Central Venous Catheter
- Article Author:
- Joshua Kolikof
- Article Author:
- Katherine Peterson
- Article Editor:
- Annalee Baker
- Updated:
- 5/24/2020 9:34:01 AM
- For CME on this topic:
- Central Venous Catheter CME
- PubMed Link:
- Central Venous Catheter
Introduction
A central venous catheter (CVC) is an indwelling device that is peripherally inserted into a large, central vein (most commonly the internal jugular, subclavian, or femoral), and advanced until the terminal lumen resides within the inferior vena cava, superior vena cava, or right atrium. These devices and the techniques employed to place them are synonymous with the terms "central line" or "central venous access." The placement of a CVC was first described in 1929.[1] Over the following decades, central venous access rapidly developed into an important experimental instrument for studying cardiac physiology,[2] as well as an indispensable clinical tool in the treatment of many disease processes. Various access techniques and devices were developed for a multitude of indications, including total parenteral nutrition administration,[1] dialysis,[3] plasmapheresis,[4] medication administration,[5] hemodynamic monitoring,[6] and to facilitate further complex interventions such as transvenous pacemaker placement.[7] Despite these advancements, the procedure itself has remained relatively unchanged since the advent of the (now universally employed) Seldinger technique in the 1960s.[8] A notable exception is the adjunct of ultrasound-guidance, which has recently become the standard of care for CVC's placed in the internal jugular vein, owing to associated decreases in complications and an increase in first-pass success.[9][10][11][12][5][13] Some controversy persists about the merits of specific site selection (e.g., which vein) and the relative associated complication rates of CVCs placed in different central veins. However, there is broad consensus that today, in the modern era, the competency to establish and manage a central venous catheter is an indisputably essential skillset for physicians involved in the care of critically ill patients. The purpose of this article is to review the indications, contraindications, technique, complications, and management of centrally placed venous catheters.
Anatomy and Physiology
There are three main access sites for the placement of central venous catheters. The internal jugular vein, common femoral vein, and subclavian veins are the preferred sites for temporary central venous catheter placement. Additionally, for mid-term and long-term central venous access, the basilic and brachial veins are utilized for peripherally inserted central catheters (PICCs). A discussion of tunneled catheters and other central access obtained via advanced interventional radiology techniques is beyond the scope of this article. We will focus on the three main sites of access routinely used for short-term (days to weeks) central access.
Understanding of the relevant anatomy and adjacent structures is crucial when placing a CVC. The decision of where to place a central line is typically based on clinical parameters, as well as individual physician experience and preference. Each anatomical site has relative advantages and disadvantages, and one site is unlikely to be the best choice in every patient. While the evidence does not suggest one superior site, there are known risks and benefits associated with each location.
The internal jugular vein (IJ) is often chosen for its reliable anatomy, accessibility, low complication rates, and the ability to employ ultrasound guidance during the procedure.[9] The individual clinical scenario may dictate laterality in some cases (such as with trauma, head and neck cancer, or the presence of other invasive devices or catheters), but all things being equal, many physicians prefer the right IJ. As compared to the left, the right IJ forms a more direct path to the superior vena cava (SVC) and right atrium. It is also wider in diameter and more superficial, thus presumably easier to cannulate.[14] The IJ is located anterolateral to the common carotid artery, typically in the superior portion of the triangle created by the two heads of the sternocleidomastoid (SCM) and the clavicle. The internal jugular vein joins the subclavian vein to form the brachiocephalic vein. The right and left brachiocephalic veins join to form the SVC. When anatomic landmarks are used, the IJ site can be accessed anteriorly, centrally, or posteriorly in reference to the bifurcation of the SCM. Generally speaking, the central approach is most commonly used, but some have argued that the posterior approach is safest (being furthest from the lung apex and the carotid artery) and that the anterior approach is the easiest (as the carotid artery forms a readily palpable reference landmark). While there may still be no consensus about the correct landmark-based approach, most experts agree that owing to anatomic variability, ultrasound guidance provides the best chance at locating the vein and avoiding other structures.[15][16]
