Pneumonitis and pneumonia after aspiration

Aspiration pneumonitis and aspiration pneumonia are clinical syndromes caused by aspiration. These conditions are clinically significant due to their high morbidity and mortality. However, aspiration as a preceding event are often unwitnessed, particularly in cases of asymptomatic or silent aspiration. Furthermore, despite the difference in treatment approaches for managing aspiration pneumonitis and aspiration pneumonia, these two disease entities are often difficult to discriminate from one another, resulting in inappropriate treatment. The use of unclear terminologies hinders the comparability among different studies, making it difficult to produce evidence-based conclusions and practical guidelines. We reviewed the most recent studies to define aspiration, aspiration pneumonitis, and aspiration pneumonia, and to further assess these conditions in terms of incidence and epidemiology, pathophysiology, risk factors, diagnosis, management and treatment, and prevention.