Which of the following is a common cause of acute respiratory distress syndrome (ARDS) related to pulmonary issues?

Pneumonia is a well-known and common cause of acute respiratory distress syndrome (ARDS) that is directly related to pulmonary issues. In ARDS, the lung's ability to transfer oxygen into the bloodstream is severely compromised, often due to inflammation and fluid accumulation in the alveoli. Pneumonia can trigger this process as it causes infection and inflammation in the lung tissue, which leads to a significant increase in alveolar permeability. This results in pulmonary edema, impaired gas exchange, and ultimately, the clinical picture of ARDS.

While sepsis is another significant cause of ARDS, it is systemic in nature and may not be solely related to pulmonary issues. Cardiopulmonary bypass is a procedure often used during heart surgery and is not directly a cause of ARDS itself but can contribute to conditions in which ARDS may develop. Drug overdose might lead to respiratory depression or failure but is also not purely a pulmonary issue in the same direct manner as pneumonia. Thus, pneumonia stands out as a primary pulmonary cause of ARDS.