The subclavian vein site has the advantage of low rates of both infectious and thrombotic complications.[17] Additionally, the SC site is accessible in trauma, when a cervical collar negates the choice of the IJ. However, disadvantages include a higher relative risk of pneumothorax, less accessibility to use ultrasound for CVC placement, and the non-compressible location posterior to the clavicle. At the site of puncture for CVC placement, the subclavian vein lies just posterior to the clavicle, but the vessel takes a tortuous route as it extends medially from the axillary vein. As the vein courses along the clavicle, from lateral to medial, it progresses from the lateral border of the first rib, slopes cephalad at the middle third of the clavicle, then caudally merges with the internal jugular vein just posterior to the sternoclavicular joint. Of note, the subclavian vein is closely associated with several important structures. The vein is typically anterior and superior to the subclavian artery. The lung is located just infero-medial to the subclavian vein, in close approximation to the lateral first rib. The phrenic nerve courses just deep to the brachiocephalic vein, at the confluence of the subclavian vein and internal jugular vein. The brachial plexus and right-sided thoracic duct are also in close proximity, and vulnerable to injury.[18] While methods for ultrasound (US) guidance[19] have been documented, access at this site is often performed without US guidance in a landmark-guided technique. Data suggests that US guidance may reduce the rates of arterial puncture, pneumothorax, and brachial plexus injury, however, many physicians, are still more comfortable with landmark-guided placement for SC central venous catheters.[16][20][21][22] The SC vein can be accessed above or below the clavicle, though the infraclavicular method is far more commonly employed. The supraclavicular approach offers a well-defined landmark for insertion at the clavisternomastoid angle, a shorter distance from puncture to the vein, and a straighter path to the SVC, with less proximity to the lung.[22] Authors have used these findings, as well as the observation that ultrasound guidance is easier to perform with the supraclavicular approach, to suggest that the infraclavicular approach should no longer be the SC CVC insertion method of choice.[23] However, other studies have found that the supraclavicular approach leads to a higher incidence of hematoma formation, with comparable rates of other complications, offering support for maintaining the status quo.[24]
The femoral site is sometimes preferable in critically ill patients because the groin is free of other resuscitation equipment and devices which may be required for monitoring and airway access. Central venous access in the common femoral vein offers the advantage of being an easily compressible site, which may be helpful in trauma and other coagulopathic patients.[25] Additionally, unlike the IJ and SC sites, iatrogenic pneumothorax is not a concern. Patients may be more comfortable with a femoral CVC because it allows relatively free movement of the arms and legs as compared with other sites. However, femoral CVCs are typically associated with increased thrombotic complications, and likely an increased rate of catheter-associated infections, although studies have shown conflicting results about the true risk of infection when the proper sterile technique is used.[26][27][5][28] Unlike IJ or SC lines, femoral central lines do not allow for accurate measurement of central venous pressure (CVP), though this is not important in every clinical scenario. The common femoral vein is located within the femoral triangle. This region is outlined by the adductor longus medially, sartorius muscle laterally, and the inguinal ligament superiorly. There are important anatomical considerations to keep in mind when accessing this particular site. Whereas in the neck, the (carotid) artery is medial to the (internal jugular) vein, in the leg, the artery is lateral to the vein. The mnemonic NAVEL is useful to recall the order of structures from lateral to medial: femoral nerve, femoral artery, common femoral vein, "empty space" (femoral canal), and lymphatics.[29] It is important to know this anatomy not only for landmark guided central line placement but also because some of these structures may also appear similar on ultrasonography.[11]
Indications
The indications for central venous access are broad and are often situational. In no particular order, they include:
- The need for multiple infusions which may be incompatible with peripheral intravenous access, such as vasopressors, total parenteral nutrition, chemotherapy, and other medications that are caustic to peripheral veins.
- Inability to obtain venous access in emergent situations.
- The initiation of extracorporeal therapies, such as hemodialysis, plasmapheresis, and continuous renal replacement therapy.
- Hemodynamic monitoring, including central venous pressures.
- For venous interventions, including inferior vena cava filter placement, thrombolytic therapy, transvenous cardiac pacing, and intra-venous stenting.
Contraindications
There are relative and absolute contraindications to placing central venous catheters, and contraindications may be site-specific. Relative contraindications may be over-ruled by the urgency with which the catheter needs to be placed and thus require careful consideration of the patient’s underlying pathology and hemodynamic status.
Absolute contraindications:
- Active skin or soft tissue infection at the potential site of the central line.
- Anatomical distortion at the site, which includes implantable/indwelling hardware, such as hemodialysis catheters and pacemakers.
- Vascular injury proximal or distal to the site of the catheter insertion, such as in traumatic injuries.
Relative contraindications:
- Coagulopathy, though the actual incidence of clinically important bleeding is around 0.8%.[30]
- Thrombocytopenia, which seems to correlate with a greater risk of adverse events.
- Uncooperative awake patient.
- Distortion of landmarks by congenital anomalies or trauma.
- Morbid obesity.
