Source: James W Bonz, MD, Emergency Medicine, Yale School of Medicine, New Haven, Connecticut, USA Central venous access is necessary in a multitude of clinical situations for hemodynamic monitoring, medication delivery, and blood sampling. There are three veins in the body that are accessed for central venous cannulation: the internal jugular, the subclavian, and the femoral vein. Central venous access via the subclavian vein has several advantages over other possible locations. The subclavian central venous catheter (CVC) placement is associated with lower infection and thrombosis rate than internal jugular and femoral CVC. Subclavian line can be placed quickly using anatomic landmarks and are often performed in trauma settings when cervical collars obliterate the access to the internal jugular (IJ) vein. The most significant disadvantage of the subclavian access is the risk of pneumothorax due to the anatomic proximity to the dome of the lung, which lies just superficial to the subclavian vein. In addition, in the event of an inadvertent arterial puncture, the access to the subclavian artery is impeded by the clavicle, which makes it difficult to effectively compress the vessel. Successful placement of the subclavian CVC requires good working understanding of the target vessel anatomy as well as fluidity in performing the Seldinger procedure (an introduction of the catheter into a vessel over the guide wire, which is inserted through a thin-walled needle). First, the subclavian vein is cannulated with an 18-gauge thin-walled needle. A guide wire is then passed thought the needle until it is appropriately positioned within the vessel. Next, the needle is removed, a dilator is passed over the wire to dilate the skin and soft tissue, and the catheter is passed over the wire until it is appropriately positioned within the vessel. Lastly, the guide wire is removed, and the catheter is sutured in place. There are several types of CVC kits commonly available marketed by different manufacturers. CVCs may have a single lumen, a double lumen, or a triple lumen. For purposes of this discussion, we will place a triple-lumen CVC, as this is commonly needed when multiple different medications need to be delivered simultaneously. The procedure for placing any type of CVC is the same.