Pulmonology · Obstructive Lung Disease
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The diagnosis of asthma is confirmed by spirometry demonstrating a reversible obstructive pattern, defined as an increase in FEV1 or FVC of ≥12% and ≥200 mL following bronchodilator administration.
GINA guidelines (Track 1) recommend ICS-formoterol as the preferred reliever at every step: as-needed low-dose ICS-formoterol alone in mild asthma (Steps 1-2) and maintenance-and-reliever therapy (MART) at Steps 3-5, to reduce the risk of severe exacerbations.
Methacholine challenge testing is the diagnostic procedure of choice to rule out asthma in patients with normal baseline spirometry but high clinical suspicion.
Pulsus paradoxus (a drop in systolic blood pressure >10 mmHg during inspiration) is a sign of severe asthma exacerbation indicating significant air trapping and increased intrathoracic pressure.
A normal or elevated PaCO2 in a patient presenting with an acute asthma exacerbation is a red flag for impending respiratory failure and requires immediate aggressive intervention.
Asthma+COPD (previously called asthma-COPD overlap, or ACO) is characterized by persistent airflow limitation with features of both asthma and COPD, typically requiring ICS-containing therapy, because these patients have a higher risk of hospitalization and death if treated with bronchodilators alone.
Exercise-induced bronchoconstriction is best managed with a short-acting beta-agonist (SABA) or ICS-formoterol taken immediately prior to physical activity.
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A 24-year-old female presents to the urgent care clinic complaining of intermittent wheezing and chest tightness that worsens at night and after running. She reports using an over-the-counter inhaler occasionally with minimal relief. On physical exam, she has bilateral expiratory wheezing and a respiratory rate of 18/min. Spirometry reveals an FEV1/FVC ratio of 0.68 with an FEV1 of 68% predicted, which increases by 16% and 340 mL after the administration of albuterol.
What is the most appropriate long-term management strategy for this patient according to current GINA guidelines?
As-needed low-dose ICS-formoterol
The patient demonstrates a reversible obstructive pattern on spirometry consistent with asthma; because she has low lung function (FEV1 68% predicted) and nocturnal symptoms, GINA 2026 places her at Step 3, where low-dose ICS-formoterol MART is the preferred initial treatment; all GINA Track 1 regimens are preferred over SABA-only therapy because they reduce the risk of severe exacerbations.
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Etiology / Epidemiology
Chronic inflammatory airway disease driven by atopy and hyperresponsiveness. Common in children with a strong genetic predisposition.
Clinical Manifestations
Triad of wheezing, dyspnea, and cough. Silent chest indicates impending respiratory failure.
Diagnosis
Spirometry showing reversible obstruction (FEV1/FVC below the lower limit of normal, FEV1 increase >12% AND >200 mL post-bronchodilator).
Treatment
As-needed low-dose ICS-formoterol is the preferred reliever/controller in mild asthma (GINA Track 1); SABA-only rescue is no longer preferred. Avoid LABA monotherapy and avoid SABA-only treatment.
Prognosis
Most achieve control with adherence. Status asthmaticus is the primary life-threatening complication.
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Epidemiology & Etiology
Asthma is the most common chronic disease of childhood, often associated with the atopic triad (asthma, eczema, allergic rhinitis). Triggers include viral infections, allergens, exercise, and cold air. Adult-onset asthma is more common in females and often linked to occupational exposures.
Pertinent Anatomy
Pathology involves the bronchioles, where smooth muscle hypertrophy and mucosal edema occur. Airway remodeling leads to permanent structural changes in the bronchial walls.
Pathophysiology
Chronic inflammation involves eosinophils, mast cells, and T-helper 2 (Th2) lymphocytes. This leads to bronchoconstriction, mucus hypersecretion, and airway edema. The resulting air trapping causes hyperinflation and increased work of breathing.
Clinical Manifestations
Patients present with episodic wheezing, chest tightness, and non-productive cough, often worse at night. Silent chest and pulsus paradoxus are signs of severe obstruction. Inability to speak in full sentences is a red flag for respiratory distress.
Diagnosis
Spirometry is the gold standard, demonstrating an obstructive pattern. A positive bronchodilator responsiveness test (FEV1 or FVC increase ≥12% and ≥200 mL) supports the diagnosis. Methacholine challenge is used to rule out asthma if spirometry is non-diagnostic.
Treatment
The cornerstone is Inhaled Corticosteroids (ICS) to reduce inflammation. GINA Track 1 (preferred) uses as-needed low-dose ICS-formoterol as the reliever at every step - alone at Steps 1-2 and as maintenance-and-reliever therapy (MART) at Steps 3-5 - rather than a SABA reliever. For acute exacerbations, use SABA (albuterol) and systemic corticosteroids. Never use LABA as monotherapy due to increased mortality risk. Use the GINA guidelines for a step-up approach based on symptom frequency.
Prognosis
Most patients maintain normal lung function with proper ICS adherence. Status asthmaticus requires aggressive management with oxygen, nebulized SABA, and systemic steroids. Monitor Peak Expiratory Flow (PEF) for objective home assessment.
Differential Diagnosis
COPD: irreversible obstruction on spirometry
GERD: cough worse when supine, no wheezing
Vocal cord dysfunction: inspiratory stridor, not wheezing
Heart failure: cardiac asthma, elevated BNP, crackles
Foreign body aspiration: sudden onset, unilateral findings