Why a Central Line Is Necessary and Associated Risks

A central line is a type of catheter (flexible tube) that allows fluids to flow in and out of your body. It is placed in a large vein so blood can be drawn and various intravenous (IV) fluids can be delivered directly into a vein.

Common reasons for central line placement include:

• Giving fluids (fluid resuscitation)
• Measuring fluids (to see if you're dehydrated or have received enough fluids)
• Monitoring heart function
• Taking blood (blood draw)
• Dialysis
• Long-term therapy (e.g., antibiotics)
• Chemotherapy

A central line, also known as central venous catheter, is larger than a typical IV line and has benefits that make it more useful in some cases.

This article covers what central lines are used for. It also explains how one is placed and some of the associated risks.

What Is the Purpose of a Central Line?

A central line may have up to five ports called lumens. These can be used to give fluids, draw blood, or take measurements.

A central line may be used for a number of reasons:

• Fluid resuscitation: This is when an individual is given large amounts of IV fluids. A central line will allow these fluids to be given quickly.
• Blood draw: Individuals who need frequent blood draws may have a central line placed. This allows the blood to be drawn without repeated punctures.
• Dialysis: In some cases, two lumens on the central line can be used to perform dialysis. This is when blood is removed and filtered through one lumen. The other lumen is used to return the filtered blood to the body.
  
• Fluid measurement: Some central lines can measure central venous pressure. This tells healthcare providers how much fluid is in the bloodstream.
• Monitoring heart function: A Swan-Ganz catheter is a type of central line. It can be used to monitor the left atrium of the heart, which is the part that receives oxygen-rich blood. This information can be valuable when an individual has a serious heart condition or has had recent heart surgery.
• Long-term therapy: A central line is often used when long-term therapy is expected. For example, an individual may need weeks of IV antibiotic treatment.
• Chemotherapy: These drugs, which are used to treat cancer, may be too harsh for a standard IV.

What Is the Difference Between a Central Line and a Standard IV?

A standard IV is the type of IV that many people are familiar with. This involves the placement of a catheter in a small vein, like on your wrist or the inside of your elbow, so that medication or IV hydration can be given.

Unlike a central line, a standard IV does not allow for the removal of fluids from the body.

While useful in many settings, a standard IV falls short in some ways that make a central line a better choice in certain circumstances.

^{Source: Centers for Disease Control and Prevention}

How Is a Central Line Placed?

If you need to have a central line placed, you'll be asked to lie flat, exposing the area where the line will be inserted. A central line can also be placed if you are unconscious, in which case practitioners will position you appropriately.

The most common veins used to place a central line are:

• The internal jugular in the neck
• The subclavian vein near the collarbone
• The femoral vein in the groin

Before the Procedure

Before the central line procedure:

• You will not be able to eat or drink after midnight the night before.
• Your healthcare provider may tell you not to take certain medications or to continue taking your regular medications.
• Let your healthcare provider know if you are pregnant.
• Remember to bring a list of your current medications with you to show your healthcare provider.

You will also sign a consent form and receive IV fluids. Be sure to ask your healthcare provider any questions you may have.

During Placement

During the procedure, the environment and equipment are kept as sterile as possible.

During placement:

• You will lie down on an X-ray table.
• Your oxygen levels are checked with a device that clips to your finger called a pulse oximeter.
• Your heart rate will be monitored with an electrocardiogram, a device with wires that attach to your body with patches.
• You will be given pain medication, as well as sedatives, which will help you feel more calm.
• The area where the procedure will take place will be cleaned and shaved.
• You will then be covered from head to toe with a sterile drape. This paper sheet has a hole in it to allow the person placing the line access to the vein.
• If you are awake, your skin may also be numbed with a local anesthetic.
• A needle will be inserted into your skin and the central line will be placed into a large vein.
• You may be asked to hum during placement to help prevent air from entering the opening made by the needle.

After Insertion

After placement, the area is cleaned again. A sterile dressing is placed over the insertion site, with the lumens accessible. The dressing is typically clear, which allows the healthcare team to check for signs of infection without exposing the site more than is necessary.

Before the line can be used, its placement must be confirmed with an X-ray, an imaging technique. This ensures that medications won't be accidentally delivered into tissue or the wrong blood vessel.

Sometimes the catheter may need adjustment if it is placed too far in the vessel or not far enough.

What Are the Risks of a Central Line?

Central lines come with risks. These risks must be weighed against the need for the line. The potential for infection is the greatest concern.

Central Line-Associated Bloodstream Infection

A central line-associated bloodstream infection (CLABSI) happens when microbes, like bacteria, enter the bloodstream through the central line.

Hospitals have best practices in place to help prevent infections, including:

• Only inserting the line if it is absolutely necessary
• Regular sterile dressing changes
• The use of a full-body sterile drape during line placement, which is the best way to prevent infection
• Removing the line as soon as it is no longer necessary
• Placing the line above the waist whenever possible to minimize the risk of infection
  

Other Risks

Other risks of a central line include:

• Pneumothorax: A collapsed lung is possible. This is especially true if the central line is placed in the vein near the collarbone. When this happens, it can be treated with a chest tube, which is a large plastic tube that is placed into the chest cavity.
• Change in heart rhythm: Some types of central lines may irritate the heart during the insertion process. This can happen while the line travels through the blood vessels near the heart, causing a change in the heart's rhythm. This usually resolves with correct placement of the line. In rare cases, medication may be needed.
• Air embolism: This is a very serious condition where air enters the bloodstream and travels through the body. This is very rare and largely preventable.

Summary

A central line is a type of catheter that goes in a large vein. It makes blood draws easier and allows for the delivery of large amounts of fluid for medication or hydration. Some types of central lines can remain in place for weeks or even months.

A central line is very useful. However, it's not without risks, including the potential for infection, a collapsed lung, and more.