Surgical resident X: “We have to get the chest X-ray before we go to CT.”

EM resident Y: “Honestly, [surgical colleague X], I don’t think we do. The FAST didn’t have any evidence of pneumothorax, so I think we’re safe to proceed to the CT scanner rather than wait for X-ray right now.”

Surgical resident X: “We always get the chest X-ray before we leave the trauma room.”

EM resident Y (not interested in a fight): “Ok.”


Not time to buck hundreds of years of tradition unimpeded by progress (and there are some other, less important, reasons for a chest X-ray on trauma patients), but it begs the question, which is better for detecting the pneumothorax in a trauma patient? We know it’s not our own ears (though you should listen, and will likely detect a larger collapsed lung this way), but is CXR or EFAST more sensitive for pneumothorax?

The way I asked the question, you may already know it’s the EFAST Exam. Several studies have looked at this concept, but one of the more cited ones shows the following relative sensitivities and specificities. Do a good job of doing the EFAST, and you’ll be doing a good job to identify this immediately relevant pathology in your trauma patients. Don’t skip the chest X-ray (not just yet), but be knowledgeable about just how much it’s helping (probably not much) and how much false reassurance it may be adding (could be substantial). 

Sensitivity Specificity
EFAST Ultrasound 86-98% 97-100%
Supine AP Chest X-ray 28-75% 100%


Need a review on ultrasound detection of pneumothorax? Check this REBEL EM article, this emDOCs article, these 5-minute sono videos, or this Ultrasound Podcast video.

June 2024