Q. A 25-year-old man comes to the emergency department due to a persistent cough of one-week duration. The cough is associated with purulent sputum. The patient’s past medical history is significant for frequent hospital admissions due to pneumonia. He never smokes but drinks alcohol socially. His vital signs today are: HR is 105 bpm, BP is 113/78 mmHg, RR is 26 bpm, and temperature is 38.9 degrees Celsius. Upon examination, chest auscultation reveals coarse crepitations at the right lower lung base. Cardiac auscultation reveals that the point of maximum impulse (apex) is located in the right fifth intercostal space at the midclavicular line. Which of the following is the expected pathophysiological mechanism in the above patient's condition?