eFAST: look at the liver tip first

Answer b. In the supine patient, fluid in the right upper quadrant tracks down to the caudal edge of the liver, so small volumes often show first at the liver tip. The space above the diaphragm holds haemothorax, not intraperitoneal fluid. The gallbladder fossa and the upper pole of the kidney sit higher and fill later.

Answer b. The right upper quadrant window lies on the flank, between the mid and posterior axillary lines, low on the ribs. It shows the liver, the right kidney and the space between them. The mid-clavicular line high on the chest is the pneumothorax window. The subxiphoid window shows the heart.

Answer c. Free fluid fills the space it lies in, so it takes on angled corners and a stripe shape. A round outline with a smooth wall suggests a structure such as the gallbladder, a cyst or bowel. Colour flow means a vessel. A bright wall with shadowing describes bowel gas or a stone, not fluid.

Answer d. A negative FAST does not exclude injury, especially to hollow viscus, diaphragm and retroperitoneum. In a stable patient, CT gives the definitive assessment. Repeat the FAST if the condition changes. Discharge on a negative FAST misses injuries. Laparotomy is not indicated in a stable patient without other findings.

Answer c. Bowel perforation releases little free fluid in the early hours, so the scan often looks normal. A large splenic bleed produces free fluid, which FAST detects well. A large haemothorax shows above the diaphragm, and a pericardial effusion shows in the cardiac view.