Prognostic value of arterial blood gas disturbances for in-hospital mortality in pediatric patients with severe traumatic brain injury

The aim of this study was to evaluate the changes of arterial blood gas as a secondary insult in children and young adults suffering from severe traumatic brain injury, and to assess the correlation, if any, with their in-hospital mortality. In this cross-sectional study, the medical data of all children and adolescents with severe head trauma admitted to the Rasht Poursina Hospital were reviewed between April 2006 and September 2011. Data including age, gender, GCS upon admission, arrival and daily ABG values for the first 3 days, results of brain CT scan, as well as in-hospital mortality rate were collected. A logistic regression model was used to determine the association between acid-base disturbance and in-hospital mortality after adjustment for potential confounding factors. Of the 108 patients, 75 % were male and 25 % were female; and 31.5 % of them died in the hospital. Univariate analysis showed a significantly higher risk of mortality in patients who developed mixed metabolic acidosis plus respiratory acidosis on their admission day (OR = 3.94, p = 0.012). Multiple logistic regression analysis demonstrated that mixed metabolic acidosis plus respiratory acidosis (OR = 3.81, 95 % CI = 1.18-12.27, p-value = 0.025) and GCS (OR = 0.457, 95 % CI = 0.31-0.65, p-value < 0.001) were two significant predictors of mortality, regardless of other confounding variables. The results of present study show that, in pediatric patients with severe head injuries, initial mixed metabolic acidosis plus respiratory acidosis and GCS are significant predictors of mortality, but other factors after adjustment for potential confounding factors had no prognostic effect.