Asthma is defined as a chronic inflammatory disorder that is characterized by reversible obstruction of the airways. Approximately 5% of adults and 10% of children in the United States suffer from asthma. Asthma is the most chronic childhood disease. Half of all cases develop before patients reach 10 years of age. It appears more frequently in inner city African-American and Hispanic populations. While acute asthmatic episodes are usually self-limiting, it can present as a clinical condition termed status asthmaticus which does not respond to bronchodilators.
Asthma is classified into 2 categories; extrinsic (allergic asthma) and intrinsic (non-allergic asthma).
Extrinsic asthma occurs more often in children. It is triggered by specific allergens such as pollens, dust, molds and highly allergenic foods such as milk, eggs, fish, chocolate, shellfish and tomatoes. Drugs and chemicals such as penicillin, vaccines, aspirin and sulfites can trigger an allergic asthmatic attack. Approximately 50% of asthmatic children outgrow extrinsic asthma by late teens or early twenties.
Intrinsic asthma usually develops in adults older than age 35 years. Attacks are precipitated by non-allergic factors; respiratory infection, physical exertion, environmental and air pollution. Psychological and physiologic stress can induce an attack. The stress of disciplinary action by a parent or entering the treatment area in a dental office can trigger an asthmatic attack in children and adults.
With either type of asthma the mechanism for initiating an attack is the same. The allergen or non-allergen factors stimulates the vagus nerve to release acetylcholine which produces constriction of the airways and increased glandular secretions which plug the small airways in the lungs leading to bronchial edema and airway obstruction.
The signs and symptoms of an acute asthmatic attack are:
The management of an asthmatic patient begins with the pretreatment history. Ask the patient:
If the patient uses a self-administered bronchodilator aerosol during acute asthmatic attacks e.g., albuterol (Proventil, Ventolin) isoproterenol (Isuprel) or metaproterenol (Metaprel, Alupent), they should bring it to their appointment. The bronchodilators produce bronchial smooth muscle relaxation. Albuterol has the least side effects of all the bronchodilators and should be the drug of choice for inclusion in the emergency drug kit.
The steps in emergency management of an acute asthmatic episode are: