From the Guidelines
Diagnosing an asthma attack requires identifying specific symptoms and clinical findings, including episodic symptoms of airflow obstruction or airway hyperresponsiveness, partially reversible airflow obstruction, and symptoms that occur or worsen in the presence of specific triggers, as outlined in the expert panel report 3 (epr-3) guidelines 1. To establish a diagnosis of asthma, the clinician should determine that:
- Episodic symptoms of airflow obstruction or airway hyperresponsiveness are present
- Airflow obstruction is at least partially reversible, measured by spirometry, with an increase in FEV1 of >200 mL and 12% from baseline measure after inhalation of short-acting b2-agonist (SABA) 1
- History of any of the following:
- Cough (worse particularly at night)
- Recurrent wheeze
- Recurrent difficulty in breathing
- Recurrent chest tightness
- Symptoms occur or worsen in the presence of the following:
- Exercise
- Viral infection
- Inhalant allergens (eg, animals with fur or hair, house-dust mites, mold, pollen)
- Irritants (tobacco or wood smoke, airborne chemicals)
- Changes in weather
- Strong emotional expression (laughing or crying hard)
- Stress
- Menstrual cycles
- Symptoms occur or worsen at night, awakening the patient The diagnosis of asthma should be based on a detailed medical history, physical examination, and spirometry, as recommended by the guidelines 1. Key diagnostic criteria include:
- Wheezing on auscultation
- Increased respiratory rate
- Use of accessory respiratory muscles
- Difficulty speaking in complete sentences
- Decreased oxygen saturation (typically below 95%) Objective measurements are crucial, particularly peak expiratory flow (PEF) or forced expiratory volume in 1 second (FEV1), with values less than 80% of the patient's personal best or predicted value suggesting an attack 1. Severe attacks may present with silent chest (absence of wheezing due to severely limited airflow), cyanosis, drowsiness, confusion, or respiratory arrest, and require urgent action to prevent a serious outcome, such as hospitalization or death from asthma 1.
From the Research
Diagnostic Criteria for Asthma Attack
The diagnosis of an asthma attack requires a combination of symptoms and demonstration of reversible airway obstruction using spirometry 2. The symptoms of asthma include:
- Wheezing
- Dyspnea
- Cough
- Chest tightness
- Breathlessness
Symptoms and Signs
Studies have reported the following pooled proportions of symptoms in patients with asthma:
- Nasal congestion: 61.57%
- Sleep disturbances: 56.56%
- Breathlessness: 50.31%
- Chest tightness: 50.41%
- Wheezing: 46.97% 3 Other signs and symptoms, such as rhinitis and allergy/atopy, are also common in patients with asthma 3.
Diagnostic Tests
Diagnostic tests, such as spirometry and inhalation challenge test, can help confirm the diagnosis of asthma 4. A large bronchodilator response makes asthma more likely, while normal spirometry is common in patients with mild asthma who are not symptomatic at the time of testing 4. Other tests, such as exhaled nitric oxide level and diffusing capacity of the lung for carbon monoxide, can also help differentiate asthma from other conditions, such as chronic obstructive pulmonary disease (COPD) 4.
Clinical Evaluation
The medical history and physical examination are moderately effective in diagnosing asthma and estimating its severity 5. However, objective measures of lung function are necessary for the accurate diagnosis of asthma 5. A thorough history is very important in making the diagnosis of asthma, and diagnostic tests can only increase or decrease the probability of the asthma diagnosis 4.