Session 6 - COPD, Lower RTI and pneumonia Flashcards
Define COPD
Characterised by airflow obstruction which is usually progressive, not fully reversible and does not change markedly over several months.
Caused predominantly by smoking.
COPD is an umbrella term encompassing emphysema and chronic bronchitis. Patients may have features of either or of both.
Define emphysema and why does it lead to hyperinflation?
- Destruction of the terminal bronchioles and distal airspaces
- Leads to loss of the alveolar surface area (bullae) and therefore the impairment of gas exchange.
- Destruction of the supporting tissue surrounding the small airways results in their closing during expiration when the pressure outside the airways rises
- Also, loss of elastic tissue leads to hyperinflation because the lungs lose their elastic tendency and cannot resist the outward pull of the ribcage.
Define chronic bronchitis and the clinical symptoms associated with it.
- Refers to chronic mucus hypersecretion in the lungs which is caused by inflammation of the large airways.
- Results in chronic productive cough and frequent respiratory infections and airways remodelling and narrowing which can result in airway obstruction.
Give 3 causes of COPD
Smoking Alpha 1 antitrypsin deficiency - A1A opposes effects of elastase, without it elastase breaks down too much elastin Occupational exposure
What symptoms are associated with COPD?
- Cough and sputum production
- Progressive breathlessness
- Exacerbations are associated with increases in breathlessness and sputum production.
How might a COPD patient breath?
Purse lip breathing - increases pressure in airways and causes a reduction in closure of the small airways
Tachypnoea - fast rep rate
Uses accessory muscles to aid breathing
What might a COPD patient present with upon examination?
Barrel chest - due to hyperinflation of lungs
Wheezing on auscultation
Cyanosis
Co2 retention with oedema
How would you confirm a diagnosis of COPD?
Measurement of airflow obstruction using spirometry – FEV1 <70%
o Occurs because of the limitation to the flow of air during expiration and therefore the volume of air expired in the first second is reduced.
- Chest x ray – not diagnostic but used to exclude other diagnoses
- Alpha 1 antitrypsin blood test for younger patients
How would you manage a patient with COPD? Give 4 methods
- Smoking cessation
- Bronchodilators e.g. salbutamol
- Steroids
- Diet – Supplements
- Supportive e.g. flu vaccine
- Long term oxygen therapy if appropriate
- Lung volume reduction if appropriate – Particularly damaged areas of the lung are removed allowing the other parts to expand and work better
- Methylxanthines:
o Mode of action – bronchodilation, increase resp drive, increase strength of resp muscles, anti inflammatory properties o Work by inhibiting PDE (which breaks down cAMP so inhibition leads to an increase in cAMP and bronchodilation)
Pulmonary rehabilitation:
o Many patients with COPD avoid exercise and physical activity due to breathlessness which leads to a cycle of getting worsening of symptoms
o Pulmonary rehab aims to break this cycle by instigating a programme of exercise and nutritional advice.
What are the 4 common flora of the resp tract?
viridans strep, neisseria, anaerobes, candida
What are 3 less common flora of the resp tract?
strep pneumonia, strep pyogenes, H. influenzae
What are the 3 main defences the resp tract has against infection?
- Cough and sneezing reflex
- Muco-ciliary clearance mechanisms:
o Nasal hairs
o Ciliated columnar epithelium
• Respiratory mucosal immune system:
o Lymphoid follicles of the pharynx and tonsils
o Alveolar macrophages
o Secretary IgA and IgG
Define pneumonia
Infection of pulmonary parenchyma (functional parts of an organ) with consolidation (a region of tissue filled with fluid). Results in impairment of gas exchange.
Define bronchopneumonia, what is it caused by and what does it result in?
- Infection starting in airways and spreading to adjacent alveoli and lung tissue.
- Affects areas around the bronchioles
- Consolidation is patchy and not confined by lobar architecture.
- Usually caused by viral infection
- Results in aspiration of gastric contents, cardiac failure and COPD.
Define lobar pneumonia. What organism causes it
- Consolidation involving a complete lung lobe.
- Most often due to Strep pneumonia.
- Usually community acquired
