The influence of hypocalcaemia on trauma patients experiencing post-induction hypotension: A retrospective observational study.

Abstract

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.