Ultrasound for Pneumoperitoneum and C-Collar Clearance

First, pneumoperitoneum on ultrasound—look for the “enhanced peritoneal stripe” and those peritoneal A-lines in the least dependent area (epigastrium or over the liver). A linear probe can help spot the air. Second, C-spine clearance after a negative high-quality CT—Trauma EAST says yes, even in obtunded patients. CT alone has an almost 100% negative predictive value, and prolonged collars can do more harm than good.