(355) Trends of Prolonged Acute Mechanical Ventilation in Adults Aged 18-44 Years

Introduction: Mechanically ventilated adults are predominantly aged 45 years or older, and nearly 40% remain ventilated for ≥96 hours (prolonged acute mechanical ventilation [PAMV]). Although older adults were predicted to drive an increase in PAMV over time, recent data show progressive decline in the incidence of PAMV among those aged >65 years with unchanged long-term mortality. However, the population-level trajectories of the incidence and outcomes of PAMV in younger adults have not been examined.

Methods: We used a statewide dataset to identify hospitalizations aged 18-44 years who received mechanical ventilation (MV) in Texas during 2010-2019. PAMV was defined by ICD-9 (96.72) and ICD-10 (5A1955Z) codes. United States Census Bureau data were used for state population estimates. Negative binomial regression was applied to estimate trends of the population incidence of PAMV and its frequency among MV, expressed as Annual Percent Change (APC). A hierarchical logistic model was fit to estimate changes in short-term mortality (in-hospital death or discharge to hospice) of PAMV hospitalizations. Temporal trends of PAMV hospitalizations undergoing tracheostomy, discharged home, and to post-acute care facilities (PACF) were examined using the Cochrane-Armitage test.

Results: Among 131,044 MV hospitalizations, 40,932 (31.2%) had PAMV. The overall incidence of PAMV was 39.4/100,000 population and remained unchanged over time (APC +0.7% [95% CI -1.1 to +2.6]). The frequency of PAMV among all MV decreased between 2010 and 2019 from 34% to 28.9% (APC -1.7% [95% -2.1 to -1.2]). Short-term mortality among those with PAMV rose between 2010 and 2019 from 21.7% to 24.2%, but decreased over time on adjusted analysis (adjusted odds ratio 0.93/year [95% 0.92-0.94]). Among those with PAMV, the overall frequency of those requiring tracheostomy, discharged home, and to PACF was 26.8%, 40.9%, and 30.6%, respectively, and decreased over time for each.

Conclusions: Nearly 1 in 3 mechanically ventilated adults aged 18-44 required PAMV, with an unchanged population burden over time, but decreasing frequency among all MV. Crude short-term mortality rose over time, but decreased on adjusted analysis. The frequency of discharge to home was low, with common discharge to PACF, and decreased for both over time.