CT detect injuries missed on CXR

A recently published study evaluated the ability of CT to detect clinically significant injuries missed on chest X-Rays in blunt trauma patients1. In this study they found chest CT detected significant intra-thoracic injury in 13.6% of cases not seen on plain CXR. Forty percent of these injuries required chest injury management changes! After crunching the numbers they found that 5.5% of all cases where chest CT was performed led to chest injury management changes not seen on CXR.

They concluded that “although chest CT frequently detects injuries missed on CXR in blunt trauma patients, it rarely changes patient management. Given this low yield and the concerns for radiation cost and ED crowding they are developing a clinical decision instrument for selective chest CT in blunt trauma.” We all acknowledge that trauma medicine is inherently high-risk (especially for the patient). Furthermore, none of us want to hear THAT QUESTION: “Remember that patient you saw the other night?” Let’s consider the potential consequences if one was to take away from this study that since the CT findings rarely lead to management we should consider not performing that CT. Which one of us would like to be a member of the 40% patient group which would not receive management changes to a significant intra-thoracic chest injury if our doctor decided to take the conclusion prematurely to heart?

The take home message: Within all of the fine emergency medicine peer reviewed literature, one must still beware of new trends and old traditions. We have to place studies like these into perspective. It is our responsibility to practice in a method which has been shown to be best for the patient until a new clinical decision instrument becomes the standard of care. Otherwise we could find ourselves in a TICU from a car accident, wondering if we were unfortunate enough to be one of those 5.5% of all cases that the trauma service was no longer looking for due to a new protocol that hasn’t met the test of time.

Reference: Does Chest CT Detect Clinically Significant Injuries Missed on Chest X-Rays in Blunt Trauma Patients? — B. Kea, San Francisco General Hospital; University of California, San Francisco, School of Medicine. Scientific Assembly 2011 Conference, 10/15-10/18. ACEP