Breathlessness and Disease (DISEASE MECHANISMS)

Question 1

What causes breathlessness?

Answer 1

heart failure 
Asthma and lung disease
PE 
Angina equivalent
Hyper-ventilation syndrome
Anaemia

Question 2

What are the anatomical categories of breathlessness?

Answer 2

Muscles, nerves, bones
Vascular, ventricular failure
Obesity, diaphragm
Brain
Airways
Parenchyma
Pleura

Question 3

What are the functional categories of breathlessness?

Answer 3

Oxygen transport
Mechanical disadavatage
Respiratory drive (in the medulla)
Perception of breathing

Question 4

Which functional issue would respiratory muscle weakness cause leading to breathlessness?

Answer 4

Mechanical disadvantage

Question 5

How can a stroke cause breathlessness?

Answer 5

Interferes with respiratory drive

Question 6

What is Fick’s equation?

Answer 6

VO2 = CO x (CaO2 - CvO2)

Question 7

What does Fick’s equation measure?

Answer 7

How much blood you pump vs absorb

Question 8

When is VO2 max reached according to Fick?

Answer 8

When oxygen consumption remains at steady state despite and increased workload

Question 9

What is the average VO2 in a male?

Answer 9

45 ml/kg/min

Question 10

Breathlessness _____ hypoxia

Answer 10

does not equal

Question 11

Hypoxia _____ breathlessness

Answer 11

does not equal

Question 12

Ho can obesityy reduce mechanical ventilation

Answer 12

Creating pressure from outside –> weakness on chest wall

Question 13

What are examples of mechanical restrictions?

Answer 13

Motor neurone disease
Obesity
Pleural effusion
Guillan-Barre syndrome 
Hyperventilation
ILD

Question 14

What can decrease the respiratory drive?

Answer 14

COPD

Ondine’s curse / CCHS

Question 15

What is CCHS?

Answer 15

Congenital central hypoventilation syndrome

aka Ondine’s curse

Question 16

How does COPD lead to type II respiratory failure?

Answer 16

Retain CO2
CO2 increases
Increases CO2 dependence
Lose hypoxic drive if oxygen given up

Question 17

Why do patients with CCHS/Ondine’s curse need to ventilated overnight?

Answer 17

Hypoxic drive stops when they sleep - respiratory arrest

Question 18

What is the normal breathing rate and volume?

Answer 18

12 breaths per minute and 6 L per minute

Question 19

Hyperventilation causes what in terms of perception of breathing?

Answer 19

Constriction of airways and possible airway obstruction

Question 20

How do you assess a patient with breathlessness?

Answer 20

History
Probability
Exam
Test

Question 21

What needs to be asked in the history of a breathless patient?

Answer 21

Exacerbating or relieving factors
Time of onset and duration
Timing (throughout)
Exercise capacity / severity assessment - ADLs
Associated symptoms
Personal / family history of respiratory disease
Social: job, smoking, other exposures

Question 22

What does an instant onset of breathlessness indicate?

Answer 22

Pneumothorax

PE

Question 23

What does an acute (min-hours) onset of breathlessness indicate?

Answer 23

Asthma
Pneumonia
Acute MI
Cardiac tamponade

Question 24

What does a subacute (days) onset of breathlessness indicate?

Answer 24

Pleural effusion
Pulmonary vasculitis
SVCO

Question 25

What does chronic breathlessness (months-years) indicate?

Answer 25

COPD
ILD
Pulmonary hypertension
Anaemia

Question 26

What are the options for investigation of breathlessness?

Answer 26

Spirometry
Measure gas transfer
Peak flow meter
CXR / CT / V/Q scan

Question 27

What is meant by using probability to diagnose?

Answer 27

Ween down number of likely outcomes using history