Moderate traumatic brain injury, acute phase course and deviations in physiological variables: an observational study

Background: Patients with moderate traumatic brain injury (TBI) are a heterogeneous group with great variability in clinical course. Guidelines for monitoring and level of care in the acute phase are lacking. The main aim of this observational study was to describe injury severity and the acute phase course during the first three days post-injury in a cohort of patients with moderate TBI. Deviations from defined parameters in selected physiological variables were also studied, based on guidelines for severe TBI during the same period.

Methods: During a 5-year period (2004-2009), 119 patients ≥16 years (median age 47 years, range 16-92) with moderate TBI according to the Head Injury Severity Scale were admitted to a Norwegian level 1 trauma centre. Injury-related and acute phase data were collected prospectively. Deviations in six physiological variables were collected retrospectively.

Results: Eighty-six percent of the patients had intracranial pathology on CT scan and 61 % had extracranial injuries. Eighty-four percent of all patients were admitted to intensive care units (ICUs) the first day, and 51 % stayed in ICUs ≥3 days. Patients staying in ICUs ≥3 days had lower median Glasgow Coma Scale score; 12 (range 9-15) versus 13 (range 9-15, P = 0.003) and more often extracranial injuries (77 % versus 42 %, P = 0.001) than patients staying in ICU 0-2 days. Most patients staying in ICUs ≥3 days had at least one episode of hypotension (53 %), hypoxia (57 %), hyperthermia (59 %), anaemia (56 %) and hyperglycaemia (65 %), and the proportion of anaemia related to number of measurements was high (33 %).

Conclusion: Most of the moderate TBI patients stayed in an ICU the first day, and half of them stayed in ICUs ≥3 days due to not only intracranial, but also extracranial injuries. Deviations in physiological variables were often seen in this latter group of patients. Lack of guidelines for patients with moderate TBI may leave these deviations uncorrected. We propose that in future research of moderate TBI, patients might be differentiated with regard to their need for monitoring and level of care the first few days post-injury. This could contribute to improvement of acute phase management.