Recent studies have raised concerns about whether CT is overused in the emergency setting for patients with symptoms like headache, but a new study in JAMA Network Open suggests that higher CT utilization could be contributing to a decline in more invasive procedures like lumbar puncture.
Earlier this month, we covered a study documenting the rapid rise of emergency head CT for patients presenting with acute-onset headache – which could be an indication of subarachnoid hemorrhage or other serious issues.
- Researchers theorized that higher CTA utilization could be a sign of overuse because the rate of positive findings over time fell 38%.
But the new study suggests that the growth in cerebral CTA use could have beneficial effects, by reducing the use of more invasive procedures and by detecting unruptured intracranial aneurysm.
- Some 5% of acute-onset headaches in emergency patients are caused by subarachnoid hemorrhage; these cases have a 50% risk of death or serious disability at one year, making accurate detection and workup a serious issue.
Researchers from Kaiser Permanente in Northern California analyzed 198k encounters for patients with headache at 21 community EDs from 2015 to 2021.
- They compared multiple workup protocols, ranging from CT only to others in which CT was used first, with nondiagnostic cases sent to either lumbar puncture or cerebral CTA.
Dramatic changes occurred in headache workup over the study period, including …
- Overall use of CT grew at an average annual percent change of 5.4%
- Cerebral CTA use grew 19% annually
- Lumbar puncture use fell 11% annually
- Detection of unruptured intracranial aneurysms grew 33%
- The ratio of unruptured aneurysms to subarachnoid hemorrhage grew
The authors noted that the findings show clinicians are shifting away from a headache workup protocol that includes lumbar puncture to one that relies more on cerebral CTA.
- The researchers were equivocal on the increase in detection of unruptured aneurysms; on the one hand, the absolute risk of rupture is low, but on the other, the consequences of rupture are severe.
The Takeaway
The new study offers a more nuanced – and perhaps more positive – view of growing cerebral CTA use in the ED. In the end, it’s possible that two conflicting statements can be true: CT indeed may be overused in the emergency department, but its growing use is also having a beneficial impact on patient care.
