# Exploring the association of mechanical power with mortality and phenotypes among patients with acute respiratory distress syndrome: a retrospective analysis

## TL;DR

This study finds that high mechanical power from ventilators is linked to higher mortality in ARDS patients, with different effects across patient subgroups.

## Contribution

The study identifies a mortality-associated MP threshold and shows how ARDS phenotypes respond differently to mechanical power.

## Key findings

- An MP threshold of 18.7 J/min is associated with significantly lower 28-day mortality.
- Three ARDS phenotypes were identified with distinct mortality risks and responses to MP.
- Respiratory rate was the strongest predictor of mortality among MP components.

## Abstract

Mechanical power (MP) quantifies the energy delivered from a ventilator to the respiratory system and is a key contributor to ventilator-induced lung injury. This study evaluated the association between MP and mortality in patients with acute respiratory distress syndrome (ARDS), and examined whether this relationship differs across data-driven ARDS phenotypes.

Patients with ARDS requiring invasive ventilation were identified from the MIMIC-IV database. The association between MP and mortality was assessed using logistic regression, Kaplan–Meier survival analysis, and Cox proportional hazards models. The optimal MP threshold was determined using maximally selected rank statistics. Unsupervised clustering was used to identify ARDS phenotypes and evaluate phenotype-specific responses to MP.

A total of 1,333 patients were included. An MP < 18.7 J/min was associated with significantly lower 28-day mortality. Among MP components, the elastic-dynamic component showed the strongest association with mortality; the elastic-static component had a weaker association, and the resistive component was not significant. Respiratory rate was the strongest predictor of mortality. Three phenotypes were identified. Phenotype I (mechanical stress-dominant): poor respiratory mechanics and the highest mortality. Phenotype II (oxygenation-preserved with mild inflammation): better oxygenation, less organ dysfunction, and the lowest mortality. Phenotype III (systemic hyperinflammation with metabolic dysregulation): significant laboratory abnormalities, strong association with high MP, and increased mortality.

High mechanical power (MP) was independently associated with increased mortality in patients with ARDS. An MP threshold of 18.7 J/min demonstrated prognostic relevance for mortality risk stratification, and the association between MP and outcomes varied across ARDS phenotypes, highlighting the potential value of phenotype-informed ventilation strategies.