NICE guidelines for the investigation of head injuries--an anticoagulant loop hole?

NICE guidelines provide clear indications for the investigation of head injuries with CT. A patient on anticoagulation is required to have lost consciousness to warrant a CT scan unless obvious stronger indications exist. We recently observed three patients who had been assessed following head injuries that did not fulfil the NICE criteria for a CT scan, but who subsequently were found to have significant brain injury, all of whom were on warfarin. This experience prompted us to categorise whether the CT scans for head injuries performed were done so with indications consistent with the NICE guidelines, and then examine the outcomes to determine the effectiveness of the NICE guidelines for picking up positive pathology.

All patients presenting to the emergency department with isolated head injuries investigated with CT scan were included for the 3-month period April to June 2008. Notes were examined retrospectively to look at age, sex, mechanism of injury, coexisting coagulopathy, indication for CT scan and the corresponding CT scan result.

39 patients were included. 28/39 CT scans were unremarkable. 11 identified acute pathology. 23 scans were performed according to NICE guidelines, which revealed pathology in 10 patients. Ten scans were not performed according to NICE guidelines and none of these revealed pathology. Six scans were performed for unclear reasons and one revealed pathology. 6/39 patients were taking warfarin. Three of these six scans revealed intracranial pathology. The mean age of these six patients was 84 y.

While NICE guidelines provide a valuable tool for the investigation of head injuries, we feel that elderly patients on anticoagulation may be at risk of having significant head injuries missed and a lower threshold for scanning should be adopted.