Overview of Central Line Placement
A central venous line, or CVL, is a big, special kind of tube put into one of the large veins in your body using very clean (sterile) procedures. If it’s an emergency, there might not be time for the whole sterile procedure. This method of inserting the tube was introduced by Sven-Ivar Seldinger back in 1953 and it’s now known as the Seldinger technique. Doctors use this process to place the tube safely and reliably into your vein. Knowing how to insert a central line is an important skill for doctors, especially in critical care units. In fact, some studies estimate that 8% of people in hospital need a central venous line. In the United States, they put in over 5 million of these tubes every year.
In the past ten years, there have been big improvements in how we insert central lines, and a decrease in the problems that are caused by it. The approach to inserting these lines is pretty standard across all hospitals now and involves using ultrasound to guide it, new designs for the actual line, and the care bundles for the line after it’s been put in. This is a routine procedure in intensive care units in hospitals. More details about the central line placement process include the body part it’s placed in, when and why it’s used, who is involved, how it’s done, how to prepare for it, and what possible complications can occur.
Anatomy and Physiology of Central Line Placement
When doctors need to insert a central line, which is a catheter or thin tube placed inside a large vein to provide medications or other treatments typically, they have three areas where they can place a central line in adults: the internal jugular vein (in the neck), the femoral vein (in the groin), and the subclavian vein (under the collarbone). The right internal jugular vein and subclavian vein can provide the quickest path to the right atrium of the heart, one of the chambers responsible for pumping blood. The femoral vein can be squeezed, so it’s usually chosen for patients who are more likely to bleed. However, accessing the subclavian vein has a higher chance of causing a lung collapse or pneumothorax, compared to the internal jugular vein approach.
Doctors often rely on ultrasound to guide them when inserting the central vein catheter. However, they can also place the catheter using just their knowledge of the body’s landmarks, in situations where an ultrasound isn’t an option.
In the context of internal jugular vein access, the vein leaves the skull from an opening known as the jugular foramen and travels along the side of the neck beneath a muscle called the sternocleidomastoid. Just below the cartilage of your voice box, you can find it between the two parts of the sternocleidomastoid muscle. It then connects to the vein under the collarbone to join the larger blood vessels of the body. This area often allows a quick, direct path to the heart and is usually the anticipated site for central line insertion. However, this might not be the case for patients having serious blood clotting disorders, those with an existing device at the site, or if the local area’s physical structure has been changed due to previous catheter insertion.
Meanwhile, the subclavian vein can be found by inserting the needle just under the collarbone’s midpoint. This vein starts from the vein in the armpit, loops upward behind the inner collarbone before sloping down and merging with the internal jugular vein. Inserting a catheter in the subclavian vein presents a dilemma to patients with severe blood clotting disorders, as it can’t be compressed to control bleeding.
The femoral vein, found near the thigh’s inner side, just beneath the inguinal ligament (the band running from the hip to the pubic bone), is another site. Placing a catheter here is more likely to cause a deep vein thrombosis, a kind of blood clot that can have serious implications. There were concerns about higher chances of infection, but recent studies have shown comparable infection rates across all three points, given that optimal insertion points are selected, and the procedure is performed using strict sterile techniques. Despite this, health guidelines still suggest that doctors should only consider using the femoral vein if they can’t use the internal jugular or subclavian veins.
Why do People Need Central Line Placement
A central venous line (CVL) is a tube that is inserted into a large vein in your body in order to transport medications, fluids, or to keep an eye on certain medical conditions. Here are some key reasons why a doctor might suggest placing a CVL:
Firstly, some drugs can cause inflammation or hardening of the veins (phlebitis or sclerosis). Injecting these drugs, such as vasopressors or solutions with a high concentration of dissolved particles (hyperosmolar solutions), through a CVL can prevent such complications.
Secondly, a CVL can be used to monitor different body functions. It can be used to measure the pressure inside your veins (central venous pressure) and the amount of oxygen in your blood (ScvO2). It can also measure the pressure in the arteries in your lungs, known as pulmonary artery pressure.
Thirdly, in emergencies, when it’s hard to locate a vein for inserting an intravenous (IV) line, a CVL can provide another way to access your veins.
