SOB differentials and pathophysiology Flashcards
SOB differentials
-PE
-pneumonia
-COPD
-asthma
-HF
-anaphylaxis
-AKI
-pneumothorax
PE presentations
-sudden onset dyspnoea
-pleuritic CP
-haemoptysis
-tachypnoea/ tachycardia
-DVT
-syncope
COPD presentations
-dyspnoea especially on exertion
-hypoxia
-tachypnoea
-increased sputum (yellow/ green)
-increased cough/ wheeze
-chest tightness
COPD pathophysiology
-chronic exposure to irritants eg. pollution or smoking
-causes chronic airway inflammation
-activates neutrophils, macrophages
Encompasses 2 conditions
1. chronic bronchitis- increase mucus production, airway narrowing, infections
2. emphysema- neutrophils release proteases which destroy alveolar walls, lose elastic recoil, decreases SA for gas exchange
Asthma pathophysiology
-exposure to triggers eg. allergens, cold air, smoke
-activates mast cells which trigger release histamines
-inflammatory mediators cause airway swelling and hypersecretion of mucus
-airway narrows, increasing resistance
-increased WOB
-less O2 = hypoxia
-CO2 retention = respiratory acidosis
Asthma presentations
-SOB / tachypnoea
-wheezing
-coughing
-chest tightness/ pressure
HF presentations
-SOB/ dys/ orthopnoea
-fatigue/ weakness
-peripheral oedema
-palpitations due to compensatory tachycardia
-pink frothy sputum
-pulmonary oedema
HF pathophysiology
-increased workload of LV causes it to enlarge with stretched tissue rather than functional tissue
-this reduces LV function and blood to pool in LV and back into pulmonary circuit
-pulmonary circulation because engorged (swollen) pushes fluid out of the vessel causing PO
-RV now pumps harder due to backflow in pulmonary circuit
-same happens for RVF but oedema= peripheral
Anaphylaxis presentations
-urticaria, flushing
-angioedema to face, lips, tongue
-throat tightness
-bronchospasm- wheeze, dyspnoea
-coughing, stridor
Anaphylaxis pathophysiology
-first exposure doesn’t lead to anaphylaxis but causes B cells to release IgE antibodies which bind to mast and baso
-exposure to allergen (trigger)
-allergen binds to IgE antibodies on mast cells
-mast cells + basophils degranulate releasing massive amounts of histamine, prostaglandins and cytokine
-causes bronchospasm, mucosal oedema and severe airway swelling
Pneumothorax presentations
-sudden onset dyspnoea
-tachypnoea
-reduced breath sounds on affected side
-hyperresonance on percussion
-decreased chest wall movement on affected side
-tachycardia
Pneumothorax pathophysiology
-when air enters the pleural space due to trauma or spontaneously
-this equalizes pleural space pressure with atmosphere pressure causing lung collapse
-this reduces SA for gas exchange causing hypoxia and leading to compensatory tachypnoea
