Mastering Cannulation: A Step-by-Step Guide for Nurses

 Overview 

Cannulation is the process of insertion of a cannula into a patient's vein. Cannulation is  a basic and important skill for Registered  nurses. Cannulation is a very important procedure in nursing for the purpose of administering medications, fluids, and nutrients to patients. However, cannulation may sometimes be a very difficult task, especially for new nurses.

 In this blog post, we'll delve into the world of cannulation, exploring best practices, tips, and  to enhance your skills.

Purposes 

•  Administration of medication
•  Fluid replacement
• Blood sampling
• Nutrient delivery

Parts of cannula 

Size and type of cannula 

Yellow cannula 

Gauge: 24

Estimated flow rate (ml/min): 20

It's commonly used for pediatrics and neonates

Blue 

Gauge: 22 

Estimated flow rate (ml/min): 36 

• It's commonly used for pediatrics, elderly and chemotherapy patients.
• It is also used for slow speed infusions.

Pink

Gauge: 20

Estimated flow rate (ml/min): 60

• It is the most commonly used cannula.
• It is suitable for analgesia and non emergency transfusion.

Green

Gauge 18

Estimated flow rate (ml/min): 125

• It's used in surgery, blood transfusions etc 

Site for intravenous cannulation 

• Veins of the fore arms
• Basilic vein
• Cephalic vein
• Median cubital vein
• Veins of the hand
• Metacarpal veins
• Dorsal venous arch

Types of cannula and their uses.

Preparation Before attempting cannulation

1. Assesing the patient: Assess vein suitability, medical history, and  allergies (if any)

2. Arrange all the equipments and materials needed for cannulation such as Cannula, needle, syringe, tourniquet, and dressing.

3. Select appropriate size and type for the patient's needs.

4.  Clean and disinfect the area.

Procedure 

Introduce yourself

• Wash hands
•  Check patient details 
•  Explain procedure

“ I need to insert a small plastic tube into your vein using aneedle"

“This will allow us to give you fluids and medications intravenously“

“It will be a little uncomfortable, but it hopefully won’t be too painful“

 Gain consent

“Are you ok for me to go head?

Equipments

• Pair of non-sterile (clean) gloves
•  Intravenous cannula of appropriate size –the standard size is 20g (pink)
• Cannula dressing
• Tourniquet
•  0.9% saline to flush with a 5mL or 10mL syringe
•  Cotton gauze with tape
•  Alcohol swab

Position the patient 

• Position the patient in lying or sitting position
• Make sure that there is adequate light and that the room is warm enough to encourage vasodilation.
•  If possible use the patient’s non-dominant arm 
• Adequately expose the arm, removing any tight clothing.
•  Place a pillow under the patient’s arm to stabilise it.

Assses the area 

• Apply a tourniquet 10 cm above the injection site.
•  tourniquet should not be left on for more than 2-3 minutes and avoid nipping the patient’s skin

 Palpate a vein

• Go for a vein you can feel.
• It should ideally be straight
• Tapping the vein & asking the patient to pump their fist can make it easier to see & feel veins.
• Avoid areas where two veins are joining (valves present)

Steps 

• Wear a pair of clean gloves
• Clean the area 3 times with different alcohol swabs in an outward circular motion. Let it air dry and do not touch this area again

 Prepare the cannula

• Open wings.
•  Check top cap is working.
• Slightly withdraw & replace needle.
•  Unscrew the cap at the back of the cannula & place it upright in a tray.
• Remove the cannula sheath.
•  Ensure needle’s bevel is pointing upwards.
• Secure the vein with your non-dominant hand from below.
•  Warn the patient of a sharp scratch.
•  Insert cannula at an angle of 30–45 degrees.
• Observe flashback of blood in the flashback chamber.
• Reduce the angle and advance the needle a further 1-2mm after flashback to ensure it’s in the veins lumen.
• Withdraw the needle slightly so that it’s sharp point is inside of the plastic tubing.
• Advance cannula fully into vein 
• Place some gauze directly underneath the cannula
• Release the tourniquet 
• Apply pressure over the vein from above
• Remove the needle
• Dispose of the needle into a sharps bin
•  Replace cap onto the cannula
• Put some tape on the cannula wings to secure it before flushing

Set up the flush

• Open 5-10ml syringe
• Get 10ml bottle of saline 0.9%
•  Confirm type of fluid & date of expiry
• Withdraw fluid from saline bottle into syringe
• Remove any air bubbles within the syringe
•  Remove the top cap from the cannula port & insert syringe
•  Inject the saline into the cannula:
•  It should go in smoothly with little resistance
•  Watch for signs of swelling around the site
• Apply the transparent dressing to the cannula site.

To complete the procedure…

•  Ensure the patient is comfortable and answer any questions
•  Thank the patient
• Wash hands
• Dispose waste material according to infection control standards.

Document the following

•  Patient details (name )
•  Date & time of cannulation
•  Reason for cannulation
•  Type of cannula used – (e.g. 20 gauge)
•  Site of insertion-vein and arm/hand