Clinical predictors of abnormal head computed tomography scan in patients who are conscious after head injury

BACKGROUND: Indication of a head computed tomography (CT) scan in a patient who remains conscious after head injury is controversial. We aimed to determine the clinical features that are most likely to be associated with abnormal CT scan in patients with a history of head injury, and who are conscious at the time of presentation to casualty. MATERIALS AND METHODS: This is a prospective observation study of patients presented to casualty with history of head injury, and who were conscious, i.e., Glasgow Coma Scale (GCS) 15 at the time of evaluation. All patients underwent head CT scan. The CT scan was reported as abnormal if it showed any pathology ascribed to trauma. The following variables were used: age, gender, mode of injury (road traffic accident, fall, assault, and others), duration since injury, and history of transient loss of consciousness, headache, vomiting, ear/nose bleeding, and seizures. Logistic regression analysis was used to identify the clinical features that predicted an abnormal CT scan. RESULTS: During the observation period, a total of 1629 patients with head injury were evaluated, out of which 453 were in GCS 15. Abnormal CT scan was present in 195 (43%) patients. Among all the variables, the following were found significantly associated with abnormal CT scan: duration since injury (>12 h) P < 0.001; vomiting odds, ratio (OR) 1.89 (1.23, 2.80), P < 0.001; and presence of any symptom, OR 2.36 (1.52, 3.71), P < 0.001. CONCLUSION: A patient with GCS 15 presenting after 12 hours of injury with vomiting or combination of symptoms has a significant risk of abnormal head CT scan.