RHABDOMYOLYSIS-INDUCED DELAYED HYPOCALCEMIA AFTER PARATHYROIDECTOMY

PRIMARY HYPERPARATHYROIDISM today is normally identified early in the course of the disease, though in previous decades it was often diagnos ed after significant pathologic change had occurred. Among the causes, solitary parathyroid adenomas account for 80%, and another 14% to 20% can be attributed to diffuse hyperplasia of multiple parathyroid glan ds.(1,2) Treatment of choice, when feasible, is surgical excision of a ny or all abnormal glands, but with preservation of functional parathy roid tissue by leaving at least a portion of one gland intact or by re implanting a portion of one gland into a muscular pocket. Up to 98% of operative procedures for the treatment of primary hyperparathyroidism are successful with the first operation.(1-3) Despite this, parathyro id surgery is associated with certain complications, one of the most s ignificant and life threatening being that of postoperative hypocalcem ia. The most common cause for this is either surgical trauma to the re maining parathyroid glands or the reversal of calcium physiology and r edeposition of calcium within the bone.(4) This situation is readily i dentified within the first few postoperative days by measurement of se rum calcium levels, and if clinically significant hypocalcemia develop s, then appropriate therapy with calcium carbonate and calcitriol can be instituted. Parathyroid hormone (PTH) levels will confirm the diagn osis, since most of the preoperative PTH should be cleared within 36 t o 48 hours in a person with normal renal function.(5) The astute physi cian must always be conscious of concomitant disease, unrelated to the parathyroid gland, that may cause complications of calcium regulation in the perioperative period. We report a case in which the excision o f a parathyroid adenoma was complicated postoperatively by hypocalcemi a due to an acute episode of rhabdomyolysis from a preexisting chronic polymyositis.