CVL also helps in the placement of a transvenous pacing wire, a wire that’s inserted into your heart through a vein to control irregular heart rhythms.
If you need to undergo certain procedures that require the transfer of large volumes of fluid or blood, such as hemodialysis (used for kidney failure) or plasmapheresis (used to remove harmful substances from your blood), a CVL might be needed.
CVL is also used for the placement of a vena cava filter, a device that prevents blood clots from reaching your lungs; and for providing thrombolytic therapy, a treatment that uses drugs to break up or dissolve blood clots.
When a Person Should Avoid Central Line Placement
There are times when a medical procedure called central venous access might not be suitable or safe for a patient due to certain conditions and the situation at hand. This can be the case if:
– The area where the procedure should be done is misshapen or infected.
– There’s a clot (or ‘thrombus’) in the vein where the procedure would be done.
– There are other pre-existing devices in the vein where the procedure is intended to be done.
It’s important to mention that having a condition that impacts blood clotting or causes bleeding—called coagulopathy—doesn’t necessarily mean this procedure can’t be done. Even in severe cases, it’s more of a situational judgment call rather than a strict “no.”
Studies have shown that the risk of major bleeding complications from this procedure in patients with moderate-to-severe coagulopathy or a low number of platelets (cells that help form clots to stop bleeding) is low. There’s also no straightforward conclusion supporting the need to correct coagulopathy before starting the procedure according to some studies.
If a patient is prone to bleed due to a problem with their blood clotting system (hemostasis), ultrasound-guided placement of the central venous line is recommended, as it’s safer and more reliable, reducing the chance of complications and the need for repeated attempts to get the central line in.
There’s no firm limits yet on how low blood platelet count can be or what levels of blood clotting measures (named INR and partial thromboplastin time) are safe for this procedure to be performed. Some evidence suggests that low blood platelet number is more problematic than longer clotting times.
Despite common beliefs, there’s not a lot of proof supporting the need to correct coagulopathy routinely before inserting the central venous line. Some studies even suggest there might not be a need to increase the platelet count or decrease the INR before the procedure.
For severe coagulopathy (very low platelet count or high INR), giving blood products like platelets or fresh frozen plasma before the procedure might be a good idea when there’s enough time. However, the benefits of doing this should outweigh the risks. Such a decision is made based on the individual patient’s situation.
Equipment used for Central Line Placement
The items usually included in central line kits, which are used for procedures that require access to major blood vessels, are:
* A syringe and needle for administering local anesthesia
* A tiny bottle containing 1% lidocaine, an anesthetic used to numb the area where the line will be inserted
* Another syringe and a larger needle to make the initial access to the vein
* A small knife, called a scalpel
* A guidewire, which helps guide the central line into the correct position
* A tissue dilator to expand the hole for the central line
* A sterile, protective covering for the insertion site
* Surgical thread and needle for securing the line
* The actual central line, a thin, flexible tube that comes in a few different types and sizes. Some lines have multiple channels, allowing more than one treatment to be given at the same time.
Additionally, the healthcare professional carrying out the procedure will need to wear disposable protective clothing (a sterile gown, cap, gloves) and also use a face mask. They will also need sterile gauze (a type of absorbent cloth), sterile saline solution (a salt water solution), and sterile fluid like chlorhexidine for cleaning the skin. They also need an ultrasound machine, which uses sound waves to provide images of the veins, along with sterile gel that helps the ultrasound probe work more effectively.
If a longer, 16-cm central line is used, this can help prevent the line from going too deep and causing heart-related issues. This is especially important when inserting the line into the subclavian vein (below your collarbone) or internal jugular veins (in your neck).
Who is needed to perform Central Line Placement?
You will need a special team of healthcare professionals to place a central venous catheter (a tube that’s inserted into a large vein in your neck, chest, or groin to give medication or fluids). The team includes a doctor who specializes in this type of procedure, a technician who assists the doctor, and a nurse who will care for you during and after the procedure. They will work together to make sure that the procedure goes smoothly and you are safe and comfortable.
Preparing for Central Line Placement
Before a doctor can place a non-tunneled central venous catheter – a type of tube that’s inserted near your heart to deliver or withdraw fluids – they will usually talk you through the process, explain the reason for it, what they plan to do, the benefits, and any potential complications. For example, there’s a risk that air could get into your lungs (called a pneumothorax) while the catheter is being inserted. If this were to happen, the doctors would have to perform an additional procedure to fix it. In emergencies, the doctors have an implied consent to perform the procedure.
