1(E) Respiratory Failure

Question 1

When does respiratory failure occur

Answer 1

When gas exchange is inadequate resulting in hypoxia

Question 2

What defines respiratory failure

Answer 2

PaO2 less-than 8kPa

Question 3

What is type I respiratory failure

Answer 3

PaO2 less than 8kPa

Normal PCO2

Question 4

What causes type I respiratory failure mainly

Answer 4

V-Q mismatch

Question 5

What are 6 causes of V-Q mismatch

Answer 5

• PE
• Pneumonia
• Pulmonary oedema
• Asthma
• Emphysema
• Pulmonary Fibrosis
• ARDS

Question 6

What else can cause type I resp failure

Answer 6

Alveolar Hyperventilation

Right-to-Left cardiac shunt

Question 7

Define type II respiratory failure

Answer 7

Hypoxia (PaO2 < 8) with hypercapnia (PaCO2 >6)

Question 8

What is the main mechanism if type 2 respiratory failure

Answer 8

Alveolar hypoventilation without V-Q mismatch

Question 9

What are the 4 etiological categories of type 2 respiratory failure

Answer 9

1. NM Disease
2. Pulmonary Disease
3. Chest wall disease
4. Reduced resp drive

Question 10

What are the 4 pulmonary diseases causing type 2 respiratory failure

Answer 10

• COPD
• Asthma
• End-stage pulmonary fibrosis
• OSA

Question 11

What are 3 causes of reduced resp drive

Answer 11

CNS Tumour
Medication (Opioids)
Trauma

Question 12

What NM disease may cause type 2 resp failure

Answer 12

Myasthenia Gravis 
MND 
Poliomyelitis 
Gullian Barre 
Cervical Cord Lesion

Question 13

What does poliomyelitis affect

Answer 13

Anterior horn cells - causing a LMN lesion

Question 14

What chest wall deformities can cause T2RF

Answer 14

Flail chest

Kyphoscoliosis

Question 15

What is a mnemonic to remember symptoms of hypoxia

Answer 15

DRAC

Question 16

What are symptoms of hypoxia

Answer 16

Dyspnoea

Restless

Agitated

Confused

Question 17

What is a sign of hypoxia

Answer 17

Cyanosis

Question 18

What are 3 consequences of long-term hypoxia

Answer 18

Polycythaemia
Pulmonary HTN
Cor Pulmonale

Question 19

What is the main symptom of hypercapnia

Answer 19

Headache

Question 20

What are 5 symptoms of hypercapnia

Answer 20

Headache 
Confusion 
Drowsiness 
Coma
Peripheral Vasodilation

Question 21

What are 4 signs of hypercapnia

Answer 21

Bounding pulse
Tachycardia
CO2 Flap
Papilloedema

Question 22

If someone has a metabolic acidosis, what should be done

Answer 22

Calculate anion gap

Question 23

How is the anion gap calculated

Answer 23

[Na+ + K+] - [Cl- + HCO3-]

Question 24

What is a normal anion gap

Answer 24

10-18mmol/L

Question 25

How is type I respiratory failure managed

Answer 25

15L Oxygen via non re-breathe mask

Question 26

When is assisted ventilation indicated in type I respiratory failure

Answer 26

If hypoxic despite 60% oxygen

Question 27

How is type II respiratory failure managed

Answer 27

Controlled oxygen therapy - start with 24% Venturi mask

Question 28

What oxygen saturations are aimed for if a person is at risk of type 2 respiratory failure

Answer 28

88-92

Question 29

If just given someone oxygen for type 2 respiratory failure, when should ABG next be checked

Answer 29

20-minutes later

Question 30

If PCO2 is steady or lower in second ABG, what should be done regarding oxygen

Answer 30

increase to 28% venturi

Question 31

When is NIPPV considered

Answer 31

PCO2 increased by 1.5kPa

Question 32

If NIPPV is ineffective, what is performed

Answer 32

Intubation and mechanical ventilation

Question 33

What are the two methods of oxygen delivery

Answer 33

Variable performance device | Fixed performance device

Question 34

What are fixed performance devices

Answer 34

Able to control FiO2

Question 35

Give an example of fixed performance device

Answer 35

Venturi mask

Question 36

What are variable oxygen device

Answer 36

Cannot control exactly how much oxygen the individual recieves

Question 37

What rate can nasal cannula deliver oxygen

Answer 37

1-4L/min

Question 38

What % oxygen can nasal cannula deliver

Answer 38

25-40%

Question 39

What is the advantage of nasal cannula

Answer 39

Patient is able to eat and drink

Question 40

What are disadvantages of nasal cannula

Answer 40

- Nasal soreness | - High-flow oxygen can cause epistaxis

Question 41

What is a Hudson mask also known as

Answer 41

Simple Face Mask

Question 42

What concentration of oxygen can go through a Hudson mask

Answer 42

15L/min Oxygen

Question 43

What is problem with simple face mask and what does this mean for its use

Answer 43

Imprecise concentration of oxygen. Means should not be used in type II resp failure

Question 44

What is a non re-breathe mask

Answer 44

Hudson mask with reservoir bag

Question 45

What is the action of the reservoir bag

Answer 45

Bag fills during expiration and empties during inspiration - increasing FiO2

Question 46

What oxygen concentration can pass through non re-breathe mask

Answer 46

15L

Question 47

When is non re-breathe mask used

Answer 47

Emergencies

Question 48

What is a Venturi mask

Answer 48

Provides precise FiO2 - used for type II resp failure

Question 49

What colour is the 24% Venturi mask

Answer 49

blue

Question 50

What colour is the 28% Venturi mask

Answer 50

white

Question 51

What colour is the 35% Venturi mask

Answer 51

yellow

Question 52

What colour is the 40% Venturi mask

Answer 52

green

Question 53

What colour is the 60% Venturi mask

Answer 53

red

Question 54

According to BTS what are indications for non-invasive ventilation

Answer 54

- COPD with respiratory acidosis - T2 RF due to chest wall deformity - Cariogenic pulmonary oedema unresponsive to CPAP - Weaning from tracheal intubation