Respiratory Flashcards
(273 cards)
Define chronic obstructive pulmonary disease
Non-reversible long-term deterioration in air flow through the lungs caused by damage to lung tissue (almost always due to smoking).
2 main types:
* Chronic bronchitis: clinical diagnosis. Daily productive cough for 3+ months, in at least 2 consecutive years. Hypertrophy and hyperplasia of mucous glands, chronic inflammation cells infiltrate bronchi > hypersecretion, ciliary dysfunction, luminal narrowing.
* Emphysema: pathological diagnosis. Permanent enlargement and destruction of airspaces distal to the terminal bronchiole. Destruction of elastin layer causes trapped air distal to blockage (large air sacs = bullae). Centriacinar emphysema = respiratory bronchioles only, smokers. Panacinar emphysema = A1AT deficiency.
Describe the epidemiology for COPD
40-60 years, smokers, males, miners/coal workers
Describe the aetiology for COPD
Smoking, pollution, genetics (A1AT)
Describe the risk factors for COPD
Smoking, increasing age, second-hand smoke exposure, occupational exposure (mining, dust, cotton, wool), pollution (heating fuel, outdoor pollutants), genetics (alpha-1-antitrypsin deficiency)
Describe the pathophysiology for COPD
Obstructed airflow through airways > difficulty ventilating the lungs > shortness of breath and prone to infection. Unlike asthma, not reversible with a bronchodilator.
Patients may experience exacerbations; if due to infections they are called infective exacerbations (H. influenza, S. pneumonia.)
What are the key presentations for COPD
Long-term smoker, shortness of breath, cough, sputum, wheeze, recurrent respiratory infections.
Barrel chest/hyperinflation, hyper-resonance on percussion, distant breath sounds on auscultation.
Describe the clinical manifestations for COPD
Signs: Chronic bronchitis: ‘blue bloaters’, chronic productive cough, purulent sputum, dyspnoea, cyanosis, peripheral oedema, haemoptysis, obesity
Emphysema: ‘pink puffers’, dyspnoea/tachypnoea, minimal cough, pink skin, pursed lip-breathing, accessory muscle breathing, cachexia (body/muscle wasting), hyperinflation (barrel chest), weight loss
What is the gold standard investigation for COPD
Clinical presentation + spirometry (FEV1/FVC <0.7 = obstruction. Bronchodilator irreversible = COPD. Bronchodilator reversible = asthma)
Describe the first line investigations for COPD
Spirometry (FEV1/FVC < 0.7 = shows obstruction. Overall lung capacity is better than their ability to forcefully expire air quickly).
DLCO (diffusion capacity of CO across lung. COPD = low). Pulse oximetry (low O2)
Chest x-ray (hyperinflation, exclude lung cancer/other pathology)
ABG (type 2 respiratory failure – raised pCO2, low pO2).
FBC (chronic hypoxia > polycythaemia). BMI (weight loss - lung cancer). ECG. Serum alpha-1-antitrypsin levels. Sputum culture.
Other: Grades: MRC dyspnoea scale
Grade 1: breathless on strenuous exercise
Grade 2: breathless walking up a hill
Grade 3: breathless that slows on the flat
Grade 4: stop to catch breath after 100m walking on flat
Grade 5: unable to leave house due to breathlessness
What are the differential diagnosis for COPD
Asthma, bronchiectasis, fibrosis, congestive heart failure, lung cancer
Describe the management for COPD
General: stop smoking!! Pneumococcal vaccine, annual flu vaccine
1st line – SABA short acting beta agonist (e.g., salbutamol or terbutaline) OR SAMA short acting muscarinic antagonist (e.g., ipratropium bromide)
2nd line – if no asthmatic/steroid response: LABA long-acting beta agonist (salmeterol), LAMA long-acting muscarinic antagonist (tiotropium). If asthmatic/steroid response: LABA long-acting beta agonist (salmeterol), ICS inhaled corticosteroids (budesonide)
3rd line – LTOT long term oxygen therapy
Describe the complications for COPD
Infective exacerbations: acute worsening of symptoms – SOB, cough, wheeze, sputum. Triggered by infection (H. influenza, S. pneumonia). ABG – raised CO2 > acidosis. Type 2 respiratory failure (raised pCO2, low pO2).
Treatment: steroids (hydrocortisone/prednisolone) + nebulised bronchodilators (salbutamol/ipratropium bromide) + antibiotics (amoxicillin).
Other complications: cor pulmonale, recurrent pneumonia, depression
Define asthma
Chronic, inflammatory condition causing episodes of reversible airway obstruction, airway hyperresponsiveness and inflamed bronchioles, due to bronchoconstriction and excessive secretion production.
Describe the aetiology for asthma
Hypersensitivity of the airways, triggered by: cold air, exercise, cigarette smoke, air pollution, allergens (pollen, cats, dogs, mould), time of day (early morning, night)
Describe the risk factors for asthma
Allergens, atopy, smoking, previous respiratory tract infection, hygienic hypothesis: Growing up in very hygienic environment
Describe the pathophysiology for asthma
Overexpressed TH2 cells in airways exposed to trigger > TH2 cytokine release, IgE production, eosinophil recruitment > IgE mast cell degranulation releasing histamines, leukotrienes, tryptase. Eosinophilia: release of toxic protein > bronchial constriction, mucus hypersecretion
Define Atopic triad and Samter’s triad
Atopic triad: atopic rhinitis, eczema, asthma. Samter’s triad: asthma, aspirin allergy, nasal polyps.
What are the key presentations of asthma
Episodes of wheeze (widespread, polyphonic – multiple musical notes starting and ending at same time), breathlessness, chest tightness and dry cough.
Atopy (family/personal history of eczema/asthma/hayfever).
Diurnal variability (typically worse at night).
What is the gold standard investigation for asthma
Spirometry with reversibility testing. Obstructive pattern: FEV1 <80% of predicted normal, FEV1/FVC ratio <0.7. Bronchodilator reversible (>12% FEV1 improved).
Describe the first line investigations for asthma
FeNO (fractional exhaled nitric oxide - raised), spirometry (obstruction FEV1:FVC <0.7), peak flow measurement, chest x-ray (normal/hyperinflated), FBC (raised eosinophils or neutrophils)
What are the differential diagnosis for asthma
Cystic fibrosis, COPD, bronchiectasis, alpha-1-antitrypsin deficiency
Describe the management for asthma
Management 1st line – SABA short acting beta 2 adrenergic receptor agonists (salbutamol) – bronchodilation
2 – add ICS inhaled corticosteroids (budesonide) – reduce inflammation and reactivity of airways
3 – add LRTA leukotriene receptor antagonist (montelukast) – block leukotriene effects (inflammation, bronchoconstriction, mucus secretion)
4 – add LABA long-acting beta agonist (salmeterol)
5 – increase ICS dose
For exacerbations OSHITME: oxygen, SABA salbutamol, Hydrocortisone (ICS), Ipratropium bromide, Theophylline, MgSO4, escalate (ventilation – BiPAP bilevel positive airway pressure)
Describe the complications for asthma
Exacerbation, airway remodelling, oral candidiasis/dysphonia (voice disorders) from inhaled steroids
Define tuberculosis
Infectious granulomatous caseating disease caused by mycobacterium tuberculosis bacteria