SAT-397 Characteristics and Outcomes of Severe Hypercalcemia Related Admissions - a Single Centre 5 Years’ Experience

Introduction: Severe hypercalcemia (corrected calcium ≥3.5mmol/L) is typically associated with multi-organ dysfunction and increased mortality. We audited 47 consecutive patients who were admitted to a single tertiary referral center over 5 years period (2014-2019) with severe hypercalcemia. Results: The median age 69 years (10-97yrs); 55% females, and median length of stay was 9 days (1-120). Most patients (30%) were admitted under general medicine and 53% received endocrinology consultation. Renal dysfunction (91%) dominated the clinical presentation, but gastrointestinal abnormalities (70%), neuropsychiatric manifestations (53%), and musculoskeletal involvement (45%) were also very common. PTH was measured in 43/47 patients with 37 PTH independent (calcium level 3.82 mmol/L) and 6 PTH dependent (calcium level 3.70mmol/L) hypercalcemia. Recurrence of the condition within five years was recorded for 5 patients (11%), ten (21%) patients died during the admission, and 4 patients (9%) required ICU admission in PTH independent severe hypercalcaemia, majority are due to malignancy; while none of these outcomes were observed in PTH dependent severe hypercalcaemia. The length of hospital stay is longer in PTH independent (15.5 days) as compared to PTH dependent severe hypercalcaemia (12 days). The most common cause of severe hypercalcemia was malignancy (47%) with multiple myeloma as the most common in 32% followed by lung cancer at 27%. The other non-malignancy causes are calcium supplementation, vitamin D toxicity, and hyperparathyroidism implicated in 13% each. Twenty eight patients (65%) were managed by fluid and antiresorptive agent with 26 patients able to decrease calcium level to <3mmol/L (93%). Eight patients (19%) were managed by fluid alone (not effective in 37%), 9% by antiresorptive agent alone (not effective in 25%), and 16% did not receive any fluid nor antiresorptive agent (not effective in 43%). Conclusion: Similar to previous studies, severe hypercalcaemia is commonly seen in patients with malignancy and associated with significant symptoms, recurrence in 5 years, ICU admission and mortality. Calcium and vitamin D supplementation and hyperparathyroidism are also found to commonly cause severe hypercalcemia. The most effective management is combination of fluid resuscitation and antiresorptive agent to decrease the calcium level to <3mmol/L.