Overview of Central Line
A central venous catheterization (CVC) is a process often needed in serious or emergency medical situations. Doctors use this procedure on patients who are receiving multiple medications that don’t mix well together or medications that could hurt the veins. In such cases, accessing the bloodstream through the standard method, such as through the arm (peripheral access), won’t cut it. Moreover, CVC is also carried out if a patient needs hemodialysis, a treatment for kidney failure. For this, dialysis catheters, which are bigger than regular catheters, are used.
Central lines could also be needed to insert certain tools that monitor and manage heart functions. For instance, Swan Ganz catheters are used to measure the pressure inside the heart. Likewise, temporary pacemaker leads can be inserted for patients with abnormally slow heart rates or blocked electrical pathways in the heart. Catheters used for these purposes are referred to as introducer catheters.
Most of the time, doctors use a method called the Seldinger technique to insert the catheter. It starts with a small puncture into a vein, after which a wire is placed into the vein to guide the catheter. The catheter is then inserted over the wire which is then removed. Usually, doctors use ultrasound as a guiding tool for this procedure, unless it’s not available or if there’s an emergency where they’ll rely on touch to find a vein. It’s worth noting, however, that like all procedures, CVC has potential complications too. This article will focus on those complications.
Anatomy and Physiology of Central Line
A central venous catheter is a thin tube that doctors usually insert into one of three large veins in the body. These veins, which are in close proximity to a large artery, include the internal jugular vein located in the side of the neck, the subclavian vein in the chest, and the femoral vein in the thigh.
The internal jugular vein is situated next to the carotid artery on the side of the neck, typically to the outside of the artery and beneath the sternocleidomastoid muscle (a muscle that runs down the side of your neck). Meanwhile, the subclavian vein is found next to the subclavian artery. From the armpit area (also known as the axilla), it runs across the upper side of the chest, going underneath the collar bone (clavicle), where it combines with the internal jugular vein to form the brachiocephalic vein. The right and left brachiocephalic veins then merge together to form a large vein known as the superior vena cava.
The femoral vein is positioned in the thigh region and is positioned towards the inside of the common femoral artery. An easy way to remember the arrangement in the thigh area is by using the simple mnemonic ‘NAVeL’. This stands for femoral nerve, femoral artery, femoral vein, and lymphatics, moving from the outside to the inside of the thigh.
The closeness of the veins to important structures like arteries and lungs makes it crucial for doctors to perform this procedure with utmost care to avoid causing any harm to the patient.
Why do People Need Central Line
Central lines, also known as central venous catheters, are tubes that doctors place in a large vein in your neck, chest, or groin to give medications or fluids or to collect blood for medical testing. Here are some scenarios that might require a doctor to place a central line:
1. If your body isn’t maintaining stable vital signs (like blood pressure or heart rate), a central line can be used to deliver medication that helps to stabilize you. These medications are called vasopressors.
2. There are certain medications or treatments that are very concentrated, or that can cause scarring in smaller veins. If you need to receive these types of therapies, a doctor might put in a central line to ensure these treatments can be given safely.
3. Sometimes, it’s hard for a doctor or nurse to start an IV in your smaller, peripheral veins, which are the ones in your arms and hands. This could be due to several reasons, such as if your veins are very small or not easily visible. In such cases where they’re having trouble getting access to these veins, they might opt to place a central line instead.
4. If you need a large amount of blood transplanted quickly, it may not be possible or practical to do this through the smaller peripheral veins. In such cases, a doctor might decide that a central line is your best option.
When a Person Should Avoid Central Line
There are some situations where a doctor might not be able to insert a central line, which is a type of tube that they put into a large vein in your neck, chest, arm, or groin to give medication or to take blood samples.
Common reasons why you might not be able to have a central line inserted include:
– Having a condition where your blood doesn’t clot normally (coagulopathy). This could be because you’re taking medication that prevents blood clots, or because you have a condition that affects your body’s ability to form blood clots, like disseminated intravascular coagulation (DIC), which is a serious condition that causes small blood clots and heavy bleeding. Doctors may also be more careful if they’re inserting the central line into an area of the body that can’t easily be pressed on to stop any possible bleeding, particularly if you also have a high risk of bleeding.
