A Midline Catheter is a thin, flexible tube placed into a vein in the arm. The catheter is 8-10 centimeters long and can stay in the arm for up to 29 days. This allows patients to get IV (intravenous) medicines and have blood samples drawn. The catheter is placed by a trained nurse.


The catheter must have a dressing that covers the place where it goes into the arm. The dressing may be a clear dressing or gauze and tape. Under the dressing, an antimicrobial gel square surrounds the catheter to help prevent infection. The catheter is kept in place with a device called a StatLock that secures to the arm. A nurse will change the dressing every 7 days or anytime the dressing is wet, soiled or loose.


The catheter dressing must be sealed with a waterproof cover when showering. Tell a nurse right away if the dressing has gotten wet or is loose after a shower.

Blood Draws

The nurse may use the catheter to get blood samples for testing. Some tests may not be able to be taken from the catheter. These tests will need to be drawn from another vein.


Problems are rare but can occur. Let the nurse or provider know right away if:

  • There is blood or other drainage from the place where the catheter comes out of the arm.

  • Any redness or swelling on the arm that the catheter is placed.

  • Any pain in the arm, shoulder, or neck on the side that the catheter is placed.