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Wound Drainage Culture

Medically reviewed by: Elana Pearl Ben-Joseph, MD

What Is a Wound Drainage Culture?

A wound drainage culture is a test that finds germs such as , , or in a wound.

A wound can be open or closed.

  • An open wound, in which the skin has been torn, cut, or punctured, can happen from things such as falls, bites, or burns. A surgical incision (cut) is also a type of an open wound.
  • A closed wound is when the injured area is under the skin and not exposed to the air. But it can still become infected with germs and may develop into an abscess.

A wound that's healing can produce a clear or pink fluid. An infected wound can produce a yellowish, bad-smelling fluid called pus. When fluid seeps from a wound, it is called wound drainage.

Why Is a Wound Drainage Culture Done?

Wound drainage cultures can show if a wound is infected. If it is, the culture can show what type of germ caused the infection. This helps doctors choose the best treatment.

A doctor might think there's an infection if there is pain, swelling, warmth, or redness around the wound, or if the drainage looks like pus. Wound infections can also cause a fever and a general ill feeling, especially if the infection spreads or has been present for a while.

How Should We Prepare for a Wound Drainage Culture?

You don't have to do anything special to prepare your child for a wound drainage culture. But tell the doctor about any antibiotics or other medicine your child is taking or has taken recently, as this can affect the results.

You can help prepare your child for a wound drainage culture by explaining that the test will be quick. It's important for kids to stay still during the test.

How Is a Wound Drainage Culture Done?

A doctor or nurse will clean the surface of the wound and the surrounding skin. They may place numbing cream over the skin about 30 minutes before the procedure, or give medication by mouth or through a vein if they want the child to sleep during the procedure.

They will then take a sample of the drainage to send it for culture in one of several ways:

  • If the wound is open, they can press the tip of a cotton swab into the wound and gently rotate it to collect a sample.
  • If the wound is closed, they can withdraw fluid or pus from the wound with a syringe and a small needle. This is called .
  • The skin over an abscess might need to be cut to reach the pus inside. This is known as incision and drainage. The cut is usually small.

They will clean and bandage the wound or cut after they have taken the culture.

Can I Stay With My Child During a Wound Drainage Culture?

If the text is simple, with your child fully awake, you can stay with your child. If the procedure is more complex or your child received medicine to sleep through it, you might need to stay in the waiting room.

What Happens After a Wound Drainage Culture?

The person who did the test will place the culture sample in a special container and send it to a laboratory. There, it will be observed to see if any germs grow.

A technician will report the results to your child's doctor, who will review the results with you. If nothing significant grows, the culture is called "negative." If a germ that can cause infection grows, the culture is "positive."

Results aren't available to the patient or family at the time of the test. It usually takes about 2 days for the germs to grow. Some less common kinds of germs grow slowly and may take several weeks to be seen.

If the wound looks infected or your child looks ill, the doctor may start treatment before the test results are ready. Doctors base their treatment decisions on the most likely cause of infection, but they can change the treatment if needed when the test results come back.

Are There Any Risks From a Wound Drainage Culture?

A wound drainage culture is a safe procedure. There may be some mild bleeding after the wound is swabbed or the skin is cut. Most of the time, there are no complications.

If your child will get medicine to sleep through the test, discuss the risks and benefits with your health care provider before the procedure.

How Can I Help My Child Feel Better?

After the procedure, help your child follow any other instructions the doctor gives you.

What If I Still Have Questions?

If you have questions about the wound drainage culture, contact your doctor. Before the test, you can talk to the nurse or doctor who will do the procedure.

Medically reviewed by: Elana Pearl Ben-Joseph, MD
Date reviewed: July 2018