Ultrasound-Guided Venous Catheter Placement in Prone Position.

The prone position is often used for patients with adult respiratory distress syndrome and specific surgical postures. When performing venous cannulation in this position, it is important to have a structured review to introduce the available major veins and ultrasound-guided procedure. In this review, we discuss the techniques of ultrasound-guided cannulation and provide insights into various aspects, including the anatomical locations of veins, vein sizes, placement techniques, surrounding structures at risk, and reported experiences with catheter placements. Eight major veins can be accessed in the prone position: the internal jugular vein, external jugular vein, brachiocephalic vein, basilic vein, mid-thigh femoral vein, popliteal vein, posterior tibial vein, and small saphenous vein. To minimize the risk of venous thromboembolism, the ratio of catheter diameter to vessel diameter should be less than 0.67. The review also presents the minimal requirement of venous diameter for different catheters in a tabulated form. For larger veins, real-time ultrasound guidance with the long-axis view/in-plane technique is suggested, while for smaller vessels, the short-axis view/out-of-plane technique is recommended. The review includes sonographic illustrations of the two techniques and surrounding arteries and nerves for the eight major veins. The aim of this review is to help clinicians assess the eight major veins and safely insert various types of catheters for patients in the prone position.