Mark A. Malangoni

Introduction

Understanding the anatomic relationships of the large veins used for placement of central catheters is key to successful cannulation and avoidance of complications. The internal jugular, subclavian, and femoral veins can be accessed for fluid infusion, blood sampling, hemodialysis, cardiac pacemaker placement, and measurement of central venous pressures. Ultrasonography is a safe and noninvasive imaging method that can help identify the target vessels and their relationship to surrounding structures. Ultrasound allows for assessment of the patency of the target vessel and reduces complications when using the internal jugular approach. Infection or injury in the local area, distortion at the entry site, occlusion of the target vein, and an uncooperative patient are relative contraindications to line placement in these vessels.

Common Details for Venous Catheterization

When internal jugular or subclavian vein catheterization is selected, the patient is placed in the Trendelenburg position with a roll put lengthwise between the shoulders. This position helps distend the veins, improve the line of access, and reduce the incidence of air embolism. The head is rotated slightly away from the proposed insertion site.

After the skin is prepared with a chlorhexidine-based solution, the area for insertion is draped; a cap, mask, eye protection, and sterile gowns and gloves are donned; and aseptic technique is maintained. Local anesthetic, usually 1% lidocaine, is injected into the patient’s skin and surrounding tissues. The ultrasound probe should be covered with a sterile transparent sheath and sterile acoustic gel applied.

Although a variety of methods are used for central venous cannulation, this chapter describes the most common approaches.

Internal Jugular Vein Catheterization

The internal jugular vein is located in the triangle formed by the two heads of the sternocleidomastoid muscle and clavicle in the anterior neck (Fig. 40-1). Cannulation of the right internal jugular vein is preferred to the left vein because the right provides more direct access to the right atrium, avoids the thoracic duct, and is associated with fewer complications. The ultrasound probe is placed to position the vein in the center of the image. The surgeon differentiates the internal jugular vein from the carotid artery by noting that the vein compresses with gentle pressure.

The needle is inserted 2 to 3 cm (1 inch) above the clavicle, pointed toward the ipsilateral nipple, and maintained at a 30- to 45-degree angle during advancement. The needle can be identified parallel to the vein when the probe is placed in a longitudinal orientation, but it appears only as a dot when the probe is oriented in cross section. Gentle aspiration is applied to the connected syringe as the needle is advanced. Once nonpulsatile blood return is established, the Seldinger technique is used to pass a guidewire into the vein and then a catheter over the wire.

Ultrasound can verify that the catheter is within the lumen of the vessel. The wire is removed and the catheter is secured to the skin with sutures. The catheter tip should rest about 12 to 15 cm (5 to 6 inches) from the skin insertion site. Each port is flushed with saline solution and the presence of blood return demonstrated. A sterile dressing is applied. A chest radiograph is obtained to confirm proper placement of the catheter, which should not go beyond the junction of the superior vena cava and right atrium.

Subclavian Vein Catheterization

The subclavian vein passes just below the point where the clavicle deviates from the 1st and 2nd ribs (Fig. 40-2). Here the vein is anterior and inferior to the subclavian artery. The needle is inserted at a point 2 cm lateral and 2 cm inferior to the junction of the middle and lateral thirds of the clavicle. The needle penetrates the skin at a 15- to 30-degree angle and can be directed toward a point 1 to 2 cm above the sternal notch.

Although not as useful as for internal jugular cannulation, an ultrasound probe can facilitate cannulation by detailing the relationship between the vein and subclavian artery. If ultrasound is used, Doppler flow may be needed to differentiate the subclavian vein from the artery. After the needle is inserted and blood return demonstrated, insertion is completed as previously described.

Femoral Vein Catheterization

The femoral vein lies within the femoral triangle in the inguinal-femoral area (Fig. 40-3). The triangle is formed by the inguinal ligament, adductor longus muscle, and sartorius muscle. When the inguinal ligament is not easily seen, its position can be determined as it courses between the pubic tubercle and anterior superior iliac spine. The femoral artery lies at the midpoint along the course of the inguinal ligament, and the femoral vein lies medial to the artery below the inguinal ligament.

Ultrasound is useful to determine the location of the femoral vein, which can be differentiated from the artery by its more medial position and by its easy compression with the ultrasound probe. The needle is inserted at a 30-degree angle 2 to 3 cm below the inguinal ligament and directed toward the left shoulder. When blood return is established, insertion is completed as described previously.

Complications

The use of ultrasound guidance has reduced the incidence of catheter-related complications for internal jugular vein insertion. The common complications of central vein catheterization include misplacement of the catheter, cannulation of the artery, pneumothorax, hemothorax, localized bleeding or hematoma at the insertion site, or air embolism. Late complications include infection and thrombosis of the cannulated vein.

Femoral vein catheters should not be used in ambulatory patients because of the increased risk of catheter dislodgement and fracture. Femoral vein catheterization avoids hemothorax and pneumothorax, but the risk of infection is also increased because of the proximity of the perineum and groin, both of which harbor increased levels of bacteria.

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