The doctor will position you to best access the site where the catheter will go. For instance, if it is to be placed in your neck or just below your collarbone, you may be put in a slightly head-down (15-degree Trendelenburg) position. Such a position lessens the chance of air bubbles entering your bloodstream during the procedure. If it is to be inserted into your femoral vein – a large vein in your thigh – you will need to lie flat. Throughout the procedure, the doctor will continuously monitor your heart rhythm and blood oxygen level to ensure your safety.
Prior to starting the procedure, the doctor will use an ultrasound scan to clearly see the vein where the catheter is to be placed. This helps them to perform the procedure more accurately. It is very important to maintain a sterile environment to prevent infections. This involves the doctor washing their hands thoroughly, wearing a long-sleeved sterile gown, surgical mask, gloves, and head covering. The skin where the catheter will be inserted should also be cleaned with a special antiseptic solution. Studies found that solutions with a substance called chlorhexidine are better than those with povidone-iodine.
During the procedure, you will be covered by a sterile drape, leaving only the cleaned site exposed. The doctor will then use a special ultrasound tool covered with a sterile sheath to guide them while placing the catheter. Once the procedure is done, the doctor and a helper will verify the procedure, your name, and the site where the catheter was inserted. This is to safeguard against any errors.
Groups such as SICSAG and HPS have recommended certain steps (an insertion bundle) for inserting a catheter, to reduce the risk of infection in your bloodstream. These steps include a checklist, maintaining hand hygiene and maximum barrier precautions, carefully choosing the site for the catheter, cleaning the skin, and applying a sterile dressing.
How is Central Line Placement performed
Central line placement is a technique used to insert a long, thin tube directly into a large vein. Doctors use this procedure when there’s a need to provide substantial medication or draw blood over a long period of time. Here’s a simplified explanation of how this procedure is done:
First, the doctor uses a local anesthetic, in this case, 1% lidocaine, to numb the area where the needle will be inserted. They then use a clean ultrasound gel and a bedside ultrasound machine to find the vein that they’ll use. Veins appear differently under the ultrasound than arteries, making them easy to identify.
If the ultrasound isn’t used, then the doctor will rely on identifiable body landmarks to guide the needle insertion. For example, when inserting the central line into the internal jugular vein (a vein in your neck), the needle should be put in about 5 cm above the collarbone (clavicle), at an angle of 30-45 degrees. For the subclavian vein (near your collarbone), the needle should be inserted about 2-3 cm below the midpoint of the collarbone. For the femoral line insertion (in your groin), the needle should be placed about 1-3 cm below the inguinal ligament and slightly towards your midline from where the femoral artery can be felt pulsating.
The needle is then inserted with negative pressure until venous blood is drawn out. Using ultrasound guidance if possible, the needle should not puncture the distal edge of the vein or enter an incorrect vessel.
Once venous blood is obtained, they stop advancing the needle and replace the syringe with a guide wire. It’s kept inside the needle and only inserted as far deep as the anticipated length of the catheter to avoid sending it too far into the heart. This can be monitored by watching for any abnormal heart rhythms.
Next, the doctor makes a small cut into your skin along the guide wire, just big enough for the dilator (which will help make room for the catheter). The doctor then places the dilator into the cut with a twisting motion until it reaches a depth where it is presumed the vein begins.
The doctor then pushes the catheter over the guide wire and into the vein to the required depth. Once the central line is in place, the guide wire is removed. The line is then flushed with sterile saline, and the ends of the catheter are secured with stitches before being covered with a sterile dressing.
Finally, the position of the catheter tip is confirmed with a chest x-ray before the line is used for treatment. This step is necessary when the catheter is placed in the internal jugular or subclavian veins.
Possible Complications of Central Line Placement
Placing central venous lines, or tubes in large veins to deliver medicine or fluids, can have complications. About 15% of people experience some problem. Some issues might be due to the person performing the procedure, with challenges reported in about 33% of cases.
