How to insert a cannula:
- wash hands
- obtain consent (skip this if patient is unconscious)
- prepare all necessary items (dressing tray, proper size cannula, tourniquet, alcohol/iodine/chlorhexidine swab, sterile dressing)
- apply tourniquet
- look for suitable superficial vein
- put on gloves
- prepare skin with swab
- if using cannula larger than 20G, inject a little local anaesthetic subcutaneously with a 25G needle at the site where you wish to puncture with the cannula.
- take cannula (ensure cannula is working by moving cannula freely over needle) and puncture skin next to vein at an angle of about 15o to skin
- move cannula and needle so that it pierces the vein. look for a flashback of blood in the cannula indicating that it is in the vein.
- advance the cannula and needle about 5mm further into the vein with cannula flush with skin (the idea is to try to avoid breaking through the other side of the vein).
- advance cannula over needle into vein, keeping the needle steady at all times.
- if cannula does not enter the vein properly, do not attempt to reinsert needle into cannula. remove the whole thing and try again.
- withdraw needle.
- free backflow of blood indicates that the canula is in the right place. apply digital pressure above cannula to stop blood flow.
- attach syringe with saline to cannula and flush the cannula to ensure that it is patent.
- attach blue cap to cannula
- release tourniquet
- apply dressing and transparent adhesive dressing over site.
- dispose of needles into a sharps container. dispose of gloves and syringes into specialised containers for contaminated items.
Call for help and supervision if uncertain.