Respiratory Failure

Question 1

Conditions that increase drive to breath?

Answer 1

anxiety
exercise
metabolic acidosis
hypoxaemia

Question 2

Conditions that decrease the drive to breathe??

Answer 2

breath holding
narcotic overdose
sedatives

Question 3

normal passive breathing needs to fight against which forces?

Answer 3

elastic

resistive forces

Question 4

upper airway important how?

Answer 4

humidifies, filters air
first line of defence
prevents aspiration
can become obstructed

Question 5

problems with conducting airways?

Answer 5

narrowing
collapse (emphysema)
spasm
obstruction, mucus (asthma, CF, carcinoma)

Question 6

surfactant function?

Answer 6

reduce surface tension: >lung compliance

Question 7

What promotes the diffusion across the alveolar – papillary membrane?

Answer 7

The concentration gradient between partial pressures of O2 and CO2

Question 8

arterial blood gas normal values?

Answer 8

PaO2 = 85-100mmHg
PaCO2 = 35-45mmHg
pH = 7.4 (7.35-7.45)
HCO3 =24 (22-30)

Question 9

A-a gradient is difference between what?

Answer 9

Alveolar O2 and arterial O2 concentrations

Question 10

normal (reference range) A-a gradient in young adults?

Answer 10

7-14

Question 11

where can respiratory failure occur in the lungs?

Answer 11

gas exchange

movement of gas in and out of the lungs

Question 12

hypoxaemia is when PaO2 is:

Answer 12

<60mmHg

Question 13

usual reason for type 1 respiratory failure?

Answer 13

impaired gas exchange

Question 14

hypoventilation leads to?

Answer 14

hypercapnia

Question 15

what is the value when hypercapnia?

Answer 15

PaCO2 >50mmHg

Question 16

what 2 things can causes VQ mismatch?

Answer 16

pneumonia

pulmonary embolus

Question 17

what causes impaired diffusion?

Answer 17

interstitial lung disease

Question 18

what causes loss of surface area/airflow obstruction?

Answer 18

COPD

Question 19

what is most common cause of hypercapnia?

Answer 19

intrinsic lung disease (severe COPD)

Question 20

primary ‘pump’ failure in resp leads to hypercapnia caused by?

Answer 20

Neuromuscular disease: MND, ALS, guillain Barre syndrome

Question 21

3 signs of respiratory failure?

Answer 21

1. accessory muscle use at rest
2. tachypnea
3. low O2 sats
   drowsiness, confusion

Question 22

how to assess for respiratory failure?

Answer 22

arterial blood gasses needed

Question 23

6 important investigative tests in respiratory failure?

Answer 23

1. bloods
2. CXR
3. CT chest
4. VQ study
5. sleep study
6. LFTs

Question 24

respiratory failure treatment principles? 5

Answer 24

1. maintain O2
2. reduce resp workload
3. max ventilation
4. maintain pH/electrolytes
5. target cause
   Nutrition, Physio, enough sleep