Delayed intracranial hemorrhage after blunt trauma: are patients on preinjury anticoagulants and prescription antiplatelet agents at risk?

BACKGROUND: Trauma centers are more frequently evaluating patients who are receiving anticoagulant or prescription antiplatelet (ACAP) therapy at the time of injury. Because there are reports of delayed intracranial hemorrhage (ICH) after blunt trauma in this patient group, we evaluated patients receiving ACAP with a head computed tomography (CT) on admission (CT1) followed by a routine repeat head CT (CT2) in 6 hours. We hypothesized that among patients with no traumatic findings on CT1 and a normal or unchanged interval neurologic examination, the incidence of clinically significant delayed ICH would be zero.

METHODS: We retrospectively reviewed adult blunt trauma patients admitted to our Level I trauma center from January 2006 to August 2009 who were receiving preinjury ACAP therapy. We reviewed medications, mechanism of injury, head CT results, and outcomes. Demographic data, injury severity scores, international normalized ratio, and neurologic examinations were recorded. We determined the incidence of delayed ICH on CT2 for patients with a negative CT1.

RESULTS: Five hundred patients qualified for the protocol. Of these, 424 patients (85%) had a negative CT1. Among these patients, mean age was 75 years; 210 (50%) were male. Fall from standing was the most common mechanism of injury found in 357 patients (84%). Warfarin alone was taken in 68%, clopidogrel alone in 24%, and other agents in 2%. Six percent of patients were taking two agents. Mean international normalized ratio for patients on warfarin was 2.5. Among patients with a negative CT1, CT2 was obtained in 362 patients (85%) and was negative in 358 patients (99%). Four patients (1%) with a negative CT1 had a positive (n = 3) or equivocal (n = 1) CT2. All the changes on CT2 were minor and had either resolved or stabilized on third head CT. Of the four patients with positive or equivocal CT2, none had a change in neurologic examination; however, two had symptoms that could be attributed to head injury. Three were discharged home and one died of cardiac disease unrelated to head trauma.

CONCLUSIONS: The incidence of delayed ICH in our study was 1%. However, none of the delayed findings were clinically significant. Among patients on ACAP therapy with a negative CT1 and a normal or unchanged neurologic examination, a routine CT2 is unnecessary. We recommend a period of observation to recognize those patients with symptoms that could be due to delayed ICH.