Things that might go wrong with this procedure include piercing an artery, placing the tube incorrectly, collapsed lung, a blood clot under the skin, blood in the chest area, and very rarely, a heart attack. Using real-time ultrasound to guide the procedure can lower the chance of these problems happening.
There are some complications that might happen during the procedure. For example, a pneumothorax, or a collapsed lung, is a serious problem that can happen when tubes are placed in certain veins. However, using the internal jugular vein (a vein in your neck) for this can lower the risk. Other potentially serious but rare problems, like a venous air embolism, where an air bubble blocks a vein, can be avoided by properly positioning the patient and using equipment that prevents air bubbles.
An arterial puncture, or piercing an artery, is another serious complication that should be avoided. Using real-time ultrasound can help prevent this. If the artery is accidentally pierced and a tube is placed, the best approach is treating it internally to avoid blood swellings, obstructions in the airway, stroke, and the development of a false blood vessel enlargement. If this happens, it’s usually safer to leave the tube in place and treat with a closure device that seals the puncture from inside.
Heart arrhythmias, or irregular heartbeats, can also occur with this procedure. These irregularities can result from the placement of the guide wire and tube tip beyond the junction where the big veins of the body drain into the right atrium of the heart. Carefully checking the length of the guidewire in the vein and choosing the correct tube length before securing in place can prevent this potentially fatal problem.
There could also be complications that happen after the procedure. One such problem is an infection, related to the tube, that can occur in the bloodstream. This is a recognized problem and can lead to more severe outcomes for the patients. The biggest risk factor is the longer duration the central venous tubes are in use, affecting especially dialysis patients.
Another problem down the line is central vein stenosis, or a narrowing of the veins, which is prevalent among dialysis patients who have repeated procedures performed on their central veins. The biggest risk is associated with procedures done on the left side of the neck or collarbone. Other risk factors include the use of tubes for dialysis, and longer duration of time that the tube is left in.
Blood clotting related to the tube is another complication that can occur later. This is most common in patients with cancer and those using tubes inserted at peripheral sites with multiple lumens, or channels. Below is a summary list of early and late complications with central venous line placement.
Early Complications:
– Bleeding
– Piercing an artery
– Irregular heartbeat
– Air blocking a vein
– Thoracic duct injury
– Tube placed incorrectly
– Collapsed lung
– Blood in the chest cavity (Hemothorax)
Late Complications:
– Infections
– Blood clots in the veins
– Narrowing of veins
– Blood clot in lungs
– Slow blood flow
– Defect in the tube lining
– Tube migration
– Blocked tube
– Puncture in the heart muscle
– Nerve injury.
What Else Should I Know About Central Line Placement?
Here are some key tips to remember when a doctor is placing a tube in your veins, often known as a central venous line, to deliver medication or nutrients:
* After the tube is placed in the area around your collar bone or the middle of your neck, a chest X-ray should be done right away. This is to make sure the tube is in the correct spot and no air has accidentally been let into the space around your lungs, which can cause a lung to collapse (known as pneumothorax).
* Your doctor should make sure to draw blood from the vein before placing and opening up the tube there. This acts as a double-check that they have located the correct blood vessel.
* If the attempt to place the tube in the middle of your neck doesn’t work, the doctor will try placing it around the collarbone on the same side of your body. They should not try the other side without first doing a chest X-ray or ultrasound, to prevent a collapsed lung on both sides.
* The doctor should avoid forcibly inserting a metal thread-like tool (guidewire) used to guide the tube into the vein. This is because a forced insertion could harm the blood vessel or nearby structures. It could also result in the guidewire getting twisted, making it hard to remove later, and potentially damaging the blood vessel wall. Moreover, it could cause the tube to be placed wrongly.
* During the procedure, the doctor should always cover the opening of the needle used to make a hole for inserting the tube, to stop air from getting in and potentially causing an air bubble in the bloodstream (known as an air embolism).
* The doctor should always verify the placement of the tube using an ultrasound machine. They will look for certain signs such as a specific bouncing back of the sound waves from the needle and changes in the shape of the blood vessel wall. Remember, the needle itself won’t show up on ultrasound, but the guidewire will. Therefore, using the ultrasound at that stage can be helpful too. Also, the doctor can take a sample of blood from a tube placed near your thigh (femoral line) to make sure it’s a vein and not an artery they’ve accessed.
