Paediatric venepuncture and peripheral intravenous access — OSCE

Station brief (candidate)

• State the cannulation site you would choose and the order of sites, and justify starting distally on the hand.
• State the cannula gauge for this child and the principle behind gauge selection.
• Describe the comfort bundle you would apply, naming the topical agents and their lead times.
• Outline the cannulation sequence and how you would confirm correct placement.
• Explain your escalation pathway if the first attempt fails, including the role of ultrasound and the attempt rule. [6] [7]

Scenario detail

The child is an 18-month-old (11 kg) with viral gastroenteritis and moderate dehydration, brought for fluid rehydration. The child is alert but miserable, with dry mucous membranes and reduced skin turgor; the circulation is intact with warm peripheries and normal capillary refill. No cannula is yet in place. You have been asked to lead the cannulation. The examiner will ask you to talk through your preparation and then probe a complication or a failure. [6]

Expected candidate performance

1. Site selection: Names the dorsal hand veins first, then the antecubital fossa, the forearm cephalic vein and the great saphenous at the ankle, and justifies a distal start by preserving proximal sites and ease of securing, while avoiding joints in a mobile child where possible. [6]
2. Gauge: Chooses a 22G (blue) for an infant or small child, with the next size up and down ready, and states the principle of the smallest cannula (largest gauge number) that delivers the therapy. [6]
3. Comfort bundle: Applies topical anaesthesia at the correct lead time (EMLA 60 minutes, Ametop 30 to 45 minutes, LMX4 30 minutes), gives oral sucrose at about 1 to 2 millilitres two minutes before, and uses distraction and comfort positioning on a parent's lap with a single calm operator. [7] [10]
4. Cannulation sequence and confirmation: Cleans and applies a tourniquet, stabilises the vein, inserts at 15 to 30 degrees bevel up until flashback, advances slightly, withdraws the needle while advancing the cannula, releases the tourniquet, secures with a transparent dressing, and confirms with a free saline flush and no swelling. [6]
5. Escalation: States the attempt rule (no more than two per operator, then a senior), and describes ultrasound-guided peripheral access for the difficult-access child, with intraosseous access reserved for the emergency or arrested child. [1]
6. Complication management: Names infiltration, extravasation, phlebitis, accidental arterial puncture and needlestick injury, and the correct first action for each — stop the infusion and aspirate for extravasation, withdraw and apply pressure for arterial puncture, and report immediately for a needlestick injury. [6]

Marking domains

• Correct site order and gauge for age, justified by principle.
• A complete comfort bundle applied at the correct lead times, including sucrose for the infant.
• A safe, correct cannulation sequence with flashback, advancement and flush confirmation.
• A rehearsed escalation pathway (two attempts, ultrasound, intraosseous) and the correct first actions for the common complications. [6] [7]

Common fails

• Choosing an overly large gauge or starting at the antecubital fossa in a mobile child. [6]
• Omitting topical anaesthesia or applying it too late, or forgetting sucrose in an infant. [7] [10]
• Persisting with repeated blind attempts instead of escalating to ultrasound. [1]
• Missing the immediate actions for extravasation or arterial puncture, or leaving the cannula in longer than needed. [6]