Exploring the Impact of Mechanical Power on Mortality and Phenotypes in ARDS Patients: A Retrospective Analysis

Abstract In this study, we investigated the effect of mechanical power (MP) on mortality in acute respiratory distress syndrome (ARDS) patients. Patients diagnosed with ARDS were identified from the MIMIC-IV database. Kaplan-Meier curves and Cox proportional hazards models were utilized for survival analysis. The optimal cut-off value for MP was determined by using 'survminer' package. Causal mediation analysis (CMA) further investigated the effect of MP on 28-day mortality. Key predictive indicators were used to cluster and identify characteristics of different phenotypes. A total of 1333 patients were included. MP lower than 18.7J/min was associated with reduced mortality. Arterial pH and P/F ratio separately accounted for 29.2% and 20% of the mediating effect of high MP on increased 28-day mortality. Clustering analysis showed that phenotype-I had the worst respiratory mechanical parameters and the highest 28-day mortality. Phenotype-II was correlated with less organ dysfunction, the best oxygenation index and lower mechanical ventilation hours. Phenotype-III had the most laboratory abnormalities, the worse P/F ratio and longer ICU staytime. MP is strongly associated with mortality of ARDS patients belong to phenotype-III. High MP is independently associated with increased mortality in patients with ARDS. MP of less than 18.7 J/min is safer for ARDS patients.