Ports and Whether Blood Draws are Possible

Indications, Benefits, and Potential Contaminants

woman receiving chemotherapy
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Undergoing chemotherapy can be daunting enough — avoiding lots of needle pricks is a simple way to ease this burden, and a port is one way to do this. 

Let's see what a port is, what its benefits are, and basic facts like whether or not you can get your blood draws through them. 

What is a Port?

A port is a small plastic or metal drum that has a soft, flexible tube. This tube, also called a line, is what goes through a large vein in your neck.

The drum has a silicone top through which special needles can easily be inserted without the pain and the uncertainty of a vein puncture. Ports are surgically placed under the skin in your chest or arm and can be left in for a long time. 

Who Gets Ports?

Whether or not you get a port for your chemotherapy depends on a number of factors including how long your treatment will be, the number of chemotherapy agents you need to get at once, cost, and your doctor's input. 

What is the Benefit of a Port?

The benefit of a port is that your nurse does not have to keep puncturing the veins in your body during every chemotherapy infusion. The port permanently accesses a large vein in your neck, until it's removed. 

How is the Port Used?

When you have an infusion, your nurse will insert a needle into your port, and saline will be dripped, to keep your vein open. Medications to prevent side effects may be given, and then chemotherapy drugs will be given through the silicone balloon of your port.

Saline or heparin will be used to flush your port after an infusion.

Why Doesn't My Clinic Do My Blood Draw Through A Port?

Ports can contain substances other than blood. A contaminated blood draw may result in an inaccurate laboratory result.

Because a port is sort of a way-station on the subway line of your circulation system, a certain amount of non-blood substances can remain in the silicone balloon or perhaps in the catheter line.

When you go to your clinic for a blood draw, there may be a variety of things in your port:

  • Drugs
  • Saline
  • Infections
  • Uncirculated blood cells
  • Blood clots

Guidelines To Prevent Contaminated Blood Samples

If your blood draw is done through your port, it may be contaminated unless a special procedure is used to ensure a clean blood sample. A nurse or phlebotomist must be trained in the correct method of cleaning or flushing a port before it can be used. Some clinics and hospitals require a doctor's order authorizing the use of a port for a blood draw. There are clinical guidelines in place for managing and using infusion ports -- those guidelines are in place to guard your health and ensure accurate results when your port is used.

What Should I Do?

If you do need chemotherapy for breast cancer, speak with your doctor about the options for infusion and her recommendations so together you can make an informed decision. 


American Cancer Society. (2014). Central Venous Catheters. Retrieved October 24th 2015. 

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