Intravenous Cannulation

Cannulas (a.k.a venflons) come in various colours and sizes. The size needed depends on what is to be put through, e.g. colloid/blood products, or crystalloid; or the rate at which you want the infusion to run. The other limiting factor can also be the size of the patient’s veins.

Subject steps

  1. Introduce yourself to the patient. Explain the procedure to the patient and gain informed consent to continue. It is also worth explaining that cannulation may cause some discomfort but that it will be short lived.

     

  2. Ensure that you have all of your equipment ready as follows:

    • alcohol gel
    • gloves
    • an alcohol wipe
    • a tourniquet
    • an IV cannula
    • a suitable plaster
    • a syringe
    • saline
    • a sharps bin (not pictured)
    • Equipment for intravenous cannulation
      Equipment for intravenous cannulation

  3. Sanitise your hands using alcohol cleanser.

    • Sanitise your hands using alcohol cleanser
      Sanitise your hands using alcohol cleanser

  4. Position the arm so that it is comfortable for the patient and identify a vein.

  5. Apply the tourniquet and re-check the vein.

    • Apply the tourniquet
      Apply the tourniquet
    • Re-check the vein
      Re-check the vein

  6. Put on your gloves, clean the patient's skin with the alcohol wipe and let it dry.

    • Clean the patients skin with the alcohol wipe
      Clean the patients skin with the alcohol wipe

  7. Remove the cannula from its packaging and remove the needle cover ensuring not to touch the needle.

    • Remove the needle cover
      Remove the needle cover

  8. Stretch the skin distally and tell the patient to expect a sharp scratch.

  9. Insert the needle, bevel upwards at about 30 degrees. Advance the needle until a flashback of blood is seen in the hub at the back of the cannula

    • Insert the needle, bevel upwards at about 30 degrees
      Insert the needle, bevel upwards at about 30 degrees
    • Flashback of blood is seen in the hub
      Flashback of blood is seen in the hub

  10. Once this is seen, progress the entire cannula a further 2mm, then fix the needle, advancing the rest of the cannula into the vein.

    • Advance the rest of the cannula into the vein
      Advance the rest of the cannula into the vein

  11. Release the tourniquet, apply pressure to the vein at the tip of the cannula and remove the needle fully. Remove the cap from the needle and put this on the end of the cannula.

    • Release the tourniquet
      Release the tourniquet
    • Remove the needle
      Remove the needle

  12. Carefully dispose of the needle into the sharps box.

  13. Apply the dressing to the cannula to fix it in place and ensure that the date sticker has been completed and applied.

    • Apply the plaster to the cannula
      Apply the plaster to the cannula

  14. Check that the use-by date on the saline has not passed. If the date is ok, fill the syringe with saline and flush it through the cannula to check for patency. If there is any resistance, if it causes any pain, or you notice any localised tissue swelling; immediately stop flushing, remove the cannula and start again.

  15. Finally, ensure that the patient is comfortable and thank them.

    Note that as an extension to procedure, you may be asked to set up an IV drip.