Typically, patients who have an international normalized ratio (INR) of greater than 3.0, or who have platelets less than 20 x 10^9/L are considered to have severe coagulopathy and increased risk of bleeding.[31] It may be warranted to consider giving fresh frozen plasma and/or platelets before the procedure or shortly thereafter, depending on the urgency of the clinical situation. Site-specific contraindications must be assessed on a case-by-case basis. The SC site is contraindicated in coagulopathic patients, given its anatomical proximity to several other major vessels, and the inability of the proceduralist to hold pressure in the event of an accidental arterial puncture or laceration of the vein itself. The IJ site may be relatively contraindicated if a cervical collar is in place, or if the IJ site will be required for another invasive procedure during the same admission. Similarly, the femoral site should be avoided if it is anticipated that femoral access will be required for a procedure such as cardiac catheterization.
Equipment
There are various manufacturers of central venous catheter insertion kits, and there are also several different types of catheters. Generally speaking, one will require an ultrasound machine with a high-frequency linear transducer, sterile products, mask, and head covering, the introducer kit with a central venous catheter, lidocaine, various sterile syringes, sterile saline flushes in 10 cc syringes, a sterile occlusive dressing, and a bio-patch if available.
- Non-sterile products:
- Bouffant or surgeon's cap
- Mask with eye shield
- Sterile products:
- Personal protective equipment: including gloves, gown
- Drape
- Gauze (4x4)
- Chlorohexidine swabs or similar antiseptic agent
- Sterile ultrasound probe cover with sterile ultrasound gel
- Biopatch
- "Luer locks" or catheter caps for each lumen
- Central venous catheter kit, which generally includes:
- Central venous catheter (triple-lumen, dual-lumen, or large bore single-lumen)
- 18 gauge introducer needle, with a syringe
- #11 blade Scalpel
- Guidewire
- Venodilator
- Suture material (generally 3-0 silk suture with a straight needle or a needle driver)
- Saline lock (number depends on the type of device)
- 1% lidocaine, small gauge needle (25 or 27 gauge), syringe
- Ultrasound machine with a high-frequency linear transducer
Preparation
It is important to first obtain consent for the procedure, if possible. Discuss the risks, benefits, and potential complications of the procedure. Once consent is obtained, inform nursing that the patient will be undergoing central venous catheter insertion. Gather the above equipment and necessary personnel, and clear the room of any visitors or non-essential staff to maintain maximum sterility. Use the ultrasound machine to assess the preferable access site (internal jugular, subclavian, or common femoral veins), taking note of anatomical variations, adjacent structures, and the ease with which the procedure can be performed at that site. Place the patient in an anatomically advantageous position for the procedure. For the internal jugular vein and subclavian, the patient should be placed in Trendelenburg position to increase the size of the vessel and improve the chance of first-pass success. For femoral vein access, the patient should be in a supine position. Adjust the height of the bed, and clear away clothing, jewelry, and any non-essential equipment which may impede preparation of a clear sterile field. The patient should be placed on a cardiac monitor that can cycle vital signs every 5 minutes or so, and can maintain telemetry.
Once a cursory anatomy scan is performed with ultrasound, clean, and prepare the patient for the procedure. When the primary nurse is present, and the patient is prepared, perform hand hygiene, and don the non-sterile personal protective equipment. Open the sterile equipment, creating a “sterile field.” This can be accomplished by grasping the corners of the sterile wraps and opening them out and away from the proceduralist. Once a sterile field has been created, clean the site with the antiseptic of your choosing. Prepare the vascular probe in such a way that it can be easily sheathed with a sterile probe cover. Thereafter, don the sterile personal protective equipment, and prepare the central venous catheter by attaching saline locks with saline flushes, and flushing all of the ports to ensure that there are no equipment issues. Next, remove the saline lock from the most distal port. Place the sterile drape over the patient, with the access point over the procedure site. Sheath the ultrasound probe with the sterile probe cover. The needle driver from the central line kit may be used to clamp the proximal portion of the probe cover to the sterile drape, to avoid the probe falling off the sterile field during the procedure. Assure that all equipment is within reach before initiating the procedure. Immediately prior to the procedure, a “time out” with nursing should be performed.
Technique
The patient should be positioned in Trendelenburg for IJ, or flat for common femoral vein or subclavian access. Depending on patient anatomy, a cushion may be placed beneath the vertebral column, which will facilitate needle insertion and dilation of the SC vein.
After preparation is completed, the following steps should be followed:
- Under ultrasound guidance, identify the vein (check that the vessel is compressible, and if in doubt, check doppler color flow) and use 1% lidocaine to anesthetize the skin and subcutaneous tissue (in awake patients).
