A 48-year-old man comes to the office for an initial visit. He says that he feels well and has no medical problems. The patient has a 20-pack-year smoking history and does not use alcohol or illicit drugs. He is counseled on smoking cessation. To explain how smoking affects lung function, the patient is shown a graph of the expected change in forced expiratory volume in 1 second (FEV1) over time if he continues to smoke at the same rate (curve D in image). Which of the following curves most likely demonstrates the expected FEV1 over time if this patient were to stop smoking now?

Question

A 48-year-old man comes to the office for an initial visit.  He says that he feels well and has no medical problems.  The patient has a 20-pack-year smoking history and does not use alcohol or illicit drugs.  He is counseled on smoking cessation.  To explain how smoking affects lung function, the patient is shown a graph of the expected change in forced expiratory volume in 1 second (FEV1) over time if he continues to smoke at the same rate (curve D in image).  Which of the following curves most likely demonstrates the expected FEV1 over time if this patient were to stop smoking now?

Quizplus · Accepted Answer

11ec160b_3b33_94b4_9249_3b3e2d6a9f34_MD0001_00 Smoking is the strongest risk factor for chronic obstructive pulmonary disease (COPD). Cigarette smoke contains numerous toxins (eg, formaldehyde, cadmium) that impair ciliary function (contributing to chronic bronchitis) and cause oxidative cellular damage (contributing to centrilobular emphysema). These changes are responsible for the airway obstruction and air-trapping that cause the reduction in forced expiratory volume in 1 second (FEV1) that characterizes COPD. Beginning at approximately age 30, there is a gradual decline in FEV1 with age. Smoking-induced lung damage in COPD rapidly accelerates this normal age-related decline in FEV1, and once the decline occurs it is not recoverable. However, smoking cessation can markedly slow the decline in FEV1 in patients with COPD, an improvement that is typically apparent within the first year of smoking cessation. Following smoking cessation, the trajectory of this patient's FEV1 decline will improve compared with if he had continued to smoke, but his FEV1 will not return to the level it would have been had he never smoked. This trajectory is best represented by curve C. (Choice A) It is not physiologically possible for FEV1 to increase with age in either smokers or nonsmokers. (Choice B) The FEV1 does not remain constant after age 30, even in nonsmokers. (Choice D) With smoking cessation, the trajectory of this patient's FEV1 decline will improve rather than stay the same. (Choice E) This patient would experience a more rapid decline in FEV1 if he were to increase his rate of smoking. Educational objective: Smoking is the strongest risk factor for chronic obstructive pulmonary disease (COPD) and is responsible for accelerated decline in forced expiratory volume in 1 second (FEV1) in patients with COPD. Smoking cessation will slow the accelerated decline in FEV1, but FEV1 will not return to the level it would have been had the patient never smoked. __________ References: Smoking cessation: effects on symptoms, spirometry and future trends in COPD. (http://www.ncbi.nlm.nih.gov/pubmed/11514700)

A 48-Year-Old Man Comes to the Office for an Initial