8165 A Case Of Rhabdomyolysis-Induced Hypocalcemia And Hypercalcemia

Abstract Disclosure: A. Desai: None. A.L. Izzi: None. B. Flores Chang: None. A. Sajan: None. Introduction: Rhabdomyolysis is a syndrome characterized by muscle breakdown and the release of intracellular muscle contents into circulation. It is associated with electrolyte abnormalities and acute renal failure that can lead to prolonged hospitalization. We report a case of persistent hypercalcemia from recovery of acute renal failure and severe rhabdomyolysis. Case Description: A 47-year-old man with past medical history of polysubstance use initially presented with opiate-induced acute encephalopathy and respiratory failure. He developed severe rhabdomyolysis during the hospital course leading to acute renal failure requiring hemodialysis with hypocalcemia. The initial labs showed corrected calcium 6.2 mg/dL 9.2-11.0, ionized calcium 3.48 mg/dL 4.65-5.28, creatinine kinase level was 72,600 U/L 38-174, BUN 110 mg/dL 8-23, creatinine 7.8 mg/dL 0.6-1.2, and GFR 7 ml/min/BSA. His renal function improved over the next several days in the hospital. The serum creatinine improved to 4 mg/dL, BUN 49 mg/dL and GFR 20 ml/min/BSA respectively after couple of intermittent dialysis sessions. Six days after the last hemodialysis session, patient developed severe hypercalcemia with corrected calcium values ranging from 13.5 to 14.7 mg/dL and ionized calcium 7.41 mg/dL. Labs showed PTH 10 pg/mL 15-65, 1,25-dihydroxyvitamin D 10.0 pg/dL 21-65 and 25-OH Vitamin D levels 15.3 ng/ mL 30-96, which is consistent non-PTH medicated hypercalcemia. The 24-hour urine calcium was 696 mg 0-300 mg/24 hrs, 2900 cc. PTH-related peptide was not collected. He was treated with intermittent doses of calcitonin and a single dose of pamidronate when the calcium levels were 13 mg/dL. Hypercalcemia resolved in eleven days after initially noted to have hypercalcemia. The corrected calcium improved to 10.1 mg/dL on the day of discharge. Discussion:Severe rhabdomyolysis is associated with acute kidney injury. The initial hypocalcemic phase during rhabdomyolysis is due to entry of calcium into damaged myocytes and deposition of calcium salts in damaged muscle. This is seen in the oliguric phase of acute kidney injury. After the recovery of rhabdomyolysis, the polyuric phase persists during renal recovery. During this time, up to one third of patients may have rebound hypercalcemia due to massive muscle calcium release. As per case reports the hypercalcemia phase lasts from 8 days to 3.5 months. In our case, the patient initially developed hypocalcemia in the oliguric phase of acute kidney injury from rhabdomyolysis. He developed hypercalcemia in the polyuric phase of renal recovery. The hypercalcemia resolved with intravenous hydration, calcitonin and pamidronate. Rhabdomyolysis is a rare cause for both hypocalcemia and hypercalcemia. Our case highlights the biphasic calcium response associated with rhabdomyolysis in the setting of renal impairment and recovery. Presentation: 6/1/2024