Wilderness and Rescue Medicine 8th Edition

Chapter 9: Severe Asthma

Asthma is a chronic inflammatory disease that causes lower airway constriction. The mechanism involves both spasm of the smooth muscle walls and swelling of the mucous membrane lining of the bronchial tubes. Acute asthma attacks are sometimes triggered by infection, cold air, exer- cise, or other stressors. Sometimes asthma flares without apparent reason. Some patients need to use medications daily to keep their asthma under control.

non-productive cough. Fortunately, most people with asthma are aware of their condition and are familiar with its presentation. Acute symptoms are usually relieved with self-administered medi- cation, such as inhaled albuterol, that reverses the characteristic bronchospasm. Occasionally, an asthma attack will not respond to inhaled medication. This is usually due to the patient waiting too long to administer it or not having it available at all. When early treatment is delayed or ineffective, the initial bronchospasm in the lower airways is made worse by secondary swelling. At this point, it will be difficult or impos- sible for the patient to inhale medication deep into the bronchioles where it can exert its effect. Severe respiratory distress can rapidly progress to respiratory failure, at which stage respiration will be labored and the patient will be able to speak only one or two words between breaths. Immediate treatment is required, and it should not wait for evacuation or for ALS to be brought to the scene. You should first assist your patient in the proper use of their HFA inhaler. Be sure that you are using the fast-acting bronchodilator. The patient may recognize this as their “rescue inhaler” which is usually red in color. The distinction is important because some patients also use an inhaled ste- roid or other medication as an adjunct to therapy.

General Principles

Severe Asthma

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Mechanism: • Acute exacerbations of bronchospasm and swelling. • Can be triggered by exercise, cold air, infection, and allergens. Assessment: • History of asthma. • Wheezing, coughing, chest tightness, forced exhalation, respiratory distress.

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Low Risk

High Risk

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An acute asthma attack can be mild or severe. It can be a major critical system problem when it causes respiratory distress. If bronchospasm is allowed to persist, the lower airway constriction will be exacerbated by secondary swelling. Early signs and symptoms include respira- tory distress, chest tightness, wheezing, and a