Aspiration pneumonia in the world's most aged society: age-stratified ICU management and outcomes from a nationwide Japanese registry.

OBJECTIVES: To describe the age-stratified clinical characteristics, ICU management, and in-hospital outcomes of adults admitted to Japanese ICUs with aspiration pneumonia. DESIGN: Multicenter, retrospective, observational cohort study. SETTING: Multiple ICUs participated in the Japanese Intensive Care Patient Database (JIPAD), a nationwide registry of the Japanese Society of Intensive Care Medicine, from 2015 to 2023. PATIENTS: Adults ≥ 18 years admitted to ICUs with a primary diagnosis of aspiration pneumonia. MEASUREMENTS AND MAIN RESULTS: Among 3,906 eligible ICU admissions (median age, 76 years [IQR, 68-83]; 75.5% male), illness severity at admission increased with age (median APACHE III score, 74 [56-91] in patients aged 18-64 years vs. 96 [81-120] in those aged ≥ 85 years). Invasive mechanical ventilation (MV) was used in 68.8% of patients and was less frequent in older age groups (18-64 years: 73.2%; 65-74 years: 74.2%; 75-84 years: 69.9%; ≥ 85 years: 55.4%). Overall in-hospital mortality was 28.3% and increased across age groups (18-64 years: 13.7%; 65-74 years: 25.0%; 75-84 years: 32.1%; ≥ 85 years: 39.3%). Median hospital and ICU lengths of stay were 32 days (IQR, 16-58) and 120.4 h (IQR, 54.4-234.8), respectively. In-hospital pathways differed markedly across age groups: among patients aged ≥ 85 years, in-hospital mortality reached 39.3%, and home discharge was achieved in only 19.9%, compared with 13.7% and 45.2% among patients aged 18-64 years, respectively. In the exploratory adjusted analyses, the probability of in-hospital mortality increased with age, whereas that of MV use decreased, particularly in patients aged > 75 years. CONCLUSIONS: Older patients with aspiration pneumonia had higher illness severity yet received less MV, and had higher in-hospital mortality and lower home discharge rates. These nationwide data describe the current state of ICU-managed aspiration pneumonia in a super-aged society and may provide a reference point for future comparative studies.