shared:pulm:asthma
Asthma
- Chronic inflammatory disease of respiratory tree to various sensitizing stimuli resulting in reversible airway obstruction
- Characterized by
- Bronchial hyperresponsiveness
- ?
Types
- Allergic
- Atopic
- Extrinisic
- Most common form
- Triggered by inhaled antigens (dust mites, pollen, pet dander, mold)
- Biologics
- Immunologic based
- Non-allergic (intrinisic)
- non-atopic
- intrinisic* 10% of asthmatics
- triggered by factors not related to allergies
- exercise
- cold/dry allergic
- smoke
- viruses
- stress/anxiety
Immunology
- Main immunologic cells
- Macrophages
- Dendritic cells
- Eosinophil
- Immunity
- Innate
- Adaptive
- Humoral (B cells)
- Memory
- Effector (plasma)
- Antigen presenting cell
- Cell-mediated (T cells)
- T helper cells (CD4): mainly TH2
- IL-4 and IL-13 (dupilumab)
- indications
- adults
- moderate-to-severe atopic dermatitis (eczema)
- IL-5 (mepolizumab, benralizumab, reslizumab)
- indications
- age 18 and above
- severe persistent asthma, refractory to other treatment
- eosinophilia, but not elevated IgE
- side effects (OI: herpes zoster with mepolizumab)
- IgE (omalizumab)
- indications
- age 12 and above
- moderate to severe persistent asthma, refractory to other treatment
- serum IgE elevated (dose by IgE and weight)
- only administered in health care setting
- possible anaphylaxis
- Cytotic T-cells (CD8)
Diagnosis
- Pattern of symptoms and response to therapy
- Spirometry and/or PFTs + BD response (≥12%)
- FEV1/FVC, FEV1, FVC
- TLC, DLCO
- Challenge testing
- Exercised induced bronchoconstriction & chronic cough
- Exercised
- Cold air
- Methacholine
- Fraction of exhaled NO
- High values of FENO in asthma that returns to normal after treatment with glucocorticoids
- Eosinophilic inflammation in airways stimulates airway epithelial cells to produce NO
- Sputum eosinophiles
- Charcot leyden crystals
- Curschmann's spirals
Treatment
- Anti-inflammatory medications
- Corticosteroids: PO, inhaled, IV, IM
- Direct bronchodilators (short and long acting)
- b2-agonists (increases cAMP): salbutamol, albuterol, levalbuterol
- anti-cholinergics (M3 receptor in airway smooth muscle)
- helpful/recommended in acute setting
- ipratropium bromide
- methylxanthines
- theophylline
- aminophylline (short acting)
- ?
- Mast-cell stabilizers
- Leukotriene inhibitors
- Zileuton (Zylfo): leukotriene synthesis inhibitor
- Monteleukast (Singulair): leukotriene receptor antagonist
- Combination medications
- Dulera: mometasone furoate and formoterol fumarate
- Symbicort: budesonide and formoterol fumarate
- Advair: fluticasone and salmeterol
- Bronchial thermoplasty: approved for severe persistent refractory asthma, intrinisic and extrinisic (but other options better for extrinsic)
Caution
- aspirin
- ACE inhibitor
- permissive hypercapnia
shared/pulm/asthma.txt · Last modified: 2020/03/05 18:06 by 127.0.0.1