Asthma Flashcards
What are obstructive airway diseases?
Diseases that affect the airways
What is the triad of asthma?
- Airway hyper responsiveness
- Airway inflammation
- Reversible obstruction
What is the end result of asthma on the airways?
Airway remodelling.
What are the three hallmarks of airway remodelling
- Basement membrane thickens
- collagen deposition on Sub mucosa
- Smooth muscle hypertrophy
Summarise the pathogenesis of asthma (steps) (4)
- Genetic predisposition/ Triggers
- Eosinophilic inflammation
- TH2 cytokines and mediators
- Twitchy smooth muscle
Common allergens for asthma?
- Animal dander
- dust mites
- pollen
- fungi
Are symptoms and signs of asthma episodic/non?
Episodic
What kind of cough does asthma produce
Non productive. Can have wheeze tho
Does the asthma get worse at specific times?
Diurnal variablility
What other diseases can asthma be linked to?
Allergic triad
Can asthma be dependent on family history
Yes, common to have asthmatics in the family
What findings can confirm asthma?
- history/ exam
- Diurnal variability of PEFR
- Reduced FEV1/FEV <75%
- response to salbutamol >15%
- Provocation test: bronchospasm
How would you treat an acute presentation of asthma?
- Oral steroid- Prednisolone
2. B2 agonist- NEBULISED salbutamol.
What are the treatment steps for chronic asthma? (4)
- SABA
- Inhaled steroid
- Add LABA/LAMA
- Anti IgE, Anti IL5, Leukotriene antagonists, theophylline, Cromone
Example of SABA?
Salbutamol/ terbutaline
Example of LABA?
Salmeterol/ formoterol
What is the action mechanism for SABA’S/LABA’S? (Refer to the specific molecular pathway)
- B2 Agonist joins to adenylyl cyclase
- AC produces CAMP
- CAMP= Reduces Ca conc
- CAMP= stimulates PKA
- PKA= inactivates MLCK, Activates MLCphosphatase
- Relaxation
End result of B2 agonists?
- Relaxes smooth muscle
- Dilates bronchial airways
What are the common combination therapies used of B2 agonists in Asthma? Eg?
LABA/LAMA + ICS
Eg- Formoterol + beclamethasone
Example of an inhaled steroid used in asthma?
Beclomethasone
Why is a spacer device useful?
- Avoids systemic effects
- Good lung deposition
- Lowers oropharyngeal and laryngeal side effects
- Avoids coordination problems
What are the actions of Cromones?
Anti inflammatory- Mast cell Stabilisers
Prevent histamine release.
Example of Cromone?
Cromoglycate
How do Leukotriene antagonists work?
Competitively block CysLT1 receptor.
Receptor to LTC4, LTD4 & LTE4 which cause smooth muscle contraction, mucus secretion and oedema
