Is Mechanical Power the Trojan Horse? Emphasizing the Role of Driving Pressure.

Background and

Objectives

Driving pressure (DP) and components of mechanical power (MP) have been proposed as prognostic markers in ARDS. The prognostic significance of these parameters in COVID-19-associated ARDS (C-ARDS), particularly during the early phase of intensive care unit (ICU) stay, remains uncertain. Materials and

Methods

A retrospective single-center cohort of 310 C-ARDS patients receiving invasive mechanical ventilation was analyzed. Ventilator data from the first 72 h after ICU admission were retrieved. DP, total mechanical power (MPtot), and dynamic mechanical power (MPdyn) were calculated. The primary endpoint was defined as ICU mortality; secondary endpoints were ventilator-free days (VFDs) and length of stay (LOS) in ICU. ROC analyses, Cox proportional hazards regression, and Kaplan-Meier survival estimates were applied.

Results

DP ≥ 15.72 cm H2O and MPdyn ≥ 10.08 J/min were found to be significantly associated with increased ICU mortality (HR 1.9 [1.5-2.5], p < 0.0001; HR 1.5 [1.2-1.9], p = 0.0036, respectively), whereas MPtot ≥ 18.6 J/min was not (p = 0.1). Patients with DP below the threshold demonstrated longer VFDs, and higher survival probabilities. No significant differences in VFDs were identified for MPdyn or MPtot.

Conclusions

In C-ARDS patients, early measurements of DP and MPdyn were independently associated with ICU mortality, while MPtot was not. Among these parameters, DP may be regarded as the most practical marker due to its ease of calculation and potential utility in guiding lung-protective ventilation strategies.