Reappraising the need for a control CT in mild head injury patients on anticoagulation Abstract Background Head injury is a frequent reason for admission to the emergency department. In parallel, there is a growing use of anticoagulants in an increasingly aging population, which renders this particular group of trauma patients more frequent. In several countries, including Portugal, a 24-h surveillance period followed by repetition of head computed tomography (CT) is the standard procedure for these patients. However, these recommendations have not been based on studies of prevalence of intracranial hemorrhages in control head CTs, namely in this group of anticoagulated patients. This study intends to evaluate the prevalence of de novo intracranial hemorrhages in control head CTs in anticoagulated patients. Method An observational study was carried out, which included patients admitted to Hospital de Braga between June 2017 and January 2018, victims of head injury and on anticoagulation therapy, whose admission head CT excluded intracranial hemorrhage. Results We collected a total of 201 patients, with a mean age of 81.6 years, and 57.5% of them were prescribed warfarin; 181 of these patients repeated the head CT 24 h later. Of these 181 patients, 3 (1.66%) exhibited intracranial hemorrhage in control CT, without surgical indication. All patients were followed up 1 month after the trauma, and there was no readmission requiring hospitalization, surgery or death. Conclusions In conclusion, de novo intracranial hemorrhage in control head CT of anticoagulated patients is rare. We propose that these patients may be discharged if the admission CT does not reveal intracranial hemorrhage, providing that they are accompanied by a caregiver and informed about red flags.