- Under ultrasound guidance: using the finder needle with a 10 cc syringe attached, at a 45-90 degree angle, advance needle through the skin, holding negative pressure on the syringe until a flash of dark venous blood appears. Be sure to maintain dynamic visualization of the needle tip as it enters the vessel.
- Once you have aspirated venous blood, stabilize the needle with the dominant hand, disconnect the needle from the syringe, and thread the guidewire through the needle. The wire should advance easily. If there is any resistance, you may not be in the vessel, there may be an obstruction distal to the entry site, or the j-tip of the wire may be advancing retrograde. Attempt to remove the wire and re-thread. If the wire enters the right atrium, ectopy can be appreciated. Should telemetry demonstrate any ectopy or arrhythmia, the wire should be immediately pulled back until arrhythmia resolves. Typically the wire does not need to be pulled out completely.
- Once the wire is at 15 cm (three hash marks), stabilize the wire between two or more fingertips and withdraw the needle making sure not to inadvertently sustain a needlestick. Never let go of the wire!
- Once the needle has been removed, re-image the vessel with ultrasound in both a transverse and longitudinal plane. The wire should be visualized within the vessel lumen. If you do not see the wire within the lumen, do not proceed to the next step. If you are uncertain that the wire is in the lumen of the vessel, remove the wire, hold pressure on the site, and either re-attempt obtaining access to the vessel with the finder needle, or switch to a different anatomic site.
- In addition to the dynamic visualization of the procedure with the use of ultrasound, some practitioners use manometry to ensure that the catheter is in the venous system and not the arterial system. In order to do this, an angiocatheter is threaded over the wire, the wire is removed, and the included extension set for the central venous catheter is attached and held upright in the air. The meniscus formed by the column of blood that slowly fills the extension tubing should plateau if the angiocath is in the venous system. However, this method is time-consuming and is not entirely reliable in shock states. Regardless, it can be helpful with the subclavian approach, which is often difficult to fully accomplish with dynamic ultrasound visualization.
- Once the wire is verified to be within the vessel lumen, “preload” the dilator onto the guidewire and thread it toward the junction of the skin and wire. Leave approximately 2-3 cm between the dilator and the skin edge. Use the scalpel to create a small nick in the skin by sliding the blunt end of the scalpel blade along the wire to make a skin incision that is approximately 0.5 cm in width and half the depth of the scalpel blade. Remove the scalpel, and thread the dilator into the incision. Pre-loading the dilator minimizes blood loss and improves the ease of insertion.
- Grasping the dilator in the middle portion, apply gentle, steady pressure, sometimes with a slight twisting motion, in order to dilate the soft tissue and enable passage of the central venous catheter. Approximately 1/3 to 1/2 of the length of the dilator will need to be inserted into the skin/soft tissue space. This depends upon the anatomic site, as well as the specific type of central venous catheter. Dialysis catheters will require several stages of dilation with increasingly larger dilators, and potentially multiple uses of a scalpel to widen the incision.
- Remove the dilator, and place sterile gauze over the site to maintain sterility and minimize bleeding. Again, at no point should the proceduralist lose control of the guidewire.
- Thread the central venous catheter over the guidewire. Slide the guidewire slightly out of the skin to help control guidewire while advancing the catheter.
- Holding the distal aspect of the central venous catheter, slowly insert the central venous catheter through the vessel lumen until the proximal hub is adjacent to the insertion site. Throughout this process, always ensure one hand is holding the guidewire. Sliding the guidewire slightly out of the skin can help control the guidewire when advancing the catheter. Once the catheter is fully inserted, the guidewire can be gently pulled through the distal port (usually brown)
- Using a syringe, aspirate blood and remove air from each of the ports, and flush with sterile saline solution. “Luer locks” may be attached to the end of each port either before or after this step.
- The central venous catheter should be sutured in place with two sutures, a bio-patch should be placed between the catheter hub and the skin, and a sterile occlusive dressing should be placed over the catheter/skin entry site. Sterile drapes and soiled non-sharp products should be disposed of in biohazard bins. All sharps should be placed in sharps bins. The patient should be placed back into a position of comfort, and the proceduralist should verify that the line is appropriately placed within a central vein.
- In addition to dynamic ultrasound guidance, there are three methods to ensure that a central venous catheter is properly placed. A venous blood gas can be obtained from the distal port of the central line, a chest x-ray can be performed, and a central venous pressure can be obtained from the distal port. The blood gas and central venous pressure (CVP) are optional, but a chest x-ray should be performed in all IJ and SC CVC insertions, both to confirm placement and to verify that no complications (such as iatrogenic pneumothorax) have occurred. The x-ray should demonstrate the distal tip of the central venous line within either the superior vena cava (SC/IJ) or inferior vena cava (femoral).
