Central Venous Access via Subclavian Approach to the Subclavian Vein

Overview

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 monitoring.

Central line equipment is depicted in the image below.

Central venous catheter equipment. Image courtesy of Wikimedia Commons.

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 to femoral site access, internal jugular or subclavian access has been associated with a lower risk of catheter-related bloodstream infections in earlier studies, but newer studies (2008-2010) indicate that there is no difference in the rate of catheter-related bloodstream infections between these three sites.[8]

The advent of bedside ultrasonography has changed the overall technique of the placement of central venous catheters in both the internal jugular and femoral veins, but the subclavian approach remains the most commonly used blind approach. Its advantages include consistent landmarks, increased patient comfort, and lower potential for infection or arterial injury compared with other sites of access. 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.

NextIndicationsVolume resuscitationEmergent venous accessNutritional supportAdministration of caustic medications (eg, vasopressors)Central venous pressure monitoringTransvenous pacing wire introductionHemodialysisPulmonary artery catheterizationPreviousNextContraindicationsAbsolute contraindications to central venous access Distorted local anatomy (eg, vascular injury, prior surgery, radiation history)Infection at insertion siteRelative contraindications to central venous access Presence of anticoagulation or bleeding disorderPatient who is excessively underweight or overweightUncooperative patientCurrent or possible thrombolysisAbsolute contraindications to the subclavian approach Trauma to the ipsilateral clavicle, anterior proximal rib, or subclavian vesselsCoagulopathy (Direct pressure to stop bleeding cannot be applied to the subclavian vein or artery due to their location beneath the clavicle.) Relative contraindications to the subclavian approach Chest wall deformityChronic obstructive pulmonary disease (COPD)PreviousNextAnesthesiaLocal anesthesia using 1% lidocaine is required.For more information, see Local Anesthetic Agents, Infiltrative Administration.PreviousNextEquipmentCentral venous catheter tray (line kit)Sterile glovesAntiseptic solution with skin swabSterile drapes or towelsSterile gownSterile saline flush, approximately 30 mLLidocaine 1% (obtain additional vial of lidocaine 1% if needed)GauzeDressingScalpel, No. 11PreviousNextPositioningPlace the patient in the supine position.If possible, the bed should be raised to a comfortable height for the operator so bending over is unnecessary.Do not place towels between the shoulder blades or turn the head, as this has been shown to decrease the size of the subclavian vein.[5] Place the patient in 15 º of Trendelenburg position to reduce the risk of air embolism. Increasing this angle does not improve vessel distention as the subclavian vein is fixed within surrounding tissue. Needle insertion site options include the following: One centimeter inferior to the junctions of the middle and medial third of the clavicleInferior to the clavicle at the deltopectoral grooveJust lateral to the midclavicular line, with the needle perpendicular along the inferior lateral clavicleOne fingerbreadth lateral to the angle of the clavicleSternal notch: Direct the insertion needle toward this target in the coronal plane.PreviousNextTechniqueExplain the procedure, benefits, risks, and complications and obtain a signed informed consent.Position the patient.Identify landmarks.Open the line kit, and position the equipment so it is easy to reach. One may want to retract the curved J-tip wire into the plastic loop sheath for easy directing 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 x 4 cm gauze soaked in a povidone iodine solution (e.g., Betadine). 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, which 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 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 3 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 using a kit that allows for the wire to be placed directly through a port on the syringe, then it is not necessary to disconnect the syringe. Beware 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 centimeters. Holding the wire in place, withdraw the introducer needle and set 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 exist 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 needed samples and then flush the line with saline and recap. Repeat this step with all lumens. Verify line placement with chest radiograph. 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 prior to suturing.Apply a clean dressing.PreviousNextPearlsThe 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. (For details, see Medscape Reference article 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 lumens required; increasing the number of lumens has been shown to increase infection rates.[9] To date, ultrasonographic guidance has mainly been used in a "mark & go" fashion to identify points of insertion and in this usage may not improve the overall success rate of placement as it does for both the femoral and internal jugular vessels. However, a ICU-based prospective, randomized study suggested that real-time ultrasonographic guidance in sedated and ventilated patients was useful for the subclavian approach in the hands of experienced operators.[10] Further studies are needed to confirm these results and to evaluate the success of educational methods for learning this technique. PreviousNextComplications

The table below shows complication rates for the various approaches.

Table 1. Complication Rates of Central Venous Catheterization Approaches[6, 11, 7] (Open Table in a new window)

Internal Jugular Subclavian Femoral Arterial puncture6.3-9.13.1-4.99.0-15.0Hematoma1.2-2.13.8-4.4HemothoraxN/A0.1-0.6N/APneumothorax1.5-3.1N/AThrombosis7.61.921.5Total6.3-11.86.2-10.712.8-19.4Local site or systemic infection: Multiple studies have shown lower infection rates 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 and to save an estimated $167 per catheter inserted.[6] Arterial puncture: Lacerating the subclavian artery is theoretically possible, but the risk of this complication is higher with other approaches. The subclavian artery cannot be compressed; so, the subclavian approach should be avoided in anticoagulated patients. Hematoma: A hematoma usually requires monitoring only.Hemothorax: Check the chest radiograph for evidence of a hemothorax. If evidence is found, consult a surgeon immediately.Pneumothorax: Check a chest radiograph when finished or before switching to the contralateral side after failed insertion on one side. Catheter-related thrombosis: This complication may lead to pulmonary embolism.Air 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 occurs, 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. One hundred percent oxygen should be administered to speed the resorption of the air. If a catheter is located in the heart, aspiration of the air should be attempted. Dysrhythmias: Dysrhythmia is due to cardiac irritation by the wire or catheter tip. This 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: This complication leads to pericardial tamponade.Lost guide wire: If the clinician is not conscientious about maintaining control of the guide wire, it may be lost into the vein and require retrieval by interventional radiology. Anaphylaxis: Patients who are allergic to antibiotics may experience anaphylaxis upon insertion of an antibiotic-impregnated catheter. Catheter tip too deep: Check for this complication on the postprocedure chest radiograph, and pull the line back if the tip disappears into the cardiac silhouette. Catheter in the wrong vessel: When the subclavian catheter is not in the correct position, it most often deviates cranially up the internal jugular 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 misplaced subclavian venous catheters into the ipsilateral internal jugular.[12] Chylothorax: This complication is possible on the left side.PreviousNextCommon Errors in Technique

Kilbourne and colleagues analyzed failed subclavian catheter placement attempts by resident physicians in an effort to describe common technical errors and to direct future teaching strategies. Subclavian cannulations were videotaped. Analysis of 86 patients revealed 6 common errors in technique that occurred in the following frequencies over 277 attempts.[13]

Table 2. Common Errors in Technique (Open Table in a new window)

Error Percent of Failures (n = 277) Inadequate landmark identification14.7Improper insertion position32.3Insertion of needle through periosteum21.9Taking too shallow a trajectory with needle16.1Aiming the needle too cephalad7.5Failure to keep needle in place for wire passage7.5Previous, Central Venous Access via Subclavian Approach to the Subclavian Vein