Obstructive Airway Disease 1 Flashcards
What is obstructive airway disease?
Any respiratory disease characterised by air trapping caused by either decrease airway diameter or increased airway secretions, or both
what are 3 obstructive airway disease?
AsthmaChronic bronchitisEmphysema
What is asthma/ COPD overlap syndrome?
Not clearly defined but patients with features of asthma and COPD (e.g. atopic smoker with partially reversible airway obstruction) - COPD with reversibility and eosinophilia who are steroid responsivE
What causes the turbulent airflow in asthma and COPD?
Mucosa and sub-mucosa become inflamed and invaginate and therefore obstruct airflow
what type of leukocytes are involved in COPD and asthma?
COPD = neutrophilAsthma = eosinophil
How can the tone of the smooth muscle be described in COPD and asthma?
COPD = hypertrophicAsthma = twitchy
What 3 sets of words can be used to describe asthma?
Early onset/ late onsetAtopic (allergic)/ non-atopicExtrinsic (external factor)/ intrinsic (internal factor)
What is the asthma triad?
Airway inflammationReversible airflow obstructionAirway hyperresponsivenes (hyperreactivity)
What is the evolution of asthma?
Bronchoconstriction (brief symtpoms)Chronic airway inflammation (exacerbations airway hyperresponsiveness)Airway remodelling (fixed airway obstruction = COPD like symptoms)
What are the hallmarks of asthma remodelling? (3)
Basement membrane = thickenedSubmucosa = collagen depositionSmooth muscle = hypertrophy
What is the inflammatory cascade in asthma? + treatment?
Genetic predisposition + triggers (viruses, allergen, chemical, nutrition) - avoidanceEosinophilic inflammation - anti-inflamatory (corticosteroid)TH2 cells release mediators (Interleukins e.g. IL-12, IL-4, IL-5) - anti-leukotriene/ histamine, anti-IgE, anti-IL5)Twitchy smooth muscle (hyper-reactivity) - bronchodilators (beta-2 agonists, muscarinic antagonists)
What are examples of the environmental factors that can affect asthma?Genetic factors?
Age, gender, obesity, infeciton, atopic status, allergin exposureGenetic = Epithelial-specific asthma gene signature
Examples of some asthma triggers?
Animal danderDust mitesPollensFungiExercise Viral infectionSmokeColdChemicalsdrugs (NSAIDs, beta-blockers)
What are the clinical signs of asthma?
Episodic symptoms and signsdiurnal variability (nocturnal/ early morning)non-productive cough, wheezetriggersassocaited atopyfamily history
What can be used to help diagnose asthma?
History and examinationdiurnal variation of peak flow rateReduced forced expiator rate (FEV1/FVC 15%)Provocation testing leads to bronchospasm