Emerg Med J 30:28-31 doi:10.1136/emermed-2011-200176
  • Original articles

An analysis of predictive markers for intracranial haemorrhage in warfarinised head injury patients

  1. John S Batchelor
  1. Department of Emergency Medicine, Manchester Royal Infirmary, Manchester, UK
  1. Correspondence to John S Batchelor, Consultant In Emergency Medicine, Department of Emergency Medicine, Manchester Royal Infirmary, Oxford Road, Manchester M13 9WL, UK; johnbatchelor{at}
  1. Contributors SR collected the data, JB advised on the analysis. Both the authors contributed to the writing of the text.

  • Accepted 26 January 2012
  • Published Online First 22 February 2012


Introduction Minor head injury in older patients on warfarin may present in a variety of ways that often fall outside the remit of conventional guidelines. The aim of this study was to determine the relative risks for intracranial haemorrhage (ICH) in patients with subtherapeutic, therapeutic and supratherapeutic INR levels, in addition to the relative risks for the common symptoms at presentation.

Methods The notes were retrospectively reviewed of all patients who had a CT scan requested by the emergency department over a 2-year period (January 2008 to December 2009) and from these warfarinised head injuries were identified.

Results 82 warfarinised head injury patients were identified from 3338 requested CT scans. 12 of these patients (15%) had evidence of ICH on the CT. 72 patients had their INR checked (88%) and the RR of ICH for the INR subgroups were calculated: INR <2 (RR 1.89; 95% CI 0.65 to 5.55); INR 2–3 (RR 0.84; 95% CI 0.27 to 2.64); and INR >3 (RR 0.53; 95% CI 0.13 to 2.29). The greatest proportion of those with ICH (42%) had a subtherapeutic INR. 2 out of the 12 patients (17%) were found to have intracranial bleeding despite not meeting the criteria for a CT scan according to the NICE guidelines.

Conclusion The results of the INR subgroup analysis suggest that a subtherapeutic INR may not be protective against ICH in patients with minor head injury.


  • Competing interests None.

  • Ethics approval This study was given institutional approval.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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Among patients with minor TBI (GCS 13-15) getting CT scans ≥ 24 hours after injury, what proportion have a traumatic finding?


0.5% - 43% response rate
3% - 41% response rate
10% - 16% response rate

Related original article: PCT head imaging in patients with head injury who present after 24 h of injury: a retrospective cohort study

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