Peripheral Intravenous Cannulation



  • Cannula:
    • 20 gauge for most adults
    • 22 gauge if for quick IV ABs or for children
    • 18/16 if bleeding internally
  • Syringes:
    • 1 for blood (10mls usually adequate unless for blood cultures = 20mls)
    • 1 for flushing with saline
  • Saline
  • Persist Plus (chlorhexidine) swab
  • Tegaderm
  • Cap
  • Dressings Kit / Gauze


  • Find appropriate vein
    • Keep Arm in dependent position
    • Apply tourniquet or blood pressure cuff inflated to 80-100mmHg for large arms.
    • Apply proximally over mid to distal humerus; there is a vein running between the radius and ulna so applying over forearm will not work
    • Tapping veins can help to become more prominent
  • Using Persist Plus, swab over and around (using circular sweeps) area around the vein(s) you wish to use
  • Stabilise arm / skin distal to vein (ensure that hand / thumb NOT near needle)
  • Hold needle with bevel facing UP and needle pointing downwards on 30 degree angle, stab needle through skin into vein approximately 1-2mm until blood seen to move up needle and into plastic base (“flashback”). If no flashback seen, may need to stab again a little deeper (particularly if patient elderly / atherosclerotic. Might also need to jiggle slightly to ensure in vein)
  • Once happy with position of needle, stabilise the needle end with one hand to prevent movement. Push the plastic cannula forwards off the needle and into position.
  • Press on vein proximally
  • Retract the needle
  • Then
    • Take blood using syringe, release tourniquet and flush with saline (5-10mls)
    • Cap end
    • Clean blood from around area and using apply tegaderm to hold cannula down = work quickly as blood clots quickly and need to get blood from syringe into tubes
  • Only try twice – if unsuccessful, get someone else to try.