Midline catheter factsheet

Introduction

A midline catheter is a medium-length tube that is about 5–8cm long. 

It is placed in a vein in the upper arm and used to give medicines like antibiotics when treatment is needed for more than a week.

 About the device

A midline is inserted in an operating theatre using an anaesthetic to numb the area so your child does not feel any pain. 

It can be inserted while your child is:

Your child’s treatment team will give you information about the procedure and how to prepare.

 Care of the device

Looking after the midline at home

The midline is covered with a dressing and held in place with a securement device. A soft bandage can be used on top to help it feel more comfortable.

Your child may go home with the midline still in place. If this happens, a Hospital in the Home (HITH) nurse will visit to check the midline and remove it when treatment is finished. They will also show you how to care for the midline to prevent infection and keep it working properly.

The following tips can help you look after the midline at home.

Hygiene

  • wash hands well and wear gloves when changing dressings or cleaning the area around the midline.

Showering

  • always keep the dressing dry and clean
  • for baths, keep the midline out of the water
  • for showers, cover the area with plastic cling wrap, taped at each end.

Dressing

  • check daily that the dressing is secure and not peeling off
  • change dressing every seven days, following the instructions given by your child’s treatment team
  • this includes removing the old dressing, cleaning the skin with antiseptic, and applying a new one.

Checking the midline

  • check the midline is not kinked or bent
  • make sure the Needleless Access Device (NAD) on the end of the catheter stays connected at all times
  • be careful when helping your child get dressed to avoid pulling or accidentally removing the midline.

Avoiding damage

  • make sure your child avoids contact sports or rough play to avoid damage
  • do not allow anyone to touch the midline catheter, except for trained health professionals.

When to seek help

If the midline is accidentally removed: 

  1. lie your child down and apply firm pressure over the site with cotton wool or a clean, disposable towel for 5 minutes to stop the bleeding
  2. cover the site with a spare dressing
  3. call your child’s treatment team or HITH nurse.

If the infusor becomes disconnected:

  1. clamp the midline
  2. do not attempt to reconnect
  3. call your child’s treatment team or HITH nurse.

If the midline breaks: 

  1. stop the infusion
  2. clamp the midline above the break, closest to the skin where it was inserted
  3. if you cannot clamp it, bend the midline above the break and tape it firmly together
  4. cover with gauze or a clean, disposable towel
  5. secure with a spare dressing
  6. call your child’s treatment team or HITH nurse.

If the NAD falls off:

  1. clamp the midline
  2. if you are unable to clamp it, bend it above the break and tape firmly together
  3. attach a new NAD if you have one - DO NOT reuse the old one
  4. If you do not have a spare NAD, wrap the end with a spare dressing and tape it
  5. call your child’s treatment team or HITH nurse.

If your child has a fever or signs of infection:

  1. stop the infusor
  2. clamp the midline
  3. call the HITH nurse and take your child to the nearest emergency department.

Signs of infection can include:

  • a fever
  • swelling, redness, or pain at the entry site
  • swelling, redness or pain in the arm.

If the dressing is loose, wet or dirty:

  1. do not remove it
  2. cover it with a spare, clean dressing
  3. call your child’s treatment team or HITH nurse.

If the line appears longer or shorter than before:

  1. secure it with a spare dressing
  2. call your child’s treatment team or HITH nurse.

If there is leaking or drainage at the site:

  1. stop the infusor and clamp the line
  2. call your child’s treatment team or HITH nurse.

If there is blood in the line:

  1. stop the infusor and clamp the line
  2. call your child’s treatment team or HITH nurse.

 Management

Removal of the midline

The catheter is removed when treatment is finished or if it stops working.

Removal is simple and is done by a trained doctor or nurse. Your child will not need a general anaesthetic.

Flushing and locking

Flushing is when a normal salt water or saline solution is pushed into the midline catheter by a syringe. This helps to stop it from becoming blocked and is done after medication has been given.

Locking is when an anti-blood clotting and antibacterial solution is left in the line if it’s not used for a few days to a week. This helps prevent infection and blockages.

Rare but serious complications

Because the midline catheter sits inside the body, there is a small chance it could:

  • damage a blood vessel
  • cause a blood clot
  • cause an infection.

These problems are very rare but can be life-threatening.

Your child’s doctor will explain the risks and benefits before the procedure. Make sure to ask any questions you have about the midline and how to care for it.

Disclaimer

This factsheet is provided for general information only. It does not constitute health advice and should not be used to diagnose or treat any health condition.

Please consult with your doctor or other health professional to make sure this information is right for you and/or your child.

The Sydney Children’s Hospitals Network does not accept responsibility for inaccuracies or omissions, the interpretation of the information, or for success or appropriateness of any treatment described in the factsheet.

© Sydney Children’s Hospitals Network 2025


This factsheet was produced with support from John Hunter Children's Hospital.