Hypocalcemia as a prognostic factor in mortality and morbidity in moderate and severe traumatic brain injury

Objectives: Our main objective was to evaluate whether serum hypocalcaemia (defined as <2.1 mmol/L [8.5 mg/dL]) and ionized serum calcium (defined as <1.10 mmol/L [4.5 mg/dL]) is a prognostic factor for mortality and morbidity (defined as Glasgow outcome score [GOS] ≤3) in early moderate and severe traumatic brain injury (TBI).

Materials and methods: We developed a retrospective study and evaluated clinical profiles from included patients from January 2004 to December 2012. Patients were between 16 and 87 years old and had a Glasgow coma scale of 3-13 points following TBI, with demonstrable intracranial lesions in cranial computed tomography.

Results: We found a significant statistical difference (P < 0.008) in the ionized serum calcium levels on the 3(rd) day of admission between the groups: GOS ≤3 and >3 (disability/death). According with the receiving operative curves analysis, we found that the best level of higher sensitivity (83.76%) and specificity (66.66%) of hypocalcaemia of serum ionized calcium on 3(rd) day was the value of 1.11 mmol/L, with an odds ratio value of 6.45 (confidence intervals 95%: 2.02-20.55).

Conclusions: The serum levels of ionized calcium on day 3 could be useful for the prediction of mortality and disability in patients with moderate and severe TBI.