Practising venous cannulation
Nicholas B N Timmis and Geoffrey N Morris give an alternative method for developing this practical skill
- By: Nicholas B N Timmis, Geoffrey N Morris
All junior doctors need to be able to insert a peripheral cannula confidently, but the teaching of this technique to medical students is somewhat hit and miss. When we get an opportunity to practise in the wards, we often fail because we haven't had the chance to practise in a relaxed environment, where we can iron out our early fumbling. The system that we describe here gives a good opportunity for students to practise cannulation on a simple but surprisingly realistic model so that cannulation in patients becomes more successful and, importantly, less painful.
Before beginning it is important to choose the correct size of cannula. The options, in order of decreasing bore size, are 16 gauge (grey) for surgical emergencies; 18 gauge (green) for blood transfusions; 20 gauge (pink) for maintenance of intravenous fluids; and 22 gauge (blue) for difficult veins, slow intravenous fluids, or intravenous drugs in a