Oxygen Therapy Flashcards
When do we need oxygen therapy?
Any illness where oxygen supply to tissues is likely to be reduced – i.e. to avoid the need for anaerobic respiration.
At what SpO2, PaO2 and lactate values should oxygen therapy given?
SpO2 <93%
PaO2 <70mmHg
Lactate >2.0mmol/l
Why is it important to identify anaemia in patients receiving oxygen therapy?
Could be 100% saturated with oxygen, but not enough RBCs - still hypoxic
Give examples of situations in which oxygen therapy is needed
Ventilation/perfusion mismatch or diffusion impairment:
- Pleural space pathology e.g. pneumothorax
- Lung pathology e.g. pneumonia
- Perfusion abnormalities e.g. hypovolaemic shock
Reduced global delivery of oxygen (DO2):
- distributive shock
- anaemia
- acid bas disturbances (acidosis reduces Hb affinity=> increased O2 offloading, alkalaemia increases Hb affinity => decreased O2 offloading)
- R to L shunts (de-oxy blood into circulation)
- death
What are the pros and cons of flow by oxygen therapy?
Pros:
- easy
- Quick
- minimal equipment needed
- need to be conscious
- non-invasive
Cons:
- only a short term solution
- relies on patient being able to breathe - patent airway
- wasted oxygen in environment - FiO2 < 30& (fractured of inspired oxygen)
- need someone holding it
- high flow rates => expensive
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What are the pros and cons of mask oxygen delivery
Pros:
- Higher FiO2 than flow by (~40%)
- non-invasive
- quick
- easy
- conscious
Cons:
- someone needs to hold
- short term
- need a tight seal to maximise effectiveness - size dependent (tricky in small patients)
- low tolerance
- equipment dependency
- relies on patent airway
What are the pros and cons of using a tent/cage for oxygen therapy?
What are the pros and cons of using nasal prongs for oxygen therapy?
What are the pros and cons of using a nasal catheter for oxygen therapy?
What are the pros and cons of intubation for oxygen therapy?
