Clinical features of COPD Flashcards
What is COPD defined as ?
Lung disease characterised by chronic lung airflow that interferes with normal breathing and is not fully reversible
What is the epidemiology of COPD ?
1.2 million with diagnosis of COPD 2nd most common lung disease after asthma ~50% underdiagnosed Prevalence is increasing F>M
What is the main cause of COPD ?
Smoking
What are the effects of smoking ?
Greater decline in FEV1
<50% of smokers develop COPD
Environmental tobacco smoke may be factor
Smoking during pregnancy may affect foetal lung growth
What rare disease can cause COPD (emphysema ) ?
Alpha-1-antitrypsin deficiency
What is Alpha-1-antitrypsin deficiency ?
Rare inherited disease
AAT is a protease inhibitor made in liver
Limits damage caused by activated neutrophils releasing elastase in response to infection/ cigarette smoke
When absent/low-> alveolar damage and emphysema
Basal predominance to emphysema
What are other aetiological factors of COPD ?
Pollution
Occupational exposures
Increasing age
What are the symptoms of COPD ?
Cough SOB Sputum Frequent chest infection Wheezing
Weight loss
Fatigue
Oedema in ankles
What is useful findings in the history of COPD ?
Age >35
Smoking history
Onset/progression
Productive cough for 3 consecutive months for at least 2 years
What are some examination findings in diagnosed COPD ?
Cyanosis Raised JVP Cachexia Wheeze Pursed lip breathing Hyperinflated chest Use of accessory muscles Peripheral oedema Acute exacerbations
What is the mMRC breathlessness scale ?
0- only breathless with strenuous exercise
1- SOB when hurrying on level ground/ walking up hill
2- on level ground, walk slower than people of same age because of breathlessness
3- I stop for a breath after walking ~100 yards or after a few minutes
4- I am too breathless to leave the house or I am breathless when dressing
Is there any single test to diagnose COPD ?
No
What criteria needs to be met to diagnose COPD ?
Typical symptoms
>35 years
Presence of risk factor (smoking or occupational exposure)
Absence of clinical features of asthma
AND
Airflow obstruction confirmed by post-bronchodilator spirometry
What are the investigations of COPD ?
Airflow obstruction confirmed on spirometry:
- FEV1 reduced (70%) - FVC usually reduced - FEV1/FVC (<0.7)
Chest X-ray:
- exclude alternative pathology + screen for malignancy - Hyperinflated lungs - Bulla - Vascular hila - Flat diaphragm
What is the severity scoring of COPD ?
Stage 1 - Mild - FEV1 80%
Stage 2 - Moderate - FEV1 50-79%
Stage 3 - Severe - FEV1 30-49%
Stage 4 - Very severe - FEV1 <30%
If we are unsure if it is COPD what are other useful investigations ?
Pulmonary function tests:
- lung volumes: increased RV
increased TLC
RV/TLC >30%
- transfer factor: reduced gas transfer
reduced Dlco and Kco
What are the clinical features differentiating COPD and asthma ?
COPD Asthma
Smoker/ ex-smoker - nearly all possibly
Symptoms <35yrs - rare often
Chronic productive cough - common uncommon
Breathlessness - persistent/progressive variable
Night time waking with SOB/wheeze - uncommon common
Diurnal or day-day variability of symptoms - uncommon common
What is an acute exacerbation ?
Worsening of pre-existing symptoms
What are the symptoms of an acute exacerbation ?
SOB
Wheeze
Chest tightness
Cough
Sputum- purulence/ volume
In addition to above signs of severe exacerbation:
- RR >25/min
- accessory muscles in use
- purse lip breathing
- cyanosis (SaO2 <92%)What are the causes of an acute exacerbation ?
Often viral
Sometimes bacterial secondary to viral infection
What is the management of acute exacerbations in primary care ?
Change in inhalers (technique, device, add bronchodilator, increase or add inhaled steroid)
Oral steroids (Prednisolone tablets)
Antibiotics
Self- management for select patients
What can trigger an acute exacerbation in secondary care ?
Viral/bacterial infection - most common
Sedative drugs, pneumothorax, trauma
What is the management for Acute exacerbations ?
Oxygen Nebulised bronchodilator (B2 & anti-muscarinic) Oral/IV corticosteroid +/- antibiotic (IV aminophylline, respiratory stimulant, NIV)
How can the severity of COPD be measured ?
Spirometry
Nature and magnitude of symptoms
- MRC breathlessness scale
History of moderate and severe exacerbations and future risk
Presence of co-morbidityWhat is respiratory failure caused by ?
Reduced V/Q- matched
What is type 1 respiratory failure ?
Reduced pO2
What is type 2 respiratory failure ?
Reduced pO2
Increased pCO2 (ventilatory drive)
- severe ventilatory problems can lead to reduced sensitivity of CO2 chemoreceptors in
medulla therefore some COPD patients develop a “hypoxic drive”
What is Cor pulmonale ?
Right sided heart failure due to lung disease
Smoking, hypoxia
Tachycardia, oedematous, raised JVP, congested liver
What is Secondary polycythaemia ?
Body produces increased erythropoietin in repsonse to low O2
Raised Hb levels
Raised blood viscosity
What are some complications of severe COPD ?
Respiratory failure
Cor pulmonale
Secondary polycythaemia
What is End stage COPD ?
Terminal illness
Unpredictable decline
Palliation of symptoms- breathlessness, anxiety
Social aspects- care, housebound, O2 at home
