The Peaceful Pill eHandbook Face Masks vs Exit Bags
Common, inexpensive face masks are often used to deliver oxygen to patients. Held in place by elastic, the mask loosely covers the nose and mouth with oxygen delivered through a plastic tube attached to the mask base. There is no attempt to seal the mask and face. This is in contrast to masks that seal, preventing entry of external air which are more complex, difficult to fit, and prone to leakage (eg. a seal is difficult with a beard). CPAP devices used for sleep apnea, and the mask used in the DeBreather end of life device (see next chapter) are of this type
An Exit bag produces rapid loss of consciousness by ensuring that no oxygen is inhaled, and with gas flow giving a slight positive pressure within the bag, no external oxygen can be inhaled. For a mask to be effective, a perfect seal would need to be maintained till death. Even with a well fitting sealing mask this is difficult as the muscles and contours of the face change as a person loses consciousness. Attempting a hypoxic death using a face mask is risky and is not recommended.
Hyperventilating & the Alarm Response
To minimise the chance of experiencing panic and air hunger, it is recommended that before pulling down the bag, one spends a short time (1-2 mins) hyperventilating (ie. deeply inhaling and exhaling air into the lungs at an increased frequency). This hyperventilation has the effect of pre-lowering the carbon dioxide level in the blood, and will significantly reduce the possibility of an increase in CO2 and any associated alarm response when the bag is pulled down.