Primary Versions of Bronchitis
The following are two primary versions of bronchitis (inflammation/disease of the bronchi):
- Acute bronchitis is usually a viral transient infection of the bronchi that is self-resolving and characterized by coughing that lasts from five days to three weeks. It is treated symptomatically, and antibiotics or steroids have little effect on the course of the illness.
- Chronic bronchitis is not transient and is a type of chronic obstructive pulmonary disease (COPD).
What exactly is COPD?
According to the Global initiative for chronic Obstructive Lung Disease (G.O.L.D.) report of 2017, COPD is as follows:
“A common, preventable, and treatable disease that is characterized by persistent respiratory symptoms and airflow limitation that is due to airway and/or alveolar abnormalities usually caused by significant exposure to noxious particles or gases. The chronic airflow limitation that characterizes COPD is caused by a mixture of small airways disease (e.g., obstructive bronchiolitis) and parenchymal destruction (emphysema), the relative contributions of which vary from person to person. Chronic inflammation causes structural changes, small airways narrowing, and destruction of lung parenchyma. A loss of small airways may contribute to airflow imitation and mucociliary dysfunction, a characteristic feature of the disease.”
In other words, COPD is caused by damage that is preventable (e.g. smoking), and such damage causes airflow obstruction and tissue destruction of lung tissue to the point that oxygenation is compromised, mucus production is abnormal, and the cilia that function to move particulate matter up and out of the lungs are either paralyzed or destroyed.
The ominous spectrum of COPD
COPD is a spectrum of disease that involves the obstruction of the airflow, particularly these following diseases:
The honeycomb separations among the alveoli are destroyed, which reduces the amount of surface area available for the oxygen/carbon dioxide (O2-CO2) exchange.
This is defined as a chronic productive cough that lasts for three months in two successive years. This is diagnosed when other causes for the chronic cough have been ruled out. Note its difference form acute bronchitis, which will resolve all by itself after less than three weeks, which is a much shorter duration than the minimum duration of three months that is required to diagnose chronic bronchitis.
Chronic obstructive asthma
This is a chronic inflammation of the airways that causes a tissue response that leads to wheezing, breathlessness, chest tightness, and coughing, especially at night and early morning.
Is COPD a mixture of all three of these things at once?
COPD can be; however, it is usually a mix of two. Whether any one of these or any combination of them is officially COPD is determined only if there is airway obstruction.
How is airway obstruction determined?
There are a few methods that can be used to determine airway obstruction. Spirometry is one such method. This is the breathing into and out of a device that measures the amount of “wind” in the process. This wind is a volume, not a speed. Another method involves a ratio between Forced Expiratory Volume (FEV) and Forced Vital Capacity (FVC). The former is the amount of air that can be blown out in one second. The latter is the amount of air that can be exhaled from the lungs after taking the deepest breath possible.
Since both the FEV and FVC can be similarly affected by other conditions (e.g., asthma) that can confuse the diagnosis, doctors use a ratio between the FEV and FVC to determine airway obstruction in respect to COPD. This ratio, the FEV/FVC number, is also necessary because there is a significant degree of overlap between COPD and other disorders that cause airflow limitations. If the FEV/FVC ratio comes out to less than 0.7, that is COPD. Since the ratio decreases normally with age, the values have to be compared to tables to assign the correct interpretation.
An internal medicine doctor or a specialist called a pulmonologist will test for airway obstruction. A respiratory therapist will be involved as well.
How bad can COPD get?
COPD can be severe enough that patients have to carry around extra oxygen.
Is smoking the only cause?
Any exposure to the chronic polluting effects of what is taken into the lungs can cause COPD. The occupational hazards of jobs like mining, chimneysweeps, tunnels, etc., can pollute the lungs. A vitamin D deficiency is also thought to contribute to lung compromise.
How is COPD or its different manifestations treated?
- Oxygen: As mentioned above, supplemental oxygen is used to make up for the deficiency due to airway destruction from the disease.
- Preventative strategies: Since COPD patients are at a higher risk for infectious attacks on the lungs, further compromising the airway, annual flu vaccines are necessary, particularly pneumococcal vaccination.
- Inhalers: Short-acting inhalers are used to treat intermittent symptoms.
- Bronchodilators: These are helpful long-term.
This article is the companion piece to the article on acute bronchitis, but the difference between the acute and chronic versions of bronchitis are vastly different in terms of severity, morbidity, and mortality.