What are the clinical manifestations of bronchospasms in patients with a history of asthma or Chronic Obstructive Pulmonary Disease (COPD)?

Clinical Manifestations of Bronchospasms in Asthma and COPD

Bronchospasms present as audible wheezing (typically diffuse, polyphonic, bilateral, and especially expiratory), accompanied by shortness of breath, chest tightness, and cough—symptoms that characteristically vary in intensity, worsen at night, and are triggered by specific exposures. 1

Primary Symptoms

The hallmark symptoms of bronchospasm are variable and intermittent rather than constant 1:

• Wheezing is the cardinal auditory sign, usually diffuse, polyphonic, bilateral, and particularly expiratory 1
• Shortness of breath (dyspnea) that worsens with exertion, ranging from breathlessness on moderate activity like climbing hills in moderate disease to severe breathlessness at minimal exertion or rest in advanced disease 1
• Chest tightness that may vary between days and throughout a single day 1
• Cough, which is often the first symptom in COPD and may be productive with sputum 1

In asthma specifically, these symptoms tend to be worse at night and provoked by triggers including exercise, allergens, cold air, and irritants 1. When cough dominates without prominent wheeze, this is termed cough variant asthma 1.

Physical Examination Findings

During acute bronchospasm, objective signs include 1, 2:

• Audible wheezing on auscultation during tidal breathing, especially on forced expiration 1, 2
• Prolonged forced expiratory time (>5 seconds) indicating airflow limitation 2
• Use of accessory respiratory muscles (sternomastoid, intercostals) implying severe obstruction 1, 2
• Pursed-lip breathing usually indicating severe airflow obstruction 2
• Diminished breath sounds though these are poor guides to severity 2

Critical warning: Between acute episodes, physical examination may be completely normal with no objective signs of bronchospasm present, making the diagnosis unreliable without objective testing. 1, 3

Signs of Severe Bronchospasm Requiring Urgent Intervention

Recognize these features indicating respiratory distress 1, 2, 3:

• Central cyanosis indicating significant hypoxemia 1, 2
• Altered mental status suggesting severe hypercapnia 2
• Severe breathlessness at rest indicating respiratory failure 2
• Hoover sign (paradoxical inward movement of lower ribcage during inspiration) associated with severe diaphragmatic flattening and respiratory muscle dysfunction 2, 3
• Uncoordinated ribcage motion or paradoxical abdominal wall movement indicating respiratory muscle fatigue 2, 3
• Signs of hypercapnia: flapping tremor, bounding pulse, drowsiness (though these are inconsistent and unreliable) 1, 2, 3

Objective Measurements During Bronchospasm

Functional testing reveals 1:

• Decreased peak expiratory flow (PEF) and forced expiratory volume in one second (FEV1) 1
• FEV1/FVC ratio <70% confirming airflow obstruction 1
• Reversibility: In asthma, >15% improvement in FEV1 or PEF after bronchodilator or spontaneously suggests the diagnosis 1
• Oxygen saturation <94% warrants specialist referral 2

Important caveat: Lung function may be completely normal between episodes of bronchospasm, and if repeatedly normal in the presence of symptoms, the diagnosis of asthma must be questioned. 1

Distinguishing Features Between Asthma and COPD Bronchospasm

While symptoms overlap significantly 4, 5:

Asthma characteristics 1:

• Symptoms are highly variable and intermittent
• Significant reversibility with bronchodilators (>15% improvement)
• Often triggered by specific exposures (allergens, exercise, cold air)
• May have personal or family history of atopy

COPD characteristics 1, 2:

• Progressive, persistent symptoms with less variability
• Chronic productive cough, especially morning cough
• Smoking history >40 pack-years (likelihood ratio 12 for airflow obstruction) 2
• Little variability in serial peak flow measurements 1
• Signs of chronic overinflation: loss of cardiac dullness, decreased cricosternal distance, increased AP chest diameter 1

Common Pitfalls

• Do not rely on physical examination alone—sensitivity for detecting bronchospasm is poor, and objective spirometry is essential for diagnosis 1, 3
• Classic signs of hypercapnia are inconsistent and unreliable; do not depend on physical examination to assess gas exchange 3
• Absence of wheeze does not exclude bronchospasm—patients may have "silent chest" in severe obstruction 1
• Normal oxygen saturation does not exclude significant bronchospasm—spirometry remains necessary 2