Ultrasound vs. blood test: which spots trauma bleeding faster?

This study looks at 126 adults with serious injuries from accidents or violence. Researchers want to see if a simple ultrasound of a large vein (the IVC) can detect low blood volume as reliably as a standard blood test (lactate). If the two measures match, doctors might use the ultrasound to make faster treatment decisions when lab results aren't available. The study does not test any new treatment—it only observes and compares these two methods.