9. COPD Flashcards
What is COPD? It is an umbrella term covering what 3 diseases? Describe them briefly.
What is COPD predominantly caused by?
What are some other causitave agents (incl. the 5 c’s)?
Progressive disorder characterised by airway obstruction that is not fully reversible. Umbrella term for irreversible aspect of:
Chronic bronchitis: chronic productive cough + sputum for at least 3 months in each of 2 successive years.
Emphysema: enlarged alveolar spaces and loss of alveolar walls.
Asthma (can be so bad lung fn doesn’t get better)
Smoking
Indoor air pollution (biomass fuels, tobacco smoke), occupational dusts (organic/inorganic), chemical agents and fumes, outdoor air pollution. Coal, Cotton, Cement, Cadmium, (Corn) Grain. Infections -> progression, α-antitrypsin deficiency.
What is chronic bronchitis?
What is emphysema?
How does inflammation in COPD lead to airflow limitation?
Describe how inflammation in asthma and COPD differ.
Hypertrophy of mucus secreting glands -> increased mucous production -> sputum expectoration -> chronic cough. Infiltration of bronchial walls with inflammatory cells (mainly neutrophils)-> airway narrowing.
Loss of elastic recoil -> airflow limitation + air trapping. Bulla formation (large air pockets replacing lung tissue).
Small airway disease (airway inflammation + remodelling) + parenchymal destruction (loss of alveolar attachments + decrease of elastic recoil).
(pic). Asthma = Th2 driven disease characterised mainly by eosinophils - give steroids. COPD mainly neutrophils, steroids don’t help.
What can you see in this electron micrograph (arrow)?
What is the typical COPD patient presentation and symptoms?
What is the formula for pack years?
How do diagnoses differ between:
a) COPD?
b) asthma?
Alveoli destruction, bullae. L = thick and spongy :) , R = holey, useless :(
>35 yo, smoker/ex-smoker. Symptoms: exertional breathlessness, chronic cough, regular sputum production, frequent winter “bronchitis”, wheeze.
Pack years = number of packs/day x years smoked. 1 pack = 20 cigarettes. E.g 20/day for 30yrs = 30 PkYrs. 10/day for 40yrs = 20 Pk Yrs.
a) Mid-life onset, symptoms slowly progressive, long smoking hx, dyspnea during exercise, largely irreversible airflow limitation.
b) Early-life onset, symptoms vary day to day, symptoms at night/early morning, allergy, rhinitis and/or eczema also present, family hx of asthma, largely reversible airflow limitation.
Differential Diagnosis
Compare asthma, COPD and heart failure with the following:
Age of onset
Smoking history
Symptoms
Peak flow
Bronchodilator (e.g. salbutamol)
Corticosteroid (e.g. beclometasone)
What are some signs of COPD?
What are some investigations (diagnostic and prognostic)?
What are the spirometry results A and B showing compared to normal (red)?
Wheeze, tachypnoea, prolonged expiration, use of accessory muscles, pursed lip breathing, hyper-inflated lungs, cyanosis, heart failure. BMI, 6 min walk test and degree of obstruction predicts mortality in COPD. Dahl’s sign (pic): areas of darkened (hyperpigmentation) and thickened (hyperkeratotic) skin on lower thighs and elbows from chronic tripod position.
Dx: Spirometry - obstructive. CXR
Prognostic: ABG, FBC - polycythaemia, eosinophilia.
A) Obstructive
B) Restrictive
How is spirometry used to assess and monitor COPD?
How is COPD managed?
Should be performed after administration of an adequate dose of a short-acting inhaled bronchodilator to minimize variability. A post bronchodilator FEV1/FVC <0.7 confirms the presence of airflow limitation that is not fully reversible. Value should be compared to age-related normal value to avoid overdiagnosis of COPD in elderly.
Stablisation. Health education e.g. smoking cessation!! No existing medication for COPD modifies the long-term decline in lung function, so pharmacotherapy for COPD is used to decrease symptoms and/or complications/exacerbations.
What 5 drug types are used to treat COPD (give examples)?
What are the 2 non-pharmacologic treatements are used to manage stable COPD?
How is COPD managed?
