Giving oxygen

Table 6.3 Oxygen flow rates  

How much oxygen to give (adult and child)

  • Important to check person's response to oxygen treatment often, and increase or decrease if needed. If not sure — medical consult
  • Aim for O₂ sats of 94–98%
  • If improving — use less oxygen via nasal prongs
  • If not breathing, or very poor respiratory effort — use bag-valve-mask at 8–15L/min
  • If critically unwell — use non-breather mask at 10–15L/min
  • If condition such as chest pain or respiratory condition (eg pneumonia, asthma) — first use simple oxygen mask (eg Hudson mask) at 5–10L/min
  • If moderate/severe COPD — use nasal prongs or air-entrainment (venturi) mask and less oxygen — aim for O₂ sats of 88–92%

Oxygen delivery devices

Nasal prongs/cannula — Figure 6.23

  • Uses
    • Oxygen needed for long periods. Lets person eat, drink, talk
    • Babies/young children with pneumonia who won’t tolerate face mask
  • Flow rate
    • 2L/min = 28% inspired oxygen concentration
    • 4L/min = 36% inspired oxygen concentration

Figure 6.23  

Simple mask — Figure 6.24

  • Uses
    • Adults/older children with pneumonia or other moderate respiratory illness
  • Flow rate
    • 5–6L/min = 40% inspired oxygen concentration
    • 7–8L/min = 60% inspired oxygen concentration
    • Need to give over 4L/min (child) or 6L/min (adult) to remove expired air from mask and prevent rebreathing of CO2
    • Giving over 10L/min does not increase percentage of oxygen given

Figure 6.24  

Non-rebreather mask — Figure 6.25

  • Uses (for high flow oxygen)
    • Critically ill but adequate breathing — shock, major trauma, sepsis
  • Before using — make sure
    • Reservoir bag full
    • Mask seals properly around mouth and nose (strap tight)
  • Flow rate
    • 15L/min = 85–90% inspired oxygen concentration

Figure 6.25  

Air-entrainment (venturi) mask — Figure 6.26

  • Uses
    • Acute exacerbation of COPD
  • Flow rate
    • Gives 24%, 28%, 31%, 35%, 40%, or 60% inspired oxygen concentration
    • Oxygen must be set at recommended flow rate for required concentration
    • Flow rate listed on valve

Figure 6.26  

Bag-valve-mask — Figure 6.27

  • Uses (for positive pressure ventilation)
    • Not breathing (apnoea), cardiac arrest, inadequate respiratory effort
  • Before using — make sure
    • Valve opens properly
    • Reservoir bag full
    • Mask seals properly around mouth and nose (essential)
    • Airway open (essential)
  • Flow rate
    • 15L/min = 90–100% inspired oxygen concentration

Figure 6.27