Asthma Clinical Guideline
Diagnosis Confirmation of the diagnosis of asthma is based upon two key elements : 1 . The history or presence of respiratory symptoms consistent with asthma . 2 . The demonstration of variable expiratory airflow obstruction .
Alternative diagnoses must be excluded .
Physical Examination Evaluate for :
• Widespread , high-pitched musical wheezes
• Hyper-expansion of the thorax
• Increased nasal secretions , mucosal swelling and / or nasal polyps
• Atopic dermatitis / eczema or other manifestation of an allergic skin condition
Pulmonary Function Testing Pulmonary function tests are critical tools for the diagnosis of asthma . Measurement of lung function can confirm the diagnosis by quantifying the severity , reversibility , and variability of airflow limitation .
Spirometry is the recommended test to establish a diagnosis of asthma . It measures :
• FEV1 -- forced expiratory volume in one second
• FVC -- forced vital capacity is the volume of air differential between full inspiration and maximal expiration
• FEF -- forced expiratory flow between 25 % and 75 % of the vital capacity
• FEV6 -- forced expiratory volume in six seconds
The results of spirometry can be used to :
• Distinguish normal from abnormal lung function
• Categorize abnormalities into obstructive or restrictive patterns
• Assess the reversibility of the obstructive abnormality if the testing is repeated after administration of a bronchodilator
The National Asthma Education and Prevention Program recommends that spirometry before and after administration of a bronchodilator be performed on all adolescents and adults being considered for the diagnosis of asthma .
History There are key indicators that heighten the probability of asthma :
• Episodic symptoms -- these symptoms typically come and go , over minutes not seconds , and resolve spontaneously when the triggering stimulus is removed or in response to anti-asthmatic medications
• Characteristic triggers -- respiratory symptoms that are triggered by exercise , cold air , and exposure to allergens ( dust , mold , furred animals , cockroaches , and pollens )
• Strong family history of asthma
• History of asthmatic symptoms as a child
• Exercise-triggered symptoms develop 5 to 15 minutes after a brief period of exertion or about 15 minutes into prolonged exercise and resolve with rest over approximately 30 to 60 minutes
Triggers
• Occupational exposure , e . g ., paint fumes , wood dust
• Irritants : tobacco smoke , air pollution , strong odors
• Inhalant allergens : dust mites , animal allergens , cockroach allergens , mold , mildew , pollens , grass
• Medications : non-selective beta-blockers , aspirin , NSAIDs
• Respiratory infections
• Dietary sulfites
Future Evaluations Asthma assessments at each office visit should include the following :
• Patient history
• Physical examination
• Pulmonary function ( spirometry , peak flow meter )
• Exacerbations
• Frequency of short-acting beta2-agonist use
• Nighttime awakenings
• Irritant exposures
• Consider Asthma Control Test or equivalent
• Comorbid conditions -- sinusitis / rhinitis -- gastroesophageal reflux disease -- obesity ( BMI greater than or equal to 30 ) -- depression -- allergic bronchopulmonary asbergillosis
Chest radiography is recommended for patients with severe asthma and for patients with any of the following :
• Fever
• Chronic purulent sputum production
• Localized wheezing
• Hemoptysis
• Weight loss
• Clubbing
• Inspiratory crackles
• Significant hypoxemia
• Airflow obstruction that does not resolve with bronchodilators
• Diffuse arthralgia
• Vascultitic rash
Triad of Symptoms
• Wheezing
• Cough ( typically worse at night )
• Shortness of breath or difficulty breathing
Categories of Asthma Severity There are three elements used to determine the severity of asthma in adolescents over the age of 12 and adults : 1 . Current level of lung function ( FEV1 / FVC values ). 2 . Reported symptoms over the previous two to four weeks . 3 . Number of exacerbations requiring oral glucocorticoids per year .
Asthma - 2