Trauma Ultrasound

Focused Assessment with Sonography in Trauma (FAST)


Rapid evaluation of blunt or penetrating trauma to the torso to evaluate for:

  • Pericardial effusion with or without cardiac tamponade
  • Intra-peritoneal bleeding
  • Hemothorax (e-Fast)
  • Pneumothorax (e-Fast)

Key Ultrasound Anatomy


At least 5 views must be documented:

  1. RUQ - Morrison’s pouch and supra-diaphragmatic space
  2. LUQ - Splenorenal and supra-diaphragmatic spaces
  3. Subxyphoid or other cardiac view
  4. Pelvis longitudinal view
  5. Pelvis transverse view


4 standard views:

  • Right Upper Quadrant / Hepatorenal – evaluating Morrison’s Pouch & base of right hemithorax 
  • Left Upper Quadrant / Splenorenal – evaluating subdiaphragmatic space & base of left hemithorax 
  • Pelvic / Suprapubic
  • Subxyphoid Cardiac

PLUS lung exam for an e-FAST (extended-FAST)

Additional views:

  • Paracolic gutters
  • Apical or parasternal cardiac
  • Trendelenberg positioning with upper quadrant views

Probe & Positioning

  • 2-5 MHz curvilinear abdominal probe or smaller footprint curved array or phased array probe
  • Patient is supine or Trendelenburg positioning

Clinical Question & Exam Interpretation

  • Does this trauma patient have blood in the peritoneum, pleural spaces or pericardium?
    • Positive: Any anechoic collection of free fluid in the peritoneum, pericardial space, or pleural space
    • Negative: No quantity of fluid was seen and all 4 standard views were technically adequate
    • Equivocal/Inadequate:  Technical or artifact problems make the exam difficult to interpret
  • Does the patient have a pneumothorax?
    • Positive: Visualized lung point or absence of lung sliding with clinical signs of pneumothorax
    • Negative: Lung sliding bilaterally in multiple intercostal spaces
    • Equivocal/Inadequate: Technical or artifact problems make the exam difficult to interpret

Pearls and Pitfalls

  • May need multiple windows and probe positions to evaluate ALL perihepatic and perisplenic areas
  • May need to rotate the probe in between rib spaces to evaluate eliminate rib shadow artifact in the RUQ (counterclockwise rotation) and LUQ (clockwise rotation) views
  • Consider use of the anterior liver as a window to view Morrison's Pouch if the lateral window is technically difficult 
  • Free fluid can be missed superior to the spleen on the LUQ view so be sure to visualize the diaphragm
  • Consider reverse Trendelenburg to evaluate for hemothorax or pelvic free fluid
  • Perinephric fat may be misinterpreted as intraperitoneal free fluid.  Look at the other kidney for comparison
  • Consider obtaining your cardiac view with a parasternal long axis view in obese patient as the subxiphoid may be technically difficult
  • Consider a repeat FAST exam if the initial exam is negative and clinical suspicion remains high


FOAMed Curriculum