Resp - SOB

Question 1

What are the key presentations in a resp history?

Answer 1

Dyspnoea/SOB, Chest pain, Cough, Haemoptysis, Night sweats, Wheeze

Question 2

What are the causes of SOB? (general)

Answer 2

• insufficient oxygen to lungs
• insufficient oxygen getting into blood
• insufficient oxygen getting around the body
• increased respiratory drive

Question 3

Give specific examples of how insufficient o2 to lungs can lead to SOB

Answer 3

Obstructed airways e.g. asthma, COPD

Reduced lung volume e.g. INTRA thoracic via pneumothorax, effusion
e.g. EXTRA thoracic e.g. kyphoscoliosis

Reduced vol of functioning lung e.g. interstitial lung disease

inability to inflate lungs due to increased work eg. obesity, weak resp muscles e.g. Guillain Barre/myasthenia gravis or hyperinflated lungs (COPD)

Question 4

Give specific examples of how insufficient o2 getting into blood causes SOB

Answer 4

Alveolar membrane damage e.g. emphysema, fibrosis

Fluid between alveolar wall and capillary e.g. oedema and inflammation e.g. pneumonia

Reduced blood supply e.g. PE

Question 5

Give specific examples of how insufficient o2 getting around the body can cause SOB

Answer 5

Reduced CO e.g. HF, aortic stenosis

Anaemia

Shock e.g. sepsis, hypovolaemia

Question 6

Give specific examples of how an increased resp drive can cause SOB

Answer 6

Hysterical hyperventilation

Acidaemia ( e.g. diabetic ketoacidosis, lactic acidosis)

Question 7

Which probable conditions lead to a SUDDEN onset of SOB?

Answer 7

Vascular cause e.g. PULMONARY EMBOLISM

Mechanical cause e.g. PNEUMOTHORAX

Question 8

Which probable conditions lead to a GRADUAL onset of SOB?

Answer 8

CHRONIC diseases e.g. lung cancer, pulmonary fibrosis, COPD, asthma, airways disease

Question 9

Describe the alleviating and exacerbating factors for SOB

Answer 9

Most tend to be worse on EXERTION

SOB from HF or pulmonary oedema worse at NIGHT when LYING FLAT

Asthma worse at certain times of year, certain places, intense exercise, early morning

Anxiety and stress trigger psychogenic hyperventilation

Question 10

What are some risk factors for SOB?

Answer 10

Smoking (pack years)

Pets (allergies)

Occupational history (asbestos, silica dust and coal- risk of pneumoconioses)

Medications (amiodarone, methotrexate, cyclophosphamide….)

Nutritional status (alcoholic/elderly- risk of anaemia and so SOB)

Question 11

What medications can cause pulmonary fibrosis?

Answer 11

amiodarone
methotrexate
cyclophosphamide
bleomycin
hydralazine
busulphan

Question 12

Which associated symptoms should you be wary of with SOB?

Answer 12

Cough
Chest Pain- pleuritic?- PE/pneumothorax
Muscular weakness/fatigue
Tender limbs-DVT
Weight loss/Night sweats/Loss of appetite
Loss of blood- anaemia

Question 13

Which conditions must you exclude, due to their need for urgent Tx or poor prognosis?

Answer 13

acute asthma attack
anaphylaxis
laryngeal oedema (secondary to burns or chemical irritation)
PE
Inhaled foreign body
Tension pneumothorax
Acute epiglottitis/supraglottitis

Question 14

How would you differentiate SOB in COPD from that in chronic asthma, pulmonary fibrosis, HF, anaemia, bronchiectasis

Answer 14

COPD- history of chronic bronchitis (productive cough on most days of 3months for 2 consecutive years). Risk factors- smoking, occupational exposure to irritants, alpha-1-antitrypsin deficiency (liver failure, fam Hx), signs- hyperexpanded chest, pursed lips breathing, reduced air entry/expansion, hyper-resonant percussion note

Chronic asthma- Hx of transient, reversible cough, wheeze and SOB worse at night, during exercise or exposed to allergens/cold. Exacerbated by NSAIDS and BB

Pulmonary fibrosis- Hx of asbestos silica coal exposure/drug exposure. Signs- clubbing, reduced air entry/expansion, late inspiratory fine crackles

HF- SOB on exertion, orthopnoea, paroxysmal-nocturnal dyspnoea. Risk factors- IHD, other atherosclerotic disease, hypertension, valvular disease. Signs- displaced apex, 3rd and 4th heart sound, raised JVP, hepatomegaly, peripheral oedema.

Anaemia- Hx of bleeding or malnutrition. Fatigue as well as SOB. Sings of central or peripheral cyanosis. Koilonychia, glossitis, angular stomatitis

Bronchiectasis- Hx of productive cough and recurrent chest infections, hx of CF

Question 15

What are the initial investigations you would like to arrange for someone with SOB?

Answer 15

Bloods
FBC for anaemia. Blood cholesterol, glucose and HbA1c- risk factors for IHD-HF. TFTs, U&Es

Imaging
CXR-signs of HF, pneumonia, fibrosis
ECG- path q waves- prev MIs

If lung pathology:
Peak expiratory flow rate (PEFR)- asthma
Spirometry- distinguish obstructive and restrictive lung disease. see whether total lung capacity is >70% or <70%.

Question 16

How would you manage someone presenting with dyspnoea?

Answer 16

give o2 if sats low
sit up
inhalers if needed salbutamol nebs
treat underlying cause of dyspnoea