– However, a past study has shown that patients with coagulopathy did not have increased risk of bleeding when placing a central line, and giving platelets or fresh frozen plasma (which can help blood clot) before the procedure didn’t lower bleeding complications.
– If you have a skin infection (like cellulitis, which is a painful, red infection, or an abscess, which is a pocket of pus) at the place where the doctor is planning to insert the central line, they might not be able to do the procedure.
– If you’ve had surgery or been injured at the place where the doctor is planning to insert the central line, this might also mean that they can’t do the procedure.
– There may also be other things to consider, such as if you’re currently wearing a neck brace (for a broken or injured neck), it might not be safe to insert a central line into a vein in your neck. Similarly, if you are wearing a pelvic binder (which helps stabilize your pelvic area after an injury), they might not be able to place a central line in your groin.
Equipment used for Central Line
When your doctor needs to insert a central line, which is a long, thin tube that’s inserted into a large vein in your body to deliver medications or treatments, they use a central line insertion kit. This kit usually contains everything they need for the procedure, including a central venous catheter (the tube that goes into your vein), a guidewire (a thin wire that guides the catheter into place), a syringe, a needle for introducing the other instruments, a small knife (scalpel), a special kind of thread (silk suture) for stitching up the wound, and a tool for widening the incision (skin dilator).
Your doctor will also use sterile gloves and a gown to avoid introducing any germs into your body, and a hat and mask for added sanitation. They will also use special sterile sheets or towels to create a clean area around the site where the central line will be inserted. These sheets help to protect the equipment and materials from becoming spoiled by bacteria and other contaminants.
Before starting the procedure, your doctor will clean your skin with an antiseptic agent to kill any bacteria. After the central line has been placed, your doctor will cover each tube end (port) with a cap, and cover the site of insertion with a dressing to prevent infection. To make you comfortable, a local anesthetic (usually 1% to 2% lidocaine) will be used to numb the area. This is usually included in the kit.
Sometimes, other items might be required depending on the specific rules at your hospital, like antibiotic sponges which help to keep the area clean. If your doctor plans to use an ultrasound for guidance during the procedure, they will also need a sterile cover to keep the ultrasound probe clean too.
Who is needed to perform Central Line?
If possible, it’s beneficial to have a helper during the procedure. But, a well-prepared healthcare provider who has done the procedure many times can insert a central venous catheter (a flexible tube inserted into a large vein in the neck, chest, or groin area to give medications or fluids) without any help. It’s also suggested that a second team member, such as a nurse, ensures that the wire is removed from the patient and notes this down in the nursing records. This should match the notes made by the doctor.
Preparing for Central Line
Before starting a medical procedure, it’s important that the patient knows what’s going to happen. The doctor should explain the risks and benefits to the patient, who then has to give written agreement, if they are able to do so. It’s important to take a moment to double-check that the person being treated is indeed the right patient and that they are about to have the correct procedure at the correct place on the body. This is known as a “time out”.
Once everything is confirmed, they will clean the site on the body where the procedure will take place. This is done by applying a special skin-cleaning liquid in circles, starting small, then making each circle bigger. This liquid is called a ‘topical antiseptic’ like chlorhexidine or betadine. The antiseptic should be fully dry before the procedure starts to make sure that it works best at killing any germs on the skin.
Once the medical device, often a catheter or a tube, is inserted, doctors usually rinse it with a saltwater-like solution which is known as sterile saline. This is done to keep the tube from getting blocked by blood clots and to make sure that the tube is working properly. This rinse is done both before and after the tube is put into the patient.
How is Central Line performed
After wearing a sterile gown, gloves, and a mask, the doctor first prepares the area where the tube will enter your vein. This involves cleaning the area, then injecting a local anesthetic — a medicine to numb the area so it doesn’t hurt. This injection creates a small raised area, or “wheal,”, beneath your skin.
