Poster Presentation ESA-SRB-ANZBMS 2024 in conjunction with ENSA

To evaluate the outcomes of inpatients treated for hypercalcaemia according to intervention strategy.

A retrospective review of inpatients (October 2023 – July 2024), >18 years of age, admitted > 48 hours for confirmed hypercalcaemia. Data collected included serial biochemistry, aetiology of hypercalcaemia (if known), contributing factors, treatment strategy, and mortality.

There were 35 patients included in this study. Characteristics are described in Table 1. Groups were divided into IV fluids (IVF, N=16), bisphosphonate (BP, N=7), and denosumab (Dmab, N=7). There was a low prevalence of adjunct calcitonin use (N=5). Baseline renal function was more impaired in the Dmab group. PTH mediated aetiologies were more prevalent across all groups. The final cCa level was significantly reduced compared to the baseline cCa level with Dmab use (p=.039) but not BP (p=.085) or IVF (p=.378). The use of Dmab compared to patients with no Dmab (IVF or BP therapies) had a significantly lower final cCa level (p=.026). Malignancy was associated with a higher final and peak cCa level, compared to patients without malignancy, however this was not significant (p=.164). Solid organ malignancies were present in 87%, with only 9% having bone metastases. Anti-resorptive therapy was associated with a faster time to resolution than IVF alone, and this was significant with Dmab use (p=0.002) but not BP use (p=.308) (see Image 1). 9% of patients overall developed hypocalcaemia resulting from therapy.

In conclusion, the use of anti-resorptive therapy was infrequently used due to clinician differences in management. Denosumab showed significant improvement in calcium levels. Hypercalcaemia is associated with a significant mortality, and optimal management remains elusive. This study forms part of a much larger hypercalcaemia audit, to further explore the trajectory of hypercalcaemia and associated management.