Do these results signify an obstructive process or a restrictive process? How do you know?

Theodore (“Teddy”) is sitting in his athletic training suite feeling sorry for himself.  He moved from Southern California to play soccer at Michigan State University (MSU) as a highly recruited player.  All was well until he got sick with a miserable cold.  He soon recovered, but now he finds himself with a lingering dry cough and difficulty catching his breath any time he exerts himself.  He also notices it has gotten worse as the weather has become colder. To make things worse, Teddy feels, and looks, like he’s out of shape, so his coach has been criticizing him for “dogging it.”

A few days later, Teddy relays his story to Al, the head athletic trainer at MSU.  “I’m thinking my cold is coming back, or something else is wrong with me. When I’m just hanging out, like now, I feel fine. But as soon as I start to run, I get winded and can’t stop coughing.”  Al listens to Teddy’s breathing sounds with his stethoscope but hears nothing abnormal. He tells Teddy to come back as soon as the symptoms return during soccer practice.  Twenty minutes later, Teddy is back in the athletic training suite, audibly wheezing, coughing, and short of breath.  The team physician, Dr. Gibson, happens to be there and performs a complete physical exam.  He also does pulmonary function tests with Teddy using spirometry, including a forced vital capacity (FVC) and forced expiratory volume in one second (FEV1).  He instructs Teddy to take a maximal inhalation and then exhale as forcefully and maximally as possible into the spirometer.

Based on his findings, Dr. Gibson tells Teddy he thinks he is experiencing cold-induced bronchoconstriction, or cold-induced asthma, which is made worse by exertion. The doctor explains to Teddy that his recent upper respiratory infection probably inflamed his airways, making them hypersensitive and reactive to irritants, such as cold and physical exertion.  When Teddy exercises in the cold, autumn afternoons of Michigan, his sensitive airways temporarily bronchoconstrict, causing the symptoms he is experiencing.  Dr. Gibson prescribes two puffs of an albuterol inhaler, to be used 10 minutes before a bout of exercise in the cold.

1. When Teddy is experiencing an asthmatic attack, his forced vital capacity (FVC) is 53% of normal, and his FEV₁ (Forced expiratory volume in 1 second) is 45% of normal. Explain these test results and what they represent in Teddy’s case. Do these results signify an obstructive process or a restrictive process? How do you know?. [4 POINTS]

 

 

2. Spirometry testing is routinely performed on patients with lung disease. Describe how the various lung volumes and respiratory capacities would be predicted to change (from normal) in a patient with a restrictive lung process (i.e pulmonary fibrosis) as well as a patient with an obstructive lung process (i.e asthma or COPD). Using the pathophysiology underlying restrictive and obstructive lung diseases, explain why you predicted each volume and/or capacity to increase, decrease, or stay the same in each type of lung disease. [16 points]