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, including vascular access, vasopressor and caustic medication delivery, central venous pressure monitoring, volume resuscitation, total parental nutrition, hemodialysis, and frequent phlebotomy. There are three veins in the body that are accessed for central venous cannulation: the internal jugular, the subclavian, and the femoral. Each of these vessels has distinct advantages and disadvantages with unique anatomical considerations. Femoral vein cannulation can be easily performed both under ultrasound guidance and using the surface landmarks; therefore, femoral access is often used when emergent placement of a central venous catheter (CVC) is needed (such as in the case of medical codes and trauma resuscitations). In addition, cannulation of the femoral artery allows one to simultaneously perform other procedures needed for stabilization, such as cardiopulmonary resuscitation (CPR) and intubation. Successful placement of a femoral CVC requires working understanding of the target anatomy, access to with procedural ultrasound, and fluidity in the Seldinger technique. Seldinger technique is the introduction of a device into the body over a guide wire, which is placed through a thin-walled needle. In the case of CVC insertion, the device is an intravascular catheter and the target vessel is a central vein. First, the target vessel is cannulated with an 18-gauge thin-walled needle. A guide wire is then passed through the needle until it is appropriately positioned within the vessel. The needle is removed and a dilator is passed over the wire to dilate the skin and soft tissue to the level of the vessel. The dilator is then removed and the catheter is passed over the wire until it is appropriately positioned within the vessel. Lastly, the guide wire is removed. The main disadvantage of a femoral CVC is the high incidence of infection due to proximity to the groin (and often as a result of the quasi-sterile nature under which emergent CVCs are placed). Femoral lines should be replaced early on in the patient's hospital course if sustained central access is needed. A line placed with minimal sterility should be replaced as soon as the patient is stable.