Head injury on Warfarin: likelihood of delayed intracranial bleeding in patients with negative initial head CT

OBJECTIVE: To determine the likelihood that head injured patients on Warfarin with a negative initial head CT will have a positive repeat head CT. A retrospective chart review of our institution’s trauma registry was performed for all patients admitted for blunt head trauma and on Warfarin anti-coagulation from January 2009 to April 2014. Inclusion criteria included patients over 18 years of age with initial GCS ≥ 13, INR greater than 1.5 and negative initial head CT. Initial CT findings, repeat CT findings and INR were recorded. Interventions performed on patients with a delayed bleed were also investigated. RESULTS: 394 patients met the study inclusion criteria. 121 (31%) of these patients did not receive a second CT while 273 patients (69%) underwent a second CT. The mean INR was 2.74. Six patients developed a delayed bleed, of which two were clinically significant. No patients had any neurosurgical intervention. Our results demonstrate a low rate of delayed bleeding. The utility of repeat head CT in the neurologically stable patient is thus questioned. Patients who have an abnormal baseline neurological status and those with INR >3 may represent a subgroup of patients in whom repeat head CT should be performed.