Twice not as nice: Repeat CT for mild head trauma often unwarranted

Routine repeated CT scans are largely unnecessary for stable patients after mild head trauma as an additional scan is unlikely to affect treatment, according to a study published in the January issue of Neurosurgery.

When an initial CT shows bleeding within the brain, a decision about repeated scans should be based on the patient’s neurological condition, according to Saleh Almenawer, MD, and colleagues from McMaster University, Hamilton, Ontario, Canada.

The standard of care in many trauma centers after a mild head injury patient with a positive initial CT is admitted is to obtain a repeat scan within 24 hours to rule out the need for intervention, according to the authors. “However, a common observation among the authors of the present study is that this practice does not yield a change in the management except when neurological examination changes have occurred, warranting a more urgent CT that accordingly would help with the management,” they wrote. “The rules for obtaining an initial CT for patients with mild head injury are well defined, although the same cannot be said for routine follow-up imaging.”

Results were based on a review of the authors’ hospital trauma database. A total of 445 patients were included in the review, all of whom had experienced a mild head injury and had evidence of intracranial hemorrhage on an initial CT. Almenawer and colleagues then assessed how many patients needed additional treatments and whether these treatments were triggered by changes in patient neurological condition, which automatically initiated a second CT, or on the basis of routine follow-up CT alone.

Results showed that 25 patients, 5.6 percent, required a change in treatment after the second CT scan, and most underwent craniectomy to relieve pressure on the brain. For 23 of these patients, neurological deterioration was the predictive factor and in only two patients were treatment changes based on a routine follow-up CT scan. These two patients received a drug to reduce intracranial pressure.

Almenawer and colleagues used the same methodology to extend the analysis to outcomes in 15 previous studies of CT scanning after mild head injury that included a total of 2,693 patients. This wider analysis showed 2.7 percent of patients had a change in management based on neurological changes and 0.6 percent had treatment changes based solely on routine CT scans.

The authors wrote that an analysis of the benefits of follow-up CT is important because of the resources they require and the additional radiation exposure administered to patients by multiple scans. “The meta-analysis did not show statistical evidence supporting the utility of routine follow-up imaging for unchanged or improving patients after mild traumatic brain injury,” they wrote. “Considering that this practice is neither risk nor cost free, evidence-based rules should be implemented.”