Definition
A.Asthma is chronic airway inflammation characterized by recurrent episodes of wheezing, breathlessness, chest tightness, and cough, particularly at night and in the early morning. Episodes are associated with widespread, variable, often reversible airflow obstruction and bronchial hyperresponsiveness when airways are exposed to various stimuli or triggers. Asthma is responsible for lost school days, lost productivity, and presenteeism.
B.Classifications of asthma:
1.Mild intermittent.
a.Symptoms of cough, wheezing, chest tightness, or difficulty breathing less than or equal to two per week.
b.Flare-ups are brief, but intensity may vary.
c.Nighttime symptoms less than or equal to two per month.
d.No symptoms between flare-ups.
e.Lung function test: Forced expiratory volume in 1 second (FEV1) is 80% or more above normal values.
f.Peak flow has less than 20% variability a.m.-to-a.m. or a.m.-to-p.m., day-to-day.
2.Mild persistent:
a.Symptoms of cough, wheezing, chest tightness, or difficulty breathing three to six times a week.
b.Flare-ups may affect activity level.
c.Nighttime symptoms three to four times a month.
d.Lung function test FEV1 is above 60% but below 80% of normal values.
e.Peak flow has more than 30% variability.
3.Moderate persistent:
a.Symptoms of cough, wheezing, chest tightness, or difficulty breathing daily.
b.Flare-ups may affect activity level.
c.Nighttime symptoms five or more times a month.
d.Lung function test FEV1 is above 60% but below 80% of normal values.
e.Peak flow has more than 30% variability.
4.Severe persistent:
a.Symptoms of cough, wheezing, chest tightness, or difficulty breathing are continual.
b.Frequent nighttime symptoms.
c.Lung function test FEV1 is 60% or less of normal values.
d.Peak flow has more than 30% variability.
Incidence
A.Asthma affects 25 million people in the United States.
B.Asthma rates in the general population are increasing, including developed countries.
C.Up to 95% of patients with asthma also suffer from persistent rhinitis.
D.Asthma is often associated with other comorbid conditions, including gastroesophageal reflux disease (GERD) and obesity.
E.The diagnosis is more common in adult females than males.
F.Puerto Ricans, African Americans, Filipinos, and Irish Americans have higher rates than other ethnicities.
G.Asthma control and asthma outcomes are worse for lower socioeconomic groups.
Pathogenesis
A.Asthma arises from a complex cycle of processes initiated by airway inflammation resulting from physical, chemical, and pharmacologic agents (such as environmental irritants, allergens, furry animals, cockroaches, dust mites, pollens and mold, cold air, viral respiratory infections, and exercise). It progresses to airway hyperresponsiveness, bronchoconstriction, airway wall edema, chronic mucus plug formation, and chronic airway remodeling.
Predisposing Factors
A.Family history.
B.Coexisting sinusitis, nasal polyps, and sensitivity to aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs).
C.Exposure in workplace to wood dust, metals, and animal products.
D.Premenstrual asthma (PMA).
E.Smoking.
F.Early menarche.
G.Obesity.
H.Postmenopausal hormone replacement therapy.
I.Viral respiratory infections.
J.Gastroesophageal reflux.
Common Complaints
A.Recurrent cough (worse at night and early morning).
B.Recurrent wheezing.
C.Recurrent shortness of breath (SOB).
D.Recurrent chest tightness (may worsen with moderate activity).
Other Signs and Symptoms
A.Nocturnal awakening from symptoms.
B.Variation of symptoms with seasons or environment.
C.Chest discomfort, tightness with moderate activity.
Subjective Data
A.Ask about onset, duration, and course of symptoms.
B.Inquire about sudden severe episodes of coughing, wheezing, and SOB and whether precipitating factors can be identified.
C.Ask whether the patient has chest colds that take more than 10 days to resolve.
D.Ask if the patient is a smoker, how much, for how long, and if interested in quitting.
E.Ask whether symptoms seem to occur during certain seasons or during exposure to the following environmental irritants:
1.Tobacco smoke.
2.Perfume.
3.Household pets.
4.Fireplaces.
5.Woodburning stoves.
6.Mold.
7.Dust mites.
8.Cockroaches.
9.Occupational triggers.
F.Find out how often coughing, wheezing, or SOB awakens the patient.
G.Ask if symptoms are caused or exacerbated by moderate exercise or physical activity.
H.Determine the family history of asthma, allergies, and eczema.
I.Determine if the patient is pregnant or has medical problems. In pregnancy, treatment is based on the same step therapy as in nonpregnant patients.
J.Administer the asthma control test. The test is available online from www.asthmacontrol.com. A score greater than 20 points indicates the patient’s asthma is well controlled. Scores of 16 to 19 points indicates the patient is not well controlled.
K.Evaluate if the patient has ever been tested for allergies.
L.Ask how many times the patient has gone to the emergency room or had to be hospitalized for an asthmatic attack.
