OXYGEN

Question 1

Drug class

Answer 1

oxygen

Question 2

How does it work? (2)

Answer 2

• increases the PO2 in alveolar gas

- it drives a more rapid diffusion of oxygen into the blood

Question 3

What is the additional benefit of supplemented oxygen therapy in a pneumothorax? (3)

Answer 3

• reducing the fraction of nitrogen in alveolar gas
• accelerates the diffusion of nitrogen out of the body
• hence increasing the rate of reabsorption

Question 4

How is oxygen beneficial in CO poisoning? (4)

Answer 4

• O2 competes with CO
• in the binding of haemoglobin
• this shortens the half life of carboxyhaemoglobin
• this returns haemoglobin to a form that can transport O2

Question 5

Indications (3)

Answer 5

1. hypoxemia
2. pneumothorax
3. CO poisoning

Question 6

Contra-indications (2)

Answer 6

1. chronic type 2 resp failure

2. heat source or flame

Question 7

Side effects (2)

Answer 7

1. discomfort from face mask

2. dry throat

Question 8

Interactions

Answer 8

none

Question 9

Elimination

Answer 9

not applicable