A nurse is caring for a client who has acute respiratory distress syndrome (ARDS). The nurse should identify that which of the following conditions is the most common cause of ARDS?

Acute respiratory distress syndrome is a severe inflammatory response resulting from direct or indirect lung injury. The nurse must identify the primary systemic trigger that leads to widespread alveolar-capillary membrane damage and subsequent refractory hypoxemia in clinical settings. Choice A rationale Aspiration of gastric contents causes direct chemical injury to the lung parenchyma. While it is a common cause of localized lung injury and ARDS, it occurs less frequently than systemic inflammatory triggers. Choice B rationale Sepsis is the most common cause of ARDS due to the systemic release of inflammatory mediators. These cytokines damage the alveolar-capillary membrane throughout the lungs, leading to severe pulmonary edema and impaired gas exchange. Choice C rationale Major trauma from motor vehicle accidents can lead to ARDS through lung contusions or indirect systemic inflammation. However, statistically, trauma accounts for fewer cases of ARDS compared to the high prevalence in septic clients. Choice D rationale Pneumonia is a frequent cause of direct lung injury leading to ARDS. While it is a significant risk factor, systemic sepsis remains the leading overall trigger for the development of acute respiratory failure.