Central venous catheterization (CVC) is a procedure frequently required in acute or critical care resuscitation. Indications include patients with multiple, incompatible intravenous (IV) medications with limited peripheral access, or who are being treated with vasoactive or phlebosclerotic agents which may not be suitably cared for with a peripheral IV alone. Some central lines are also placed for temporary or permanent hemodialysis access; these dialysis catheters are significantly larger than traditional double, triple, or quadruple lumen catheters placed in the emergency department (ED) or intensive care unit (ICU) setting. Central lines may also be placed to introduce Swan Ganz catheters to measure internal hemodynamics of the heart, or to introduce temporary transvenous pacemaker leads in the critically ill patient who has severe bradycardia or high-degree heart block: these are called introducer catheters. Most central lines are placed today via the Seldinger technique (a safety enhancement over the previous "cut-down" technique), in which the chosen vein is cannulated with a needle, a guide wire is inserted to maintain a tract through the skin into the vein, and the catheter is then inserted over the wire into the vein before the wire is removed. This procedure is generally performed with ultrasound guidance unless an ultrasound machine is unavailable or there are other exigent circumstances, in which case a palpation guided approach can be used. Despite the general overall safety of this procedure, complications do occur. This article focuses on the complications of line placement. ,,
Central venous catheters are placed typically in one of 3 large central veins: the internal jugular vein (IJ), subclavian vein (SCL), or femoral vein. These large diameter central veins are located universally near a large artery. In the lateral neck, the IJ is located next to the carotid artery, with the vein lying lateral to the artery in most patients, deep to the sternocleidomastoid muscle. The subclavian vein lies next to the subclavian artery, and courses out of the axilla across the lateral upper chest where it quickly dives deep to the clavicle before forming a confluence with the internal jugular vein which then becomes the brachiocephalic vein. The right and left brachiocephalic veins then join together to form a common superior vena cava. The femoral vein lies in the femoral triangle of each thigh and maintains a medial relationship to the common femoral artery. A common mnemonic to remember the anatomic relationship of the femoral triangle is 'NAVeL' from lateral to medial indicating femoral nerve, femoral artery, femoral vein and lymphatics. Proximity to adjacent vital structures (arteries and lungs principally) is perhaps of greatest concern when striving to perform this procedure without causing harm to the patient.,
Central lines are placed for the following indications:
Contraindications to central line placement may vary based on the site chosen to cannulate. Common contraindications to central line placement are:
It is also helpful to ask if any specific additional items are needed per your institutional protocols (such as antibiotic sponges). If an ultrasound-guided technique is used, a sterile probe cover should also be available.,
When possible, having an assistant present during the procedure is helpful. However, the well-prepared and well-practiced clinician can place a central venous catheter with little to no assistance.
If the patient is conscious and available to provide consent, risks and benefits of the procedure should be reviewed and written consent should be obtained. Before any medical procedure, it is appropriate to take a moment to confirm that you are with the right patient, performing the right procedure at the right site (commonly called a "time out"). Once the site is chosen, a topical antiseptic such as chlorhexidine or betadine is applied circularly to the skin in ever-enlarging circles. Once applied, the antiseptic should be allowed to dry to maximize the decrease in skin surface bacterial cell count. After securing the line in vivo, it is also common practice to flush the central line with sterile saline to prevent clotting within the catheter.
After donning sterile gown and gloves, and a hat and mask, and after the selected vein is prepped and draped, anesthetize the insertion site by injecting local anesthetic sufficient to create a wheal under the skin. Continue to aim this needle towards the venous target, aspirating then injecting anesthetic into the subcutaneous tissue. Once the area is anesthetized, place the introducer needle into the skin, and advance toward the vein being cannulated, all the while aspirating with steady pressure. Once blood return is seen in the syringe attached to the introducer needle, the syringe can be removed. A guidewire is inserted through the needle into the vein, to a depth of at least 15 centimeters (although this will vary based on the insertion site). Some commercial kits include a syringe with a wire-port located on the base of the plunger; another option is to insert the wire through this port into the vein. Make sure to insert enough wire to pass through the needle and syringe, as well as at least 10 centimeters into the cannulated vein. Next, remove the needle (and syringe if still attached), careful to leave the wire inserted in the skin and vein. Use the scalpel to make a small stab incision (approximately 2 mm) into the path of the guidewire, then slide the skin dilator over the wire into the subcutaneous tissue, to dilate the soft tissue all the way to and into the vein. Remove the dilator, you will likely have increased bleeding from the site due to the dilation. Then carefully insert the central line over the wire without ever taking one hand off the wire. Before allowing the distal tip to enter the skin, manually back the guidewire through the central line until the wire emerges from the central line port. Secure the proximal end of the wire and continue to guide the central line into the skin, subcutaneous tissue, and vein, over the wire. Remove the wire, apply appropriate caps to the central line ports (or clamp the line so that no blood can escape, and no air can enter the patient). Secure the central line to the skin with suture or staple per institutional guidelines, and apply a sterile dressing to cover the insertion site.
With a central line, the patient cannot only be resuscitated, but the hydration status can be monitored by measuring the right atrial pressure. One can also administer medications and total parenteral nutrition (TPN) via a central line.