22.1.4 Selecting the IV cannula
Gauge is pronounced ‘gage’. The largest commonly available cannula is gauge 18 or 20.
You must choose a cannula with the appropriate size of needle for the required purpose. The size is referred to as the gauge of the cannula, and each size is given a number – the larger the number, the bigger the cannula.
Why do you think you should choose a large gauge cannula if you are giving IV fluid therapy to a pregnant woman who is haemorrhaging?
The woman has lost a significant amount of blood. Therefore, you need to get replacement fluids into her blood system as quickly as possible. You need a large gauge cannula so you can infuse a large amount of fluid into her vein in a short time.