Next, the doctor inserts a special needle and progresses towards the vein that is targeted for treatment, all while applying gentle suction. Once they see blood return into the syringe attached to the needle, the syringe can be removed. The guide wire, a thin flexible tube, is then placed through the needle into your vein, reaching about 15 centimeters deep.
Afterwards, the needle is removed, but the guide wire remains in place within your skin and vein. A small cut is made to create a pathway for the guide wire. Then, a device called a skin dilator is placed over the wire to create a larger opening in the skin and vein.
The doctor then inserts the central line, a longer tube, over the top of the wire. The central line will pass under your skin, through your tissues, and into your vein, following the path of the wire. Once the central line is in place, the guide wire is removed. The end of the central line outside your body is then secured, with a sterile dressing applied over the area where it enters your skin.
Following this, the doctor makes sure all parts of the central line work properly, and will flush each part with saline to prevent any blood from clotting within the tube.
Lastly, they run tests to confirm that the central line was placed in the correct location and check for any potential complications after the procedure.
Possible Complications of Central Line
When a doctor places a line, or tube, into your body for medical treatment, there are some risks they need to monitor for. The risks include a collapsed lung (pneumothorax), fluid build-up around the heart (pericardial effusion/tamponade), bleeding, accidental puncture of an artery that could lead to a growing blood clot (expanding hematoma), infection, blood clots in a vein (thrombosis), nerve damage, accidental loss of guidewire in a vein, air bubbles entering the bloodstream and blocking it (air embolism), and irregular heartbeats (arrhythmias).
After a line placement is done, your doctor will carefully monitor for these complications. If the line has been placed in your chest area, like in subclavian, IJ, supraclavicular approaches, they’ll keep a continuous check on your heart using a monitor to watch for any changes in your heart rhythm. This could indicate the line might have been placed too deep or the heart muscle is irritated.
Some rare but serious complications like lethal arrhythmias have been reported. The doctor will also look out for signs of bleeding, expanding blood clot, nerve injury, pericardial effusion, and pneumothorax. If you’re awake during this, a neurological check may be done to confirm there is no peripheral nerve damage. The doctor may use an ultrasound scan as a quick tool to check for these complications.
While an X-ray was traditionally the main method for checking the correct placement of the line and possible complications, ultrasound is significantly useful too. For example, it can be used to see any air in the chest cavity (pneumothorax) and to check for fluid around the heart and the expanding blood clot. Finally, a simple and quick test involves flushing some saline solution under the ultrasound and watching it flow in the heart. This is a fast and accurate method to confirm successful placement of the central venous catheter.
What Else Should I Know About Central Line?
A central line is a tube that doctors insert in a large vein in your neck or chest. This gives medical staff a way to give you fluids, medications, monitor your hydration, and measure your heart’s pressure. It’s especially valuable in serious medical situations. It can also be used to deliver something called total parenteral nutrition (TPN), which is special food given through a vein to patients who can’t eat or absorb nutrients from their intestine.
However, it’s important to note that the typical triple or quad lumen catheter, often used for cooling body temperature, isn’t the best option to quickly give lots of fluids or blood products. Instead, a single big peripheral line (such as a 16 or 18 gauge line) is more effective for speedy fluid infusion.
Here’s why: To infuse the same amount of fluids quickly, all three ports of a triple lumen need to be infusing under pressure at the same time. This is to match the infusion speed of a single 16 gauge peripheral line with the same level of pressure. The reason the central line isn’t as effective for rapid fluid infusion is due to the length of the tubing and the resistance to the flow of liquid caused by the longer catheter.
That said, multi-lumen central venous lines (tubes with multiple channels) are beneficial for patients who need multiple medications at the same time (especially medications that can harm smaller blood vessels), frequent blood draws, close monitoring of the pressure in their veins, or dialysis, which is a treatment commonly used for kidney patients.