1) Short-acting bronchodilators - salbutamol and terbutaline
2) Anti-cholinergics - long-acting (tiotropium, aclidinium), short-acting (ipratropium bromide)
3) Long-acting bronchodilators: - salmeterol, formoterol, indacterol, vilanterol
4) Inhaled corticosteroids - beclometasone, budesonide, fluticasone
5) Phosphodiesterase inhibitors - theophyllines, roflumilast
Inhaler technique important. FEV1 better for large airways than small.
- *Rehabilitation:** exercise training programmes - improve exercise tolerence, dyspnoea and fatigue
- *O2 therapy:** long-term administration (≥15hrs/day) increases survival of pts with chronic respiratory failure. Use if PaO2 <7.3 or <8 with polycythaemia/ noctural hypoxaemia (<90% > 30% of night)/ peripheral oedema/ pulmonary HT
(pic)
What vaccines are useful when managing stable COPD?
What other treatments can be used?
Can anything prolong life?
- *Influenza** vaccines can reduce serious illness.
- *Pneumococcal polysaccharide** vaccine is recommended for COPD pts ≥ 65 yo or < 65 yo with FEV1 <40% predicted.
Abx: to treat infectious exacerbations of COPD.
Antioxidant agents: n-acetylcysteine can effect exacerbation frequency in patients not treated with glucocorticosteroids.
Mucolytic agents, antitussives and vasodilators (not recommended in stable COPD).
Lung transplant.
Smoking hx should always be documented for all with COPD. Pts should be encouraged to stop - what help can be offered?
When is NRT used, and what forms does it come in?
NRT, varenicline (Champix - selective nicotinic receptor partial agonist, avoid if hx of psyc illness -> suicidal thoughts) or bupropion (Zyban - antidepressant, reduces severity of nicotine cravings and withdrawal symptoms, increases seizure risk, avoid in alcohol withdrawal, EDs or bipolar disorder) combined with an appropriate support programme. Choice of drug depends on likely compliance, availability of support, pt previous experience, contra-indications/adverse effects, and pt preference.
Use as replacement in abrupt cessation or to slowly reduce. Forms: patches, gum, inhaler, lozenges, sublingual tablets, nasal spray. SEs related to local irritation.
What is pulmonary rehabilitation?
What are some complications of COPD? How are they treated?
What is an exacerbation of COPD? What are some symptoms?
Multidisciplinary programme, tailored to individual. All pts functionally disabled by COPD. Includes physical training, disease education, nutritional advice, psychological and behavioural support.
Respiratory failure: PaO2 <8 and/or PaCO2 >7
Cor pulmonale: heart disease 2o to chronic lung disease
ABG if: FEV1 <30% predicted, cor pulmonale, O2 sat <92% on air
Treat with LTOT +/- NIV (non-invasive ventilation).
Sustained worsening of patient’s symptoms from their usual stable state which is beyond normal day-to-day variations, and is acute in onset.
Symptoms: worsening breathlessness/cough, increase in sputum production, change in sputum colour.
List some differential diagnoses for COPD exacerbations.
What investigations would you do?
Exacerbations of COPD often have a viral cause - what viruses may be responsible?
Pneumonia, pneumothorax, malignancy, PE, heart failure/ACS (acute coronary syndrome).
Clinical dx, may use ix to:
Gauge severity: O2 sat, ABG, sputum + blood cultures.
Exclude other dx: CXR, ECG, bloods (FBC, U&E, CRP, theophylline level, cardiac enzymes), CT/CTPA.
Pneumonia - H. influenzae, M. catarrhalis, Streptococcus pneumoniae.
Describe how you would manage COPD exacerbations.
What O2 sat should you aim for?
What should you do if hypercapnoeic?
What is the most common cause of COPD exacerbation?
Bronchodilators: nebulised/air driven
Steroids: prednisolone 30mg OD for max 14d
Abx: if purulent sputum/pneumonia on CXR, empirical Rx with aminopenicillin, macrolide or tetracycline. Change if cultures/sensitivites known.
88-92%. ABG to exclude hypercapnoea.
Exclude hyperoxia (e.g. >92%). Maximise medical therapy. NIV if no improvement (improves respiratory acidosis, increases pH and reduces PaCO2, resp rate and severity of breathlessness, hospital stay length and mortality).
Infection of tracheobronchial tree and air pollution. 1/3 causes can’t be identified.
The red line indicates normal spirometry results. What do the blue lines indicate in A and B?
A) obstructive - takes long for pt to breathe out
B) restrictive - can breathe out fast but not much
