High yield criteria for emergency cranial computed tomography in adult patients with no history of head injury.

OBJECTIVES A recent American study identified clinical factors which effectively predicted those patients who would have significant findings on cranial computed tomography. It was proposed to apply these criteria in a UK setting and to determine whether modifications could be made to improve their efficiency. METHODS A prospective observational study was conducted over a four month period including all non-trauma adult patients referred from the accident and emergency (A&E) department for urgent cranial computed tomography. Presenting symptoms and signs were analysed for ability to predict clinically significant computed tomography findings, namely: acute infarct, malignancy, acute hydrocephalus, intracranial haemorrhage, or intracranial infection. RESULTS Sixty two patients were included; 22 (35%) had significant findings on computed tomography. Applying the original criteria (any of: age 60 years or older, focal neurology, headache with nausea or vomiting, altered mental status) to the study population showed that no clinically significant tomograms would have been omitted but only 11% fewer performed. Modifying the criteria by removing "age 60 years or older" and replacing "altered mental status" with a Glasgow coma score <14, still ensured 100% sensitivity and would have resulted in 19% fewer scans being performed. CONCLUSION Simple clinical criteria can be usefully applied to patients presenting to an A&E department in this country to target patients most likely to have clinically significant findings on urgent cranial computed tomography.