Respiratory distress syndrome (pulmonary critical care) is a severe clinical syndrome characterized by acute, life-threatening respiratory failure resulting from impaired gas exchange and reduced lung compliance, necessitating intensive care management. Within the domain of pulmonary critical care, this term broadly refers to conditions manifesting as severe respiratory distress requiring advanced life support. It encompasses, but is not limited to, the neonatal form primarily linked to prematurity and insufficient pulmonary surfactant, and the adult form (commonly known as Acute Respiratory Distress Syndrome, or ARDS), which is characterized by diffuse inflammatory lung injury leading to increased vascular permeability and non-cardiogenic pulmonary edema. This concept is central to critical care medicine due to the high morbidity and mortality associated with the underlying conditions and the complex supportive care, such as mechanical ventilation, required for patient survival.