Complications
Numerous potential complications can occur during the procedural placement of a central venous catheter, but also as a result of the indwelling equipment.
Procedural complications:
- Arrhythmias – typically ventricular or bundle branch blocks due to guidewire irritation of the atria or ventricles.
- Arterial puncture.
- Pulmonary puncture with or without resultant pneumothorax
- Bleeding – hematoma formation, which can obstruct the airway
- Tracheal injury.
- Air emboli during venous puncture or removal of the catheter.[32]
Post-procedural complications:
Clinical Significance
When performed properly, the insertion of a central venous catheter is safe, efficacious, and potentially life-saving. However, certain clinical pearls should be at the forefront of the proceduralist’s mind when performing this procedure.
- Whenever possible, take the time to fully prepare for the procedure, and assure that all necessary personnel and equipment are in the room and readily available. Lack of preparation will compound any potential complications that may be encountered.
- Ensure that sterile products are not contaminated and that there is no evidence of damage to the packaging. Follow sterile procedures at all times. Central line infections can be a serious and life-threatening illness.
- When using the IJ or SC site for access, be sure to obtain a stat portable chest x-ray immediately after line placement to ensure there is no pneumothorax and that the line terminates in the superior vena cava.
- If one has a failed attempt at the IJ site and needs to seek access at another site, the ipsilateral subclavian is preferred, given the risk of bilateral pneumothoraces with an attempt at the contralateral internal jugular vein. One may anticipate this possibility by cleaning and prepping both the IJ and SC site on the side of the procedure.
- If unsure of the placement of a guidewire within the vein, and limited views on ultrasound, manometry is a useful tool to establish that the guidewire is within the venous system. However, in shock states, where arterial pressure is low, this may be falsely reassuring.
- Subclavian access does appear to have fewer infections but potentially higher procedural complications, especially if performed by a clinician with limited experience.[35]
- The internal jugular, subclavian, and femoral veins have higher success rates and fewer complications when access is performed with ultrasound.
- The physician must maintain hold of the guidewire at all times while it is inside the patient. The wire can be lost inside the patient and may migrate into the right ventricle or inferior vena cava, leading additional invasive procedures to recover the wire.
- Always ensure that the catheter is appropriately placed through one or several methods: radiographic evidence,[36] measurement of CVP, or by analyzing a venous blood gas.
- Never use excessive force during any part of this procedure. It will lead to damage to local structures.
Enhancing Healthcare Team Outcomes
After a CVC placement, nurses are charged with maintaining, monitoring, and utilizing central venous catheters. The bedside nurse must be adept at recognizing complications such as infections, hematoma, thrombosis of the catheter, and signs of pneumothorax and bleeding. Nurses are also responsible for ensuring that the site is maintained in a clean and sterile fashion. Beyond the immediate complications of the procedure itself, nursing must be immediately aware of any ongoing issues and delayed complications. Their role in the interprofessional team is of monumental importance in maintaining the central venous catheter and recognizing potential complications.
Clear communication between all team members is essential to appropriate patient care.[37] The physician should inform the nurse as soon as the proper placement of the CVC is confirmed, and nursing should wait for this confirmation before using the line to administer medications. Both the nurse and the physician should be aware of and keep track of when the line was placed. CVC's are temporary, and complication rates increase when lines are left in too long.
Nursing, Allied Health, and Interprofessional Team Interventions
Daily inspection of the access site and device patency should be performed during nursing rounds. In particular, nursing must disinfect injection ports, catheter hubs, and needleless connectors with institutionally approved antiseptics. Intravenous administration sets should be changed regularly per hospital policy. The site should be checked for bleeding, hematoma formation, and signs of cellulitis, which includes erythema, purulent drainage, and/or warmth.[38]
Dressings should be changed if visibly soiled. This must be performed with proper sterile technique. Importantly, any manipulation of the catheter site should be done using a sterile procedure. A bouffant cap, mask, and sterile gloves must be worn to minimize infection. The site should be cleaned with approved antiseptics, allowed to dry, and a sterile occlusive dressing must be replaced.[38]
At interprofessional team rounds, there should be a daily discussion about whether or not the central venous catheter is still indicated. If deemed unnecessary for further management, the central venous catheter should be removed expeditiously.[39]
Nursing, Allied Health, and Interprofessional Team Monitoring
A multitude of potential complications can arise from the placement of central venous catheters. Nursing staff should be aware of the immediate and delayed complications and alert the physician in charge of the patient’s care.[39] However, physicians should also be wary of complications, and should always consider the catheter (as a source) if the patient shows signs of infection.