Patient information factsheet
www.uhs.nhs.uk
Having a midline insertion
We have written this factsheet as a guide to having a midline insertion. We hope it will
help to answer some of the questions you may have. If there is anything you do not
understand, a member of your healthcare team will be happy to explain further.
What is a midline?
A midline (also called a midline catheter) is a long, thin, exible tube that is inserted into a large
vein in the upper arm. It is used to safely administer medication into the bloodstream, similar to
a cannula (a small tube that is inserted into a vein, usually in the back of your hand or arm).
A midline can stay in place for approximately four weeks (28 days) if required. However, some
people do require replacement catheters.
Why do I need a midline?
Your reason for having a midline will depend on your medical condition and your treatment plan.
A midline can be used to give treatments, such as:
• antibiotics
• uids
• intravenous (IV) treatment at home
It can also be used to take samples of your blood for testing.
What are the benets of a midline?
A midline can make treatment more comfortable by:
• reducing the irritation that certain drugs can cause to smaller veins
• preserving the health of your vessels
• preventing the need for multiple needle punctures
Midlines are particularly helpful for people who:
• are anxious about needles
• have veins that are small or very dicult to nd
How should I prepare for the procedure?
You can eat and drink as normal before the procedure.
Before the procedure, we will explain the risks and benets of having a midline insertion, and
give you a chance to ask any questions. We will then ask you to sign a consent form.
Where will the procedure take place?
We will perform the procedure in hospital by your bedside or in a procedure room.
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What will happen during the procedure?
A midline insertion is not an operation. It is a simple, sterile procedure that takes approximately
20 minutes.
We will use an ultrasound machine to nd a suitable large vein in your upper arm. We will
then clean your arm and cover it with a sterile drape. We will then numb a small area of your
arm with a local anaesthetic injection (this may sting briey before it takes eect).
When the small area of your arm is completely numb, we will insert the midline through a ne
needle into the large vein in your upper arm. You should not experience any pain during this
part of the procedure. We will then guide the midline further into your vein until the tip (where
the medication enters the bloodstream) sits within the large vein just below your armpit. Once
the midline is in the correct place, we will remove the needle.
A small section of the midline will remain outside of your body. We will attach this section to
your upper arm using a clip (called a Statlock) and clear, adhesive dressing to hold it in place.
What will happen after the procedure?
Once the midline has been xed in place, we can begin to administer medication.
Are there any risks or complications?
Insertion
It can sometimes be dicult to nd a suitable vein or to get the midline into the correct
position. If this is the case, we may have to insert the midline into a dierent vein or discuss
alternative options with you.
Infection
It is possible for an infection to develop inside or around the place where the midline goes
into the vein (this is called the insertion site). Contact your healthcare team immediately if you
experience any of the following symptoms:
• pain, redness or swelling at the insertion site
• discoloured uid coming from the insertion site
• a fever or chills
Blood clots (thrombus)
It is possible for a blood clot to develop around the midline. If this occurs, we will give you
medication to dissolve the clot and we may need to remove the line. Contact your healthcare
team immediately if you experience any of the following symptoms:
• pain, swelling, discomfort or redness on the side of the insertion site
Vein inammation (phlebitis)
Occasionally, the midline may irritate the vein wall, which can cause pain and redness along
the length of the vein. If this occurs, use a warm compress to encourage good blood ow
around the midline. If you have any concerns, please contact your healthcare team.
Bruising or bleeding
It is common to experience some bruising or bleeding at the insertion site. Please inform us of
any blood thinners you are taking before we insert the midline, as this can increase your risk
of bleeding.
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A break or split in the midline
It is important that the midline is not broken or cut. Do not use scissors near your midline.
It is rare for a midline to break or split, but if it does happen, contact your healthcare team
immediately. The line may need to be removed, repaired or replaced.
A dislodged midline
Review your midline once a day to measure how much of the line is out of your skin. The
original length of the line can be found in your information pack. If the external part of the
midline changes length, please contact your healthcare team.
Damage to surrounding tissues or vessels (nerves and arteries)
We will minimise these risks by:
• cleaning the skin around the insertion site with antiseptic solution
• using sterile drapes and equipment
• using ultrasound guidance to locate the vein (this allows us to avoid nerves and arteries)
• discussing activities to avoid (to prevent clot formation)
• inserting the midline away from the joints (to reduce the movement of the line in the arm)
If you are not sure who to contact out of hours, please check with your healthcare team.
How can I look after my midline?
It is very important to take care of your midline to help prevent problems occurring.
You should ush your midline every day using a rm ‘push pause’ technique.
You should change your dressing within the rst 24 hours of the midline being inserted to
remove the gauze and then weekly thereafter (or sooner if the dressing starts to peel o, gets
wet or gets dirty).
A midline should not stop you carrying out day-to-day activities. However, please speak to
your vascular access specialist before starting activities that are manual or involve repetitive
motions, such as lifting weights, playing golf, y shing, painting or knitting.
Do:
• always keep your midline clamped when not in use
• keep the midline insertion site dry and use a waterproof cover or ‘cling lm’ when washing
• always wash your hands before handling your midline
Do not:
• submerge the midline under water
• swim
• undertake repetitive motions
Who should I contact if I have any concerns?
Contact your healthcare team immediately if you think something is wrong, or if you
experience any of the following symptoms:
• pain, redness, oozing or swelling around the insertion site (these can be signs of an
infection, blood clot or inammation)
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• bleeding from the insertion site (if this happens, apply pressure, raise the arm and wrap
with a rmly wound bandage. The bleeding should stop but you will need to have a new
dressing)
• an increase in the length of the tube that is on the outside of the arm (do not remove the
midline)
• a high temperature (above 37.5°C), fever or chills (these can be signs of an infection)
• pain or diculty when ushing the midline or leaking from the midline (if this happens, stop
using the midline and contact your healthcare team for a review)
When will my midline be removed?
When your treatment has nished, the midline can be removed. This is a simple, quick and
painless procedure, and is normally performed by a nurse. They will remove the dressings,
gently pull out the line, clean the removal site and cover it with a clean dressing.
Contact us
We hope this factsheet has helped to answer some of your questions. If you have any further
questions or concerns about your midline or its care, please ask the nurses or doctors looking
after you.
Radiology vascular access service
Interventional radiology
Main x-ray department
Centre block
C level
Southampton General Hospital
SO16 6YD
Version 2. Published July 2021. Due for review July 2024. 1960
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