Tunneled central venous catheter exchange: techniques to improve prevention of air embolism.

Malfunctioning tunneled hemodialysis central venous catheters (CVCs), because of thrombotic or infectious complications, are frequently exchanged. During the CVC exchanging procedure, there are several possible technical complications, as in first insertion, including air embolism. Prevention remains the key to the management of air embolism. Herein, we emphasize the technical tricks capable of reducing the risk of air embolism in long-term CVC exchange. In particular, adoption of a 5 to 10 degrees Trendelenburg position, direct puncture of the previous CVC venous lumen for guide-wire insertion, as opposed to guide-wire introduction after cutting the CVC, a light manual compression of the internal jugular vein venotomy site after catheter removal. The Valsalva maneuvre in collaborating patients, valved introducers, and correction of hypovolemia are also useful precautions. Principles of air embolism diagnosis and treatment are also outlined in the article.