3. Obstructive Lung Disease, PE, TB and Interstitial Lung Disease Flashcards
name three mechanisms of airways obstruction
- excess mucous
- bronchial smooth muscle hypertrophy
- alveolar destruction - loss of traction which keeps the bronchial walls open
Define the following:
- FVC
- FEV1
- Name 5 factors that influence expected spirometry values
- the amount of air that can be forcibly exhaled from the lungs after taking the deepest breath possible
- maximal amount of air that you can forcibly exhale in one second
- age, gender, height, weight, ethnicity
What is the normal reference ranges of the following:
- FEV1
- FVC
- FEV1/FVC ratio
- > 80% expected
- > 80% expected
- > 0.7
- What are the spirometry results in airway obstruction?
2. what is reversibility?
- FEV1 <80% expected/best
FEV1/FVC <0.7 - improvement of >15% following use of bronchodilator
What are the three characteristics of asthma?
- reversible airflow limitation
- airway hyper-responsiveness
- bronchial inflammation
name 4 precipitating factors of asthma
- occupational sensitisers - spray paints, flour/organic dusts
- cold air and exercise
- atmospheric pollution
- drugs - NSAIDs and beta blockers
describe the Th2 driven inflammatory process driving asthma
- dendritic cells present allergen to T cell
- T cell differentiates into Th2 cell
- Th2 produces Il-4 - this promotes IgE production by B cells
- IgE binds to mast cells in the airway
- mast cells degranulate when antigen binds. release of inflammatory mediators
- cytokines activate T and B cells; IL-5 attracts eosinophils
- Eosinophils produce leukotrienes
Name the 4 classic signs and symptoms of asthma
- dyspnoea
- expiratory wheeze
- cough
- chest tightness
Name 3 factors in a history that could indicate asthma
- symptoms often worse at night
- exacerbated by particular triggers
- exercise/cold may make symptoms worse
Name 4 investigations for ?asthma
- spirometry
- PEFR
- FBC (raised eosinophils)
- FeNO (exhaled nitric oxide) - raised
Describe the 5 steps of asthma management
- SABA
- add ICS
- Add LABA
- increase steroid and add 4th drug (leukotriene antagonist or theophyline)
- Add steroid tablet, and refer
- Name 4 signs/symptoms of status epilepticus
2. name 4 signs that this could be life threatening
- inability to complete sentences in one breath
tachypnoea
tachycardia
PEFR <50% - silent chest; feeble respiratory effort
exhaustion, confusion
bradycardia or hypotension
PEFR <30%
define chronic bronchitis
productive cough that lasts for more than 3 months, with recurring bouts occurring for at least 2 consecutive years
What does the lymphocytic infiltrate in chronic bronchitis consist of?
CD8 cells and neutrophils
How does emphysema cause airflow obstruction?
loss of radial traction - therefore pleural pressure>radial traction, leading to reduced alveolar pressure, leading to collapse of airways prematurely.
Name 4 symptoms of COPD
- cough - usually productive
- progressive dyspnoea
- wheeze
- frequent infective exaverbations
What might a patient with COPD demonstrate on general examination?
intercostal indraping pursed lip breathing use of accessory muscles hyperinflation of chest flapping tremor due to hypercapnia clubbing
- What will a patient with COPD have on percussion?
2. What will a patient with COPD have on auscultation?
- hyperresonance
2. wheeze and/or coarse crackles
Name 5 investigations for ?COPD
- spirometry
- pulse oximetry
- ABG
- CXR - reveals hyperinflation (flattened diaphragm, increased intercostal spaces, hyperlucent lungs)
- sputum culture
What is the FEV1% predicted in the following COPD stages?
- mild
- moderate
- severe
- very severe
- ≥ 80%
- <80%
- <50%
- <30%
Describe the 3 step management of COPD
- SABA or SAMA
- add LABA or LAMA
- Add ICS if severe, had frequent exacerbations and significant symptoms
what is carbocystine used for?
mucolytic
- What is the aim of long term oxygen therapy?
2. When is it indicated?
- to minimise pulmonary hypotension
2. sats <88% confirmed twice over a 3 week period, or if there is evidence of pulmonary hypotension
How are acute exacerbations of COPD managed? (4)
- antibiotics if cause is infective
- bronchodilators
- oxygen therapy
- oral corticosteroids
Name 3 clinical markers of COPD severity
- FEV1
- hyperaemia
- MRC dyspnoea scale
Name the only 2 methods which can improve prognosis of COPD
- LTOT
2. smoking cessation
What is a pneumothorax?
an accumulation of air in the pleural space
Describe the following causes of pneumothorax
- primary spontaneous pneumothorax
- secondary spontaneous pneumothorax
- Traumatic Pneumothorax
- occurs without precipitating event in a person without clinically apparent pleural disease
- occurs as a complication of underlying pulmonary disease, typically COPD
- Results from a penetrating injury to the chest
What is a tension pneumothorax?
a pneumothorax whereby the air is trapped within the pleural cavity under positive pressure. Air accumulates in the plural space on inspiration but can’t escape.
Name 3 symptoms of pneumothorax
- ipsilateral chest pain
- shoulder tip pain
- dyspnoea