Respiratory System and Diseases 2 Flashcards
What is COPD?
Chronic Obstructive Pulmonary Disease
How is COPD characterised?
by poor reversible airflow limitation which is usually progressive
What is COPD associated with?
persistent inflammatory response of the lung
What is COPD caused by?
predominantly cause by smoking in developed countries
COPD Epidemiology
- develops over many years - rarely symptomatic before middle age
- common in UK - 18% of male smokers - 14% of female smokers - one of the leading causes of lost working days
Aetiology of COPD
smoking is the dominant causal agent
Pathogenesis of COPD
cigarette smoke -> macrophage epithelial cells ->chemotactic factors -> granulocytes -> proteases -> damage
Factors causing COPD
atmospheric pollution
- a minor role compared to smoking
alpha 1 - antitrypsin deficiency
- a rare cause of early-onset emphysema
Pathology of chronic bronchitis - COPD
- chronic inflammation of the airways
(predominantly lymphocytes) - enlargement of mucus-secreting glands of trachea and bronchi
- airway narrowing and hence airflow limitation
Pathology of Emphysema - COPD
- dilation and destruction of the lung tissue and distal to terminate bronchioles
- loss of elastic recoil - expiratory airflow limitation and airtrapping
Characteristic symptoms of COPD
cough
sputum
breathlessness
wheeze
Signs of COPD
tachypnoea
use of accessory muscles of respiration
hyperinflation
poor expansion
others - cyanosis - cor pulmonale
Investigations of COPD
- lung function tests
- chest x-ray
- arterial blood gases
- haemoglobin and PCV
- ECG or achocardiology
COPD results of lung function tests
decreased FEV1
decreased FEV/FVC
COPD results of chest x-ray
lungs hyperinflated
COPD results of arterial blood gases
normal or hypoxia and hypercapnia
COPD results of haemoglobin and PCV
high levels
ECG or achocardiology of COPD
to assess cardiac status if clinical features of cor pulmonale
Treatment of COPD
- smoking cessation
- drug therapy - bronchodilators, corticosteroids, antibiotics etc
- treatment of respiratory failure
- other measures - heart failure, secondary polycythaemia
Complications of COPD
- respiratory failure
- cor pulmonale - right heart failure secondary to lung disease
Prognosis of COPD
- 50% patients with severe breathlessness die with in 5 years
Asthma
a common chronic inflammatory condition of the lungs
What is asthma?
hyper-reactivity of bronchial tree with paroxysmal narrowing of the airway
What are the three characteristics of asthma?
- airflow limitation
- airway hyper-responsiveness
- inflammation of the bronchi
Are airflow limitation reversible in asthma?
yes
Epidemiology of asthma
increasing prevalence
geographical variation
more common now in developed countries
much rarer in far easter countries
Aetiology/development of asthma
atopy and allergy
- readily develop IgE against common environmental antigens - genetic and environmental factors affect IgE levels
increased responsiveness of the airways of the lungs (a fall in FEV1) stimuli
Pathogensis of asthma
Primary Abnormality
- narrowing of the airway
- thickening of the airway wall
- secretions within the airway lumen
Inflammation
- cellular components
eosinophils, t-lymphocytes, macrophages and mast cells
-> release inflammatory mediators
Remodelling
- structural changes in the airway
Precipitating factors of asthma
Occupational Sensitisers
Non-specific factors which may cause when you sneeze
-> drugs, cold air, exercise, viral infections
Rare cause of asthma
- airborne spores of aspergillum fumigates - a soil mould
Clinical Features of asthma
wheezing attacks
episodic shortness of breath
some have one or two attacks a year - others have chronic symptoms
on examination during attack
- reduced chest expansion, prolonged expiratory time and bilateral expiratory polyphonic wheeze
Treatment of Asthma
Control of extrinsic factors
Drug treatment
- bronchodilators
- anti-inflammatory agents
Examples of Bronchodilators used to treat asthma
beta2 adrenergic agonists
animuscarinic bronchodilators
theophyllines
Examples of Anti-Inflammatory used to treat Asthma
Steroids
Chromones
Leukotriene receptors antagonist
Immunosuppressive agents
Types of Lung Tumours
Primary
Secondary
What percentage of primary lung tumours are primary carcinoma?
95%
Factors about primary carcinoma of lungs?
- most common malignant tumour in the world
- poor prognosis
- 5 year survival rate <10%
Major risks of primary carcinoma?
- directly related to smoking
- associated with occupational exposure to carcinogens
- pulmonary fibrosis
Primary carcinoma pathology
- most arising from bronchi - hilum
- main histological types
-> squamous cell carcinoma
-> small cell lung carcinoma
-> adenocarcinoma
-> large cell undifferentiated carcinoma
Clinical Features of Primary Carcinoma
cough
chest pain
haemoptysis
weight loss
Diagnosis of Primary Carcinoma
Chests x-ray
CT
Biopsy and cytology
Treatment of Primary Carcinoma
surgical resection
- non small cell lung cancer
chemotherapy
- small cell lung cancer
radiotherapy
- localised tumours
poor prognosis
