Bronchospasm is when the bronchi are narrowed by either constriction of bronchial muscle, and/or swelling / mucus inside. See Lower Respiratory Tract, Diagram D (Asthma / Bronchospasm) for a picture-worth-a-whole-bunch-of-words.
Disease wich cause Bronchospasm include:
- Acute Bronchitis
- Chronic Bronchitis
- After viral lung infections, Post-Viral Bronchospasm can last up to 3 months.
- Heart Failure, which almost always sounds different, can in rare cases be heard as wheezing.
How does bronchospasm sound through a stethoscope?
- Wheezes (long, high-pitched sounds during expiration)
- Rhonchi (squeaks / gurgles, during inspiration or expiration)
- Long Expiratory Phase
Problem! Clinicians all know that wheezes mean bronchospasm. But some don’t realize that rhonchi do also. And quite a number fail to appreciate that bronchospasm may declare itself with “clear lungs,” but a long expiratory phase. Think of how we sound when we breathe normally: a brief breath in, then exhale, and pause before the next breath.
This “exhale + pause” looks longer than the breath in, when simply watching someone from the outside. But listening to the inside of the lungs with a stethoscope, it’s the opposite: inspiration normally sounds longer than expiration, because the pause sounds silent. However, with bronchospasm, we hear the high-pitched wheeze of struggled expiration all through the pause; if the pitch is too high, we can’t hear the sound itself, just the time it occupies (unless we’re a dog).
If you ever get seen for a cough, and your provider tells you, “The lungs are clear,” be sure to ask, “Does inspiration sound longer than expiration?” If not, and the normal ratio of inspiration-to-expiration is reversed, then it’s bronchospasm