principles of oxygenation

Question 1

What are the 2 main problems with oxygenation?

Answer 1

1. Shunt

2. Dead Space

Question 2

Explain the problem with ‘shunting’?

Answer 2

1. primary problem with ventilation
2. blood passes through poorly ventilated alveoli
3. remains unoxygenated
4. lowers overall pO2 of arterial blood

Question 3

What may ‘Shunting’ be caused by?

Answer 3

anything that causes blockage of avleoli

• pulmonary oedema
• pneumonia
• mucus plugging

Question 4

What is the issue with shunting management?

Answer 4

cannot be corrected by giving even 100% O2 as it is not reaching the alveli

Question 5

Explain the problem with ‘physiological dead spcae’?

Answer 5

1. primary problem with perfusion

2. lack of blood flow to otherwise ventilated alveoli

Question 6

Mx of shunting problems

Answer 6

1. ventilation and chest physio - helpt to open up alveoli rather than deliver oxygen
2. CPAP and high pressure ventilation
3. high level O2 is not necessary

Question 7

What may ‘physiological dead space’ be caused by?

Answer 7

1. PE
2. CVS shock
3. Emphysema

Question 8

What is the definition of V/Q ratio?

Answer 8

1. ratio of how much air moves through lungs in 1 minute

2. compared to how much blood perfusion runs through them in the same time

Question 9

What is normal V/Q ratio?

Answer 9

0.8

litre of air vs litres of blood passing through

Question 10

What are the 4 main steps of intubation?

Answer 10

1. pre oxygenation
2. sedation
3. laryngoscopy
4. insertion