COPD Flashcards
What is the GOLD 2015 definition of COPD?
Chronic obstructive pulmonary disease (COPD) is a common and treatable disease, is characterised by persistent air flow limitation that is usually progressive and is enhanced with a chronic inflammatory response in the airways and the lung to noxious particles and gases.
Exacerbations and co-morbidities contribute to the overall severity in individual patients.
What are the histological features of COPD?
Thickened pulmonary arteriolar wall & narrowed lumen from chronic hypoxia
- There are vascular changed in COPD due to hypoxic pulmonary vasoconstriction
- COPD also leads to arterial remodelling, causing thickening of arterial walls
- This leads to Pulmonary HTN + RV Hypertrophy in COPD pts
Connective tissue deposition
Inflammatory cells β predominantly neutrophils (Th1 response) vs eosinophils in asthma
Submucosal hyperplasia π‘ͺ mucous hypersecretion π‘ͺ chronic productive cough
What are the risk factors for acquiring COPD?
- Tobacco smoke **
- Smoke from home cooking: esp kerosene
- Smoke from heating fuels
- Occupational dusts and chemicals
- Genetic factors (Ξ±1-anti-trypsin deficiency, MMP12 gene)
- Ageing
What is the definition of chronic bronchitis?
- Defined clinically as the presence of a chronic productive cough for 3 months during each of 2 consecutive years (other causes of cough being excluded)
- Result of bronchial inflammation
- Causing excessive mucous production + thickening of bronchial walls + narrowing of lumen π‘ͺ obstruction to airflow
What is the definition of emphysema?
- Defined pathologically as an abnormal, permanent enlargement of the air spaces distal to the terminal bronchioles, accompanied by destruction of their walls and without obvious fibrosis
- Air becomes trapped and with reduced SA π‘ͺ air exchange becomes difficult
What are the symptoms of COPD?
- Dyspnoea β progressive, persistent, worse w exercise
- Chronic cough
Chronic sputum production - Others: wheezing, chest tightness, cough syncope
- History of exposure to risk factors
- Family history of COPD
Post-bronchodilator FEV1/FVC <0.7 (ie. persistent limitation)
What are the physical examination findings in a patient with COPD?
Trachea
- Central
- Reduced cricosternal distance
- Tracheal tug (due to stretching of the mediastinum by the low diaphragm)
Expansion
- Reduced bilaterally
- Hooverβs sign (inward movement of lower ribcage on inspiration β implying flat diaphragm from emphysematous changes)
- Increased AP diameter π‘ͺ sign of hyperinflation
Percussion
- Normal or increased in emphysema
- Loss of cardiac / liver dullness π‘ͺ Sign of Hyperinflation
Auscultation
- Reduced air entry (emphysema)
- May have bilateral expiratory rhonchi β essentially low-pitched wheeze (rattling expiratory sounds resembling snoring; due to secretions/ narrowing of bronchi)
Vocal Resonance
- Normal
Other features
- Nicotine stained fingers - Quiet heart sounds
- Intercostal indrawing - Barrel Chest (not specific)
- Pursed lip breathing
How do you assess severity of impairment of lung function in COPD patients?
GOLD 1
- Mild severity
- FEV1 >80% predicted
- FEV1/ FVC < 0.7
GOLD 2
- Moderate severity
- FEV1 50%- 80% predicted
- FEV1/ FVC < 0.7
GOLD 3
- Mild severity
- FEV1 30- 50% predicted
- FEV1/ FVC < 0.7
GOLD 4
- Mild severity
- FEV1 < 30% predicted
- FEV1/ FVC < 0.7
How do you assess the severity of symptoms in COPD patients?
Symptoms: COPD Assessment Test (CAT)
- <10 low impact of symptoms
- β₯10 high level of symptoms, requires comprehensive assessment of symptoms
- Cat is similar to mMRC but also includes sputum etc
Breathlessness: mMRC breathlessness scale
- mMRC β₯2 significant impact of life
What are the investigations to be conducted in COPD patients?
