Shortness of Breath Flashcards
In broad terms, what pathological processes can cause shortness breath
Insufficient oxygen entering the lungs
Insufficient oxygen entering the blood from the lungs
Insufficient oxygen being delivered to the body
Increased respiratory drive
What may cause insufficient oxygen from entering the lungs
Obstruction (asthma, COPD, tumour, anaphylaxis)
Reduced lung volume (pneumothorax, effusion, kyphoscoliosis)
Reduced functioning lung volume (bullous, cystic disease, ILD)
Inability to inflate (obesity. ILD, GBS, MG, COPD)
What may cause insufficient oxygen from entering the blood from the lungs
Damage to the alveolar membrane (emphysema, fibrosis in ILD)
Fluid between the alveolar walls and capillaries (oedema, inflammation)
Disrupted blood supply - PE
What may cause insufficient oxygen from being delivered to the body
Reduced cardiac output - HF, aortic stenosis
Anaemia
Shock
What may cause an increased respiratory drive
Hysterical hyperventilation, psych disorders, anxiety
Acidaemia (metabolic) - DKA
What questions should be asked about SOB itself
Timing and Onset - acute is more mechanical or vascular, chronic more lung cancer, fibrosis
Alleviating or exacerbating factors e.g. lying flat (HF), certain times of year or on exercise (asthma), Anxiety and stress (psychogenic)
What questions should be asked about risk factors for SOB
Smoking
Pets
Occupation - in particular coal, silica, asbestos
Medication - nitrofurantoin, amiodarone, methotrexate, bleomycin -> EAA
Past medical history - autoimmune conditions e.g. RA< SLE
What associated symptoms should be asked about with SOB presentation
Cough Chest pain Muscular weakness or fatigue Tender limbs Constitutional symptoms Loss of blood
What does a cough with SOB suggest
Suggests resp pathology
Persistent, productive cough over days - pneumonia
Persistent productive cough over months = bronchitis
Dry cough with SOB episodes - asthma or LVF
Bloodstained sputum - LVF, PE, cancer, cavitating lesion
What does chest pain with SOB suggest
Pleuritic - PE, pneumothorax
NOn pleuritic - cardio
What does muscular weakness of fatigue with SOB suggest
GBS Myasthenia gravis Lambert Eaton Syndrome Polymyositis MND
What does tender limbs with SOB suggest
PE, esp if lower limbs (DVT)
What does loss of blood with SOB suggest
Anaemia will exacerbate SOB, ask about menstrual bleeding, haematochezia and melaena
What are the differentials for SOB that develops in seconds to minutes
Bronchospasm (asthma or COPD exacerbation) Anaphylaxis Laryngeal oedema PE pneumothorax (+ tension) hyperventilation Inhaled foreign body Epiglottitis
What are the differentials for SOB that develops in hours to days
pneumonia Heart failure pleural effusion post-op atelectasis chronic pulmonary emboli GBS/MG ARDS Lung collapse
What are the differentials for SOB that develops in weeks to months
COPD Asthma HF Pulmonary fibrosis Anaemia Bronchiectasis Obesity/physical deconditioning Pulmonary HTN Mesothelioma TB MND
What are the main features of COPD that may distinguish it from other causes of SOB
Hx of chronic bronchitis and permanent irreversible SOB
Presence of risk factors - smoking (>20PY), occupational exposure, alpha-antitrypsin deficiency
What are the signs of COPD
Hyperexpanded chest Breathing through pursed lips Reduced expansion Prolonged expiratory phase Hyper-resonant precussion note
What are the main features of chronic asthma that may distinguish it from other causes of SOB
Hx of wheeze, SOB, chest tightness, cough (often worse at night/early morning/during exercise/exposure to allergens or cold)
Associated atopic conditions or FHx e.g. eczema, hayfever, nasal polyps, allergies
Exacerbation by NSAIDs or beta blockers
Wheeze on auscultation
What are the main features of interstitial lung disease that may distinguish it from other causes of SOB
Hx of exposure to asbestos, silica, coal (pneumoconiosis) or exposure to drugs (methotrexate, amiodarone)
What are the signs of ILD on examination
Clubbing
Reduced chest expansion
Late inspiratory fine crackles (base OR apices)
What are the main features of heart failure that may distinguish it from other causes of SOB
SOB on exertion, orthopnoea, PND, swollen ankles
Risk factors: IHD ( smoking, DM, cholesterol, HTN, south east asian, FHx), stroke, TIAs, limb claudication, HTN, valvular disease, cardiomyopathy
What are the features of heart failure on examination
Ascites, hepatosplenomegaly, peripheral oedema, raised JVP
Bi-basal crackles that do not move on coughing (pulmonary oedema)
Displaced apex beat
Third or fourth heart sounds
What are the main features of anaemia that may distinguish it from other causes of SOB
Hx bleeding (menorrhagia, melaena), fatigue, SOB on exertion Signs of cyanosis, koilonychia, glossitis, angular stomatitis
