Identifying traumatic brain injury in patients with isolated head trauma: are arterial lactate and base deficit as helpful as in polytrauma?

Background: Increase in lactate (LAC) within the central nervous system after head trauma is an established marker of traumatic brain injury (TBI). Objective: To investigate the utility of arterial base deficit (BD) and LAC in identifying TBI in patients with isolated head injury (IHI). Materials and methods: TBI was defined as Glasgow Coma Scale <= 8, head Abbreviated Injury Severity Score >2 or brain haematoma on CT scan. Patients were divided into two groups: IHI with and without TBI. Data were reported as means (SDs). 131 patients with IHI were studied (mean (SD) age 39 (19) years, 78% male). Results: 17% of the patients sustained TBI. The mean differences for arterial BD (0.65 mmol/l, 95% CI -0.8 to 2.1) and LAC (0.34 mmol/l, 95% CI -0.7 to 1.4) in patients with and without TBI were not significant. Analysis of receiver operating characteristic curves confirmed that arterial BD and LAC were unable to detect TBI in patients with IHI. Conclusion: Arterial BD and LAC are poor predictors of TBI in isolated head trauma.