Immobilization-induced hyperphosphatemia and functional hypoparathyroidism successfully treated with oral bisphosphonates

摘要

A previously healthy 46-year-old man with 5-month history of T5-T6 level paraplegia after a motor vehicle accident was admitted to the spinal cord rehabilitation center. The patient was found to have persistent hyperphosphatemia in the range of 6.5 to 6.7 mg/dL during routine laboratory evaluations. His phosphorus (Pi) level was previously normal (3.1 mg/dL) at the time of the motor vehicle accident. Physical examination was remarkable for T5-T6 level paraplegia and left elbow calcification. The patient was also found to have mildly elevated serum calcium (Ca) (10.4 mg/dL), suppressed parathyroid hormone (PTH) (10 pg/mL) and elevated fibroblast growth factor-23 (FGF-23) (263 RU/mL). Additional laboratory data are shown in Table 1. The oral intake consisted of 1 L of "Peptamen" bolus tube feeding containing 667 mg of Pi per liter. The patient was not taking any medications or oral supplements. Sevelamer carbonate 2.4 g with meals was initiated to reduce intestinal absorption.