The incidence of admission ionised hypocalcaemia in paediatric major trauma—A systematic review and meta-analysis

Objectives In adult major trauma patients admission hypocalcaemia occurs in approximately half of cases and is associated with increased mortality. However, data amongst paediatric patients are limited. The objectives of this review were to determine the incidence of admission ionised hypocalcaemia in paediatric major trauma patients and to explore whether hypocalcaemia is associated with adverse outcomes. Methods A systematic review was conducted following PRISMA guidelines. All studies including major trauma patients <18 years old, with an ionised calcium concentration obtained in the Emergency Department (ED) prior to the receipt of blood products in the ED were included. The primary outcome was incidence of ionised hypocalcaemia. Random-effects Sidik-Jonkman modelling was executed for meta-analysis of mortality and pH difference between hypo- and normocalcaemia, Odds ratio (OR) was the reporting metric for mortality. The reporting metric for the continuous variable of pH difference was Glass’ D (a standardized difference). Results are reported with 95% confidence intervals (CIs) and significance was defined as p <0.05. Results Three retrospective cohort studies were included. Admission ionised hypocalcaemia definitions ranged from <1.00 mmol/l to <1.16 mmol/l with an overall incidence of 112/710 (15.8%). For mortality, modelling with low heterogeneity (I2 39%, Cochrane’s Q p = 0.294) identified a non-significant (p = 0.122) estimate of hypocalcaemia increasing mortality (pooled OR 2.26, 95% CI 0.80–6.39). For the pH difference, meta-analysis supported generation of a pooled effect estimate (I2 57%, Cochrane’s Q p = 0.100). The effect estimate of the mean pH difference was not significantly different from null (p = 0.657), with the estimated pH slightly lower in hypocalcaemia (Glass D standardized mean difference -0.08, 95% CI -0.43 to 0.27). Conclusion Admission ionised hypocalcaemia was present in at least one in six paediatric major trauma patients. Ionised hypocalcaemia was not identified to have a statistically significant association with mortality or pH difference.