Cases from General Practice - Breathlessness

Question 1

When assessing a patient with shortness of breath, what two types of causes should be considered?

Answer 1

• RESPIRATORY
• NON-RESPIRATORY

Question 2

What parts of the brain are involved in breathlessness?

Answer 2

• Anterior insula, anterior cingulate gyrus and prefrontal cortex involved
• Same areas that feel pain
• Fear and anxiety exacerbate breathlessness

Question 3

Define dyspnoea.

Answer 3

• Labored breathing
• Subject conscious of shortness of breath

Question 4

What characteristics are indicative of breathlessness?

Answer 4

• Sensation of ‘air hunger’
• Difficulty in inspiration and expiration
• Feeling chest is filled up

Question 5

What causes breathlessness?

Answer 5

• Hypoxia / high CO2
• Airway obstruction
• Decreased lung compliance
• Acute right heart strain
• Chest wall stiffness
• Acidosis
• Anaemia

Question 6

What are the respiratory causes of sob?

Answer 6

• Asthma
• COPD
• Pneumonia
• Pneumothorax
• Lung cancer

Question 7

What are the non-respiratory causes of SOB?

Answer 7

• Hypovolaemic/cardiac/septic shock
• Anaemia
• Pulmonary oedema
• MSK/neurological conditions

Question 8

How does hypoxia influence breathlessness?

Answer 8

• Increases respiration and sensation of breathlessness
• Present in patient with pneumonia with low PO2
• Sensation not increased by hypoxia following chest wall paralysis

Question 9

What is the effects of increased PCO2 on breathlessness?

Answer 9

• Feeling of air hunger and increases respiration
• Effects on chemosensitive areas of brainstem

Question 10

What are the effects of airway obstruction?

Answer 10

• Breathing against resistance sensed by individual
• Increased input from chest wall muscles and stretch receptors
• Increase in brain activity

Question 11

Describe hyperinflation.

Answer 11

• Within airway narrowing and collapse, air trapping and increase in residual volume
• Sensation increases during exercise
• Activates pulmonary stretch receptors

Question 12

Describe sensation from the chest wall.

Answer 12

• Muscle spindle afferents transmit signals reflecting strength of contraction and length of muscle
• Paralysis or vibration over chest wall reduces inputs send to brain
• Common when residual volume increased/inflation

Question 13

Describe what occurs in decreased lung compliance.

Answer 13

• Local congestion activates J receptors in bronchial wall (exception - in transplants)
• Harder for lungs to expand when full of fluid or inflamed
• More energy required to expand chest wall

Question 14

Describe J receptors.

Answer 14

• Situated next to capillaries in bronchial wall
• Input to brainstem via vagus
• Activated by congestion, oedema and irritants
• Activation shortens expiration, increases respiration frequency

Question 15

Describe acute right heart strain.

Answer 15

• Occurs when pulmonary artery occluded even if hypoxia is mild e.g during pulmonary emboli
• Rise in arterial pressure due to right heart failure causes pulmonary vasoconstriction. Symptoms worsen

Question 16

Describe the role of the chest wall and muscles in breathlessness

Answer 16

• Increased load or effort by the chest wall means increased breathlessness
• Hyperinflation - muscle contraction less efficient. Increased breathlessness
• Ventilation reduced in chest stiffness/weakened breathing muscles

Question 17

Describe acidosis.

Answer 17

• During metabolic acidosis, increase in respiration and therefore air hunger

Question 18

Describe dysfunctional breathing.

Answer 18

• During hyperventilation, increased expiration of CO2. Produced alkalosis. Increased effort involved in breathing
• Occurs during spasms of the larynx and reduced size of orifice during inspiration

Question 19

Describe the sensations of breathlessness.

Answer 19

• Consciously sensed
• Information received from chest wall and lungs

Question 20

Describe hyperventilation.

Answer 20

• Breathless at rest and on exercise - excess ventilation with decrease in PCO2
• Wide range of causative factors

Question 21

A patient has a rapid onset of breathlessness. What conditions could this indicate?

Answer 21

• Airway obstruction
• Anaphylaxis
• Shock
• Cardiac Arrythmias
• Pulmonary emboli

Question 22

A patient has gradual onset of breathlessness developing from hours-days. What conditions could this indicate?

Answer 22

• Community acquired pneumonia
• Influenza
• Silent MI, PE or bleeds
• Spontaneous pneumothorax
• Pulmonary oedema

Question 23

A patient has gradual onset of breathlessness developing from weeks-months. What conditions could this indicate?

Answer 23

• Anaemia
• Tumour
• Valve disease
• COPD
• Heart failure

Question 24

What factors and signs often present with SOB and what do they indicate?

Answer 24

• Stridor + SOB = Upper airway obstruction
• Wheeze + SOB = Lower airway obstruction
• Cough = Airway irritation
• Sputum = Infection/inflammation
• Fever = infective cause. Opposite for non-fever

Question 25

In stridor, what conditions could the different speeds of onset and symptoms indicate?

Answer 25

- Gradual onset + no fever = tumour - Vary rapid onset + no fever = Aspiration, anaphylaxis - Rapid- onset + fever = Epiglottitis, croup

Question 26

In wheeze, what conditions could the different speeds of onset and symptoms indicate?

Answer 26

- Gradual onset + no fever + night sweats + smoker + monophonic = Tumour - Very rapid onset + no fever + urticaria = Anaphylaxis - Rapid onset + no fever + no urticaria = Acute asthma - Gradual onset + no fever + smoker + polyphonic = COPD

Question 27

What should assessments of patients with acute-on-chronic SOB aim to establish?

Answer 27

- Whether cause is exacerbation of pre-existing condition - Whether cause is new condition in same body/arising elsewhere

Question 28

What are the two key questions to ask in chronic illness?

Answer 28

- Is this similar to your normal exacerbation of ...? - If not, what is different this time?

Question 29

What should be beared in mind during the history of presenting complaint? PART 1

Answer 29

- When were they normal - What did they first notice - What does it feel like - Is it at rest or exercise - Is there anything else they have noticed at the same time - How does it affect their day-to-day life?

Question 30

What should be beared in mind during the history of presenting complaint? PART 2

Answer 30

- Do they smoke? - Are they on any treatment? - SYSTEMS REVIEW - any fever, weight loss, sputum or night sweats

Question 31

What should be established ina physical examination of a patient with SOB? PART 1

Answer 31

- How fast are they breathing? - Are there any difficulties moving around the room? - Are they struggling to breath? - Any cyanosis or paling? - Are there signs of chest inflation?

Question 32

What should be established ina physical examination of a patient with SOB? PART 2

Answer 32

- How many words are they saying per breath? - Does breathing ease when they relax? - Is breathing noisy or labored?

Question 33

What are some examination findings that would be red flags?

Answer 33

- Difficulty moving chest and reduced expansion - Dull percussion - Crackled breathing - Labored breathing - No air entry could mean air trapping or solid lung

Question 34

What tests could be done to measure extent of breathlessness?

Answer 34

- Measure respiratory rate and oxygen saturation - Ask them to stand and sit and measure how long it takes - Breathless score text - MMRC system (measure before and after interventions)