Ultrasound guided vessel cannulation in critical care patients

Obtaining vascular access is currently the most common invasive procedure performed in critical care patients. Venous and arterial catheters are the mainstay of measuring hemodynamic variables and allow delivery of medications, catecholamine administration, hemodialysis and parenteral nutritional support. Such use of catheters, however, is potentially associated with severe complications that can be injurious to patients and expensive to treat. Critical care patients are oftentimes cannulated in suboptimal conditions, while many factors, such as prior surgical procedures, trauma, edema, volume depletion, obesity, abnormal anatomy, thromboses, prior catheterization attempts, cardiac arrest or mechanical ventilation per se could render technical difficulties. Traditionally, performing blind puncture procedures using the landmark technique depended greatly on a precise knowledge of the surface and vascular anatomy and on clinical experience. Currently, there is an increasing literature support for the use of ultrasound guidance in placement of central venous catheters in the internal jugular, the femoral and the subclavian vein. Moreover, multiple studies have proven that ultrasound guidance facilitates peripheral vein cannulation as well as arterial line placement in critically ill patients. Ultrasound guided vessel cannulation has undoubtedly become a welcome addition to the arsenal of all critical care physicians, as it allows for more precise assessment of the vessel location and its adjacent structures, evaluation of the vessel patency and direct visualization of needle placement. Furthermore the use of real-time ultrasound imaging may identify patients in whom vascular access may be more difficult or hazardous, thus improve the success rate, reduce the number of needle passes, minimize complication rates and enhance patient’s safety.