Session 6: Hypoxia And Respiratory Failure

Question 1

Define hypoxaemia

Answer 1

Hypoxaemia is where there is a low pO2 in the blood

Question 2

Define hypoxia

Answer 2

Hypoxia is inadequate supply of o2 to the tissue

Question 3

Give an example of where tissues can be hypoxic without hypoxaemia

Answer 3

Anaemia

Question 4

Give the levels of O2 saturation and pO2 used to diagnose respiratory failure

Answer 4

O2 sat < 90%

pO2 < 8kPa

Question 5

What is type 1 respiratory failure?

Answer 5

Impairment in gas exchange causing hypoxia

Question 6

What is type 2 respiratory failure?

Answer 6

Impairment in gas exchange causing hypoxia with hypercapnia

Question 7

What two non respiratory causes are there of hypoxia?

Answer 7

Low inspired pO2

Right to left shunt in the heart

Question 8

What should the ventilation perfusion ratio be?

Answer 8

1

Question 9

What type of respiratory failure does hypoventilation lead to?

Answer 9

Type 2 respiratory failure - get both hypoxia and hypercapnia

Question 10

Define hypoventilation

Answer 10

Poor ventilation of the entire lung

Question 11

How do you get hypoxia and hypercapnia from hypoventilation?

Answer 11

V/Q mismatch - Perfusion remains the same but ventilation rate falls

Question 12

Why is chronic hypoventilation better tolerated than acute?

Answer 12

The body has time to compensate

Question 13

What can cause acute hypoventilation?

Answer 13

Opiate overdose
Head injury
Severe, acute asthma attacks