Paediatric venepuncture and peripheral intravenous access — formative SAQs

SAQ 1 (10)

A 14-month-old, 10 kg child is brought to the emergency department with gastroenteritis and moderate dehydration, and requires a peripheral cannula for rehydration. ^{[7] [9]}

1. State the cannula gauge you would prepare and your preferred site order, giving the reason for starting distally on the hand. (4) ^[6]
2. Outline the comfort bundle you would apply, naming each topical agent with its correct lead time and the role of oral sucrose. (4) ^{[7] [10]}
3. Describe how you would confirm correct cannula placement and state the rule on the number of attempts. (2) ^[6]

Model answer

Gauge and site. For a 14-month-old, a 22G (blue) cannula is the most appropriate starting gauge (24G for neonate and infant, 22G for infant and small child, 20G for the older child). The preferred site order is the dorsal hand veins first, then the antecubital fossa, the forearm cephalic vein, and finally the great saphenous vein at the ankle. Starting distally on the dorsum of the non-dominant hand is preferred because the veins are superficial and easy to secure, and a distal site leaves the more proximal sites available if the first attempt fails. The principle is to use the smallest cannula (largest gauge number) that delivers the therapy. ^[6]

Comfort bundle. Apply topical anaesthesia at the correct lead time — EMLA (lidocaine and prilocaine) about 60 minutes before, Ametop (tetracaine 4 per cent) about 30 to 45 minutes, or LMX4 (liposomal lidocaine 4 per cent) about 30 minutes — and occlude it with a dressing. Give oral sucrose at about 1 to 2 millilitres roughly two minutes before the procedure in this infant. Deploy age-appropriate distraction, comfort positioning on a parent's lap, and a single calm operator. ^{[7] [10]}

Confirmation and attempt rule. Confirm placement with a free flashback, an easy saline flush with no resistance and no swelling, and a blood return. The rule on attempts is that no operator should make more than two attempts before calling a more senior clinician; the difficult-access child is the indication for ultrasound-guided peripheral access. ^[6]