Oxygen

Question 1

What is the method of action of oxygen?

Answer 1

• ↑ PO2 in alveolar gas
• ↑ diffusion of O2 into blood
• ↑ delivery of O2 to tissues
• In a pneumothorax, nitrogen levels are ↓
• In CO poisoning, O2 competes with CO to bind to haemoglobin

Question 2

What are the indications for oxygen?

Answer 2

• ↑ tissue oxygen delivery in states of hypoxaemia
• ↑ reabsorption of pleural gas in pneumothorax
• ↓ half life of carboxyhaemoglobin in CO poisoning

Question 3

What are the contraindications for oxygen?

Answer 3

• Chronic type 2 respiratory failure - ↑ CO2 levels and respiratory acidosis
• Heat source/naked flame inc. smoking

Question 4

What are the side effects of oxygen?

Answer 4

• Facemask discomfort

* Dry throat – use humidification system

Question 5

What information should be given to a patient on oxygen?

Answer 5

• Should be kept in place continuously, may be briefly removed for eating/drinking