Point-of-care ultrasound is one of the most rapidly evolving areas of medicine. In addition to becoming the “stethoscope of the future” for bedside diagnostic evaluations, ultrasound has improved the safety and efficiency of a wide range of procedures. The use of ultrasound to assist in central venous cannulation was first studied in 1993 by Uretsky et al. In this prospective evaluation, 302 patients underwent ultrasound-guided internal jugular cannulation and were compared to 302 patients undergoing landmark based internal jugular cannulation. The authors showed a significantly increased success rate using the ultrasound. Further, access times and complication rates were decreased by the ultrasound-guided approach.1 Since 1993, multiple randomized investigations have confirmed higher success rates using ultrasound guidance for internal jugular vein cannulation and lower incidences of carotid puncture, carotid hematoma, hemothorax and pneumothorax.2,3,4,5 In 2001, in its Quality Evidence Report, the Agency for Healthcare Research and Quality (AHRQ) strongly recommended real-time, dynamic guidance for all central venous catheter insertions to prevent complications.6
Despite the AHRQ recommedation, ultrasound-guided central line placement has not been universally adopted for a number of reasons. Access to affordable point-of-care ultrasound machines, has been limited, especially in smaller hospitals. Training of novice ultrasonographers, while shown to be cost effective, is not widely available. Also, despite evidence to the contrary, many providers still hold the belief that ultrasound-guided access requires more time and resources. Novice users, may indeed require more time to prepare the ultrasound machine and probe, and are more likely to require a second proceduralist to hold the ultrasound probe during the cannulation; however, proficiency with the ultrasound-guided technique has been demonstrated after a single one hour training session.7 Furthermore, despite improved clinical outcomes, ultrasound guidance has not yet been shown to save money. The only cost analysis to date, has shown increased cost using ultrasound guidance ($494,820,000 vs $390,780,000). This cost difference was not mitigated by its reduction in the cost of managing pneumothoraces and hematomas, but still needs to be considered in the context of safety and patient satisfaction.
Evidence supporting ultrasound-guided internal jugular venous catheter insertion continues to grow. But what about venous cannulation in the femoral and subclavian veins? Similar to internal jugular lines, femoral venous catheters placed under ultrasound guidance have been placed with higher success rates and with fewer complications.8 Some early studies have also demonstrated successful placement of subclavian venous catheters under ultrasound guidance.9 Currently, few clinicians perform ultrasound-guided subclavian venous catheters because it is technically challenging. The subclavian vein, for most of its course, runs beneath the clavicle. This creates a sonographic shadow, preventing direct visualization of the needle entering the vein. In the July issue of Critical Care Medicine, Fragou et al present a study of 463 patients randomized to ultrasound-guided or landmark based subclavian venous cannulation. Not only did the authors show a decreased time to cannulation and decreased rate of complications, they also achieved a 100% success rate in the ultrasound-guided group.10 The authors describe the technique used for ultrasound guidance: If a portion of the subclavian vein was not directly visible, the operator would slide the ultrasound probe laterally until able to visualize the compressible axillary vein. The axillary vein was then cannulated under direct visualization. Next the ultrasound probe was moved medially and tilted in such a way that the subclavian vein could be visualized under the clavicle, and passage of the guidewire into the subclavian vein was verified by ultrasound.
So do you have to use the ultrasound? In my practice, I try to perform ultrasound-guided cannulation when possible. I don’t routinely use the ultrasound for femoral venous lines, but because of increased rates of catheter related blood stream infections and venous thrombosis, I try to only place femoral lines in emergent circumstances, such as codes and severe hemorrhagic shock. In accordance with AHRQ and IHI guidelines, I do place all internal jugular venous catheters under ultrasound guidance. For subclavian lines, there is a growing body of evidence, including last month’s CCM article, that ultrasound guidance is achievable, efficient and improves safety. So don’t forget your anatomy, but consider ultrasound-guided simulation training if you are not currently proficient in this technique.
1. Denys BG, et al. Ultrasound-assisted cannulation of the internal jugular vein. A prospective comparison to the external landmark-guided technique. Circulation. 1993 May;87(5):1557-62. Link.
2. Keenan SP, et al Use of ultrasound to place central lines. J Crit Care. 2002 Jun;17(2):126-37. Link.
3. Slama M et al. Improvement of internal jugular vein cannulation using an ultrasound-guided technique. Intensive Care Medicine, 1997;23:916-919. Link.
4. Randolph AF, et at. Ultrasound guidance for placement of central venous catheters: a meta-analysis of the literature. Critical Care Med. 1996; 24:2053-2058. Link.
5. Miller AH et al. Ultrasound guidance vs landmark technique for central venous catheter placement in the emergency department. Acad Emerg Med. 2002. Aug 9(8):800-5. Link.
6. Agency for Healthcare Research and Quality. Making health care safer: a critical analysis of patient safety practices. Evid Rep Technol Assess 2001;(43);i-x; 1-668. Link.
7. Evans LV, et al. Simulation training in central venous catheter insertion: Improved performance in clinical practice. Acad Med. 2010. Sep;85(9):1462-9. Link.
8. Prabhu MV, et al. Ultrasound-guided femoral dialysis access placement: a single center randomized trial. Clin J Am Soc Nephrol. 2010 Feb;5(2):235-9. Link.
9. Gualtieri E, et al. Subclavian venous catheterization: greater success rate for less experienced operators using ultrasound guidance. Crit Care Med. 1995; 23:692–697. Link.
10. Fragou M et al. Real time ultrasound-guided subclavian vein cannulation vs the landmark method in critical care patients. A prospective randomized study. Crit Care Med. 2011 Jul;39(7):1607-1612. Link.