Anatomy Specifics

 

 

From the diagram above, the most common places for cannulation and blood taking include the dorsal aspect of the hand and the cephalic vein in the forearm whereby success rates, pain level and complication rates are similar for both sites.

If having to use the cephalic vein, it is important to avoid the area of the anatomical snuffbox due to the increased risk of inadvertent puncture or cannulation of the distal radial artery.

If available, it is always best to target the larger looking veins that are easy to palpate and where the cannula will not impair the movement of the wrist or elbows.

Sites to avoid when performing cannulation include:

  • Anatomical snuffbox
  • Arms where there are arterio-venous fistulas (eg in dialysis patients)
  • Areas where lymphatic drainage has been affected (eg the arm following axillary surgery)
  • Areas of cellulitis or burns
  • Small veins in the lower limbs and feet, especially in diabetic patients
  • Areas of peripheral vascular disease, varicose veins, venous hypertension, or oedema
  • Joint Surfaces

 

Veins and Veins to be Avoided

 

Good Veins Veins to Avoid
Bouncy Hard
Soft Thin/Fragile
Straight Inflamed
Visible Bruised
Well supported Near to bony Prominences (painful)
Has a large lumen Areas/sites of infection
Refills when depressed Has undergone multiple previous punctures