Flashcards in Resp - SOB Deck (16):
What are the key presentations in a resp history?
Dyspnoea/SOB, Chest pain, Cough, Haemoptysis, Night sweats, Wheeze
What are the causes of SOB? (general)
- insufficient oxygen to lungs
- insufficient oxygen getting into blood
- insufficient oxygen getting around the body
- increased respiratory drive
Give specific examples of how insufficient o2 to lungs can lead to SOB
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)
Give specific examples of how insufficient o2 getting into blood causes SOB
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
Give specific examples of how insufficient o2 getting around the body can cause SOB
Reduced CO e.g. HF, aortic stenosis
Shock e.g. sepsis, hypovolaemia
Give specific examples of how an increased resp drive can cause SOB
Acidaemia ( e.g. diabetic ketoacidosis, lactic acidosis)
Which probable conditions lead to a SUDDEN onset of SOB?
Vascular cause e.g. PULMONARY EMBOLISM
Mechanical cause e.g. PNEUMOTHORAX
Which probable conditions lead to a GRADUAL onset of SOB?
CHRONIC diseases e.g. lung cancer, pulmonary fibrosis, COPD, asthma, airways disease
Describe the alleviating and exacerbating factors for SOB
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
What are some risk factors for SOB?
Smoking (pack years)
Occupational history (asbestos, silica dust and coal- risk of pneumoconioses)
Medications (amiodarone, methotrexate, cyclophosphamide....)
Nutritional status (alcoholic/elderly- risk of anaemia and so SOB)
What medications can cause pulmonary fibrosis?
Which associated symptoms should you be wary of with SOB?
Chest Pain- pleuritic?- PE/pneumothorax
Weight loss/Night sweats/Loss of appetite
Loss of blood- anaemia
Which conditions must you exclude, due to their need for urgent Tx or poor prognosis?
acute asthma attack
laryngeal oedema (secondary to burns or chemical irritation)
Inhaled foreign body
How would you differentiate SOB in COPD from that in chronic asthma, pulmonary fibrosis, HF, anaemia, bronchiectasis
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
What are the initial investigations you would like to arrange for someone with SOB?
FBC for anaemia. Blood cholesterol, glucose and HbA1c- risk factors for IHD-HF. TFTs, U&Es
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%.