A young adult M was BIBEMS with a penetrating stab wound to the R mid abdomen/flank. EMS had placed combat gauze into the wound. He's pale, groggy, hypotensive, and tachycardic.
Big lines are placed, blood is transfused, POCUS RUQ (Hepatorenal space) of the E-FAST shows the caudal tip of the liver surrounded by hypoechoic (black) free fluid. The combat gauze is causing the black shadowing that you see to the left of the screen obscuring the cranial tip of the liver and kidney. He has no pericardial effusion, good lung sliding bilaterally without pleural effusions. The problem, not surprisingly, is in the abdomen.
Sono pearls: You need to evaluate the caudal tip of the liver to call the RUQ portion of the E-FAST negative.