Central venous catheterization is a commonly performed procedure and is an essential skill for critical care physicians. Common indications for placement of a central venous catheter (CVC) include hemodynamic monitoring, lack of peripheral venous access, administration of vasoactive agents, nutritional support, and long-term vascular access. Although traditionally performed by emergency and critical care physicians, anesthesiologists and surgeons, it has been shown that with proper training, this procedure can be safely performed by advanced practice practitioners such as nurse practitioners and physician assistants.1
Central venous catheter placement can be attempted via two methods: surface landmark approach or using real-time ultrasound guidance. While the landmark method is the traditional approach taught, real-time ultrasound guided CVC placement has emerged as the preferred and recommended practice, and is endorsed by majority of quality assurance agencies and professional societies. Knowledge of surface and deep anatomy is crucial in minimizing complications related to placement of internal jugular, subclavian, and femoral venous catheters.
The internal jugular (IJ) vein is formed by the inferior petrosal sinus and sigmoid sinus. It forms the brachiocephalic vein after it runs under the clavicle at the level of the sternum. The IJ vein, internal carotid artery and vagus nerve form the carotid sheath which runs under the sternocleidomastoid muscle. The IJ vein runs anterolateral to the common carotid artery, however it may be directly anterior to the common carotid artery on the right side in 26% and in 20% on the left side.2 The right IJ vein follows a direct course to the superior vena cava (SVC) joining the right subclavian vein and forming a short and steeply angled right brachiocephalic vein. The left IJ vein forms a longer and shallow angled left brachiocephalic vein as it joins the left subclavian vein. The right IJ vein is larger than the left IJ vein given its direct relationship with the right ventricle.
The subclavian vessels are a valveless continuation of the axillary veins. Similar to the IJ veins, the path of the right and left subclavian veins is not symmetrical. The right subclavian vein forms an angled arc as it merges with the right IJ vein forming the right brachiocephalic vein which enters the SVC, whereas the left subclavian vein merges into the left brachiocephalic vein along a shallow trajectory. The subclavian vein lies posterior to the clavicle after crossing the first rib. This isolated region is the only area where the subclavian vein directly communicates with the clavicle. The subclavian artery runs superior and posterior to the subclavian vein. The subclavian artery and vein are separated by the anterior scalene muscle. The phrenic nerve also runs over the lateral aspect of the anterior scalene muscle. The apices of the lungs may reach as far as the first rib.