Ultrasound Guidance for Central Venous Catheterization

The central venous catheter (CVC) is a valuable tool in the care of patients in both inpatient and outpatient settings. It facilitates the administration of fluids or medications in patients with difficult peripheral access and provides timely therapies to critically ill patients. The classical method of CVC placement employs the landmark technique based on known anatomical relationship, which is between the vessel and surrounding tissue. Ultrasound (US) was introduced in 1978 as a guide for nonradiologists in the placement of CVC. Since then, numerous studies have been conducted addressing the merits and shortcomings of this US indication. Two-dimension US converts the sound waves reflected from tissue into a gray scale image, where vessels appear as tubular structures filled with hypoechoic “dark” blood. The advent of portable light-weight machines has made US a suitable modality for the guidance of CVC placement. The US probe is kept over the located vein and a local anesthetic is applied to the subcutaneous tissue.