You may find varying suggestions for what to consider in what is usually referred to as your 'scene assessment' (Harris, 2016: 1; Pilbery & Lethbridge, 2016: 126) or 'end of bed [...] assessment' (Spurr, 2014). This is a cheat sheet to assist you in identifying these important factors.
The largest number is the smallest cannula. Cannulas range from the 26g purple to the 14g orange. As a list: - 26g purple - 24g yellow - 22g Blue - 20g Red - 18g Green - 16g Grey - 14g Orange