Why a Central Line Is Necessary and Associated Risks

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

This type of catheter can also be used to measure fluid volume status to help determine if a patient is dehydrated or has received enough fluids.

A central line is larger compared to a typical IV line, but it has benefits that make it more useful in some cases.

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

Administering drugs through a central line.
Science Photo Library / Getty Images 

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 a patient is given large amounts of IV fluids. A central line will allow these fluids to flow as quickly as possible.
  • Blood draw: Patients who need frequent blood draws may have a central line placed. This allows the blood to be drawn without the need to repeatedly "stick" the patient.
  • Dialysis: In some cases, two lumens on the central line can be used to perform dialysis. This is when blood is removed and filtered. The other lumen can be 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 very valuable when a patient has serious heart problems or has had recent heart surgery.
  • Long-term therapy: A central line is often used when long-term therapy is expected. For example, a patient may need weeks of IV antibiotic treatment.
  • Chemotherapy: These drugs may be too harsh for a standard IV.

Central Line vs. Standard IV

A standard IV is the type of IV that most people are familiar with. This involves the placement of a catheter in a small vein (e.g., on your wrist or the inside of your elbow) so that medication or IV hydration can be dripped or pushed.

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.

Central Line
  • Can remain in place for weeks or months

  • Can deliver a greater volume of fluids at one time

  • Placed in a large vein to allow medications to work more quickly

  • Allows blood to be drawn easily

  • Greater risk of infection

Standard IV
  • Can stay in place for 72 to 96 hours

  • Lower limit to how much fluid can be delivered per hour

  • Place into a smaller vein near skin's surface; fluids take more time to circulate

  • Does not allow for drawing of blood

  • Less risk of infection


Source: Centers for Disease Control and Prevention

A peripherally inserted center catheter (PICC) is another type of IV access that can be maintained for weeks and months. This is not the same as a central line, but it does share many of the same qualities.

Recap

Central lines have a variety of uses. They can help deliver medications, allow for dialysis to be performed, make blood draws easier, measure fluids, and more. They have some benefits that standard IVs do not, including that they can be left in for weeks or months, rather than a few days.

Insertion of a Central Line

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:

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.

Once you are draped, the skin is cleaned with antiseptic. If you are awake, the skin may also be numbed with a local anesthetic.

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

Ultrasound helps the healthcare provider locate the blood vessel. A hollow catheter is inserted into the vein. The catheter is then stitched in place. In some cases, an adhesive device may be used to hold the catheter still.

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 check for signs of infection without exposing the site to air more than necessary.

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

Sometimes the catheter may need adjustment. This could be because it is too far in the vessel or not quite in far enough.

Recap

Central lines are always inserted under sterile conditions. Placement is confirmed with an X-ray.

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 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: Studies have shown that covering the entire body, rather than just the area where the line will be placed, is the best way to prevent infection.
  • Removing the line as soon as it is no longer necessary

Central lines are placed above the waist whenever possible. This also minimizes 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.
  • 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.

Recap

Infection is the greatest risk of having a central line. Other risks include collapsed lung, changes in heart rhythm, and air entering the bloodstream.

Summary

A central line is a type of catheter that goes in a large vein. It makes blood draws easier, allows for the delivery of large amounts of fluid (medication, hydration), and can remain in place for weeks or even months. In contrast, a standard IV must be changed every three to four days.

A central line is very useful and can make healthcare providers jobs easier. It can also make a hospital stay more bearable for you. For example, having a central line in place means avoiding multiple "sticks" for blood draws.

However, it's not without risk, including the potential for infection, collapsed lung, and more.

Frequently Asked Questions

  • How is a PICC line different from a central line?

    Peripherally inserted center catheter lines are placed in the arm rather than the chest, neck, or groin. They are a very long type of catheter that is threaded up through a vein in the arm toward the heart. A central line can stay in place longer than a PICC line. It also delivers a higher volume of fluids.

  • How long can a central line remain in place?

    Days, weeks, or months. This is true as long as there are no complications, such as an infection or blockage.

  • How is a central line removed?

    A person is placed on their back so their head rests slightly below the heart and feet. They may be asked to breathe out strongly while holding their nose with the hand opposite the catheter. At the same time, the person performing the removal puts pressure on the site and gently pulls the line out.

  • What are common IV placements for a central line?

    The internal jugular vein in the neck, the subclavian vein near the clavicle, and the femoral vein in the groin are common sites for a central line.

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9 Sources
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