Placing a Cannula
Cannulae can be placed to infuse fluids, medication, or take venous blood samples.
Wash your hands
Introduce yourself to the patient, explain purpose of cannula and gain consent.
- Correct gauge cannula- blue is too small to give fluids or meds rapidly. Pink is fine for most patients, green or larger if they are likely to need fluids faster.
- Cleaning device
- Tape & Plaster
- Secure Tourniquet, Identify Vein, Release Tourniquet
- Clean injection area for 30 seconds, leave to dry for 30 seconds
- Remove equipment from packaging, remove cap from cannula (place near at hand and DO NOT LOSE)
- Tourniquet on again
- Say you would wash hands again at this point
- Put gloves on
- Remove cover from needle
- Tether skin with fingers distal to insertion point....best to use your non-dominant thumb. See video
- Insert needle until flashback, advance a millimetre or so more, withdraw needle into cannula and advance. Keep the skin tethered throughout using your non-dominant thumb
- Tourniquet off and apply pressure with finger immediately proximal to cannula to prevent blood spillage
- Retract needle fully, place straight in sharps bin
- Place cap on cannula, tape it down to the skin, cover with plaster.
- "I would rinse with 10ml Saline, fill out a cannula observations form, and attach any appropriate extensions."
Tips for real life
- The lower the vein is below heart level, the bigger and easier it will be
- Asking patient to clench fist to increase size of veins is fine for cannula placement, providing you don't want to immediately take a K+ reading from it - it may be falsely elevated
- Don't panic! Look all over for veins, from antecubital fossa to the veins on the back of the hand. "Houseman's vein" is often easily cannulated, on the lateral (radial) surface of wrist
- Feel as well as touch - self palpate to learn this
- Cannulating the back of a patient's dominant hand is annoying...