COPD Flashcards
What is COPD?
Chronic obstructive airway disease
- incompletely reversible poor airflow + inability to breathe OUT fully
Give 2 examples of COPD. Why are they classified as COPD?
Emphysema
Chronic bronchitis
- poor airflow due to breakdown of lung tissue
- small airway disease
- results in poor absorption and release of respiratory gases
When is there the greatest reduction of airflow in COPD and why?
Breathing out/exhalation
The pressure in the chest compresses the airways
What are the risk factors for COPD?
- Smoking (BIGGEST risk factor)
- -> women more susceptible to harmful effects than men - Air pollution
- Occupational exposure
- Genetics (⍺-1-antitrypsin deficiency)
other risk factors may include:
- asthma + airway hyperactivity
- LBW
- HIV/AIDS and TB
When should COPD be suspected?
In anyone over the age of 35-40 who has:
- SOB
- chronic cough
- sputum production
- frequent winter colds
- history of exposure to risk factors
How is COPD diagnosed?
- Spirometry:
- FEV1:FVC is < normal range (~0.75-0.8) - Decrease in DLCO/TLCO (due to decreased surface area int he alveoli, as well as capillary bed)
*in the elderly spirometry would over-diagnose COPD
therefore, COPD symptoms, low FEV1:FVC and an FEV! < 80% of predicted is required for diagnosis
Why can smoking lead to COPD?
- Smoking inactivates the elastase inhibitor ⍺-1-antitrypsin
- there is release of serine elastase
- elastic tissue of lung is destroyed
Describe the different GOLD grades for severity of COPD.
- Mild/GOLD1 = ≥ 80% of predicted FEV1
- Moderate/GOLD2 = 50-79%
- Severe/GOLD3 = 30-49%
- Very severe/GOLD4 = <30%
Describe the MRC shortness of breath scale in determining the severity of COPD.
- grade 1 = only on strenuous activity
- grade 2 = vigorous walking
- grade 3 = with normal walking
- grade 4 = after a few minutes of walking
- grade 5 = with changing clothes
What would a CXR of a COPD patient show?
- overexpanded lungs
- flattened diaphragm (most reliable sign)
- increased retrosternal airspace
- bullae
What is the differential diagnoses for COPD?
- congestive heart failure
- pulmonary embolism
- pneumonia
- pneumothorax
- bronchopulmonary dysplasia
What are the goals of treatment for COPD?
- reduce risk factors
- manage stable COPD
- prevent and treat acute exacerbations
- manage associated illnesses
Which vaccines must a person with COPD have and how often?
- influenza vaccine once a year
- pneumococcal vaccine every 5 years
What are the treatment options for a COPD patient?
- smoking cessation (reduce mortality)
- O2 supplementation (reduce mortality)
- exercise (pulmonary rehabilitation, ideal BMI)
- bronchodilators
- corticosteroids
- long-term antibiotics (to reduce frequency of exacerbations)
- surgery (transplant, or volume-reduction)
When should O2 supplementation be given to a COPD patient?
When their ppO2 is <50-55mmHg or SaO2 <88%
**do not let SaO2 rise above 92%
What kinds of bronchodilators are given? (give examples)
Major types are: 𝛃2 agonists and anticholinergics (long and short-term)
- reduce SOB, wheeze, exercise limitation, improve QOL
- long-acting partly work by reducing hyperinflation
Short-acting 𝛃2 agonists = salbutamol, terbutaline
Long-acting 𝛃2 agonists = formoterol, salmeterol, indacterol
*the anticholinergics used in COPD are antimuscarinics = ipratropium (short-acting) and tiotropium (long-acting)
What is the MOA of antimuscarinics (anticholinergics)?
- blocks muscarinic receptors (some block M3 - tiotropium -, some are non-specific - ipratropium)
- this promoted the degradation of cyclic guanosine monophosphate (cGMP)
- decreased intracellular cGMP
- reduces intracellular cGMP
- reduces intracellular Ca2+
- prevents contraction if smooth muscle = bronchodilator etc
What can trigger COPD exacerbations?
- environmental pollutants (poor air quality)
- infections
- personal smoke and second-hand smoke
- cold temperature
*bear in mind that pulmonary embolism can worsen the S+S of COPD
How would a person with an acute exacerbation of COPD present?
- SOB
- increased sputum production
- change in colour of sputum (clear –> green/yellow)
- increase in cough
- tachypnoea
- tachycardia
- sweating
- active use of accessory muscles
- cyanosis
- confusion
- crackles on auscultation
What happens/changes occur in a COPD patient when there is increased airway inflammation?
- increased hyperinflation
- reduced expiratory flow
- worsening of gas transfer
- can lead to insufficient ventilation = low SaO2
- result in narrowing of arteries of the lungs + breakdown of capillaries (emphysema)
- increased BP in pulmonary arteries
**can lead to cor pulmonale
What is cor pulmonale?
abnormal enlargement of the right side of the heart
- can be caused by increased BP in pulmonary arteries as a result of COPD exacerbation
How should a COPD exacerbation be treated/managed?
- usually by increasing the use of SABA
- can also combine with short-acting anticholinergics
- in this case you SHOULD give O2 as SaO2 is <88%
- continue to monitor pulse oximetry and ABGs
- corticosteroids could improve recovery and reduce duration of symptoms
