Titration of Ventilator Settings to Target Driving Pressure and Mechanical Power

BACKGROUND:

Driving pressure (ΔP) and mechanical power (MP) may be important mediators of lung injury in ARDS; however, there is little evidence for strategies directed at reducing these parameters. We applied predictive modeling to estimate the effects of modifying ventilator parameters on ΔP and MP.

METHODS:

Two thousand six hundred twenty-two subjects with ARDS (Berlin criteria) from the Medical Information Mart for Intensive Care IV version 1.0 database admitted to the ICU at Beth Israel Deaconess Medical Center between 2008–2019 were included. Flexible confounding-adjusted regression models for time-varying data were fit to estimate the effects of adjusting PEEP and tidal volume (V_T) on ΔP and adjusting V_T and breathing frequency on MP.

RESULTS:

Reduction in V_T reduced ΔP and MP, with more pronounced effect on MP with lower compliance. Strategies reducing frequency consistently increased MP (when V_T was adjusted to maintain consistent minute ventilation). Adjustment of PEEP yielded a U-shaped effect on ΔP.

CONCLUSIONS:

This novel conditional modeling confirmed expected response patterns for ΔP, with the response to adjustments depending on subjects' lung mechanics. Furthermore, a V_T-driven approach should be favored over a breathing frequency-driven approach when aiming to reduce MP.