Central Venous Access via Infraclavicular (Subclavian/Subclavicular) Approach to Subclavian Vein

First described in 1952, central venous catheterization, or central line placement, is a time-honored and tested technique of quickly accessing the major venous system. Its benefits over peripheral access include greater longevity without infection, line security in situ, avoidance of phlebitis, larger lumens, multiple lumens for rapid administration of combinations of drugs, a route for nutritional support, fluid administration, and central venous pressure (CVP) monitoring.

Overall complication rates range up to 15%,[1, 2, 3, 4] with mechanical complications reported in 5-19% of patients,[5, 6, 7] infectious complications in 5-26%,[1, 2, 4] and thrombotic complications in 2-26%.[1] These complications are all potentially life-threatening and, invariably, consume significant resources to treat.

Placement of a central vein catheter is a common procedure, and house staff require substantial training and supervision to become facile with this technique. A physician should have a thorough foreknowledge of the procedure and its complications before placing a central vein catheter.

Compared with femoral site access, internal jugular or subclavian access was associated with a lower risk of catheter-related bloodstream infections (CRBSIs) in earlier studies, but subsequent studies (since 2008) found no significant differences in the rate of CRBSIs between these three sites.[8]

The subclavian (also referred to as infraclavicular or subclavicular) approach remains the most commonly used blind approach for subclavian vein cannulation. Its advantages include consistent landmarks, increased patient comfort, and lower potential for infection or arterial injury compared with other sites of access.

The advent of bedside ultrasonography (US) has changed the overall technique of the placement of central venous catheters in both the internal jugular vein and the femoral vein. However, the use of this modality for subclavian routes has been infrequently studied, though there are some reports suggesting that it is feasible and safe.

Because of the anatomy of the subclavian approach, there is little room to effectively position the transducer while manipulating the needle. With the advent of newer transducers, however, reports are emerging of effective US-guided techniques.[9]  Compared with the studies evaluating the internal jugular approach, the studies evaluating US-guided approaches to the subclavian vein have been fewer in number and lower in quality; nevertheless, their results have been encouraging with respect to patient safety and quality.[10, 11, 12]

The physician’s experience and comfort level with the procedure, however, are the main determinants as to the success of the line placement in cases with no other patient-related factors that may increase the incidence of complications.

Indications for central venous access via the subclavian approach to the subclavian vein include the following:

• Volume resuscitation
• Emergency venous access
• Nutritional support
• Administration of caustic medications (eg, vasopressors)
• CVP monitoring
• Transvenous pacing wire introduction
• Hemodialysis
• Pulmonary artery catheterization

Absolute contraindications for central venous access are as follows:

• Distorted local anatomy (eg, from vascular injury, prior surgery, or previous irradiation)
• Infection at insertion site

Relative contraindications for central venous access are as follows:

• Presence of anticoagulation or bleeding disorder
• Patient who is excessively underweight or overweight
• Uncooperative patient
• Current or possible thrombolysis

Absolute contraindications for the subclavian approach are as follows:

• Trauma to the ipsilateral clavicle, anterior proximal rib, or subclavian vessels
• Coagulopathy (direct pressure to stop bleeding cannot be applied to the subclavian vein or artery, because of their location beneath the clavicle)

Relative contraindications for the subclavian approach are as follows:

• Chest-wall deformity
• Chronic obstructive pulmonary disease (COPD)

Before the procedure, a discussion should be held with the patient to explain the procedure, in particular with regard to its benefits, risks, and complications. Signed informed consent must be obtained.

Equipment required for central venous access via the subclavian (or infraclavicular or subclavicular) approach to the subclavian vein includes the following:

• Central venous catheter tray (line kit; see the image below)
• Sterile gloves
• Antiseptic solution with skin swab
• Sterile drapes or towels
• Sterile gown
• Sterile saline flush, approximately 30 mL
• Lidocaine 1% (obtain additional vial of lidocaine 1% if needed)
• Gauze
• Dressing
• Scalpel, No. 11

Local anesthesia using 1% lidocaine is required. For more information, see Local Anesthetic Agents, Infiltrative Administration.

Place the patient in the supine position. If possible, the bed should be raised to a height that is comfortable for the operator, so that bending over will be unnecessary. Do not place towels between the shoulder blades or turn the head; these have been shown to decrease the size of the subclavian vein.[5]

Place the patient in 15º of Trendelenburg position to reduce the risk of air embolism. Increasing this angle does not alleviate vessel distention, because the subclavian vein is fixed within surrounding tissue.

