Bronchodilation as fundamental therapeutic measure in COPD
Posted Jul 16 2013 11:57am
What is bronchodilation?
In COPD there is a typical and fundamental feature which is “persistent bronchoconstriction”. Bronchoconstriction is narrowing of the lung airways or passages. The passages in the lungs are called bronchi. In COPD, the bronchi are continuously under tension due to, among other reasons, the continuous contraction of the muscle bands that surrounds them. When these muscle bands get relaxed, the bronchi caliber widens and air flows easier. Bronchodilation is the widening of the caliber in lung airways which leads to better air flow.
Why to bronchodilate?
Bronchodilation is necessary in COPD because of the persistent tension in the airways. Although patients do not complain of bronchoconstriction, resultant situation leads them to have breathlessness that will bring patients to the doctor. Unfortunately, when breathlessness has already established, the bronchoconstriction might have advanced and treatment could get complicated. It is important to assure that bronchodilators are part of treatment as well as patients are educated on the use and available bronchodilators.
How to bronchodilate?
There are 2 types of bronchodilators that are useful in COPD management. They are short-acting and long-acting agents. Short-acting agents are preferred as emergency medications. Emergency medications are intended to relieve sudden symptoms that are related to bronchoconstriction. There are several reasons why sudden symptoms may occur. These include: low adherence to maintenance treatment, increased physical effort without preparation, exacerbation of the disease, pollutants in the environment. These situations might lead to increased air demand or reduced airflow as a result of reactive increased tone in muscle at airways level. This increased tone, when persistent, is highly responsible of air trapping within the lungs which also reduces airflow. The reduction in air flow will then require to be relieved and bronchodilators enter into the play. Short-acting agents will relieve the sudden worsening of bronchoconstriction. However, most patients will need long-acting agents in the long term. Most long-acting bronchodilators will also reduce the need of rescue bronchodilators. The reduced need for using short-acting agents, is important because it indicates that the patient is better controlled and the risk of getting frequently worse will be also reduced.
Patient and treating doctor must have the conversation around bronchodilation, needs, agents, and follow up. Perhaps, bronchodilation might not be well reflected in spirometry through FEV1 measures. However, symptoms will be a reflection of the impact of bronchodilators on the ongoing air trapping that is due to bronchoconstriction. Long-acting agents might have a duration of action that goes from 12 to 24 hours. Which agent is preferred is a topic that will need to clarified based on the need and preferences of the very patient. The experience of the doctor is also an important factor when deciding on which agent to choose.
What to do?
Having an open conversation on bronchodilation needs, available agents, costs, short and long-acting agents, adherence, etc, will help to understand the topic and make wise decisions to manage COPD.