A 64-year-old man is brought to the emergency department due to worsening shortness of breath. The patient is able to speak in short sentences only and becomes hypoxemic with minimal exertion. His medical history includes hypertension and dyslipidemia. He smoked a pack of cigarettes a day for 40 years and worked for 25 years as a nickel miner. His father died of chronic respiratory failure. While in the emergency department, he rapidly develops respiratory failure and is intubated. Despite appropriate treatment, he dies several days later in the intensive care unit. Autopsy is performed, and examination of the bronchi reveals thickened bronchial walls, inflammatory infiltrates, mucous gland enlargement, and patchy squamous metaplasia of the bronchial mucosa. Which of the following factors was likely the greatest contributor to this patient's pathological findings?

Question

A 64-year-old man is brought to the emergency department due to worsening shortness of breath.  The patient is able to speak in short sentences only and becomes hypoxemic with minimal exertion.  His medical history includes hypertension and dyslipidemia.  He smoked a pack of cigarettes a day for 40 years and worked for 25 years as a nickel miner.  His father died of chronic respiratory failure.  While in the emergency department, he rapidly develops respiratory failure and is intubated.  Despite appropriate treatment, he dies several days later in the intensive care unit.  Autopsy is performed, and examination of the bronchi reveals thickened bronchial walls, inflammatory infiltrates, mucous gland enlargement, and patchy squamous metaplasia of the bronchial mucosa.  Which of the following factors was likely the greatest contributor to this patient's pathological findings?

Quizplus · Accepted Answer

Eductional Objective: Thickened bronchial walls, lymphocytic infiltration, mucous gland enlargement, and patchy squamous metaplasia of the bronchial mucosa are features of chronic bronchitis.  Tobacco smoking is the leading cause of chronic bronchitis.

A 64-Year-Old Man Is Brought to the Emergency Department Due