Acute Respiratory Distress Syndrome in Hospital-Acquired/Ventilator-Associated Pneumonia.

Acute respiratory distress syndrome (ARDS) represents a major cause of morbidity and mortality in critically ill patients and is most frequently triggered by severe respiratory infections, including nosocomial pneumonia. Hospital-acquired and ventilator-associated pneumonia (HAP/VAP) are highly prevalent in intensive care units and share overlapping pathophysiological mechanisms with ARDS. Despite this close interrelationship, the proportion of patients with nosocomial pneumonia who subsequently develop ARDS remains poorly defined, underscoring the need to identify potential predisposing factors and improve early recognition of patients at risk. While the development of pneumonia in patients with an established diagnosis of ARDS has been extensively investigated, limited data are available on patients who develop ARDS as a complication of HAP/VAP. This narrative review summarizes the limited direct evidence on this topic and discusses potential clinical characteristics, risk factors, and predictive tools, while considering indirect evidence from CAP and broader ARDS populations.