eFAST has been introduced to the management protocol for patients after trauma, in particular those with cardiovascular instability. With over 90% sensitivity and specificity, it can detect air in the pleural cavity and free fluid in the abdominal, pelvic, and pleural cavities, as well as the pericardial sac.
eFAST involves placing the ultrasound probe in five places:
1. In the right upper quadrant – the right diaphragmatic angle is visible here, where it is possible to visualise any free fluid present in the right pleural cavity and/or the hepatorenal interface (Morrison’s pouch).
2. At the highest point of the chest – in patients lying prone, this is specifically the anterior surface of the chest in the mid-clavicular line, between IV to VI intercostal spaces. In this projection, check for the presence of a sliding lung, i.e. movement of the pleural line on the screen during breathing. Its absence indicates the presence of pneumothorax.
3. Under the xiphoid process – to detect fluid in the pericardial sac and cardiac tamponade.
4. In the left upper quadrant – by applying the probe transverse and longitudinally along the posterior axillary line, the spleen, left kidney and left diaphragmatic rib angle may be visualised.
5. In the suprapubic area – the ultrasound transducer should be positioned horizontally to detect fluid in the vesicorectal pouch in men, and rectouterine pouch (Douglas pouch) in women.
Limitations: False negatives may occur when the amount of fluid is less than what is detectable during the examination, in obese patients, and in patients with subcutaneous edema.False positive results are rare, but they can occur if free fluid was present before the injury, for example in patients with ascites or peritoneal dialysis.The biggest limitation, however, is the operator’s skill. Well-trained medical personnel and a a large number of tests performed significantly increases the diagnostic value of the eFAST protocol and insures accurate assessment of anomalies.
Fast Exam Normal Ultrasonography