Recent data has shown that ultrasound can accurately detect PTX in critically ill patients. Furthermore, bedside ultrasound is an easy technique to investigate the subclavian and internal jugular veins, and can improve the success rate of catheter insertion. Ultrasound also allows visualization of central venous catheters in vivo. Ultrasound has been reported as a tool to detect catheterization complications and misplacement when performed by ICU physicians, but has never been studied in the ED.