Using the Bag & Mask
Using the Bag and mask in an emergency situation can be a lot different to it's use on a training mannequin or dummy. The main differences are:
Contamination of the equipment by patient aspiration making ventilation difficult. Blood etc. can make the equipment difficult to use. The Internal parts may become partially or completely blocked. Non-Patient contamination can take place. Animal faeces, urine, mould, chemicals etc. You name it!
To avoid this as much as you can by placing your equipment on a plastic bag laid out on the floor beside you. Most Services use different colour coded bags of various sizes and any of these are ideal.
Getting a seal on some patients can be much more difficult. For a start no mannequin's seem to have beards. Or strange shapes or have injuries to the face or head. Getting a seal on a guy with severe facial trauma is almost impossible. Intubation is required in this type of patient.