Asthma. Flashcards
Essentials of diagnosis
(1) Episodic or chronic symptoms of wheezing, dyspnea, or cough.
(2) Symptoms frequently worse at night or in the early morning.
(3) Prolonged expiration and diffuse wheezes on physical examination.
(4) Limitation of airflow on pulmonary function testing or positive Broncho provocation challenge.
(5) Reversibility of airflow obstruction, either spontaneously or following bronchodilator therapy.
Asthma
Definition and pathogenesis
- common disease, affecting approximately 8–10% of the population.
- is a chronic disorder of the airways characterized by variable airway obstruction, airway hyperresponsiveness, and airway inflammation.
Asthma
Definition and pathogenesis
Dx which usually begins in childhood and is associated with other allergic diseases such as eczema, allergic rhinitis, or food allergy.
allergic asthma
Definition and pathogenesis
include upper respiratory tract infections,
rhinosinusitis, postnasal drip, aspiration, and gastroesophageal reflux, changes in the
weather, stress, and exercise.
Exposure:
products of combustion
Air pollution
medications
Occupational asthma
catamenial asthma
Exercise-induced bronchoconstriction
“Cardiac asthma”
Cough-variant asthma**
Nonspecific precipitants
Nonspecific precipitants
methamphetamines, diesel fuel, and other agents) increases asthma symptoms and the need for medications and reduces lung function.
Products of combustion
Nonspecific precipitants
(increased air levels of respirable particles, ozone, SO2, and NO2) precipitates asthma symptoms and increases emergency department visits and hospitalizations.
Air pollution
Nonspecific precipitants
is triggered by various agents in the workplace and may occur weeks to years after initial exposure and sensitization.
Occupational asthma
Nonspecific precipitants
predictable times during the menstrual
cycle.
Catamenial asthma
Nonspecific precipitants
begins during exercise or within 3 minutes after its end, peaks within 10–15 minutes, and then resolves by 60 minutes.
Exercise-induced bronchoconstriction
Nonspecific precipitants
wheezing precipitated by pulmonary edema in the setting of decompensated heart failure.
“Cardiac asthma”
Nonspecific precipitants
has cough instead of wheezing as the predominant
symptom of bronchial hyperreactivity.
Cough-variant asthma
Sign and Symptoms
-characterized by episodic wheezing, shortness of breath, chest tightness, and cough.
-Symptoms vary over time and in intensity; often worse at night or in the early morning.
-Symptoms may occur spontaneously or be precipitated or exacerbated by many different triggers
The following features decrease the likelihood symptoms are due to this disease are isolated cough with no other symptoms, chronic sputum production, chest pain, shortness of breath with paresthesias.
Asthma
Physical examination findings
Nasal mucosal swelling, increased secretions, and polyps are often seen in patients with allergies
Eczema, atopic dermatitis, or other allergic skin disorders may also be present.
Wheezing or a prolonged expiratory phase during normal breathing correlates well with the presence of airflow obstruction; wheezing during forced expiration does not.
Chest examination may be normal between exacerbations in mild asthma.
During severe exacerbations, airflow may be too limited to produce wheezing, and the only diagnostic clue on auscultation may be globally reduced breath sounds with prolonged expiration.
Hunched shoulders and use of accessory muscles of respiration suggest an increased work of breathing.
Asthma
Testing:
Lab:
Arterial blood gas (ABG) measurements may be normal in a mild exacerbation
Pulmonary Function Testing
Imaging:
-Routine chest radiographs usually normal or show only hyperinflation.
-Bronchial wall thickening and diminished peripheral lung vascular shadows can also be seen
-Chest imaging is indicated when pneumonia, another disorder mimicking asthma, or a complication of the disease such as pneumothorax is suspected
Asthma
The evaluation for asthma should include spirometry before and after the administration of a short-acting bronchodilator.
These measurements help determine the presence and extent of airflow obstruction and whether it is immediately reversible.
Airflow obstruction is indicated by a reduced FEV1/FVC ratio.
A positive bronchodilator response strongly supports the diagnosis of asthma but a lack of responsiveness in the this test does not preclude success in a clinical trial of bronchodilator therapy
Pulmonary Function Testing (PFT)
- Assessing this asthma control and severity
- Distinguishing between severe asthma and uncontrolled asthma
- Personalized pharmacologic therapy for asthma
- Treatment of modifiable risk factors and control of environmental factors
- Guided self-management education and skills training
Five important aspects of chronic disease management:
Medications:
Inhaled corticosteroids are essential controller medications.
Beta-agonists are divided into short-acting beta-2-agonists (SABAs) and long-acting beta-2 agonists (LABAs). SABAs are mainstays of reliever or rescue therapy.
ALL asthmatics should have immediate access to a SABA
Systemic corticosteroids
Vaccinations: All asthmatics should receive annual influenza vaccine and Pneumovax 23
Asthma
Treatment of exacerbations
Management of asthma exacerbations in primary care clinic: Oxygen (O2), peak expiratory flow (PEF) measurement using peak flow meter; SABA
If have poor response to initial treatment with SABA (PEF < 50% predicted personal best using peak flow meter) and have symptoms of respiratory distress, refer patient to the emergency room.
Small subset will not respond to treatment, will progress to respiratory failure, and require intubation.
Asthma
Treatment of exacerbations
Characterized by only minor changes in airway function (PEF greater than 60% of best) with minimal symptoms and signs of airway dysfunction
Many patients respond quickly and fully to an inhaled SABA alone. However, an inhaled SABA may need to be continued at increased doses, e.g., every 3–4 hours for 24–48 hours.
Patients may also require a short-term increase in inhaled corticosteroid to four times the usual dose.
In patients not improving after 48 hours, a 5- to 7-day course of oral corticosteroids (e.g., prednisone 0.5–1.0 mg/kg/day) may be necessary.
Mild to Moderate Asthma
Treatment of exacerbations
Can be life-threatening, start treatment immediately!
Should immediately receive oxygen, high doses of an inhaled SABA, and systemic corticosteroids
Early initiation of oxygen therapy is paramount because asphyxia is a common cause of asthma deaths
Supplemental oxygen should be given to maintain an SaO2 greater than 90% or a PaO2 greater than 60 mm Hg.
Severe Asthma
Treatment
Albuterol: MAIN STAY
Short Acting Beta Antagonist (SABA)
Examples: ProAir, Proventil HFA, Ventolin HFA
Acute treatment: 1 to 2 inhalations; additional inhalations may be necessary every 4 to 6 hours as needed if inadequate relief however patients should be advised to promptly consult health care provider or seek medical attention if no relief from acute treatment.
Prednisone - is an oral systemic corticosteroid
Dose: 40 mg PO daily for 5 days (there are many different doses and ways to taper longer courses of Prednisone).
Inhaled Glucocorticoids:
Asthma
Disposition:
Atypical presentation or uncertain diagnosis of asthma
Complicating comorbid problems
Occupational asthma
Uncontrolled symptoms despite treatment
Patient not meeting goals of asthma therapy after 3–6 months of treatment
Frequent asthma-related healthcare utilization
More than two courses of oral prednisone therapy in the past 12 months
Any life-threatening asthma exacerbation or exacerbation requiring hospitalization in the past 12 months
Presence of social or psychological issues interfering with asthma management
When to refer: Asthma
