COPD (Obstructive Airway Disease) Flashcards
What is COPD?
It is a progressive disorder characterized by airway obstruction with little or no reversibility
What is the type of inflammation involved in COPD?
Chronic neutrophilic inflammation of the airways, alveoli and pulmonary vasculature, with the principle cause of this being smoking.
What are the two underlying pathophysiological mechanisms to COPD?
Chronic bronchitis and Emphysema
Why does chronic bronchitis occur?
Due to inflammation within the airways
What is the resulting effect of chronic bronchitis on the airways?
Fibrosis of the bronchiole walls, airway oedema, bronchoconstriction and mucous hypersecretion
What symptoms occur as a result of chronic bronchitis?
A chronic cough and narrowing of the airways
What is the clinical definition of bronchitis?
A productive cough on most days for greater than 3 months of the year over two successive years
How does emphysema occur?
Inflammation of the smaller airways distal to the terminal and the alveoli results in the release of enzymes that breakdown the alveolar walls and capillaries
What is the resulting effect of emphysema on the airways?
Enlargement of the air spaces, reduced gas exchange and air trapping on expiration due to loss of elastic recoil
What type of deficiency can cause emphysema?
Alpha 1 anti-trypsin deficiency
What is the general presentation of COPD?
History of smoking, progressively worsening SOB / productive cough ( grey / white sputum) and reduced exercise tolerance and ability to carry out daily activities
What are some general signs of COPD?
- Cyanosis
- Tachypnoea
- Use of accessory muscles of respiration
- Barrel chest (due to hyperinflation)
- Hyper resonance on auscultation
- Wheeze and quiet breath sounds
What is the impact of emphysema clinically?
The body acts to overcome the reduced gas exchange through hyperventilation, which allows a near normal Pa02 and PaC02 to be maintained
What are the typical presenting features of emphysema?
- Pink complexion (as not really cyanosed)
- Hyperventilation with use of accessory muscles and leaning forward to help with air movements
- Mild cough
- Thin and cahexic
- Reduced breath sounds on auscultation
What is meant by the term ‘pink puffers’ when referring to COPD?
Patients who present with predominantly Emphysema
What is the impact of chronic bronchitis clinically?
Due to the airway narrowing, there is a reduction in the ventilation of the alveoli. The body acts to overcome this by increasing cardiac output. This results in a V/Q mismatch, hypoxia (low Pa02) and hypercapnia (high PaCO2). The hypoxia results in pulmonary hypertension and eventually cor pulmonale.
What are the typical presenting features of chronic bronchitis?
- Blue complexion (as cyanosed)
- Not breathless
- Prominent cough with lots of sputum
- Peripheral swelling due to cor pulmonale
- Wheeze on auscultations
What is meant by the term ‘blue bloaters’ when referring to COPD?
Patients who present with predominantly Chronic Bronchitis
What investigations can be used to confirm a diagnosis of COPD?
Spirometry, bronchial challenge, DCLO, CXR & ABG
What spirometry results would be indicative of COPD?
Decreased FVC & FEV1 and FER <75%.
What bronchial challenge results would be indicative of COPD?
<15%
What DCLO results would be indicative of COPD?
Reduced in emphysema
What CXR results would be indicative of COPD?
Hyperinflation of chest, bullae
What ABG results would be indicative of COPD?
Hypoxia +/- hypercapnia
What FEV1 result would indicate mild COPD?
> 80%
What FEV1 result would indicate moderate COPD?
50 – 79%
What FEV1 result would indicate severe COPD?
30 – 49%
What FEV1 result would indicate very severe COPD?
<30%
What are the main complications of COPD?
Acute exacerbations, respiratory failure, cor pulmonale or pneumothorax.
What is the general non-pharmacological management of COPD?
- Smoking cessation
- Encourage exercise
- Flu jag to prevent infections
- Pulmonary rehab
- Dietary advice: either for low or high weight
What is the main complication of inhaled steroids?
Increased risk of pneumonia
What is step one of the general formula for the management of COPD?
SABA e.g salbutamol or SAMA e.g ipratropium
What is step two of the general formula for the management of COPD?
- Depends on FEV1
- If FEV1 >50% = LABA e.g salmeterol or LAMA e.g tiotropium
- If FEV1 <50% = LABA + ICS (e.g folmeterol + beclomethasone) or LAMA
What is step three of the general formula for the management of COPD?
Combination of LABA + ICS + LAMA
What medications are used to treat mild COPD?
Ipratropium PRN then Salbutamol PRN.
What medications are used to treat moderate COPD?
Ipratropium PRN then Tiotropium or Salmeterol + inhaled steroids or consider oral theophylline
What medications are used to treat severe COPD?
Triotropium, salmeterol + inhaled steroid then consider oral steroids
What is used to treat pulmonary hypertension
Long term oxygen therapy
When do acute exacerbations of COPD tend to occur?
Most commonly seen in winter and may or may not be associated with infections
What is the presentation of an acute COPD exacerbation?
Increasing SOB / wheeze / cough and decreased exercise tolerance.
What investigations would be done for an acute COPD exacerbation?
- Bloods: FBC, CRP, ABG
- Peak flow
- CXR / ECG
- Culture: sputum / blood
What is the general management plan for an acute COPD exacerbation?
- Controlled 02 (24 – 28%), with target of 88 – 92%
- Nebulized salbutamol + ipratropium
- Steroids: IV hydrocortisone (200) or oral prednisolone (30-40)
- Amoxicillin if infection suspected
