Asthma Basics/Rescue Therapy Flashcards
Asthma
- disease characterized by increased responsiveness of the trachea/bronchi to various stimuli
- end result is REVERSIBLE airway narrowing
What are the 4 things that asthma exacerbations are commonly due to?
- Asthma control status
- H/o previous asthma exacerbation
- Environmental triggers: Exercise, smoke, cold, drug-induced
- Seasonal, genetic, & immunologic risks (URIs, atopic asthma, allergic rhinitis)
Early asthma phase
- Bronchospasm/mucosal edema
- Causes wheezing, cough, SOB
- Lasts 1-2 hours
- Responds to nebulized bronchodilators*
Late asthma phase
- Increased inflammation and mucus production
- within 4-6 hours
- Responds to anti-inflammatories* (steroids)
When is anti-inflammatory therapy (steroids) indicated in asthma? Which is the most effective?
- SABA is being used >2x/week
- ICS are the most effective
Rescue Therapy options
- Inhaled short-acting beta-agonists*** (SABA)
- SAMA
- Systemic steroids
Maintenance therapy
- ICS**
- LABA
- LAMA
- Leukotriene modifiers
- Mast Cell stabilizers
- Methylxanthines
- Anti-IgE Abs
- IL-4 & 5 Abs
4 main forms of inhaled drugs
- Metered dose inhalers*** (MDI -shake before each puff)
- Soft mist inhalers (SMI)
- Dry powder inhalers (need to be kept dry)
- Nebulization of inhaled medications
What is a pearl about valved holding chambers (VHCs) and spacers when used with MDIs?
-Both avoid need to coordinate actuation & inhalation
Asthma inhaler expiration
- if it comes wrapped in foil, it is good for 3o days
- If NOT wrapped in foil, it is good for up to 2 years
Inhaler pearls
MDI –> Breath slowly and deeply as they press down
SMI–> Aerosolized drug, no need to shake the inhaler
DPI –> Breath in QUICKLY & deeply, depends on force of inhalation
Make sure the patients know how to use each device. Can bill for teaching technique
Which NSAID may cause acute exacerbation of asthma symptoms?
ASA
SABA products
Albuterol HFA (+ solution for nebulizer) Albuterol DPI Levalbuterol HFA (+ solution for nebulizer)
SABA Mechanism of action
Stimulates adenylyl cyclase which increases cAMP in airway tissues leading to the relaxation of respiratory smooth muscle
-Onset in 5 min, peak effect 30-60 min, 4-6 hr duration
Indications/Dosing
- Relief of bronchospasm symptoms and prophylaxis prior to exercise
- MDI/DPI –> 2 puffs q 4-6 hours PRN dyspnea
SABA metered dose inhaler pearls
- most widely used sympathomimetics for asthma
- Inhalers usually have dose counters so they know how much is left
SABA nebulizer pearls
- particle size is much larger
- NOT more effective than MDI
- used mostly for “uncoordinated” patients
SABA Interactions
-Historically thought that Beta blockers may decrease the effectiveness of SABAs, but data suggests this to be false
SABA ADRs
Tachycardia, palpitations, tremor possible –> all unlikely with only 2 puffs
Antimuscarinics (SAMA)
Nebulized ipratropium + albuterol has been used for years to help manage severe asthma exacerbations OR patients not responding to albuterol alone
-Not used for routine rescue therapy
“Older options”: systemic steroids used for rescue
- Prednisone
- Methylprednisolone
Newer options: systemic steroids for rescue
-Dexamethasone
Becoming more common
-Works as well as prednisone and has a shorter tx course
Systemic steroids MOA
- Inhibits production of inflammatory cytokines
- Reduces bronchial reactivity & increases airway caliber
Systemic steroid indications
- when pt has worsening symptoms despite maintenance therapy
- Used in conjunction with SABAs +/- ipratropium
***Wean them off!
Systemic steroids ADRs
-Insomnia, nervousness, increased appetite, hyperglycemia
