Asthma Flashcards
Asthma
Chronic inflammatory disorder of the airways. Characterized by variable and recurring symptoms, airflow obstruction, bronchial hyperresponsiveness, and underlying inflammation. Airflow limitation is reversible, but over time may lead to airway remodeling.
Asthma risk factors
Genetic: 60-80% susceptibility. Atophy or family history of atopic disease, parental history of asthma.
Environmental: Low socioeconomic status, family size, second hand smoke, allergen exposure, occupational exposure.
Pathophysiology of asthma
Inflammation leads to airway obstruction and airway hyperresponsiveness, both of which contribute to symptoms.
Triggers: cold air, allergens, exercise, particulate, air pollution.
Cough, SOB, wheezing, chest tightness.
Anatomy of an asthma attack
Smooth muscle found in lungs surrounding airway spasm, tightening of airway, swelling and inflammation of inner airway space. Occur due to fluid build up, infiltration by immune cells, excessive mucous secretions in airways. Airway becomes blocked.
Signs & symptoms
Cough, recurrent wheezing, SOB, chest tightness, nocturnal cough, exercise-induced cough or wheezing, onset of symptoms after exposure to airborne allergens or stimuli, history of respiratory tract infections, associated conditions.
Evidence of bronchial obstruction: wheezing, prolonged expiration.
Airway obstruction at least partially reversible.
Evidence of atopy on physical exam (nose, eyes and skin).
Spirometry
Objective test to assess severity of lung disease and responsiveness to treatment.
Ratio of FEV1/FVC gives useful index of airflow limitation. Measured before and after a short-acting bronchodilator.
A 12% increase in FEV1 after bronchodilator is consistent with asthma. A decrease in >15% FEV1 after an exercise test is consistent with exercise induced asthma.
FEV1
Forced expired volume in one second
FVC
Forced vital capacity
Treatment goals
Reduce impairment, reduce risk.
Initial visit
Diagnose asthma, assess asthma severity, initiate medication and demonstrate use, develop asthma aciton plan, schedule follow-up appontment
Asthma triggers
Smoking (#1!), indoor allergens, outdoor allergens, exercise, cold air, pollutants, medications (b-blockers, aspirin, NSAIDs), sulfites, repiratory tract infections (#2!), medical comorbidities (GERD, depression/stress, rhinitis)
Follow-up visit
Assess & monitor control, review medication technique & adherence; assess SE, review environmental control, maintain, step up or step down medication, review asthma action plan, revise if needed, schedule next follow-up appointment.
Modifying therapy per CONTROL
Stepwise approach:
Well controlled: maintain or consider step down if well controlled x3 months.
Not well controlled: step up at least 1 step,
Very poorly controlled: step up 1-2 steps and consider short term course of oral steroids.
Always review adherence to meds, technique and environmental control before stepping up.
Rescue medications
SABA’s (B2), systemic corticosteroids (acute exacerbation)
Controller medications
Inhaled corticosteroids, LABA’s, leukotriene receptor antagonists, mast cell stabilizers, methylxanthines
SABA’s
“-terol”
Increase cAMP, relax airway smooth muscle.
Relief of bronchospasm during exacerbation, pretreatment for exercise induced asthma.
Every patient should have one!
1 puff Q4-6 hours
SE: tachycardia, tremor, palpitations, dizziness, headaches
Inhaled corticosteroids
“-sonide”, “-asone”
Main treatment.
Decrease inflammation and hyperresponsiveness.
Reduce symptoms, improve quality of life, and improve lung function. Reduce severity and frequency of exacerbations, reduce asthma mortality.
Available in MDI and dry-powder inhalers
SE: cough, dysphonia, oral thrush, minimal systemic effects.
LABA’s
Relax airway smooth muscle with longer duration of action
NOT for monotherapy or exacerbations
Increase risk of asthma-related deaths
*Add-on therapy to ICS
SE: tachycardia, skeletal muscle tremor, hypokalemia
Salmeterol
LABA
Formoterol
LABA
Leukotriene receptor antagonists
Interfere with pathway of leukotriene mediators, which are released from mast cells, eosinophils, and basophils.
Alternative to inhaled steroids in mild persistent
Can be adjunct to ICS but not preferred in children >12 and adults compared to addition of LABA
SE: headache, GI upset, hepatotoxicity
Singulair
Leukotriene receptor antagonists
Zafirlukast
Leukotriene receptor antagonist
Zileuton
Leukotriene receptor antagonist
Mast cell stabalizers
Stabilize mast cells and interfere with chloride channel function. Weak anti-inflammatory effects.
Alternative, not preferred. Can be used for exercise-induced bronchospasm. May need 4-6 week trial to determine max benefit. Used 3-4 times daily.
SE: unpleasant taste, dry throat, headache, N/V
Cromolyn
Mast cell stabalizer
Methylxanthines
Relax smooth airway muscle, modest anti-inflammatory properties.
May be beneficial add on therapy to ICS, but less effective than LABA
SE: n/v, diarrhea, tachycardia, cardiac arrhythmias, seizures, headache
Lots of drug interactions. Oral, inhalation not effective.
MONITORING REQUIRED: narrow therapeutic range, 5-15 mcg/mL
Theophylline
Methylxanthine
Follow-up care
Every 2-6 weeks while gaining control, every 1-6 months to monitor control, every 3 months if step down is anticipated.
Oral corticosteroids
Rescue med during acute asthma exacerbations, use short oral burst over 3-10 days, may or may not need a taper.
SE of oral corticosteroids
Acute use:
Fluid retention, mood changes, sleep disturbances, appetite increase, hypokalemia, hyperglycemia, hypertension
Chronic use:
cushingoid changes, growth suppression in children, cataracts, osteopenia, osteoporosis, HPA axis suppression
Quality measures
Adults: flu shot, pneumonia vaccine, tobacco use
Pediatric: flu shot
PERSISTENT: controller meds, asthma action plan, admissions/er visits prior year
