Flashcards in Asthma + management Deck (27):
what are 3 characteristics of asthma?
1. Bronchoconstriction, 2. inflammation, 3. mucous hypersecretion
how can we test bronchial hyper responsiveness?
Bronchoprovocation testing- Bronchial hyperresponsiveness is a characteristic feature of asthma and can be demonstrated by asking patients to inhale gradually increasing concentrations of histamine or methacholine .
Other testing stimuli= exercise + cold air, mannitol or saline
how does exercise induce asthma?
cold air and drying of the epithelial lining in the airways during exercise stimulates neural reflexes that cause LT, HA and cytokines to be released from mast cells.
which drugs can trigger an asthma attack?
NSAIDs like aspirin can cause asthma in about 5% of asthmatics; as well as beta blockers like atenolol. So if possible other BP lowering drugs should be used in asthmatics
What are some key inflammatory cells implicated in asthma pathogenesis?
Mast cells and Eosinophils
Briefly describe the pathogenesis of asthma
ACUTE: It is a Type 1 Hypersensitivity reaction (triggered by allergen) --> allergen binds to IgE-mast cells, these mast cells degranulate and release histamine, leukotrienes and cytokines. Histamine binds to H2 receptors and cause vasodilation and increased vascular permeability. LT induce bronchoconstriction. Eosinophils further enhance this response.
--> bronchoconstriction, oedema, mucous
Asthma is classified generally as a 'reversible obstructive process'. what causes the obstruction?
Bronchoconstriction, oedema and mucous plug
what are some key questions you must ask an asthmatic patient in a history?
• Have you ever been hospitalised from an asthma attack?
• Do you have ezcema, dermatitis, other allergies?
• Do you have pets at home?
• Are you are smoker? What is your occupation? i.e need to take a comprehensive social history!! Medication compliance?
• Family medical history
+Psychological impact on life
list some triggers for asthma attack?
• There may be certain triggers (pollen, cold air, cat hair, smoke, dust, UR infection, NSAIDs + emotion and anxiety)
list some key symptoms and signs of an acute asthma attack
• SOB (episodic, nocturnal or early morning, often with exercise)
• Chest tightness
• Cough (usually dry but may have some sputum production)
• Tachypnoea with increased work of breathing
• Wheeze (turbulent flow of air through narrowed airways)
how might you ask about a patient's adherence to asthma medication?
How often are you getting a new puffer?
How often do you fill out your prescription for ventolin?
what are signs of a SEVERE asthma attack?
• Low O2 sat
• High HR
• High RR
• Hyperinflation on CXR
• Alkalosis (ABG)
• His AA gradient is very high
Faint whistling heard through the chest.
Describe airway remodelling in chronic asthma?
Loss of ciliated columnar cells in the epithelium, with increased metaplasia of mucous secreting goblet cells. Thickened basement membrane + hyperplasia of airway smooth muscle
what might you see in a CXR of an asthma attack?
Usually nothing, although you may find signs of hyperinflation
what are the 5 aims of management for asthmatics?
1. Reduce frequency of exacerbations
2. Symptomatic relief
3. Maximise lung function and prevent lung function decline
4. Maintain normal levels of activity
5. Lowest dose of medication to achieve suitable asthma control and minimise side effects
how should a patient with mild asthma and occasional attacks manage their asthma? (medical management)
Short acting bronchodilators b2 agonists PRN such as salbutamol and terbutaline. If they are increasingly relying on b2 agonist mono therapy then this may indicate deterioration and they should seek medical assistance.
For a patient with frequent attacks of asthma- what is their medical management? What would you give if their attacks are becoming more severe?
1. oral corticosteroids + LABA; such as fluticasone + salmeterol, or budicasone + formoterol;
2. salbutamol PRN
3. if becoming severe, add a LTRA such as montelukast
how does sodium cromoglycerate work?
Works by preventing activation of many inflammatory cells, particularly mast cells, eosinophils and epithelial cells, but not lymphocytes, by blocking a specific chloride channel which in turn prevents calcium influx
what is the most widely used inhaled corticosteroid?
why is inhalation technique so important?
We want a larger proportion of the drug to directly deposit on the airways. If we have poor inhalation technique, then a lot of it will be either exhaled or swallowed. If swallowed, ti will take longer to exert its effects as it has to go through the liver
why do we advise the patient to wash their mouth after using inhaled medication?
side effect of inhaled corticosteroids is oral thrush + hoarseness. So need to wash mouth after administration of medication.
what is the difference between oral corticosteroids and inhaled corticosteroids?
Inhaled corticosteroids are first line for persistant moderate asthma. For asthma that is not controlled with inhaled corticosteroids, then a last line option would to administer oral corticosteroids. We would try to limit the dose of oral corticosteroids by using other steroid sparing drugs
how might we lower the dose of oral corticosteroids?
use steroids sparing drugs like low dose methotrexate and ciclosporin
Briefly tell me about Omalizumab
Recombinant humanized monoclonal antibody directed against IgE, chelates free IgE and downregulate the number and activity of mast cells and basophils.
It is given subcutaneously every 2–4 weeks, depending on total serum IgE level and body weight.
Although expensive, it is cost-effective in patients with frequent exacerbations requiring hospital admission
would we administer antibiotics for an exacerbation of asthma as we would for an exacerbation of COPD?
not really. Usually the green/yellow sputum coughed up by asthmatics is due to eosinophils and not due to bacteria. Usually it's caused by viruses which would not respond to antibiotics anyway
how do we manage a severe asthma attack in hospital?
• Beta agonist (regular bronchodilators) (nebulised)
• Oral prednisolone or IV hydrocortisone (nebulised)
+ tiotropium antimuscarinic (nebulised)
• Urgent ICU assessment for observation and possible intubation
+ CXR and ABGs for Ix