Obstructive Lung Disease Flashcards
What is the definition of asthma?
Intermittent wheeze and SOB secondary to reversible bronchoconstriction
What are classical symptoms of asthma?
Diurnal variation
Exacerbated by cold, allergens and exercise
Hx of hayfever and eczema
What two medications can exacerbate asthma?
NSAIDS
BB
What is the first line investigation to diagnose asthma?
Spirometry with reversibility testing with bronchodilators
What method is used to monitor asthma severity between attacks?
PEF
What are other investigations can be used if spirometry is inconclusive diagnosis for asthma ?
Challenge testing - use of histamine or methacholine in a safe enviromonent to produce symptoms
Fractional exhaled nitric oxide - indirect marker of airway inflammation
What is first line management for asthma?
Short acting Beta 2 agonist e.g. Salbutamol
What is second line treatment for asthma and when would it be indicated?
Inhaled corticosteroid
Using SABA >3x a week or night waking with asthma symptoms
What are the 3rd and 4th line treatment for asthma when not controlled by SABA and ICS?
- Addition of Montelukast - LTRA
2. Start LABA, Stop LTRA
What are side effects of Beta 2 agonists?
Tachycardia
Hypokalaemia
Tremor - activation of B2 in skeletal muscle
When would you refer to a respiratory physician for asthma?
Frequent use of oral steroids
What monoclonal antibody therapy can be initiated in severe asthma and what are its indications and actions ?
Omilizumab - IgE receptor inhibitor
When oral steroids are required >4 times in 12 months
An improvement of what percentage would indicate asthma in a bronchodilator reversibility challenge?
200ml or 12% increase in FEV1
If asthma is uncontrolled on SABA, ICS and LABA what is the next line of management and what does it mean?
Start MART - Maintenance and reliever therapy
Combined ICS and LABA in single inhaler
What is the definition of COPD?
Chronic condition where there is airflow limitation secondary to inflammation due to exposure to substances or stimuli.
What is the difference between the emphysematous lung destruction in patients who smoke in comparison to patients who have alpha-1 antitripsin deficiency?
Alpha-1 antitripsin deficiency tends to effect the lower lobes and it is panlobular
Smokers tend to develop centrilobular which typically impacts the upper lung and proximal acini
What diagnosis should you consider in a younger patient presenting with Emphysema and what organs would you want to investigate?
Alpha 1 antitripsin deficiency
Liver function
What is the pathophysiology of alpha 1 antitripsin deficiency?
Alpha-1 antitripsin prevents the breakdown of elastin by neutrophil elastase resulting in the sub sequential breakdown of alveolar cells
Congestion of the liver with the enzyme alpha-1 antitripsin which is produced there in an attempt to compensate eventually causes hepatocyte destruction.
What two syndromes involve the development of asthma?
Churgg Strauss - 90% of patients. Inflammatory vasculitis effecting small to medium blood vessels
Someter syndrome - Triad of nasal polyps, aspirin insensitivity and asthma
What are the classical symptoms of COPD?
Recurrent chest infection Wheeze SOB Weight loss Sputum production - classically white
What are important investigations in the diagnosis of COPD and what would you expect to see?
Spirometry - Reduced FEV1 and FVC, Increased RV. Consider reversibility testing with SABA to rule out asthma if diagnostic uncertainty
FBC - ? Polycythemia due to reduced O2
XRAY - Hyperinflation >10 posterior ribs, Bullae and flattened hemidiaphragm
What are symptoms of an exacerbation of COPD and what is the most common causative organism?
Increased SOB and cough
Increased sputum production or change in sputum colour
Haemophilus influenzae
What is the management of an acute exacerbation of COPD?
Increase SABA use
Add 30mg of Prednisolone for 7 to 14 days
If purulent sputum or other sx of pneumonia - Add amoxicillin or doxy
What is first and second line inhaled therapy for stable COPD?
1st - SABA OR SAMA
2nd - Use FEV1 levels to determine: <50% ICS + LABA or LAMA IF >50% add LABA or LAMA