There are various devices or apparatus for the therapeutic administration of O2 (see also Chapter 49). Selection of the appropriate mode of administration depends on a number of factors:
- Desired inspired O2 concentration.
- Need to avoid CO2 accumulation.
- Available O2 (i.e. efficiency and economy).
- Need to assist or control ventilation.
- Acceptance of the method by the patient.
Various methods for the administration of O2 are shown in Table 16.2 (see Chapter 49). Most plastic masks deliver less than 60 per cent of the fraction of inspired O2 unless a reservoir bag is incorporated, and this increases the risk of CO2 retention.