Ultrasound first, second, and last for vascular access.

Vascular access is the most commonly performed invasive procedure in medicine. For more than 20 years, ultrasound has been shown to improve the success and decrease complications of central venous access; however, it is still not universally used for this procedure. Ultrasound may also be used to facilitate difficult peripheral vascular access, potentially avoiding other more invasive procedures such as central or intraosseus vascular access. This article reviews some of the indications and evidence for ultrasound-guided vascular access, provides tips for successful ultrasound guidance, and discusses barriers to adoption.