title: Routine repeat head CT may not be indicated in patients on anticoagulant/antiplatelet therapy following mild traumatic brain injury.
abstract: BACKGROUND
  Evaluation recommendations for patients on anticoagulant and antiplatelet (ACAP) therapy that present after mild traumatic brain injury (TBI) are controversial. At our institution, an initial noncontrast head computed tomography (HCT) is performed, with a subsequent HCT performed six hours later to exclude delayed intracranial hemorrhage (ICH). This study was performed to evaluate the yield and advisability of this approach.
  
  
  METHODS
  We performed a retrospective review of subjects undergoing evaluation for ICH after mild TBI in patients on ACAP therapy between January of 2012 and April of 2013. We assessed for the frequency of ICH on both the initial noncontrast HCT and on the routine six-hour follow-up HCT. Additionally, chart review was performed to evaluate the clinical implications of ICH, when present, and to interrogate whether pertinent clinical and laboratory data may predict the presence of ICH prior to imaging. We used multivariate generalized linear models to assess whether presenting Glasgow Coma Score (GCS), loss of consciousness (LOC), neurological or physical examination findings, international normalized ratio, prothrombin time, partial thromboplastin time, platelet count, or specific ACAP regimen predicted ICH.
  
  
  RESULTS
  144 patients satisfied inclusion criteria. Ten patients demonstrated initial HCT positive for ICH, with only one demonstrating delayed ICH on the six-hour follow-up HCT. This patient was discharged without any intervention required or functional impairment. Presenting GCS deviation (p<0.001), LOC (p=0.04), neurological examination findings (p<0.001), clopidogrel (p=0.003), aspirin (p=0.03) or combination regimen (p=0.004) use were more commonly seen in patients with ICH.
  
  
  CONCLUSIONS
  Routine six-hour follow-up HCT is likely not indicated in patients on ACAP therapy, as our study suggests clinically significant delayed ICH does not occur. Additionally, presenting GCS deviation, LOC, neurological examination findings, clopidogrel, aspirin or combination regimen use may predict ICH, and, in the absence of these findings, HCT may potentially be forgone altogether.
authors: University of California, San Diego, Department of Radiology, San Diego, California.
authors: Kevin C
authors: KC
authors: McCammack
authors: University of California, San Diego, Department of Emergency Medicine, San Diego, California.
authors: Charlotte
authors: C
authors: Sadler
authors: University of California, San Diego, Department of Radiology, San Diego, California ; University of California, San Diego, School of Medicine, San Diego, California.
authors: Yueyang
authors: Y
authors: Guo
authors: University of California, San Diego, Department of Radiology, San Diego, California.
authors: Raja S
authors: RS
authors: Ramaswamy
authors: University of California, San Diego, Department of Radiology, San Diego, California.
authors: Nikdokht
authors: N
authors: Farid
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000009:adverse effects*; D001930:Brain Injuries / Q000150:complications / Q000000981:diagnostic imaging*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020300:Intracranial Hemorrhages / Q000139:chemically induced* / Q000000981:diagnostic imaging / Q000209:etiology; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D000925:Anticoagulants; D010975:Platelet Aggregation Inhibitors