Insertion
The skin is cleaned, and local anesthetic applied if required. The location of the vein is then identified by landmarks or with the use of a small ultrasound device. A hollow needle is advanced through the skin until blood is aspirated; the color of the blood and the rate of its flow help distinguish it from arterial blood (suggesting that an artery has been accidentally punctured), although this method is inaccurate. Ultrasound probably now represents the gold standard for central venous access and skills, within North American and Europe, with landmark techniques are diminishing.
The line is then inserted using the Seldinger technique: a blunt guidewire is passed through the needle, then the needle is removed. A dilating device may be passed over the guidewire to slightly enlarge the tract. Finally, the central line itself is then passed over the guidewire, which is then removed. All the lumens of the line are aspirated (to ensure that they are all positioned inside the vein) and flushed. A chest X-ray is typically performed afterwards to confirm that the line is positioned inside the superior vena cava and, in the case of insertion through the subclavian vein, that no pneumothorax was caused as a side effect. Vascular positioning systems can also be used to verify tip placement during insertion without the need to a chest X-ray, but this technique is not yet a standard of practice.
Videos are available demonstrating placement of a central venous catheter without and with ultrasound guidance.
Read more about this topic: Central Venous Catheter