Aims: To determine the number, aetiology and mortality of hospital admissions with severe hypercalcaemia (corrected calcium >/= 3.5mmol/L) in an Australian inpatient cohort pre, during and post the COVID-19 pandemic.
Methods: Retrospective analysis of Monash Health medical records, pre (July 2018 – Feb 2020), during (March 2020 – October 2021) and post (November 2021 – June 2023) COVID.
Results: 139 individual presentations (mean age 64±15.6 years, 56.1% female) with 23 presentations pre, 38 during and 78 post-COVID. Median corrected Ca (cCa) was 3.72 mmol/L (IQR 0.39) and not statistically different across time periods. Most frequent aetiology was Hypercalcaemia of Malignancy (HCM) 80/139 (57.6%); 48 solid tumours (bone metastases 70.8%, breast cancer 37.5%) and 29 haematological malignancies. Iatrogenic hypercalcaemia occurred in 14/139 (10.0%), primary hyperparathyroidism (PHPT) in 12/139 (8.6%) and other aetiologies in 33/139 (23.7%).12/80 cases of HCM, 2/14 iatrogenic and 1/12 PHPT occurred pre-COVID. 20/80 HCM, 4/14 iatrogenic and 4/12 PHPT during COVID, and 48/80 HCM, 8/14 iatrogenic and 7/12 PHPT occurred post-COVID. HCM accounted for 52.1%, 52.6% and 61.5% of all cases pre, during and post-COVID. For PHPT 4.3% pre, 10.5% during and 9.0% post-COVID, for iatrogenic hypercalcaemia 8.7% pre, 10.5% during and 10.3% post-COVID, and for other aetiologies 34.8%, 26.8% and 19.2% pre, during and post-COVID.Hospital length of stay was 8.5 days pre, 7.9 during and 11.0 post-COVID. Of 37 deaths, 5 occurred pre, 14 during and 18 post-COVID; 25/37 occurred in the HCM group (mortality rate 31%), 11/12 in ‘other’ and 1 in PHPT group
Conclusion: There was a trend towards an increase in severe hypercalcaemia presentations; 3 and 2-fold respectively, during and post, compared with pre-COVID. 11 of 12 PHPT presentations occurred during and post-COVID. Most cases were due to HCM. This combined with the high death rate in HCM raises the possibility of COVID associated care delays.