Obstructive Lung Disease Flashcards
(33 cards)
In obstructive disorder what is the FEV1, FVC and FEV1/FVC radio?
FEV1 - Reduced
FVC - usually reduced but to a lesser extent.
Ratio - Reduced (<0.7)
In restrictive disorder what is the FEV1, FCV and FEV1/FCV radio?
FEV1 - Reduced,
FVC - Reduced
The ratio is normal (>0.7)
Define:
- FEV
- FEV1
- FVC
- FEV = Forced expiratory volume.
- FEV1 = Amount of air forced out per second.
- FVC = Forced vital capacity
What is the FEV1/ FVC ratio a measure of and what is normal?
It is a measure of airflow obstruction, above 0.7 is normal
When does hypoxia tend to occur?
When the V/Q ratio is mismatched.
What are some common obstructive lung diseases?
- Asthma
- COPD
- Bronchiectasis
- Cystic Fibrosis
Describe the difference between asthma and COPD?
Asthma - Non-smoking related, history of atopy, tends to present in younger patients, intermittent, non-progressive, eosinophil infiltration.
COPD - Smokers, non-allergic, occurs in over 50s, chronic, progressive decline and neutrophils
What is asthma?
Clinical diagnosis which should be considered when a patient presents with one of the following symptoms:
- Wheeze, breathlessness, chest tightness and cough. Especially if diurnal variation and symptoms of atopy
Describe the pathophysiology of asthma?
- Airway narrowing/obstruction.
- Airway hyper-responsiveness.
- Airway inflammation
What are important mediators in asthma?
Leukotrienes, interleukins and tissue damaging eosinophil proteins. T-lymphocytes in allergic asthma
What are some genetic predisposition and triggers for asthma?
- Viral,
- Allergens, eg, animal dander, dust mites, pollen and fungi.
- Food/nutrition,
- Chemicals (smoke)
- Exercise
What are some of the non-pharmacological treatments for asthma?
- Achieve and maintain a normal BMI if overweight.
- Breathing exercise programmes.
- Stop smoking (patient and/or household members)
What is the pharmacological treatment for asthma?
Beta(2) agonists and steroids
Describe the clinical features of life-threatening asthma
Altered consciousness, exhaustion, arrhythmias, hypertension and cyanosis. SpO2 < 92%
What are the clinical features of near fatal asthma?
Raised PCO2, and/or requires ventilation
Describe the immediate management of acute severe asthma
Immediate treatment;
- Oxygen (maintain sats @ 94-98%),
- SABA (salbutamol or terbutaline) via nebuliser.
- IV steroid (hydrocortisone).
- Add or take away antibiotics or muscarinic antagonists
What treatment is given to patients with severe acute asthma that has not responded to immediate treatment?
IV magnesium sulphate (bronchodilator and anti-inflammatory)
Switch from nebulised to IV salbutamol or IV methylxanthine. Continue to monitor blood gases and patient exhaustion.
What is COPD characterised by?
Persistant airflow limitation that is usually progressive and associated with an enhanced inflammatory response in the airways/lungs to gases.
What are some of the main causes of COPD?
- Tobacco smoking,
- Individual susceptibility,
- In/outdoor pollution from biomass fuels,
- Genetic abnormalities (alpha antitrypsin deficiency),
- Abnormal lung function,
- Age and sex (females at greater risk)
Describe the effects of cannabis with lung disease
- It has a different pattern of inhalation meaning people breath in deeper which can mean smokers getting COPD at a younger age. Joints can also be contaminated with aspergillosis.
Describe features of alpha 1 antitrypsin deficiency?
- Increases the risk of lung and liver disease.
- It is an enzyme that is produced in the liver which counteracts proteinases
Describe how smoking results in emphysema
It causes a decrease in alpha1 antitrypsin activity and causes the attraction of inflammatory cells (causing release of elastase which inhibits the action of alpha antitrypsin resulting in a deficiency) both resulting in a destruction of elastic fibres in the lung and emphysema.
What is the pathophysiology of COPD?
- Inflammation and fibrosis of the bronchial wall.
- Hypertrophy of submucosal glands and hypersecretion of mucous.
- Loss of elastic parenchymal lung fibres.
When should you consider diagnosing someone with COPD?
Breathlessness, chronic cough/sputum production and exposure to risk factors.
