Low risk of late intracranial complications in mild traumatic brain injury patients using oral anticoagulation after an initial normal brain computed tomography scan: education instead of hospitalization

Background and purpose Mild traumatic brain injury (mTBI) is a common neurological disorder. Whether oral anticoagulation (OAC) use is a risk factor for secondary deterioration in mTBI patients after a normal computed tomography (CT) scan is unclear. Therefore data were retrospectively collected on patients with mTBI who used OAC to determine the incidence of secondary clinical deterioration after an initial normal head CT scan. Methods This was a retrospective single-centre patient record study. All patients with an mTBI who presented at the emergency department between January 2007 and October 2011 were selected. Inclusion criteria were mTBI and at least 1week of OAC use resulting in an international normalized radio >1.1. CT scans were re-evaluated for this study. Results A total of 211 mTBI patients using OAC and with an initial CT scan without abnormalities were included in the analysis. In five patients a secondary deterioration was found. One patient developed a subdural hematoma after 15h of clinical observation. The other four patients became symptomatic between 2 and 28days after trauma. Conclusions A low risk of secondary deterioration within 24h in mTBI patients taking OAC with a normal first head CT scan was found. Our study does not support the recommendation of the current guidelines that these patients should be clinically observed for at least 24h. The fact that in our series the majority of secondary deteriorations occurred between 2 and 28days after trauma underscores the importance of patient instructions upon discharge from the hospital.