The Influence of Hypocalcaemia on Trauma Patients Experiencing Post‐Induction Hypotension: A Retrospective Observational Study

Objective Hypocalcaemia is a common electrolyte disturbance in major trauma patients, particularly those with haemorrhagic shock. Trauma patients are often intubated as part of their care, which can result in post‐induction hypotension. We aimed to estimate the effect of hypocalcaemia on post‐induction hypotension. Methods We conducted a retrospective observational study of trauma patients ≥ 18 years old intubated in a tertiary Australian Emergency Department between 1st January 2020 and 30th September 2024. Epidemiological and clinical management data were extracted to estimate the effect of hypocalcaemia on outcomes. Results Of 478 eligible patients, 151 had available haemodynamic and calcium measurements. Post‐induction hypotension occurred in 38/47 (81%) of hypocalcaemic and 69/104 (66%) of non‐hypocalcaemic patients. Hypocalcaemia was associated with higher odds of post‐induction hypotension (adjusted odds ratio [aOR] 2.15, 95% confidence interval [CI] 0.84–5.51), with considerable uncertainty in this estimate. Hypocalcaemic patients were more likely to receive red blood cells within 15‐min post‐induction (OR 2.13, 95% CI 1.12–4.04). Minimal differences were observed in cardiac arrest 15‐min post‐induction (OR 0.65, 95% CI 0.07–5.73) or mortality at discharge (OR 1.00, 95% CI 0.51–1.97). Conclusions Hypocalcaemia may be associated with higher odds of post‐induction hypotension in trauma patients; however, our findings require corroboration across a larger multi‐centre prospective observational study. If corroborated, a randomised controlled trial is warranted to establish the utility of calcium replacement for the prevention of post‐induction hypotension.