Life in the eFAST Lane: Sonography for Trauma (Part 3)

Everything in the you need to know about the eFAST in 2 minutes or less…

Who Needs an eFAST Ultrasound:
  • Blunt and penetrating abdominal trauma
  • Blunt and penetrating chest trauma
  • Ectopic pregnancies
  • Any patient you suspect has abdominal or thoracic free fluid/bleeding
The Technique: 5 Scans in 1 Exam 


  • Probe position: subxyphoid
  • Image: four chambers of the heart and pericardium
  • Evaluation for: pericardial effusion and cardiac tamponade

Right Upper Quadrant (Perihepatic)Right Upper Quadrant (Perihepatic)

  • Probe position: RUQ
  • Image: Morrison’s Pouch (liver and kidney), diaphragm, and costophrenic angle
  • Evaluation for: intra-abdominal bleeding or fluid and hemothorax

Left Upper Quadrant (Perisplenic)

  • Probe position: LUQ
  • Image: Spleen, kidney, diaphragm, and costophrenic angle
  • Evaluation for: intra-abdominal bleeding or fluid and hemothorax


  • Probe position: over the bladder
  • Image: in men- bladder and rectum, in women- bladder, uterus, and rectum
  • Evaluation for: intra-abdominal bleeding or fluid


  • Probe position: anterior chest at the 3rd and 4th intercostal space
  • Image: ribs, pleura, and lung
  • Evaluation for: pneumothorax, pulmonary contusions
eFAST 1 Minute Ultrasound

Facts, Pearls, and Pitfalls

Advantages of Ultrasound

  • Faster than CT or x-ray
  • Radiation-free!
  • Performed at the bedside simultaneously with other medical care
  • A superior test is many cases (hemothorax, pneumothorax, etc.)

Limitations of Ultrasound

  • It’s not as reliable for detecting solid organ lesions
    • But these probably aren’t as emergent as a raging hemorrhage into the abdomen and if the patient is stable that can go to CT.
  • Too much fat is bad. It’s bad for the patient and bad for ultrasound. Getting good images on an obese patient is hard! So practice on stable chunky patients
    • Personally, I troll the ER for obese trauma patients and re-eFAST them, so I’ll be better at obese patient ultrasound when there’s an emergency and it really counts.
  • Subcutaneous air can distort ultrasound images. If you feel subcutaneous rice krispies, ultrasound imaging might be difficult.


  • Repeat the eFAST if your clinical suspicion remains high. Repeat scanning increases the test’s sensitivity.
    • There may be a slow bleed and there wasn’t enough free fluid for a positive exam initially
    • Lower limit of fluid detection in the abdomen is 200 ml of fluid
  • Trendelenburg position can make the upper quadrant views more sensitive
  • Reverse Trendelenburg can make the pelvic view more sensitive
  • Don’t be afraid to get low on the pelvic view. If it feels awkward, you’re probably doing it right.
  • Get your pelvic view before they put in the Foley. A full bladder is a visible bladder.
  • If you can can’t get the LUQ view, move superior and posterior. The kidney is higher on the left side. Make sure you’re knuckles touch the bed. If they’re not, you’re not posterior enough.


  • Don’t get tricked by perirenal fat. Free fluid is darker than fat.
  • Don’t get tricked by epicardial fat pads. Same rule as above. Fluid is darker than fat.
  • Don’t delay care waiting for an eFAST on patients that obviously need surgical intervention (like an abdominal evisceration).
  • Don’t crank your probe to extreme angles to visualize the bladder. Keep your probe perpendicular to the patient to avoid false positives and negatives in the pelvis.
  • Don’t miss blood because it’s clotted. Clotted blood has varying echogenicity (shades).


The eFAST is a great ultrasound exam. It’s faster than other imaging and can be done in just a few minutes (a huge plus for the hemodynamically unstable patient). It can be performed at the bedside without interrupting ongoing medical care. There’s no radiation, unlike CT or x-ray. It’s sensitive, specific, and accurate. And it’s a superior diagnostic tool for a number of conditions, like pneumothorax and hemothorax. The scan consists of a RUQ, LUQ, pelvic, cardiac, and lung ultrasound. And to top it all off, it’s not that hard to learn… I promise. This is a foundational ultrasound exam in emergency medicine and should be a part of any physician’s exam skills. Now go practice some eFASTs! And be sure to check out the Part 1 and Part 2 SonoMojo posts if you haven’t read them already!

Other Resources

Here are some extra eFAST resources. I highly recommend the Ultrasound Podcast anytime you want to learn more about ultrasound!

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