Airway Pathological Alterations Selectively Associated With Acute Respiratory Distress Syndrome and Diffuse Alveolar Damage Narrative Review

Abstract

Acute respiratory distress syndrome (ARDS) is a frequent and life-threatening entity. Recently, it has been demonstrated that diffuse alveolar damage (DAD), which is considered the histological hallmark in spite of presenting itself in only half of living patients with ARDS, exerts a relevant effect in the ARDS outcome. Despite the fact that the bronchial tree constitutes approximately 1% of the lung volume, discovering a relation between DAD and bronchial tree findings could be of paramount importance for a few reasons; (a) it could improve the description of ARDS with DAD as a clinical-pathological entity, (b) it could subrogate DAD findings with the advantage of their more accessible and safer analysis and (c) it could allow the discovery of new therapeutic targets. This narrative review is focused on pathological airway changes associated to Diffuse Alveolar Damage in the context of Acute Respiratory Distress Syndrome. It is organized into five sections: main anatomical and functional features of the human airway, why it is necessary to study airway features associated to DAD in patients with ARDS, pathological airway changes associated with DAD in animal models of ARDS, pathological airway changes associated with DAD in patients with ARDS, and the newest techniques for studying the histology of the bronchial tree and lung parenchyma.