Changing and filling vaporisers during use. It may be necessary to change a vaporiser during use. Where possible, repeat the leak test; failure to do so is a common cause of critical incidents [10]. Some anaesthetic workstations will automatically test vaporiser integrity. It is only necessary to remove a vaporiser from a machine to refill it if the manufacturer recommends this. Vaporisers must always be kept upright. Tilting a vaporiser can result in delivery of dangerously high concentrations of vapour [11]. Carbon dioxide absorber Inspect the contents and connections and ensure there is adequate supply of carbon dioxide absorbent. Check the colour of the absorbent
