Midline Catheter
Midline Catheter

Midline Catheter

A midline catheter is a small, thin tube that is inserted into a vein in the upper arm or at the bend in the elbow. Its tip ends at or near the armpit (axillary) area. A midline catheter is a type of IV access.

A midline catheter may be used to:
  • Give IV fluids and nutrients.
  • Give medicines.
  • Draw blood.
  • Give blood back to the body, such as during a blood transfusion or hemodialysis.
  • Inject a contrast dye for a CT scan (power injection).
  • Provide IV access for treatment that lasts 1–4 weeks.

Tell a health care provider about:

  • Any allergies you have.
  • All medicines you are taking, including vitamins, herbs, eye drops, creams, and over-the-counter medicines.
  • Any problems you or family members have had with anesthetic medicines.
  • Any blood disorders you have.
  • Any surgeries you have had.
  • Any medical conditions you have.
  • Whether you are pregnant or may be pregnant.
  • Any history of health care providers not being able to find a vein for an IV or blood draw.

What are the risks?

Generally, insertion and use of midline catheters is safe. However, problems may occur, including:
  • Blood clots. A clot can form in the midline catheter or at its tip.
  • Phlebitis. This is when the vein becomes warm, swollen, and tender. A red streak may develop along the vein where the midline catheter is inserted.
  • Leaking (infiltration) of IV fluids or medicine into the tissue surrounding the vein. This can cause swelling, pain, and tissue damage in the arm.
  • Infection.
  • Nerve or tendon injury or irritation during midline catheter insertion.

What happens before the procedure?

  • Follow instructions from your health care provider about eating or drinking restrictions.
  • Ask your health care provider about changing or stopping your regular medicines. This is especially important if you are taking diabetes medicines or blood thinners.

What happens during the procedure?

  • Your skin at the IV site will be washed with a germ-killing (antiseptic) solution to help prevent infection.
  • A bandage or cord (tourniquet) will be tightly wrapped around your upper arm.
  • An ultrasound may be used to identify the correct vein.
  • You may be given a medicine to numb the area (local anesthetic). This may be applied to or injected into the skin where the IV catheter will be placed.
  • A sharp needle will be used to enter the vein, and the catheter will be placed into the vein.
  • The needle will be taken out, and the catheter will stay in place.
  • The tourniquet will be removed.
  • A syringe may be attached to the catheter to make sure that you can draw blood from it.
  • The catheter may be flushed with a liquid called normal saline or heparin.
  • A clear bandage (dressing) or tape will be applied to hold the catheter in place.

The procedure may vary among health care providers and hospitals.

What can I expect after the procedure?

  • The catheter may be capped for use later on, or an IV tube may be attached to give fluids, medicine, or blood.
  • Your health care provider will check the IV site as needed to make sure:
    • There is no bleeding, swelling, or pain.
    • Fluid is flowing through the catheter properly.
    • There are no signs of infection.

Follow these instructions at home:

Follow instructions from your health care provider about how to take care of your midline catheter at home. To make sure that your catheter works well:
  • Wash your hands with soap and water for at least 20 seconds before and after caring for or using your midline catheter. If soap and water are not available, use hand sanitizer.
  • Before connecting a syringe or tubing to your midline catheter, scrub the tip of your catheter with a new alcohol wipe for 10–14 seconds. Allow the catheter tip to dry completely. Do this every time before you connect the syringe or tubing to your catheter.
  • Do not let the midline catheter dressing get wet. Change the dressing right away if it becomes wet.
  • Do not take baths, swim, or use a hot tub until your health care provider approves. Cover the dressing with a watertight covering when you take a bath or a shower.
  • Do not pull on the midline catheter or tubing. Doing this can move the catheter out of its place in the vein. If the midline catheter is pulled out of place, the IV fluids or medicine you are getting can leak into the surrounding tissue.
  • Do not allow blood pressure monitoring or needle punctures on the side where the midline catheter is located.
  • Do not lift anything that is heavier than 10 lb (4.5 kg) or the limit that you are told by your health care provider.

Check your insertion site every day for signs of infection. Check for:
  • Redness, swelling, or pain.
  • Fluid or blood.
  • Warmth.
  • Pus or a bad smell.

Contact a health care provider if:

  • The dressing is loose and the midline catheter insertion site is exposed.
  • The skin is irritated where the dressing has been applied.

Get help right away if:

  • You have chills or a fever.
  • There is bleeding at the site where the midline catheter enters your arm.
  • There is drainage, redness, swelling, discomfort, or warmth in the arm with the midline catheter.
  • You are unable to flush your midline catheter, or it feels blocked.
  • The midline catheter is partially or completely pulled out.
  • Your catheter is broken or leaking.
  • You are dizzy.
  • You have chest pain or shortness of breath.
  • You have an irregular heartbeat.

These symptoms may represent a serious problem that is an emergency. Do not wait to see if the symptoms will go away. Get medical help right away. Call your local emergency services (911 in the U.S.). Do not drive yourself to the hospital.


  • A midline catheter is a small, thin tube that is inserted into a vein in the upper arm or at the bend in the elbow.
  • A midline catheter may be used to give IV fluids or nutrients, give medicines, draw blood, give blood back to the body, inject a dye for a CT scan, or provide IV access for treatment that lasts 1–4 weeks.
  • Check your insertion site every day for signs of infection. Signs include redness, swelling, pain, fluid, blood, warmth, pus, or a bad smell.

This information is not intended to replace advice given to you by your health care provider. Make sure you discuss any questions you have with your health care provider.