Acute lung injury (ALI)

Acute lung inflammatory damage, more formally termed Acute Lung Injury (ALI) or its severe clinical form Acute Respiratory Distress Syndrome (ARDS), is a life-threatening syndrome characterized by rapid-onset widespread inflammation in the lungs. It is defined by acute respiratory failure, bilateral pulmonary opacities, and severe hypoxemia that cannot be fully explained by heart failure (Matthay et al., Nature Reviews Disease Primers, 2019). The condition involves a profound breakdown of the alveolar-capillary barrier, allowing protein-rich fluid to leak into the airspaces, which leads to pulmonary edema and impaired gas exchange (Fan et al., JAMA, 2018). This inflammatory cascade is driven by a 'cytokine storm' involving mediators such as TNF-α, IL-1β, and IL-6, alongside the recruitment and activation of neutrophils that release reactive oxygen species and proteases (Mokra & Kosutova, Physiological Research, 2014). Because it is a systemic pathophysiological state resulting from various underlying insults like sepsis or pneumonia, it is considered a disease state rather than a specific therapeutic target molecule (StatPearls, 2023). Pharmacological interventions typically aim to modulate the various molecular pathways within this cascade to prevent progressive lung architecture destruction (Butt et al., Archives of Pathology & Laboratory Medicine, 2016).

Other names

Acute respiratory distress syndromeARDSAcute lung inflammatory damageDiffuse alveolar damageNon-cardiogenic pulmonary edema

Therapeutic strategies for acute lung injury focus on mitigating the local and systemic inflammatory cascade. Glucocorticoids like dexamethasone act via the glucocorticoid receptor to suppress the transcription of pro-inflammatory genes, while neutrophil elastase inhibitors like sivelestat prevent proteolytic degradation of lung tissue and vascular components. Additional approaches involve blocking specific cytokines such as IL-6 or TNF-alpha to dampen the 'cytokine storm' and reduce alveolar-capillary barrier disruption.