Previous case reports on 1,1-difluoroethane inhalation have not reported a patient with preexisting osteoporosis or refractory hypocalcemia.