What equipment do you need for cannulation?
- Clean procedure tray
- Non-sterile gloves
- Disposable apron (optional)
- Tourniquet
- Cannula (size appropriate to the indication for cannulation)
- Sterile dressing pack (to provide a sterile field)
- Cannula dressing
- Luer lock cannula cap or extension set
- Gauze swabs
- Normal saline 0.9% (10 ml)
- Syringe (10ml)
- Alcohol swab (2% chlorhexidine gluconate in 70% isopropyl)
- Sharps container
How would you explain cannulation to the patient?
“Today I need to perform cannulation, which involves inserting a small plastic tube into your vein using a needle. This will allow us to administer fluids and medications via the cannula. You may briefly experience a sharp scratch as the needle is inserted.”
How would you position the patient?
Positionthe patient so that they are sitting comfortably. If a bed is available, the patient can lay down for the procedure (this is sometimes preferable, particularly if the patient is prone to vasovagal syncope).
Adequatelyexposethepatient’s armsfor the procedure.
How would you prepare for cannulation?
- Don gloves (if not already wearing some).
- Open the dressing pack and place the cannula, cannula dressing and other items onto the field.
- Prepare the normal saline flush by drawing the saline into your syringe (if you have a pre-filled flush you can ignore this step).
- If you are planning on using an extension set, you should attach this to the flush and prime the line.
- Choose an arm to cannulate
- Place a pillow under the arm to be cannulated to make the procedure more comfortable for the patient.
- Place a field below the patient’s arm to prevent blood spillage.
What are the different sized cannulas used fir?
24- paediatrics, fragile veins
22- paediatrics, fragile veins
20- everyday use, fluids, antibiotics, analgesia
18- everyday use, blood products, potassium, large volumes, surgery, IV contrast
16- trauma, major surgery, obstetrics, GI bleeds, large volumes
14- trauma, rapid infusion of large volumes
How would you choose a vein during cannulation?
You should select a site that is the least restrictive for the patient such as the posterior forearm or dorsum of the hand.
Avoid joints, bruised and erythematous areas
How would you prepare the patient for cannulation?
- Position the patient’s arm in a comfortable extended position that provides adequate access to the planned cannulation site.
- Apply the tourniquet approximately 4-5 finger-widths above the planned cannulation site.
- Palpate the vein you have identified to assess if it is suitable
- Once you have identified a suitable vein you may need to temporarily release the tourniquet, as it should not be left on for more than 1-2 minutes at a time.
- Clean the site with an alcohol swab for 30 seconds and then allow to dry completely for 30 seconds
How would you insert the cannula?
- Wash your hands again, removing gloves if these were worn for setting up the saline flush.
- Don a new pair of non-sterile gloves.
- Re-apply the tourniquet if removed previously.
- Remove the cannula sheath.
- Prepare the cannula
- Anchor the vein with your non-dominant hand from below by gently pulling on the skin distal to the insertion site.
- Warn the patient that they will experience a sharp scratch.
- Insert the cannula directly above the vein, through the skin at an angle of 10-30º with the bevel facing upwards.
- Observe for a flashback of blood into the cannula chamber, which confirms that the needle has punctured the vein.
- Lower the cannula and then advance the needle a further 2mm after flashback is observed to ensure it’s within the vein’s lumen.
- Partially withdraw the introducer needle, ensuring the needle end is within the plastic tubing of the cannula
- Carefully advance the cannula into the vein as you simultaneously withdraw the introducer needle until the cannula is fully inserted and the needle is almost removed.
- Release the tourniquet.
- Place some sterile gauze directly underneath the cannula hub.
- Apply pressure to the proximal vein close to the tip of the cannula to reduce bleeding.
What are you looking for when you’re flushing the cannula?
The flush should be easy to administer with minimal resistance.
Observe for signs of swelling around the site or pain during administration and stop if this occurs.
How would you complete the consultation?
Observe for signs of swelling around the site or pain during administration and stop if this occurs.
Document:
- The patient’s details: full name, date of birth and unique identification number.
- The date and time that cannulation was performed.
- The indication for cannulation.
- The type of cannula used (e.g. 20 gauge).
- The site of cannulation (e.g. dorsum of the left hand).
- The date on which the cannula should be removed or replaced.
- Your name, grade and contact details.