Position the patient (see Periprocedural Care, Patient Preparation). Identify anatomic landmarks (including the clavicle, the deltopectoral groove, and the sternal notch) to facilitate appropriate insertion of the needle (see the image below).

Numerous landmarks have been described for determining the needle insertion site. The following are some of the options mentioned, any of which will work:

• 1 cm inferior to the junctions of the middle and medial third of the clavicle
• Inferior to the clavicle at the deltopectoral groove
• Just lateral to the midclavicular line, with the needle perpendicular along the inferior lateral clavicle
• One fingerbreadth lateral to the angle of the clavicle

Open the line kit, and position the equipment so that it is easy to reach. One may want to retract the curved J-tip wire into the plastic loop sheath to facilitate direction into the introducer needle. Also, uncap the distal lumen, which is commonly the brown lumen.

Prepare the insertion site with the iodine or alcohol solution provided in the kit. This amount of preparation is often inadequate, and a wide area around the insertion site should be liberally prepared with 4 × 4 in. (10 × 10 cm) gauze soaked in a povidone-iodine solution. Prepare the neck as well, in case the subclavian approach fails and another approach must be attempted.

Put on sterile mask, gown, and gloves. Drape the patient in a sterile fashion, with the insertion site exposed. Using a generous amount of lidocaine 1%, infiltrate the skin, subcutaneous tissue, and, possibly, the clavicular periosteum.

Position the bevel of the introducer needle in line with the numbers on the syringe. Upon insertion, orient the bevel to open caudally; this facilitates smooth caudal progression of the guide wire down the vein toward the right atrium.

Insert the introducer needle at the desired landmark while gently withdrawing the plunger of the syringe. Advance the needle under and along the inferior border of the clavicle, making sure that the needle is virtually horizontal to the chest wall. Once under the clavicle, the needle should be advanced toward the suprasternal notch until the vein is entered. If the vein is difficult to locate, remove the introducer needle, flush it clean of clots, and try again. Change insertion sites after three unsuccessful passes with the introducer needle.

When venous blood is freely aspirated, disconnect the syringe from the needle, immediately occlude the lumen to prevent air embolism, and reach for the guide wire.

Insert the guide wire through the needle into the vein with the J-tip directed caudally to improve successful placement into the subclavian vein. If the kit used is one that allows the wire to be placed directly through a port on the syringe, then it is not necessary to disconnect the syringe. Be aware that disconnecting the syringe gives the added benefit of allowing verification of nonpulsatile flow of venous blood.

Advance the wire until it is mostly in the vein or until ectopy is seen on the cardiac monitor. Then, retract the wire 3-4 cm. Holding the wire in place, withdraw the introducer needle and set it aside.

Use the tip of the scalpel to make a small stab just against the wire to enlarge the catheter entry site. Thread the dilator over the wire and into the vein with a firm and gentle twisting motion while maintaining constant control of the wire. After the introducer is inserted, hold the wire in place and remove the dilator.

Thread the catheter over the wire until it exits the distal (brown) lumen, and grasp the wire as it exits the catheter. Continue to thread the catheter into the vein to the desired length.

Hold the catheter in place, and remove the wire. After the wire is removed, occlude the open lumen.

Attach a syringe with some saline in it to the hub, and aspirate blood. Take any needed samples, and then flush the line with saline and recap. Repeat this step with all lumina.

Verify proper line placement with chest radiography. The tip of the line should end in the vena cava at the manubriosternal angle, not in the right atrium.

Suture the catheter in place. For patient comfort, the clinician may need to infiltrate this area before suturing. Apply a clean dressing.

Common technical errors

Kilbourne et al analyzed failed subclavian catheter placement attempts by resident physicians in an effort to describe common technical errors and to direct future teaching strategies.[13] Subclavian cannulations were videotaped. Analysis of 86 patients revealed six common errors in technique that occurred over 277 attempts (see Table 1 below).

