Question

Joe suffers from exercise-induced asthma. With this condition, as his exertion level increases, irritants in the air stimulate his bronchioles to constrict. He experiences severe dyspnea (shortness of breath, difficulty breathing) and must stop exercising immediately. He carries with him an inhaler. After using his inhaler, he recovers and is able to make his way home to rest from the incident. What “rule” is important to Joe’s condition (1 pt)? Within the context of this rule – explain each parameter and its importance to breathing in general (3 pts). What did the drug do and where (what tissue type) did it act (1pt)?

Answer 1

The "rule of 2" is important to Joe's condition. This is used to determine whether a patient needs better asthma control. It includes the following questions:

• Do you use a quick-relief inhaler more than 2 times a week?
• Do you wake up at night with asthma more than 2 times a month?
• Do you refill your inhaler prescription more than 2 times a year?
• Does your peak flow drop more than 2 times 10, or 20%, with symptoms? The peak expiratory flow is a person's maximum speed of expiration, as measured with a peak flow meter. It measures the airflow through the bronchi and is an indicator of the degree of obstruction of the airways.

The inhaler contains the drug salbutamol. This is a beta-2 receptor agonist. It acts on the beta-2 adrenergic receptors on the smooth muscles in the bronchial wall. It works by relaxing the muscles of the airways into the lungs, which makes it easier to breathe.