Paediatric Acute care Guidelines PMH Emergency Department


  • Ultrasound (US) is a very useful tool for difficult intravenous (IV) cannulation


  • Previously confirmed case of difficult IV cannulation
  • Failed IV cannulation
  • Anticipated difficult IV access (e.g. vein neither visible nor palpable, high adiposity)



  • IV cannula and associated equipment for cannulation
  • Use the linear ultrasound probe 25mm (small one)
  • US gel: both non-sterile and sterile
  • Ultrasound probe sterile sleeve
  • Clean gloves or sterile gloves (preferred)


Positioning and technique

  • Wash hands
  • Prepare everything as you would for IV cannulation and blood collection
  • Put on gloves +/- gown
  • Clean large area of skin over the vein with an alcohol wipe or chlorhexidine solution
  • Scan and locate a suitable vein (use non-sterile US gel)
  • Cubital fossa area or volar aspect of mid forearm are good locations to start with. Otherwise, have a look at the saphenous vein.
  • Scan the cross-section of the vein, then turn the probe 900 slowly to scan it longitudinally to see the alignment of the vein

Use either of the two methods below:

  • LAMP  = Locate, Align, Mark, Puncture – use US to mark and then cannulate
  • LAP = Locate, Align, Puncture – visualise with US in real time

LAMP Approach:

  • Scan the vein as above (using non-sterile US gel)
  • Mark the vein location using a pen (or tip of a pen cap to make an indentation), on both sides of the probe after aligning the centre of the probe on the vein (cross section view)
  • Wipe the gel off with gauze
  • Clean the skin again with alcohol wipe or chlorhexidine
  • Cannulate the vein as usual using the two marks on the skin

LAP Approach: 

  • Cover the US probe with the sterile sleeve
  • Apply sterile gel inside the probe sleeve and some on the skin
  • Use either the cross-sectional view or the longitudinal view in real time
  • Align the centre of the probe with the vein
  • Pierce the skin close (2-5mm) to the centre of the probe
  • Look for the needle tip entering the vein
  • You can see the depression and movement of tissue around it
  • If using the cross-sectional view, you will need to slide the probe to follow the tip of the cannula needle





We want your feedback!

Help us provide guidelines that are useful to you, the clinician.

Give feedback here