Table 1. Common Errors in Technique (Open Table in a new window)

Surgical pearls

Points that should be kept in mind to facilitate the performance of the procedure include the following:

• The key to a successful line placement is meticulous preparation and setup before starting or donning sterile garb
• Prepare a sterile site from the jaw to several fingerbreadths below the clavicle
• The amount of lidocaine provided in most kits is often inadequate; the authors recommend supplementing the kit with a 10-mL syringe and a bottle of 1% lidocaine
• If the wire does not pass easily through the needle down the vein, remove the wire, reattach the syringe, and confirm that the needle is still in the lumen of the vein before reattempting
• Beware a return of red pulsatile blood; if this occurs, the wire is in an artery.
• Beware aspirating air bubbles through the probing introducer needle; this indicates a pneumothorax (see Tube Thoracostomy)
• Anesthetize the suture site as well as the insertion site
• Some clinicians find it useful to remove the contents of the line kit and lay them out in the order and configuration that they will be used
• Never place equipment on a patient
• Antibiotic ointments are contraindicated; transparent dressings are not beneficial
• Choose the central line with the fewest number of lumina required; increasing the number of lumina has been shown to increase infection rates ^[14]

Ultrasound guidance

To date, ultrasonographic (US) guidance[15] has mainly been used in a "mark and go" fashion to identify insertion points. So used, it may not improve the overall success rate of placement as it does for both femoral and internal jugular vessels. However, one study suggested that real-time US guidance in sedated and ventilated patients was useful for the subclavian approach in the hands of experienced operators.[11]

Senussi et al, with the aim of reducing the risk of mechanical complications attendant on central venous cannulation via the subclavian approach, reviewed a method that potentially affords increased safety and allows avoidance of pneumothorax during US-guided subclavian vein cannulation.[16] In this method, the needle is directed toward the subclavian vein at a point where it passes over the second rib. This offers a margin of safety by providing a protective rib shield between vessel and pleura; it also renders the vein more readily compressible in the event of a bleeding complication.

In a pilot randomized controlled study (N = 194) by Wang et al, static US-guided subclavian vein puncture was found to be superior to the traditional landmark-guided approach for critically ill patients in the ICU.[12]

Complication rates for internal jugular, subclavian, and femoral approaches to central venous access are listed in Table 2 below.[6, 7, 17]

Table 2. Complication Rates of Central Venous Catheterization Approaches ^{[6, 17, 7]} (Open Table in a new window)

Multiple studies have shown lower rates of local or systemic infection with the use of maximal sterile-barrier precautions, including mask, cap, sterile gown, sterile gloves, and large sterile drape. This approach has been shown to reduce the rate of catheter-related bloodstream infections (CRBSIs) and to save an estimated $167 per catheter inserted.[6]

Lacerating or puncturing the subclavian artery is theoretically possible, but the risk of this complication is higher with other approaches. The subclavian artery cannot be compressed; accordingly, the subclavian approach should be avoided in anticoagulated patients.

A hematoma usually requires monitoring only.

Check the chest radiograph for evidence of a hemothorax. If evidence is found, consult a surgeon immediately. In addition, check the chest radiograph for evidence of pneumothorax when finished or before switching to the contralateral side after failed insertion on one side.

Catheter-related thrombosis may lead to pulmonary embolism.

An air embolism may be caused by negative intrathoracic pressure, with inspiration by the patient drawing air into an open line hub. Be sure the line hubs are always occluded. Placing the patient in the Trendelenburg position lowers the risk of this complication.

If air embolism does occur, the patient should be placed in Trendelenburg position with a left lateral decubitus tilt, which may prevent the movement of air into the right ventricle and onward into the left side of the heart. Administration of 100% oxygen should be initiated to speed the resorption of the air. If a catheter is located in the heart, aspiration of the air should be attempted.

Dysrhythmia may occur as a consequence of cardiac irritation by the wire or catheter tip. It can usually be terminated by simply withdrawing the line into the superior vena cava. Placing a central venous catheter without a cardiac monitor is unwise.

Atrial wall puncture can lead to pericardial tamponade.

If the clinician is not conscientious about maintaining control of the guide wire, it may be lost into the vein and consequently may have to be retrieved by interventional radiology.

Patients who are allergic to antibiotics may experience anaphylaxis upon insertion of an antibiotic-impregnated catheter.

Occasionally, the catheter tip may lie too deep. Check for this complication on the postprocedure chest radiograph, and pull the line back if the tip disappears into the cardiac silhouette.

When the subclavian catheter is not in the correct position, it most often deviates cranially up the internal jugular vein instead of down the subclavian vein. Flushing 10 mL of saline through the distal port and palpating the neck for a thrill can help to detect misplacement of a subclavian venous catheters into the ipsilateral internal jugular vein.[18]

Chylothorax is a possible complication on the left side.