Association of Non-Transfusion-Related Admission Hypocalcaemia With Haemodynamic Instability in Paediatric Major Trauma: A Retrospective Single-Centre Pilot Study.

Background The 'lethal triad' of acidosis, hypothermia, and coagulopathy is now considered a diamond of death, with ionised hypocalcaemia (iHypoCa) contributing to cardiovascular decompensation and coagulopathy. iHypoCa may be associated with haemodynamic instability and adverse outcomes in paediatric major trauma patients. However, current data are limited. The primary aim of this pilot study was to report the association between admission iHypoCa and early hypotension on admission in a cohort of paediatric major trauma patients. Secondary aims include reporting the incidence and differential determinants of iHypoCa and the association with treatment (vasoactive agents, blood transfusion, interventional radiology (IR), or surgery) and adverse outcomes (length of stay, morbidity (Glasgow Outcome Scale), and mortality). Methods This pilot study is a retrospective analysis of paediatric major trauma patients (<16 years old) admitted to a major trauma centre (2016-2022). Patients with an admission ionised calcium level obtained before the administration of blood products were included. Multivariable logistic regression was used to assess the dichotomous endpoint of hypotension (systolic blood pressure of <80 mmHg for <1 year, <85 mmHg for one to five years, <90 mmHg for five to 12 years, <100 mmHg for >12 years) for association with hypocalcaemia and adjusted for other potential variables of interest (age, gender, Injury Severity Score, pre-hospital fluids, and acidosis). Results Admission iHypoCa was observed in 8/45 (17.8% (95% confidence interval (CI) 9.3-31.3%)) patients. Other than the adolescent age group ( < 0.05), there were no significant differences in the baseline characteristics. As a pilot study, this was not powered for statistical significance; however, point estimates of the odds of hypotension were almost three times higher for patients with iHypoCa (odds ratio (OR) 2.8 (95% CI 0.4-23.6), = 0.33). An association between iHypoCa and the need for IR/surgery in the first 24 hours of admission was also observed (OR 10.9 (95% CI 1.4-159.4), 0.05). Conclusion iHypoCa was observed in approximately one in six paediatric major trauma patients at admission and may be associated with increased odds of requiring IR/surgery. Larger multicentre studies are required to clarify point estimates for treatment requirements and adverse outcomes.