(282) Hypocalcemia and Hungry Bone Syndrome: A Life-Threatening Duo

Introduction: Hypocalcemia after parathyroidectomy, is usually transient and resolves by day 4 post operatively. In ESRD patients, the degree of hypocalcemia correlates with the degree of secondary hyperparathyroidism that they have developed over time due to high bone turnover and the sudden decrease in PTH activity ultimately resulting in increased bone formation and lowered serum calcium levels. (2) When hypocalcemia becomes severe, or persistent despite treatment, patients are called to develop hungry bone syndrome. Such patients are at increased risk of tetany, arrythmias, seizures, among other complications.

Description: A 31 y/o male presented to the emergency department complaining of cramps and tingling sensation over his body, confusion, general malaise. He referred being compliant with medications and hemodialysis and denied alcohol abuse or illicit drug use. His past medical history is pertinent for end stage renal disease on hemodialysis and parathyroidectomy 2 months prior to presentation on oral calcium replacement.

Upon evaluation in the emergency department, he was found afebrile, hemodynamically stable and in no acute distress. His calcium level was 5.5 mg/dL (ionized calcium levels of 0.79) and potassium 6.6 mEq/L. EKG showed mild QT prolongation with associated ST segment elongation, and peaked T waves. A right bundle branch block and posterior fascicular block were present previously and at this time. Cholecalciferol therapy was adjusted to 50,000 Units/week, calcium carbonate to 2,000mg and calcitriol 1mcg three times a day, and a calcium gluconate drip was started. Hemodialysis was administered. Despite, following calcium levels were at 4.2 mg/dL. Supplementation continued for two days, achieving calcium level of 8.5 and potassium level of 3.7. Follow up EKG 36 hours after initial EKG and resolution of electrolyte disturbances, demonstrated resolution of peaked T waves, prolonged QT due to wide ST segment with the previous mentioned heart block.

Discussion: HBS occurs in approximately 25% to 50% of ESRD patients after parathyroidectomy. Associated hypocalcemia can be a life threatening situation which needs aggresive and rational replacement, even when other electrolyte disturbances are present.