7987 Ravenous Bone

Abstract Disclosure: Y. Oo: None. L. Srisawitri: None. P. Patel: None. M. Thein: None. Introduction Hungry bone syndrome ( HBS ) is the rapid drop in serum total calcium concentration of less than 2.1 mmol/L and/or prolonged hypocalcemia for more than 4 days postparathyroidectomy. It is more frequent in hemodialysis patients with secondary hyperparathyroidism (SHPT). The severe hypocalcemia after the parathyroidectomy is believed to be due to the increased usage of calcium by the starving bones. The key management is to replenish the severe calcium deficit aggressively. Clinical Case A 44-year-old Hispanic male patient with ESRD on hemodialysis was admitted for elective parathyroidectomy for SHPT from ESRD. The hospital course was complicated with profound hypocalcemia after the surgery. The pertinent lab results before surgery were total calcium level of 7.2 mg/dl ( normal 8.4 - 10.2 ), ionized calcium level of 4.9 ( normal 4.48 - 4.92 ), and PTH level of 2184 pg/ml (normal 15 - 65). After the parathyroidectomy, the ionized calcium level became 3.4 mg/dl and the PTH level trended down to 56 pg/ml. On the post-op day ( POD ) 1, the patient was started on calcitriol 1 mcg BID and calcium carbonate 600 mg QID and also got the hemodialysis with a high calcium bath. Even with the replacement, the calcium level kept worsening and calcium gluconate infusion was started on POD 4. On POD 5, calcium gluconate infusion was on hold as the ionized calcium was improved. On POD 7, calcitriol was increased to 2 mcg BID as ionized calcium was 3.2 mg/dl and restarted on calcium gluconate infusion. On POD 8, ionized calcium was 3.5 mg/dl, and calcium gluconate infusion was titrated down. On POD 9, as the total calcium level was 8.8 mg/dl, the calcium gluconate infusion was discontinued and he was discharged with calcium carbonate 1200 mg TID and calcitriol 2 mcg TID. Unfortunately, 13 days from the discharge date, he was readmitted with the volume overload, and on this second admission, the total calcium was 7 mg/dl and ionized calcium was 3.2 mg/dl. The calcitriol dose was increased to 2 mcg TID and the same dose of calcium carbonate which was 1200 mg TID. He got hemodialysis with a high calcium bath. After being treated for the volume overload, he was discharged with calcitriol 2 mcg TID and calcium carbonate 1200 mg TID and followed up with the endocrinology team in 2 weeks. Conclusion Even with the aggressive and constant replacement of calcium, the HBS cases are challenging in terms of achieving and maintaining a normal calcium level after surgery. We, the clinicians, need a better understanding of how to avoid the development of HBS or at least minimize the severity of hypocalcemia in the postoperative course and the ultimate management regimen to maintain the normal calcium level in both inpatient and outpatient settings. Presentation: 6/1/2024