If cannulation of a paediatric patient is required, consider simultaneously taking blood samples to avoid repeated venepuncture attempts. Preparation, comfort, and communication are crucial to minimise distress.

The Difficult Intravenous Access (DIVA) prediction score helps identify patients in whom IV access may be challenging. It considers vein palpability, vein visibility, age, and history of prematurity.

• A score ≥4 predicts a significantly higher risk of first-attempt failure.

• In such cases, ultrasound-guided cannulation should be considered early.

Preparation

To minimise acute discomfort, give oral sucrose just before the procedure, or apply a topical anaesthetic cream to multiple potential cannulation sites (covered with a clear dressing after application) depending on the patient’s age. 

• Oral sucrose: For infants under 3 months; give immediately before the procedure.
• Topical anaesthetic: Apply to multiple potential sites and cover with a clear dressing.
  • EMLA (Lidocaine 2.5% + Prilocaine 2.5%) – apply for 60 minutes
  • LMX (Lidocaine 4%) – apply for 30 minutes
  • AnGel (Amethocaine 4%) – apply for 45 minutes
• Cold spray: May be used directly at the site for brief anaesthesia or away from the site as a distraction.
• Explain the procedure in age-appropriate language and encourage questions.
• Supportive measures:
  • Use distraction (tablets, toys, bubbles, play specialist)
  • Encourage relaxation and deep breathing
  • Involve the parent/carer — they may hold or comfort the child, or gently help immobilise the limb if appropriate.

Equipment

• Gloves
• Blue or yellow cannula
• Alcohol swab
• Gauze
• 0.9% sodium chloride vial
• Syringe
• Access to a sharps bin
• Tourniquet if child is older/similar size to an adult
• Blood specimen bag 
• Blood bottle:
  • If this is a small child, then you will need the little bottles where the cap comes off. You can prep them with the lids open in a paper tablet cup in your tray so they are ready
  • If this is a child that is as big as an adult (12-17) year olds then you can use normal blood bottles and a blue-ended vacutainer adapter and vacutainer. 
• Paediatric cannula dressing (preferred if dressing is designed with images/cartoons)
• Octopus/cannula port and flush: primed and ready
• Wrap: some children may pull at, or dislike seeing the cannula. Therefore, a light bandage/dressing to wrap over the cannula may be less distressing for patients.  

Procedure

1. Introduce yourself, confirm patient identity, indication for procedure, allergies, and consent (verbal assent where possible).
2. Wash hands and don PPE. Remove anaesthetic cream and clean the site thoroughly with an alcohol swab; allow to air dry fully.
3. Site selection – 
   • Common sites: dorsum of the hand, wrist, antecubital fossa, or foot (infants).
   • Warm the limb or use gentle tapping/massage to encourage venous filling.
   • Avoid areas over joints or previously cannulated sites
4. Position the child comfortably, ensuring the chosen limb is well supported and accessible. Use distraction techniques to maintain cooperation
   • A parent or carer may hold the child securely to assist in providing appropriate grasp and immobilisation of the area to act as a tourniquet. 
   • For older children, when applying a tourniquet proximal to the chosen site, beware not to pinch the skin. 
5. Clean the site again if needed with an alcohol swab and allow to dry. Anchor the vein by gently pulling the skin taut below the insertion site. 
6. Needle insertion – Hold the cannula bevel up at a shallow angle (10–30°). Insert through the skin until you see a flashback in the chamber (flashback may not occur for small veins and 24G cannula). Lower the angle slightly, advance a further 2-3mm, then thread the cannula while withdrawing the needle. If resistance or swelling occurs, stop immediately. 
7. If required, take blood samples from the cannula immediately after successful insertion and before flushing. Label bottles clearly at the bedside.
   • If using a 24G cannula, it is easier to let blood drop passively into blood collection bottles. 
   • When taking blood for culture or blood gas, aspirate blood from the hub of the cannula using a blunt needle and syringe
   • For cannulas 22G or larger, a syringe can be used to aspirate blood.
8. Secure the cannula wings with a transparent paediatric dressing — ensure visibility of the insertion site. Dispose of sharps and waste appropriately.
9. Remove the tourniquet and attach the saline-primed extension or port to the end of the cannula. Flush with saline to confirm patency (observe for swelling or leakage). Apply a light wrap or bandage if the child may pull at the cannula.
10. Document the site and size of cannula inserted, who performed the procedure, and any complications. 

Aftercare

• Observe for infiltration, phlebitis, or dislodgement.
• Ensure dressings remain secure and the site visible.
• Provide reassurance and praise to the child and parents.

Key notes

• Limit to two unsuccessful attempts per clinician before escalating to a senior or specialist (e.g. anaesthetics, NICU, or outreach IV team)
• Do not dig around if you can help it. It causes unnecessary distress to the child and it would be better to just withdraw and try at a different site.
• Use a vein-finder where possible this may also add an element of play/fun for children. if they have one.
• Make sure you have a good flat surface for your tray. Those little blood bottles don’t stand up as well as you’d like and you can’t put a lid on them until you’ve atleast taped down the cannula wings.
• Let the child sit in their adult’s lap if that is what they want. They can watch something on a phone or tablet or they can have a snack, anything to keep them occupied and comforted.
• Don’t be hard on yourself if you don’t manage or find it difficult to cope with a distressed child. The best thing you can do for both yourself and the child is to ask for help.
• For difficult access – Use warm compresses to improve venous filling. Transillumination or ultrasound guidance can help visualise deeper veins.

References

The Royal Children’s Hospital Melbourne: Peripheral IV Access Guideline

Written by Dr Amina Aslam (CTF)