Auscultatory Findings During COPD Exacerbation
During a COPD exacerbation, you should expect to hear wheezes (rhonchi), particularly on forced expiration, though their presence is not a reliable indicator of severity and they may be absent even in severe disease. 1
Primary Breath Sounds Expected
Wheezes (Rhonchi)
- Wheezes are almost invariably present during COPD exacerbations, though they are poor predictors of severity 1
- Rhonchi are especially prominent during forced expiration in patients with moderate to severe disease 1
- Wheezing during tidal breathing is a useful indicator of airflow limitation, though its absence does not exclude COPD exacerbation 1
Diminished Breath Sounds
- Decreased breath sounds may be present due to chronic overinflation and air trapping 1
- The degree of breath sound reduction does not reliably correlate with severity of airflow obstruction 1
Critical Caveat About Physical Examination
The sensitivity of physical examination for detecting or excluding moderately severe COPD is poor, and reproducibility of physical signs is variable 1. This means:
- The degree of airways obstruction cannot be predicted from symptoms or signs alone 1
- Physical signs are not sufficiently diagnostic to remove the need for objective confirmation with spirometry 1
- Even in severe exacerbations, breath sounds may appear relatively normal 1
Additional Respiratory Findings During Exacerbation
Signs of Respiratory Distress
- Prolonged forced expiratory time (>5 seconds) indicates significant airflow limitation 1
- Use of accessory respiratory muscles (particularly sternomastoid) usually implies severe airflow obstruction 1
- Tachypnea is a crude indicator of exacerbation severity 1
- Uncoordinated ribcage motion or paradoxical abdominal wall movement during inspiration suggests respiratory muscle dysfunction or fatigue 1
Signs of Gas Exchange Abnormalities
- Central cyanosis may be visible with significant hypoxemia, though its sensitivity is low and absence does not exclude hypoxemia 1
- Signs of hypercapnia (flapping tremor, bounding pulse, drowsiness) may occur during acute exacerbations, but a high PaCO2 can occur without these signs 1
Common Pitfall to Avoid
Do not rely on auscultatory findings alone to assess severity or guide treatment decisions. The classic signs of hypercapnia are inconsistent and unreliable, and the poor sensitivity of symptoms and signs emphasizes the need for objective measurements including arterial blood gases 1. If the severity of an exacerbation is in doubt based on physical examination, it should always be assessed in hospital with objective testing 1.