COPD Flashcards
What is COPD?
This is a preventable disease that encompasses both emphysema and chronic bronchitis.
The airflow limitation is usually progressive and irreversible and is associated with an abnormal inflammatory response of the lungs to noxious particles or gases.
Who is the typical patient that presents with COPD?
Suspected in patients with a Hx of smoking, occupational and environmental risk factors.
Aetiology of COPD
Tobacco smoking is by far the main risk factor for COPD.
Smoking is responsible for 40-70% of COPD cases.
Oxidative stress and an imbalance in proteinases and antiproteinases are important factors in the pathogenesis of COPD especially in patients with a1-antitrypsin deficiency.
Pathophysiology of COPD
Loss of elasticity and alveolar attachments of airways due to emphysema.
This reduces the elastic recoil and the airways collapse during expiration.
Inflammation and scarring cause the small airways to narrow.
Mucus secretion which blocks the airway.
Each of these narrows the small airways and causes air trapping leading to hyperinflation of the lungs, Va/Q mismatch, increased work of breathing and dyspnoea.
Signs and symptoms of COPD
-Productive cough with white or clear sputum, wheeze and dyspnoea usually following many years of a smoker’s cough.
Symptoms can be worsened by cold, foggy weather.
Dyspnoea particularly with exercise.
-In severe disease, tachypnoea with prolonged expiration:
There is the use of accessory muscles, bound chest, hyper-resonance on percussion.
Distant breath sounds and poor air movement on auscultation.
Wheezing, coarse crackles, clubbing and cyanosis as well as signs of right-sided HF.
Tests and investigations for COPD
In stable disease, spirometry is the 1st test for diagnosis for COPD and for monitoring disease progression:
There is reduced FEV1: FVC ratio and low PEFR
ABG is used to assess respiratory failure.
The airflow limitation is partly reversible (usually a change in FEV1 of <15%)
Presence of airflow limitation is defined by the GOLD criteria as a post-bronchodilator FEV1/FVC < 0.70
CXR is rarely diagnostic but can help to exclude other diagnoses.
Patients presenting with acute symptoms should have FBC ECG, CXR and assessment of gas exchange.
When should antibiotics be used in a suspected COPD patient?
If a patient have the 3 cardinal symptoms: Increase in: Dyspnoea Sputum volume Sputum purulence
What is the GOLD criteria?
The GOLD Criteria are used clinically to determine the severity of expiratory airflow obstruction for patients with COPD.
Should not be used to diagnose COPD, but rather to categorise clinical severity to inform prognosis and to guide therapeutic interventions.
Determining a patient’s GOLD status requires a multidimensional assessment of a patient’s spirometry, symptom burden, and frequency of COPD exacerbations.
Classification of COPD into GOLD stages based on the severity
In pulmonary function testing, a post-bronchodilator FEV1/FVC ratio of <0.70 is commonly considered diagnostic for COPD. In patients with FEV1/FVC <0.70:
GOLD 1 - mild: FEV1≥ 80% predicted
GOLD 2 - moderate: 50% ≤ FEV1 < 80% predicted
GOLD 3 - severe: 30% ≤ FEV1 < 50% predicted
GOLD 4 - very severe: FEV1 <30% predicted.
What is the GOLD guidelines?
The GOLD guideline uses a combined COPD assessment approach to group patients according to symptoms and previous history of exacerbations. Symptoms are assessed using the Modified British Medical Research Council (mMRC) or COPD assessment test (CAT) scale. These can be found in the GOLD guidelines.
Group A: low risk (0-1 exacerbation per year, not requiring hospitalisation) and fewer symptoms (mMRC 0-1 or CAT <10)
Group B: low risk (0-1 exacerbation per year, not requiring hospitalisation) and more symptoms (mMRC≥ 2 or CAT≥ 10)
Group C: high risk (≥2 exacerbations per year, or one or more requiring hospitalisation) and fewer symptoms (mMRC 0-1 or CAT <10)
Group D: high risk (≥2 exacerbations per year, or one or more requiring hospitalisation) and more symptoms (mMRC≥ 2 or CAT≥ 10).
Risk factors of COPD
Cigarette smoking Advanced age Genetic factors (strong) White ancestry Male sex Low socioeconomic status Developmentally abnormal lung
Differentials of COPD
Asthma CHF Bronchiectasis TB Bronchiolitis Upper airway dysfunction Chronic sinusitis Lung cancer
Complications of COPD
-Acute exacerbations- equally viral or bacterial infections. Bacteria include H.influenza, S.pneumonia, P.aeruginosa -Pneumonia -Pneumothorax -RV HF -Peripheral neuropathy -Cachexia -Respiratory failure -Depression -Anaemia -Polycythaemia -Cor pulmonale
What is Cor Pulmonale?
This is defined as symptoms and signs of fluid overload secondary to lung disease such as COPD>
The fluid retention and peripheral oedema is due to failure of excretion of sodium and water by the hypoxic kidney rather than HF.
It is characterised by pulmonary HTN and RVH.
On examination, the patient is centrally cyanosed (owing to lung disease) and later becomes more breathless and develops ankle oedema.
There may be a prominent parasternal heave, due to RVH and a loud pulmonary S2.
In very severe pulmonary HTN, the pulmonary valve becomes incompetent with severe fluid overload, tricuspid incompetence may develop with a greatly elevated JVP, ascites and upper abdominal discomfort due to liver swelling.
Simply put:
Hypoxia then Pulmonary artery vasoconstriction- increased pulmonary artery pressure- RVH-right ventricular failure
Management of COPD
At diagnosis and at each review appointment, offer people with COPD and their family members or carers (as appropriate):
Written information about their condition
At minimum, the information should cover:
an explanation of COPD and its symptoms
advice on quitting smoking (if relevant) and how this will help with the person’s COPD
advice on avoiding passive smoke exposure
managing breathlessness
physical activity and pulmonary rehabilitation
medicines, including inhaler technique and the importance of adherence
vaccinations
identifying and managing exacerbations