Oxygen Therapy

Question 1

Why is oxygen therapy used?

Answer 1

To correct or prevent:
- Hypoxia (insufficient oxygen available to the tissues to meet metabolic needs)
- Hypoxaemia (abnormally low oxygenation of arterial blood)

Question 2

What is oxygen therapy not a treatment for?

Answer 2

• Dyspnoea (breathlessness)
• Increased work of breathing (WOB) (unless associated hypoxaemia)

Question 3

What PaO2 is considered to be hypoxaemic?

Answer 3

< 60mm Hg
(less than)

Question 4

What kPa is considered to by hypoxaemia?

Answer 4

< 8 kPa
(less than)

Question 5

What SaO2 is considered to be hypoxaemia?

Answer 5

< 90%
(less than)

Question 6

What is important to consider about concentration of oxygen during oxygen therapy?

Answer 6

Must be delivered using the minimal concentration required to maintain tissue oxygenation to minimise cardiopulmonary overload

Question 7

True or False…
Oxygen must be prescribed.

Answer 7

True

Question 8

What are the indications for oxygen therapy in an acute setting?

Answer 8

• Acute illness
• Following severe trauma
• Myocardial Infarction (MI)
• Following surgery or procedure

Question 9

What is the target saturation for normal patients?

Answer 9

94-98%

Question 10

What is the target saturation for Type 2 RF or terminal palliative care patients?

Answer 10

88-92%

Question 11

Why would you accept a lower saturation level for a patient who is at risk of Type 2 RF?

Answer 11

• Chronic damage to lungs = natural lower state of saturation, body has adapted to maintaining that
• CO2 retention
• O2 induced hypocapnia, reduced hypoxic drive, pulmonary hypertension = V/Q mismatch long-term, leads to lower saturation level
• O2 doesn’t improve hypocapnia, but hypoxaemia as doesn’t push out Co2
• Would need BiPAP to push Co2 out

Question 12

What does FiO2 stand for?

Answer 12

Fraction of inspired oxygen (%)

Question 13

What is FiO2 defined as?

Answer 13

The % of inspired oxygen delivered to the patient

Question 14

Is SpO2% or PaO2 more important and why?

Answer 14

• SpO2 = Oxyhaemoglobin = immediate responder = so more important in medical emergency
• PaO2 = Arterial circulation

Question 15

What must a physio do to be able to give a patient oxygen?

Answer 15

• CAN independently administer O2
• CANNOT independently prescribe O2 – must have MDT involvement and sign off

Question 16

Why would oxygen be administered as treatment?

Answer 16

• Administering oxygen to treat hypoxaemia (low blood oxygen levels)
• Maintain a target oxygen saturation range

Question 17

What would you work to improve first: Hypoxia or Hypercapnia?

Answer 17

Hypoxia = low O2 will kill you immediately while, low Co2 won’t