Defining "therapeutically inconsequential" head computed tomographic findings in patients with blunt head trauma

Many injuries detected by computed tomographic (CT) imaging of blunt head trauma patients are considered "therapeutically inconsequential." We estimate the prevalence of these findings and determine how frequently affected patients had "important neurosurgical outcomes," defined as either a directed intervention or a poor Glasgow Outcome Scale score.

We prospectively enrolled all blunt head trauma patients undergoing emergency head CT imaging at 18 centers participating in the National Emergency X-radiography Utilization Study II (NEXUS). From these cases, we identified all patients whose official CT reading met predefined criteria for "therapeutically inconsequential" injuries. We obtained detailed follow-up information on all such patients at 6 sites, including the need for neurosurgical intervention and Glasgow Outcome Scale scores. Among patients having "important neurosurgical outcomes," we assessed the frequency of 2 potential clinical identifiers: altered mental status and coagulopathy.

"Therapeutically inconsequential" head CT findings were present in 155 of 8,374 subjects (1.85%; 95% confidence interval 1.57% to 2.16%). Sites participating in the follow-up study enrolled 81 of these patients, of whom 10 (12%) had "important neurosurgical outcomes." Follow-up information was available for 9 patients, all of whom had abnormal mental status at CT scanning. Coagulopathy was also present in 5 of 7 patients for whom coagulation status was known.

"Therapeutically inconsequential" findings are identified in less than 2% of blunt head trauma patients who undergo CT scanning. A small proportion of these patients have an "important neurosurgical outcome," but it appears that such patients may be identified clinically by the presence of abnormal mental status or coagulopathy.