Central venous access.

Central venous catheterization is the placement of a catheter in such a manner that its tip is positioned within the proximal third of the superior vena cava, the right atrium or the inferior vena cava. It is indicated when access for administration of drugs or extracorporeal blood circuits and haemodynamic monitoring or interventions is needed. When inserting a central venous catheter, appropriate preparation and asepsis, positioning of the patient, and the use of ultrasound should be considered. Compared to the landmark method of localization, ultrasound can account for anatomical variations, facilitate visualization of venous puncture, and safeguard against inadvertent arterial puncture. In the Seldinger technique, which is the primary mode of central venous catheterization, a needle is passed towards the chosen vessel. Once the needle is in the vein, a guidewire is introduced through the needle into the vessel and the needle is removed. Following a small skin incision at the base of the guidewire, a dilator is advanced over the guidewire and then taken out. Subsequent to this, the central venous catheter is railroaded over the guidewire into the vein and the guidewire is withdrawn. Complications of central venous catheterization can be mechanical, infectious or thrombotic.