Learning about your child's central vascular access device: Flushing the line and changing the cap

Skip Navigation
Cleaning the cap of the lumen and injecting the heparin or saline solution.

What is a central vascular access device?

A CVAD is a thin, flexible tube. It's also called a central line. It is used when your child needs to receive medicine, fluids, nutrients, or blood products for up to several weeks or more. The fluids are put through the CVAD so that they move quickly into your child's bloodstream. The same line can be used for a while, so your child isn't poked with a needle every time.

The point where it leaves the skin is called the exit site. Usually about 12 inches of the line stays outside of the body. But sometimes the line is completely under the skin. The line may have two or three ends so your child can get more than one medicine at a time. These ends are called lumens. The end of each lumen is covered with a cap.

What are some tips for being safe with a central vascular access device?

  • Always wash your hands before you touch your child's central line.
  • Check the skin near the central line every day for signs of infection.

    These signs include pain, tenderness, swelling, drainage, pus, redness, and warmth at or near the exit site.

  • Make sure that your child doesn't get the exit site wet.

    When your child showers, cover the site with something waterproof, such as plastic wrap. Be sure to cover both the exit site and the central line cap(s).

  • If your child's central line has a clamp, keep it clamped when your child isn't using it.
  • Fasten or tape the central line to your child's body to prevent pulling or dangling.

    Remind your child not to play with the line or touch the open end of the line when the cap is off. You may need to repeat the reminder a few times.

  • Never use scissors, knives, pins, or other sharp objects near the central line or other tubing.
  • Avoid clothing that rubs or pulls on the central line.
  • Avoid bending or crimping the central line.

How do you flush the line?

A CVAD should be flushed as often as your doctor tells you, to keep it clear of blood and to prevent clotting. If it has more than one line (lumen), flush them in the same order each time. Depending on the type of central line your child has, you will flush it with either heparin or saline solution. Your child's doctor or nurse will probably give you supplies and instructions on how to flush it. A nurse may come to your home to help at first.

Your child will usually lie down when you flush the line. This helps prevent air from getting into the vein.

  1. Prepare the syringe or cannula.
    1. Be sure you have all your supplies ready.

      These may include the heparin or saline solution, syringes, needleless injection cannulas, alcohol swabs, medical gloves, and a disposal box. What you need will vary with the type of central line your child has. You may have syringes that are already filled with the solution (preloaded).

    2. Wash your hands with soap and water for 15 to 30 seconds.

      Dry them with paper towels. Put on medical gloves, if your doctor told you to.

    3. Wipe the stopper of the heparin or saline solution bottle with an alcohol swab for 15 to 30 seconds.
    4. Remove the cover from the syringe, and twist the needle or cannula onto it. (It may already be attached.)
    5. Remove the cover from the needle or cannula.

      If you have a preloaded syringe, skip to step 2, "Flush the central line."

    6. Pull back the plunger of the syringe.

      Draw air into the syringe equal to the amount of heparin or saline solution you are using.

    7. Push the needle or cannula through the rubber lid of the solution bottle.
    8. Push the plunger of the syringe to force air into the bottle.
    9. Turn the bottle and syringe upside down.

      Position the tip of the needle or cannula so that it is below the surface of fluid in the bottle. Pull back the plunger to fill the syringe with the amount of solution you need.

    10. Before you take the needle or cannula out of the bottle, check for air bubbles in the liquid in the syringe.

      If there are bubbles, push the plunger back in and then pull back on it again.

    11. Remove the needle or cannula from the bottle.
    12. Fill other syringes if you need to flush more than one lumen.
  2. Flush the central line.
    1. Use an alcohol swab to rub the cap of the line you want to flush.

      Rub for 15 to 30 seconds, and then let the cap dry.

    2. Hold the end of the central line so it doesn't touch anything.
    3. If there's a clamp on the line, open it.
    4. Slowly inject the heparin or saline solution.

      If there is resistance, stop. Don't force it. Call your child's doctor.

    5. If your child's central line has a clamp, clamp it as you finish the injection and then remove the syringe. If the central line has a positive pressure cap, remove the syringe and then clamp it.
    6. Put the syringe in the disposal box.
    7. Repeat the above steps for each line you are flushing.
    8. Wash your hands again with soap.

How do you change the cap?

You need to change the cap on each lumen every 3 to 7 days or anytime it leaks, or follow the manufacturer's instructions.

  1. Wash your hands with soap and water for 15 to 30 seconds.

    Dry them with paper towels. Put on medical gloves if your doctor told you to.

  2. If there's a clamp on the lumen, be sure it's closed.
  3. Remove the new cap from the package.

    Loosen, but don't remove, the cover on the end of the new cap.

  4. Hold the lumen with one hand.

    Use your other hand to replace the cap.

    1. Clean the cap as recommended by your health care team.
    2. Remove the old cap, and set it aside.
    3. Clean the end of the lumen as instructed.
    4. Remove the cover from the new cap.
    5. Screw the new cap into place.
  5. Repeat steps 2 to 4 for each lumen.

When should you call for help?

Call 911 anytime you think your child may need emergency care. For example, call if:

  • Your child passes out (loses consciousness).
  • Your child has trouble breathing.
  • Your child has chest pain, is short of breath, or coughs up blood.

Call your doctor now or seek immediate medical care if:

  • Your child has signs of infection, such as:
    • Increased pain, swelling, warmth, or redness.
    • Red streaks leading from the exit site.
    • Pus or blood draining from the exit site.
    • A fever.
  • Your child's central line is leaking.
  • You feel resistance when you inject medicine or fluids into your child's line.
  • Your child's central line is out of place. This may happen after severe coughing or vomiting, or if you or your child pulls on the central line.

Watch closely for changes in your child's health, and be sure to contact your doctor if:

  • You have any concerns about your child's central line.

Follow-up care is a key part of your child's treatment and safety. Be sure to make and go to all appointments, and call your doctor if your child is having problems. It's also a good idea to know your child's test results and keep a list of the medicines your child takes.

Where can you learn more?

Go to http://www.healthwise.net/patientEd

Enter C220 in the search box to learn more about "Learning about your child's central vascular access device: Flushing the line and changing the cap".

The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.