Chapter 21. Ultrasound Guidance of Central Vein Catheterization

The multiple indications for central venous catheters (CVCs) include parenteral nutrition, intravascular depletion, access for vasoactive medications, hemodynamic monitoring, cardiopulmonary arrest, difficult peripheral intravenous (IV) access and long-term IV access for medications, such as antibiotics. While these catheters can be life saving, they are also associated with significant risks. These risks increase in association with several characteristics, including patient anatomy (eg, morbid obesity, cachexia, or local scarring from surgery or radiation treatment), patient setting (eg, patients receiving mechanical ventilation or during emergencies such as cardiac arrest) and co-morbidities (eg, bullous emphysema or coagulopathy). CVCs are placed by clinicians whose training and experience may vary greatly. The procedure takes place in a variety of hospital settings including intensive care units, emergency departments, operating rooms, preand post-anesthesia care units, hemodialysis units, cardiac catheterization units and other inpatient settings. Outpatient placement of CVCs has also become commonplace, occurring in hemodialysis centers and oncology centers providing outpatient chemotherapy. Percutaneous insertions of CVCs are usually performed by “blind” techniques that rely on anatomic landmarks – ie, palpable or visible structures with known relationships to the desired vein. For example, the infraclavicular approach to the subclavian vein requires correct localization of the clavicle reference site, suprasternal notch and sternocleidomastoid-clavicular triangle landmarks, proper positioning of the patient and operator and correct venipuncture point depth, direction and insertion angle. Analogously, the various approaches to the internal jugular vein require thorough knowledge of this vein’s course in relation to the sternocleidomastoid muscle and carotid artery. Newer technologies, such as portable ultrasound (US) devices, provide bedside imaging of the central veins during catheter placement. The advantages associated with US guided CVC placement include detection of anatomic variations and exact vessel location, avoidance of central veins with pre-existing thrombosis that may prevent successful CVC placement, and guidance of both guidewire and catheter placement after initial needle insertion. This review assesses the impact of real-time ultrasound guidance on improving the safety of CVC insertions.