How to perform cannulation

Introduction

Introduce yourself
Wash hands
Check patient details
Explain procedure
Gain consent

Gather equipment

Non sterile gloves
Apron
Cannula Dressing
Gauze
Cannula - the standard size is 20g (pink)
Tourniquet
Saline - 10ml
Syringe – 10ml
Alcohol swab

Prepare equipment

Put on gloves & apron

Open cannula:

Open wings
Check top cap is working
Slightly withdraw & replace needle – this will make it glide easier
Unscrew the cap at the back of the cannula & place upright

Palpate a vein

Apply tourniquet - avoid nipping the patients skin

Feel for a vein:

Go for a vein you can feel – it’s best if they feel “springy”
It should be straight
Tapping the vein & asking the patient to pump their fist can make it easier to see & feel veins
It’s often easier to feel veins without gloves on
Avoid placing the cannula where there will be lots of movement - e.g. antecubital fossa
Avoid areas where two veins are joining (valves present)

Inserting the Cannula

1. Once you have found an ideal vein it’s time to cannulate!
2. Put gloves back on if you took them off to palpate the vein
3. Clean the area with an alcohol swab for 30 seconds - outward circular motion
4. Check with the patient that its ok to proceed
5. Remove the cannula sheath
6. Ensure needle’s bevel is pointing upwards
7. Secure the vein with your non-dominant hand from below
8. Warn them of a sharp scratch
9. Insert cannula at 20-40º – do it in a smooth firm motion & don’t hesitate
10. When you enter the vein you’ll see flashback – blood filling cannula
11. Advance the needle a further 1mm after flashback to ensure it’s in the veins lumen
12. Hold the needle still & advance the cannula forwards slightly
13. Withdraw the needle slightly so that it’s sharp point is inside of the plastic tubing
14. Advance cannula fully into vein – the needle inside the tube will stop the plastic from kinking
15. Release the tourniquet – this will reduce bleeding
16. Place some gauze directly underneath the cannula - this will prevent blood dripping
17. Apply pressure over the vein from above - this should occlude the vein & reduce bleeding
18. Remove the needle
19. Get the cap you unscrewed at the beginning & quickly screw back onto the cannula
20. Ensure you dispose of the needle into a sharps bin as soon as possible
21. Put some sticky strips on the cannula wings to steady before you flush it

There are many different methods of cannulation, this is just one example
What’s important is that you find a method you are comfortable with, and practice lots

Securing the Cannula

Place the sticky dressing over the cannulated area
Remove the sticky covering to reveal the clear plastic dressing - this can be fidgety!

Flushing the Cannula

Set up flush:

Open 5-10ml syringe
Get 10ml bottle of saline
Confirm type of fluid & date of expiry
Withdraw fluid from saline bottle into syringe
Remove any air bubbles within syringe

Ask them to tell you if they feel any pain or discomfort
Remove the top cap from the cannula port & insert syringe

Inject the fluid into the cannula:

It should go in smoothly with little resistance
Watch for signs of swelling around the site – stop immediately if you see this!
If the patient complains of pain you should also stop immediately!

Close the cannula port