Tell the patient who you are and what you are going to do.
Attach the tourniquet to the upper arm.
Examine and palpate the arm for a vein. Look at
– the back of the hand – this is a common site but can be fragile and mobile in the elderly
– the antecubital fossa will always have a vein but might be uncomfortable for the patient
– the anatomical snuffbox at wrist
Swab the selected vein.
Anchor the vein and insert the cannula at a 30° angle to the skin (Fig. 2). Advance until you feel give in the vein wall.
Watch for flashback at the base of the cannula.
Pull back the needle part of the cannula (the stylet) 1–2 mm and watch blood flow into the plastic tubing.
Slide the needle back while advancing the cannula into the vein.
Remove the needle completely and place the cap on the end of the cannula.
Dispose of the needle immediately. Tape down using Vecafix™.
Flush with 5 ml normal saline.
Fig. 2 Cannulation of a vein. Ensure that the stylet and cannula have entered the vein (A) before withdrawing the stylet and advancing the cannula (B).
Finding the vein is the most important part of the exercise. If you have problems, try the following:
After putting on the tourniquet, ask the patient to drop the hand by the side and to clench and unclench the fist. Do something else in the meantime (e.g., draw-up your saline, open up the cannula).
If you cannot feel a vein in one arm, do not attempt to go in blind – stop and review the other arm.
If you still have no luck, ask the patient to put both hands in some warm water to help vasodilation
If you become really desperate, try sticking GTN patches to the antecubital fossa veins
Foot veins are sometimes used, but this can be painful for the patient and should only be used as a last resort.
