Head CT after blunt head trauma is routine. And in many hospitalized patients, repeat head CT scan is also routine. Sometimes the routine includes many repeat CT scans. But when is the last time you’ve gotten that repeat scan on a neurologically normal patient and found “actionable” pathology? By that, I mean a finding that needs some type of intervention, not just “serial monitoring?”
An interesting paper published by neurosurgeons at McMaster University in Canada looked at the value of repeat head scans in patients with mild TBI, defined as a GCS of 13-15. I wrote about this one several months ago when it was just an abstract. Now, the full paper has been published so we can scrutinize it more closely.
The authors looked at their own experience, but also did a meta-analysis of 15 other studies in the literature. They grouped the patients into those who underwent intervention (hyperosmolar infusions, ICP monitor insertion, surgery) based on clinical findings vs findings on repeat head CT. Papers included in the meta-analysis were limited to larger studies (>30 subjects), and ones in which repeat head CT was performed and the reason for intervention was clear.
In their own series, they identified 445 patients who underwent repeat head CT. This generally occurred within 24 hours, but was done more urgently if neurologic changes occurred. Interesting findings included:
- Intracranial hemorrhage was unchanged in 80% of patients and increased in 20%
- 25 patients (6%) had a change in management after the repeat head CT
- Of these, 23 had the change based on deterioration of the neurologic exam, not the CT
- Only 2 had an intervention based on the repeat head CT ( mannitol administration due to increased edema, despite no change in exam)
- The meta-analysis showed similar findings
Bottom line: This is one of several recent studies questioning the usefulness of the “routine” repeat head CT. It’s time to work with our neurosurgeons and agree that a repeat CT is not needed in low-risk, hospitalized patients who can have regular neurologic exams. I would suggest that we limit this course of management to patients with a GCS of 15 only. Repeat head CT should still be used in patients who are on any type of medication that interferes with clotting, as these can lead to insidious bleeds. But to really make this work, we need to figure out how long the patient needs to be monitored, and the cost/benefit analysis of a longer hospital stay vs repeat scan and early discharge.
- The value of repeated head CT ( about the abstract of this paper)
- More on repeat head CT
- Portable head CT?
Reference: The Value of Scheduled Repeat Cranial Computed Tomography After Mild Head Injury: Single-Center Series and Meta-analysis. Neurosurgery 72(1):56-64, 2013.