M.Ask how many times they have been on oral steroids during the past year.
N.Review all medications including over-the-counter (OTC) and herbal supplements and their effectiveness for asthma control.
O.Ask if prescription or OTC inhalers are used and to what extent.
Physical Examination
A.Check temperature (if indicated), blood pressure (BP), pulse, respirations, and pulse oximetry. Measure the patient’s height, weight, body mass index (BMI), and waist circumference because obesity is associated with asthma.
B.Inspect:
1.Comfort with respiratory pattern, skin tones, and use of accessory muscles of breathing.
2.Observe for hyperexpansion of thorax and signs that accessory muscles are being used (retractions, nasal flaring) or stridor.
3.Note appearance of hunched shoulders and/or chest deformity.
4.Inspect ears, nose, and throat. Evaluate the presence of enlarged tonsils and adenoids, and nasal polyps.
5.Inspect skin for eczema, dermatitis, or other irritation that might signal allergy.
6.Observe for allergic shiners and pebbled conjunctiva.
7.Observe for digital clubbing.
C.Auscultate:
1.Auscultate lung sounds. Note wheezing during normal expiration and prolonged expiration, which is seen with asthma.
2.Listen to all lung fields for an asymmetric wheeze.
3.Auscultate heart rate.
D.Percuss: Percuss lung fields.
Diagnostic Tests
A.Spirometry is the gold standard. Peak flow meter measurements are not a substitute for spirometry. Evaluate the forced vital capacity (FVC) and FEV1 before and after the patient inhales a short-acting bronchodilator.
B.Chest radiograph (CXR) and complete blood count (CBC) to exclude other diagnoses and infection.
C.Check peak expiratory flow rate (PEFR) after inhalation of short-acting beta-2 agonist. Diagnosis is confirmed if:
1.There is a 15% increase in PEFR after 15 to 20 minutes.
2.PEFR varies more than 20% between arising and 12 hours later in patients taking bronchodilators (or 10% without bronchodilators).
3.There is a greater than 15% decrease in PEFR after 6 minutes of running or exercise.
D.Consider a bronchial provocation test with histamine or methacholine for nondiagnostic spirometry.
Differential Diagnoses
A.Asthma.
B.Chronic obstructive pulmonary disease (COPD).
C.GERD.
D.Congestive heart failure (CHF).
E.Cough secondary to medications such as an angiotensin-converting enzyme (ACE) inhibitor or beta-blockers.
F.Pneumonia.
G.Pulmonary embolism.
H.Laryngeal dysfunction.
I.Benign and malignant tumors.
J.Vocal cord dysfunction.
K.Obstructive sleep apnea (OSA).
L.Tuberculosis (TB).
M.Postviral syndrome.
N.Obesity.
O.Allergic rhinitis.
P.Aspiration.
Plan
A.General interventions:
1.Review proper medication dosages. Short-and long-term agents come in several formulations: nebulizer, metered-dose inhaler (MDI), and a dry powder inhaler (DPI).
2.
See Section III: Patient Teaching Guide How to Use a Metered-Dose Inhaler.
The easiest delivery mechanism should be considered for the elderly.
3.See Section III: Patient Teaching Guide Asthma Action Plan and Peak Flow Monitoring.
4.Short-acting beta-2 agonists (SABA) are used for rescue from acute symptoms. Ask the patient to state or identify which inhaler he or she uses for rescue.
5.Use of a SABA more than twice a week for symptom relief indicates the patient has inadequate asthma control and needs an inhaled corticosteroid (ICS) as controller therapy.
6.See Section III: Patient Teaching Guide Asthma Action Plan and Peak Flow Monitoring.
B. See Section III: Patient Teaching Guide Asthma
:
1.Asthma is more difficult to control in obesity. Weight reduction should be included in the treatment plan for obese patients with asthma; even 5% to 10% weight loss can improve asthma control.
C.Pharmaceutical therapy: Drugs are prescribed in a stepwise fashion for the type of asthma. In pregnancy, treatment is based on the same step therapy as in nonpregnant patients. The amount of medication used depends on the severity of asthma. The 2018 Global Initiative for Asthma (GINA) guidelines outline the medication classes for the approach to Steps 1 to 5. Prior to any medication/dosage changes evaluate if the patient has been doing incorrect inhaler technique for medication delivery and monitor the patient’s compliance with use of medications. Re-evaluate the patient’s modifiable risk factors (e.g., smoking, weight, etc.) and evaluate if symptoms are due to comorbid conditions, for example, allergic rhinitis. See Table 12.1 for a list of medications for asthma. The following treatments are recommended:
1.Step 1:
a.Controller options: Consider low-dose ICSs.
b.Reliever: Use SABAs as rescue medication. May be used every 4 hours as needed to treat exacerbation.
2.Step 2:
a.Preferred controller choice: Low-dose ICSs are used daily as a long-term preventive medication.
b.Other controller options:
i.Leukotriene receptor antagonist (LTRA) OR