Asthma Flashcards
Asthma Characteristics (5)
- Chronic inflammatory disorder of the airways
- Airway hyper-responsiveness
- Bronchoconstriction
- Airway edema
- Mucus plug formation
Asthma epidimiology (2)
- Most common chronic disease among children in the US
2. Slightly higher incidence in males until adolescence then switches
Asthma etiology (3 genetic, 7 environmental)
- Genetic
–35-70% have hereditary association
–Gender
–Cytokine response
2. Environmental –RSV infection in early childhood –Socioeconomic status –Family size –Exposure to second-hand smoke –Allergen exposure –Urbanization –Decreased exposure to common infections
Asthma Triggers (6)
- Infection: RSV, rhinovirus, influenza, parainfluenza
- Allergens: Airborne pollens, dust-mites, dander, roaches
- Environment: Cold air, fog, tobacco smoke, ozone, wood smoke
- Emotions: Anxiety, stress, laughter
- Exercise: Particularly in cold, dry climates
- Medications: Aspirin, NSAIDs, sulfites, beta-blockers
Asthma Pathophysiology (7)
Airway inflammation:
- Acute and/or chronic
- Mast cell activation: Histamine, PG, LTs
- Eosinophil infiltration: Produce LT, PAF to cause smooth muscle contraction
- TH2 lymphocytes – release cytokines and interleukins
Airflow obstruction
- Bronchospasm
- Edema
- Hypersecretion
Consequences of asthma pathophysiology (6)
- Hyper-responsive airway to physical, chemical, and pharmacologic stimuli
- Mucus production
- Airway smooth muscle contraction
- Inflammation
- Nitric oxide less effective
- Remodeling of the airway
Asthma Classifications (4)
1: Mild intermittent
2: Mild persistent
3: Moderate persistent
4: Severe persistent
Diagnosis of Asthma (9)
- History of cough, recurrent wheezing, recurrent difficulty breathing, recurrent chest tightness
- Symptoms occur or worsen at night or with exercise, viral infection, exposure to allergens and irritants, changes in weather, hard laughing or crying, stress, or other factors
- In all patients 5 or older, use spirometry to determine that airway obstruction is at least partially reversible
- Considered other causes of obstruction
- Decrease in FEV1 of at least 30% following 6 minute of near maximal exercise
–Only useful in older children (i.e. 5 years old) - Elevated eosinophil count
- Elevated IgE concentration in blood
- Positive methacholine challenge
–PC20 FEV1 < 12.5 mg/mL
-Provocation concentration of methacholine to cause a decrease in FEV1 by 20%
Mild Intermittent Asthma (6)
- Symptoms < 2 days per week
- Asymptomatic and normal PEF (peak expiratory flow) between exacerbations
- Exacerbations brief, intensity may vary
- Nighttime symptoms < 2 nights per month
- FEV1 or PEF > 80% predicted
- PEF variability < 20%
Mild Persistent Asthma (5)
- Symptoms > 2 times per week but < 1 time per day
- Exacerbations may affect activity
- Nighttime symptoms > 2 nights a month
- FEV1 or PEF > 80% predicted
- PEF variability 20-30%
Moderate Persistent Asthma (7)
- Daily symptoms
- Daily use of inhaled beta-agonist
- Exacerbations affect activity
- Exacerbations > 2 times a week
- Nighttime symptoms > 1 night per week
- FEV1 or PEF > 60%, < 80% predicted
- PEF variability > 30%
Severe Persistent Asthma (6)
- Continual symptoms
- Limited physical activity
- Frequent exacerbations
- Nighttime symptoms frequent
- FEV1 or PEF < 60% predicted
- PEF variability > 30%
Goals of Asthma Therapy (6)
- Prevent chronic symptoms
- Maintain normal pulmonary function
- Maintain normal activity levels
- Prevent recurrent exacerbations
- Provide optimal pharmacotherapy with minimal side effects
- Meet expectations/satisfaction with care
Long Term Control Medications (6)
- Corticosteroids
- Immunomodulators
- Leukotriene inhibitors
- Long-Acting B-agonists
- Mast cell stabilizer (Cromolyn Sodium)
- Methylxanthines
Short Term Relief Medications (3)
- Anticholinergics
- Short-acting B-agonists
- Systemic corticosteroids
Beta-2 Agonists (2)
- Most effective bronchodilators and treatment of choice for severe acute asthma
- Chronic administration may lead to down-regulation of receptors
–May be reversed with corticosteroids
Beta-2 Agonists Mechanism of Action (4)
- Mostly beta-2 selective
- Stimulates beta-adrenergic receptors –> production of cyclic AMP –> smooth muscle relaxation –> bronchodilation
- Mast cell stabilization
- beta1 and alpha1 actions seen with high doses
Short Acting B2 Agonists (5)
- Albuterol (PO, MDI, Neb); tx of choice
- Levalbuterol
- Terbutaline (PO, IV, Subq)
- Metaproterenol - not used a lot
- Pibuterol
Long Acting B2 Agonists (2)
- Formeterol
2. Salmeterol
Combination of Short and Long Acting B2 Agonists (3)
- F/Budesonide
- S/Fluticasone
- F/Mometasone
Albuterol Dosing (2)
ProAir, Ventolin HFA
- MDI: 90 mcg/puff (max dosing outpatient: 2 puffs q4h)
- Neb: 2.5 mg/ampule (max dosing OP = 5 mg q1 – 4h)
Albuterol ADEs (6)
- HypoK+
- Excitability/hyperactivity, shakiness or tremors
- Loss of appetite, GI discomfort
- Rare: hyperglycemia, bronchospasm
- Tachycardia, palpitations
- Caution with overuse
Albuterol Onset
Inhalation almost immediate
Levalbuterol (Xopenex)
(R) enantiomer of albuterol; theoretically less tachycardia and adverse effects
Levalbuterol Dosing
- MDI: 45 mcg/puff (8 puffs q20 min up to 4 hrs)
2. Neb: 0.075 – 0.15 mg/kg/dose (comes in 0.31, 0.63, & 1.25 mg)
Levalbuterol ADEs (6)
- Hypokalemia
- Excitability/hyperactivity, shakiness
- Loss of appetite, GI discomfort
- Rare: hyperglycemia, bronchospasm
- Tachycardia
- Caution with overuse
Long Acting Beta Agonist Info (6)
- NOT FOR ACUTE SYMPTOMS
- Long-term prevention of symptoms
- MDI is FDA approved > 12 years of age
- Clinically used in younger children - Preventative agent for EIA
- 2 puffs 30-60 minutes prior to exercise
- Effective for nocturnal symptoms