Respiratory Flashcards
What is COPD?
- Chronic Obstructive Pulmonary Disease
- Irreversible airflow limitation, usually progressive. Caused by persistent inflammatory response.
What are the two diseases that comprise COPD?
- Emphysema.
- Chronic bronchitis.
What is the clinical presentation of COPD?
Respiratory presentation:
- Chronic productive cough.
- Wheezing
- SOB
- Worsens with exercise.
- Barrel chest.
Other symptoms:
- Fatigue (often due to sleep disruption).
- Ankle oedema.
- Decreased exercise tolerance.
What are the differentials for COPD?
- Asthma. Earlier onset, often with FH of type 1 hypersensitivity. Daily variability of symptoms too.
- Congestive heart failure. Will have raised BNP.
What is the pathophysiology of COPD?
- Chronic inflammation affecting central and peripheral airways, lung parenchyma, alveoli and the pulmonary vasculature.
- The repeated damage and repair leads to structural and physiological changes in the lungs:
- Airway narrowing/remodelling.
- Increased numbers of goblet cells.
- Increased size of mucous-secreting glands in the airways.
- Alveolar loss.
- Vascular changes causing pulmonary hypertension.
- The emphysema is caused by elastin breakdown, which results in loss of alveolar integrity.
- Innate immunity (macrophages, neutrophils) play an important role in COPD.
- Increasing evidence there is eosinophilic involvement too.
What are the 2 most common causes of COPD?
- Smoking
- Occupational irritants (such as car fumes).
What are the risk factors for COPD?
- Smoking.
- Old age.
- FH.
- Occupational exposure to chemicals.
What are the diagnostic tests for COPD?
- Spirometry. Will show FEV1/FVC < 0.7, suggesting obstructive disease.
- Physical examination: Tachypnoea, use of accessory muscles, expiratory wheeze, coarse crackles.
- Sometimes CXR to exclude other pathologies.
- Alpha-1 antitrypsin (AAT) should always be measured at least once to check for AAT deficiency COPD.
What is the treatment for COPD?
1st line:
- STOP SMOKING.
- SABA. Short-acting B agonist. (salbutamol) as a rescue inhaler for all patients.
- LAMA. Long acting muscarinic antagonist (tiotropium) OR LABA. Long-acting B agonist (salmeterol).
- Consider adding an ICS (ciclesonide) for patients with severe COPD.
If extremely severe, consider oxygen therapy.
If sleep apnoea develops, consider ventilation overnight.
What are the potential complications of COPD?
- Cor pulmonale. Right sided heart failure. Occurs due to pulmonary hypertension.
- Recurrent pneumonia. Usually Strep. Pneumoniae of haemophillus Influenza. (amoxicillin).
What is asthma?
- Asthma is a chronic respiratory condition associated with airway inflammation and type 1 hypersensitivity (IgE mediated).
- Usually causes intermittent symptoms.
What are the two different types of asthma?
- Extrinsic. This is triggered by external, allergic factors. (Type 1 hypersensitivity).
- Intrinsic. Triggered by non-allergic factors (e.g. stress, cold).
What is the clinical presentation of asthma?
- Expiratory wheeze
- Dyspnoea
- Chest tightness
- Dry cough (exacerbated by exercise/cold conditions).
- Night-symptoms indicate more severe asthma.
- Patients often have family members with asthma.
- Patients often have other allergy-related conditions.
- KEY FEATURE OF ASTHMA: Will have regular but distinctive exacerbations/attacks of disease.
What is the pathophysiology of asthma?
Mainly caused by inflammation. A variety of triggers will begin the inflammatory cascade within the bronchial tree:
- Leukocyte numbers increased in the bronchial wall, bronchial membranes and the secretions.
- Lymphocytes will produce ILs to start the inflammatory cascade, and IgE will be produced (IgE is strongly associated with allergic disease).
- Smooth muscle in bronchial walls will contract, causing airway obstruction. It will also hypertrophy over time, narrowing the airway further.
- Airways will remodel to contain more smooth muscle and an increased number of goblet cells.
What is the aetiology of asthma?
- Largely unknown
- An element of atopy (IgE antibodies produced as a result of exposure to common particles.)
- Increased responsiveness to inhaled stimuli (higher levels of histamine/methacholine produced).
What is the epidemiology of asthma?
- 15-20% of population affected by 20, so very common.
What are the diagnostic tests for asthma?
- History
- Evidence of obstruction (Can be gained using PEF (peak expiratory flow) or spirometry during episodes/attacks).
What are the treatment options for asthma?
1) ICS-Formoterol (LABA + corticosteroid) as needed, OR salbutamol (SABA) + ICS (2 seperate inhalers).
2) Can introduce a daily low-dose ICS for preventative measure if 1st line doesn’t work.
Potentially use a montelukast (LTRA) if ICS isn’t appropriate.
3) Use ICS-formoterol OR salmeterol (LABA) + ICS preventatively, with salbutamol (SABA) as a reliever.
What are the potential complications of asthma?
- Pneumonia (infection of lung/s)
- Pneumothorax (collapsed lung)
What are the two types of rhinitis?
- Allergic
- Non-allergic.
What is the most common form of rhinitis?
- Hey fever. This is a type of seasonal allergic rhinitis that occurs due to pollen exposure in spring/summer.
What is the pathophysiology of allergic rhinitis?
- Exposure to allergen.
- Dendritic cells present the allergen’s antigens to the immune system, triggering IgE production.
- IgE binds to mast cells, sensitising them.
- When re-exposure to the allergen occurs, mast cells degranulate to begin the inflammatory cascade:
- Histamine release.
- IL secretion.
- Migration of inflammatory cells.
What are the two phases of effects seen following mast cell degranulation?
Early phase:
- Due to histamine.
- Within minutes of allergen exposure.
- Symptoms include pruritus, sneezing, rhinorrhea,
Late phase:
- Due to inflammatory cell infiltration.
- A few hours after initial exposure.
- Symptoms include nasal congestion/ mucus production.
What are the risk factors for rhinitis?
- FH of atopic disease (allergic asthma, eczema etc.)
- Allergen exposure.
- <20 years old.