IV Cannulation Education
Choosing the Right Cannula Gauge
Bigger is not better. Gauge should follow the therapy, the vein and the expected dwell time.
20 June 2026 · 4 min read
Match the device to the therapy
20G suits most routine infusions and vitamin therapy; 22G is kinder to small or fragile veins; 18G and above is reserved for rapid volume or blood products.
Vein assessment first
Palpate before you look. A bouncy, straight, well-supported vein below the antecubital fossa beats a visible but mobile hand vein.
Dwell and care
Document insertion, secure with a sterile transparent dressing, flush to confirm patency and review daily using a visual infusion phlebitis score.