To investigate the prognostic value of serum calcium levels in patients with trauma-induced coagulopathy (TIC).

A retrospective analysis was conducted on the clinical data of 142 patients with TIC who were admitted to the ICU of the First Hospital of Jiaxing between January 2015 and January 2023. According to the prognosis of 28 days after ICU admission, patients were divided into a survival group (80 cases) and a death group (62 cases). The basic data, laboratory examination indexes within 24 h after admission to the ICU and assessment of blood consumption scores of the two groups were compared. Multivariate logistic regression was used to analyze the prognostic risk factors of TIC patients, and a receiver operating characteristic (ROC) curve was drawn to analyze the diagnostic value of serum calcium in the risk of death in TIC patients. A restricted cubic spline (RCS) was used to evaluate the linear relationship between the first serum calcium level after admission to the ICU and the risk of death in TIC patients.

Compared with the survival group, the proportions of low fibrinogen [65.0% (52/80) vs. 88.7% (55/62), χ² = 3.240, P < 0.001], hyperlactacidemia [65.0% (52/80) vs. 88.7% (55/62), χ² = 3.240, P < 0.001] and hypocalcaemia [73.8% (59/80) vs. 96.8% (60/62), χ² = 3.223, P < 0.001] and the serum chlorine level [113 (110, 116) mmol/L vs. 115 (111, 118) mmol/L, Z = 2.350, P = 0.019] were much higher, and the platelet count [118 (84, 148) × 10⁹/L vs. 94 (50, 116) × 10⁹/L, Z = 3.447, P < 0.001] and albumin level [(28 ± 6) g/L vs. (23 ± 8) g/L, t = 3.732, P < 0.001] were much lower in the death group. The multivariate logistic regression analysis indicated that hypocalcaemia [odds ratio (OR) = 5.019, 95% confidence interval (CI) (1.279, 19.690), P = 0.021] and hyperlactacidemia [OR = 3.970, 95%CI (1.353, 11.075), P = 0.012] were risk factors for death in patients with TIC. The ROC curve analysis revealed that the area under the curve for serum calcium was 0.734 [95%CI (0.652, 0.816), P < 0.001], and the best cut-off value was 1.950 mmol/L. The RCS showed that there was a linear relationship between serum calcium and prognosis of TIC patients (P = 0.023), and the risk of death decreased with the increase of serum calcium concentration in the range of 1.603 to 2.130 mmol/L after admission.

Hypocalcaemia is an independent risk factor for death in TIC patients; especially when serum calcium is lower than 1.950 mmol/L, it has important value in predicting the risk of death.