A 63-year-old male with a history of chronic cough for nearly 20 years and progressively worsening dyspnea for 3 years, now struggling with daily activities. One hour ago, after a vigorous sneeze, he experienced aggravated dyspnea with right-sided chest pain and presented to the ER. Examination reveals confusion, marked dyspnea, cyanosis, decreased breath sounds bilaterally, and fine crackles at the lung bases. The direct cause of his respiratory failure is most likely related to which of the following?