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Vascular access is a necessity for evaluation and treatment of many patients in the ED. Traditionally, knowledge of common venous anatomy in experienced hands was the standard method of obtaining venous access. Factors such as obesity, prior access, and volume depletion can increase the difficulty of the conventional approach. This increased difficulty not only leads to failure to obtain access, but also increases the risk of complications.
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Ultrasound-guided vascular access reduces the variables associated with the traditional landmark-based approach for central venous access and has become the standard of care. Additionally, ultrasound is useful for both difficult peripheral venous and arterial access.
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Position and prepare the patient as per convention for access and use a sterile sheath for the transducer.
For central venous access, the patient is supine with the access site in a dependent position.
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There are two main approaches to all venous access.
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In a transverse view, identify the structures of interest:
Confirm the vein as the collapsible vascular structure, and trace the vessel to ensure there are no anatomic variants that may disrupt your procedure.
In the short-axis approach, maintain your transverse view and position the vein in the center of the image.
Introduce the needle immediately distal to the transducer’s edge at approximately 45-degree angle to the patient’s skin and perpendicular to the long axis of the probe (Fig. 24.100).
Maintaining the probe’s orientation to the vessel, slide the probe away from the puncture site to maintain visualization of the tip of your needle by observing:
Follow the tip of the needle until it contacts the anterior surface of the vein.
Continue to advance until a venous flash is seen and the needle has reached the intended depth. If no flash is seen at the appropriate depth in the correct path, slowly withdraw the needle and observe for venous return.
Continue catheter placement as per common practice.
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