Lung Function Test β FVC, FEV1, FVC/FEV1 ratio
CXR
- Hyperinflation (>6 anterior ribs above diaphragm in mid clavicular line);
- Flat hemidiaphragm; coarsened airways;
- Narrowed mediastinum (long thin heart)
- Decreased peripheral vascular markings;
- Large central pulmonary arteries due to hypoxic pulmonary vasoC
- Right heart hypertrophy
CT thorax HR (high resolution) for emphysematous changes
Lung volume and diffusion capacity: increased TLC (total lung capacity), reduce DLCO
Oximetry and ABG analysis
- If FEV1 <35%, underlying respiratory failure
- Do ABGs if SpO2 <92%
Ξ±1 anti-trypsin deficiency β age <45 (YOUNG) and lower lobe emphysema
- Suspect homozygous of A1AT deficiency if A1AT level <15-20% normal range
- We always want to screen and Dx these patients!
- Because this is potentially reversible + consider transplant β because criteria for lung transplant is to STOP SMOKING!
Exercise tests β objective assessment of exercise impairment (e.g. 6-minute walk test, shuttled walk test)
Composite scores β BODE score (BMI, obstruction, dyspnoea, exercise). Survival prediction.
What is the differential diagnosis of COPD?
- Asthma
- CCF/cor pulmonale/LV failure
- Bronchiectasis
- TB
- Obliterative bronchiolitis
- Diffuse pan bronchiolitis
- Pneumonia
- Pneumothorax
- Pulmonary embolism
- Tumour
What is non pharmacological management of COPD?
Smoking cessation *most effective way to stop decline of lung function
- Nicotine replacement e.g. nicotine gum, inhaler, sublingual tablet, nasal spray, transdermal patch, lozenges
- Bupropion (SSRI)
- Varenicline (nicotinic receptor partial agonist)
- Nortriptyline (TCA)
- Counselling and/or CBT
Vaccination
- Important because most exacerbations caused by viral infection
- Pneumococcal (Hib/Strep pneumoniae/pertussis), Influenza
What is the pharmacological management of COPD?
GOLD A:
- Low risk, less symptoms
- ANY Bronchodilator (SABA / LABA / SAMA / LAMA)
- If ineffective, consider switching to other inhalers
GOLD B:
- Low risk, more symptoms
- LABA / LAMA
- If a LAMA is started, SAMA (including nebulisations) should be stopped.
- Patients with persistent breathlessness should be escalated to a LABA/LAMA combination
GOLD C:
- High risk, less symptoms
- LAMA as first line treatment
- If further exacerbations, consider LABA + LAMA OR LABA + ICS
GOLD D:
- High risk, more symptoms
- LAMA + LABA (preferred)
- OR LABA + ICS
- if further exacerbation: LAMA + LABA+ ICS
- consider adding macrolides
When is long term oxygen therapy indicated in COPD patients?
Long term oxygen therapy is indicated in patients with severe COPD who are in chronic respiratory failure [blood oxygen saturation (SpO2) β€ 88%].
What are the causes of acute exacerbations of COPD?
Infectious (60-80%) *
- Haemophilus influenzae
- Streptococcus pneumoniae
- Moraxella catarrhalis
- **Viruses (influenza and parainfluenza viruses, rhinoviruses, coronaviruses)
- Pseudomonas aeruginosa (investigate for underlying bronchiectasis)
- Opportunistic gram-negative species
- Staphylococcus aureus
- Chlamydophila pneumonia
- Mycoplasma pneumoniae
- Legionella pneumophilia
Non-infectious (20-40%)
- Heart failure
- Pulmonary embolism
- Non-pulmonary infections
- Pneumothorax
- Pneumonia
Precipitating and environmental factors
- Cold air
- Air pollution
- Allergens
- Tobacco smoking
- Non-adherence to respiratory medication
