Chronic Obstructive Pulmonary Disease (COPD) Flashcards
What is COPD?
Group of disorders characterised by airway inflammation and airflow limitation > not fully reversible
Progressive
Abnormal inflammatory response to noxious stimuli
What is the pathogenesis of COPD?
Noxious agent > inflammation > - Small airway disease > - Airway inflammation - Airway remodelling - Parenchymal destruction > - Loss of alveolar attachments - Loss of elastic recoil Airflow limitation
What are the mediators of inflammation in the airways, lung parenchyma, and pulmonary vessels?
Neutrophils Macrophages CD8 T cells Proteinase-antiproteinase imbalance Oxidative stress
What are the changes in lung parenchyma in COPD?
Alveolar wall destruction
Loss of elasticity
Destruction of pulmonary capillary bed
Increased inflammatory cells
What is the mechanism of emphysema?
Proteinase-antiproteinase imbalance > digestion of elastin and other structural proteins in alveolar wall
What inflammatory cells are prominent in emphysema?
Macrophages
T cells
What are the different patterns of emphysema?
Centriacinar = radiates from terminal bronchiole
Panacinar = more generalised
Bullae
What are the risk factors for COPD?
Primary = cigarette smoking Occupational exposure to irritants Alpha1- antitrypsin deficiency Bronchial hyper-responsiveness Passive smoking Air pollution - Indoor - Outdoor Recurrent respiratory tract infections in childhood Genetic predisposition
In whom should you consider COPD in?
Any past/current smoker Chronic cough Productive cough Dyspnoea History of exposure to other risk factors
How is COPD diagnosed?
Spirometry best measure of airflow obstruction FER = forced expiratory ratio FER = FEV1/FVC pr FEV1/VC - Using larger of FVC or VC FER <0.7 > airflow obstruction - Cut-off varies with age
Compare the course of COPD and asthma
COPD = progressive Asthma = variable
Compare the time of onset of symptoms in COPD and asthma
COPD = late onset of symptoms Asthma = generally young age of onset
Compare the association of smoking with COPD and asthma
COPD = usually moderately heavy smoking history Asthma = no association with smoking history
Compare airflow limitation in COPD and asthma
COPD = not completely reversible Asthma = Substantially/completely reversible
Compare the inflammatory mediators in COPD and asthma
COPD = neutrophils Asthma = largely eosinophils
Compare the airways involved in COPD and asthma
COPD = mostly peripheral airways - Fibrosis > obliterative bronchiolitis Asthma = all airways - Doesn't involve lung parenchyma - No fibrosis
Compare mucus hyper-secretion in COPD and asthma
COPD = more prominent Asthma = less prominent
What are the goals of therapy in COPD?
Control symptoms
Improve lung function and health status
Prevent exacerbations
Reduce hospital admissions
What is the management of COPD?
COPD-X plan
- C = confirm diagnosis and assess severity
- O = optimise lung function
- P = prevent deterioration
- D = develop support network and self-management plan
- X = exacerbation - manage appropriately
Does ceasing smoking in COPD have any effect?
Yes, slows decline in lung function
What is Ventolin and Airomir?
Salbutamol = SABA
What is Bricanyl?
Terbutaline = SABA
What is Serevent?
Salmeterol = LABA
What is Oxis and Foradile?
Eformoterol = LABA
What is Onbreez?
Indacaterol = LABA
What is the use of short-acting beta-agonists in COPD?
PRN
What is the use of long-acting beta-agonists in COPD?
Regular use >
- Fewer symptoms
- More exercise
- Better QOL
What are the side effects of beta agonists?
Tremor
Tachycardia
What is Spiriva?
Tiotropium = LAMA
What is Atrovent?
Ipratropium = LAMA
What is Seretide?
Fluticasone = steroid + salmeterol = LABA
What is Symbicort?
Budesonide = steroid + formoterol = LABA
What does combination therapy (inhaled steroid + LABA) do in moderate to severe COPD?
Reduce exacerbations
Improve QOL
Improve FEV1
What does pulmonary rehabilitation do?
Improves exercise capacity and QOL
May reduce exacerbations and hospitalisations
What are the two main components of pulmonary rehabilitation?
Improve fitness
Education
What are the vaccines given in COPD as part of management?
Influenza vaccine
- Yearly
Pneumococcal vaccine
- Twice 5 years apart
What is the role of home oxygen therapy in COPD?
Improves mortality
No effect on symptoms
How is home oxygen therapy administered?
2-4 L/min via nasal prongs for >16 hours/day if
- PO2 on air at rest <55 mmHg OR
- PO2 <60 mmHg with evidence of hypoxic damage
- No cigarette smoking for 3 months
What are some examples of hypoxic damage in COPD?
Cor pulmonale
Pulmonary HTN
Polycythaemia
What are some other treatments in COPD?
Chronic ABs - Generally not recommended Mucolytics - Small benefit - May help some patients Non-invasive ventilation - Unproven for chronic use - Only used in some patients Lung volume reduction surgery - Improves symptoms - Improves QOL - No clear survival advantage - Consider lung transplant
What is recommended therapy at stage I (mild) COPD?
Active reduction of risk factors
Vaccinations
Add short-acting bronchodilators
What is recommended therapy at stage II (moderate) COPD?
Add regular treatment with 1+ long-acting bronchodilators PRN
Add rehabilitation
What is recommended therapy at stage III (severe) COPD?
Add inhaled glucocorticosteroids if repeated exacerbations
What is recommended therapy at stage IV (very severe) COPD?
Add long-term oxygen if chronic respiratory failure
Consider surgical treatments
What is an exacerbation of COPD?
Change in patient’s baseline dyspnoea and/or sputum
Beyond day-to-day variations
Acute onset
What are some causes of acute exacerbations of COPD?
Respiratory infections Heart failure Arrhythmia Systemic infection Anaemia Anxiety Anything increasing metabolic rate
What are the complications of exacerbations of COPD?
Decline in QOL
More rapid loss of lung function
Mortality
What is the Anthonisen criteria for COPD exacerbations?
Increased dyspnoea
Increased sputum production
Sputum becoming discoloured
What is the management for exacerbations of COPD?
ABs to cover Strep and Gram negatives useful if all 3 Anthonisen criteria present
CXR looking for pneumonia
Cover atypical bacteria if pneumonia present
Supplemental O2
- Aim to keep SpO2 >90% and/or PaO2 >60 mmHg
How can a high dose of O2 in COPD with chronic hypercapnia cause a further rise in pCO2?
Reduced ventilatory drive
High PO2 in parts of lung overcoming hypoxic vasoconstriction > worsening V/Q mismatch
Haldane effect + O2 displacing CO2 from Hb
What are other therapies in exacerbations of COPD?
Bronchodilators Oral corticosteroids ABs if evidence of infection Physical activity to prevent deconditioning Non-invasive ventilation
How do you prevent exacerbations of COPD?
Smoking cessation Vaccinations Tiotropium LABAs Theophylline Inhaled corticosteroids Inhaled corticosteroids + LABA Pulmonary rehab Mucolytics
