Lecture 6: Oxygen Therapy

Question 1

features of oxygen cylindres

Answer 1

- widely available
 various sizes
- limited duration of supply
- suitable for short term treatment
- delivers 100% oxygen
- expensive

Question 2

features of wall supply oxygen

Answer 2

• hospital only
• may not be available in all clinical areas
• delivers 100% oxygen
• midpoint of ball marks flow rate

Question 3

features of concentrators

Answer 3

• use at home
• mains operated
• molecular sieve that removes nitrogen from the air
• for patients that need constant oxygen
• provides roughly 90% oxygen

Question 4

features of liquid oxygen

Answer 4

• more highly compressed

- allow higher flow rates

Question 5

flow rates of nasal cannulae

Answer 5

1-4 L/min

Question 6

flow rates of uncontrolled masks

Answer 6

5-10 L/min

Question 7

what is the target oxygen saturation for a patient

Answer 7

94-98%

Question 8

what is the target oxygen saturation for patients at risk of hypercapnic respiratory failure

Answer 8

88-92%

Question 9

when does a patient qualify for long term oxygen therapy

Answer 9

pO2 < 7.3
pO2 between 7.3 and 8 and:
- secondary polycythaemia
- nocturnal hypoxaemia
- peripheral oedema
- pulmonary hypertension

Question 10

how many hours a day should a patient use their long term oxygen therapy for

Answer 10

> 15 hours

Question 11

what is apnoea

Answer 11

cessation of airflow for 10 seconds or more

Question 12

what is hypopnea

Answer 12

• reduction in airflow by 50%

- and desaturation of 4% and/or arousal from sleep

Question 13

what is obstructive sleep apnoea

Answer 13

5 or more obstructive apnoeas per hour