rebound hypercalcemia in rhabdomyolysis

Q: What is rebound hypercalcemia in rhabdomyolysis?

Answer:  Calcium level go through a rollercoaster ride in rhabdomyolysis. The initial phase is marked by potentially significant hypocalcemia. This is due to 

• calcium entry into damaged myocytes, 
• deposition of calcium salts in damaged muscle, and 
• decreased bone responsiveness to parathyroid hormone

Recovery phase in rhabdomyolysis is characterized by potentially life-threatening rebound hypercalcemia taking a detour of normocalcemia. This is due to 

• release of calcium from injured muscle, 
• hyperparathyroidism from the acute renal failure, and 
• an increase in calcitriol (1,25-dihydroxyvitamin D)

#electrolytes

#musculoskeletal

References:

1. Llach F, Felsenfeld AJ, Haussler MR. The pathophysiology of altered calcium metabolism in rhabdomyolysis-induced acute renal failure. Interactions of parathyroid hormone, 25-hydroxycholecalciferol, and 1,25-dihydroxycholecalciferol. N Engl J Med 1981; 305:117.

2. Akmal M, Bishop JE, Telfer N, et al. Hypocalcemia and hypercalcemia in patients with rhabdomyolysis with and without acute renal failure. J Clin Endocrinol Metab 1986; 63:137.