What are the signs of bronchospasm?

Signs of Bronchospasm

The primary signs of bronchospasm include cough, dyspnea (shortness of breath), chest tightness, and wheezing during or after exertion or exposure to triggers. 1

Clinical Manifestations

• Respiratory symptoms: Wheezing, cough, shortness of breath, and chest tightness are the classic manifestations of bronchospasm 1
• Decreased exercise capacity: Patients may experience diminished aerobic capacity limited by shortness of breath 1
• Audible wheeze: Often heard during auscultation or even without a stethoscope in severe cases 1
• Tachypnea: Increased respiratory rate is commonly observed 1
• Use of accessory muscles: Visible use of neck and chest wall muscles for breathing indicates increased work of breathing 1, 2
• Chest retractions: Intercostal, subcostal, or suprasternal retractions may be present in more severe cases 2
• Grunting: In severe cases, especially in children, grunting respirations may occur as an attempt to maintain positive end-expiratory pressure 2
• Hypoxemia: Oxygen saturation may drop below 90% during severe bronchospasm 1, 2

Objective Findings

• Pulmonary function changes: A 15% or greater reduction in FEV1 (forced expiratory volume in 1 second) and/or peak expiratory flow after exercise or other triggers 1
• Timing of pulmonary function changes: The reduction in pulmonary function may become apparent only several minutes after the triggering event and should be monitored for at least 10 minutes 1
• Breathing reserve: A breathing reserve less than 20% (V̇E/MVV > 0.80) is consistent with a pulmonary limitation to exercise 1

Important Considerations

• Symptoms alone are insufficient: Diagnosis of bronchospasm should never be made based on symptoms alone; objective testing is required for confirmation 1
• Variable presentation: The severity of symptoms can range from mild to life-threatening 1
• Delayed onset: Symptoms may occur during exercise but often appear 5-10 minutes after cessation of activity 1
• Trigger identification: Common triggers include exercise (especially in cold, dry air), allergens, respiratory infections, and irritants 1
• Differential diagnosis: Other conditions that may present with similar symptoms include vocal cord dysfunction, cardiac conditions, and other respiratory disorders 1

Special Populations

• Athletes: Elite athletes, particularly those in endurance sports or those training in cold environments, have a higher prevalence of exercise-induced bronchospasm 1
• Children: In children, crying-induced bronchospasm may occur, with cough and/or wheeze lasting 5 minutes or more during or after crying 3
• Patients without pulmonary disease: Bronchospasm can occasionally occur in individuals without known pulmonary disease, such as after administration of certain medications (e.g., adenosine) 4

Warning Signs of Severe Bronchospasm

• Severe respiratory distress: Head nodding, persistent nasal flaring, grunting, tracheal tugging, pronounced chest wall indrawing 2
• General danger signs: Inability to drink, vomiting everything, convulsions, lethargy or unconsciousness, or stridor in a calm child 1
• Hypoxemia: Oxygen saturation below 90% at sea level 2
• Altered mental status: Confusion or decreased level of consciousness 2

Early recognition of bronchospasm is essential for prompt treatment and prevention of respiratory compromise. Objective testing, such as pulmonary function tests before and after exercise or other challenges, provides the most reliable diagnosis.