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IV Cannulas

Cannula Insertion

February 15th, 2021


Explain the procedure and ask for patient's consent.
Wash your hands.
Position the patient appropriately - raise the bed, lower the bed rail, and position the limb appropriately. Consider using a pillow to elevate the limb.


Set up all of your equipment on a trolley, and prime the line if required.
Apply the tourniquet, then wash your hands and don gloves.
Prepare the site by decontaminating with an alcohol swab then allowing the area to air dry. 
Inject 1% lignocaine if appropriate - some people prefer this, though it can distort the anatomy and make a vein more difficult to find.


Stretch the skin distal to the insertion site, and tell the patient to prepare for a sharp 'scratch'.
Insert the needle bevel up, ~30 degrees from the skin, until flashback is seen. Then flatten the needle out and advance 2mm.
Hold the needle still, and advance the cannula to its hilt.
Release the tourniquet, then remove the needle. Some cannulas will bleed as this point (if they have no stop valve) - this can be avoided by placing pressure on the skin proximal to the cannula, or anticipated by placing a piece of gauze beneath the cannula to catch any blood.
Attach the bung to the cannula, which will stop any bleeding. If blood collection is required, attach the 10-20mL syringe to the bung and withdraw the desired amount.
Flush the cannula using 10mL of 0.9% sodium chloride.
Dress the area by taping the cannula and applying the transparent dressing. If a patient is likely to move, an elastic or woven bandage can be used to cover an entire part of the limb.

Finishing Up

Dispose of sharps and other waste. Remove the gloves and wash your hands.
Document the cannula insertion including the date, site, the cannula gauge and the number of attempts.
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