Driving pressure is not predictive of ARDS outcome in chest trauma patients under mechanical ventilation

The relationship between the driving pressure of the respiratory system (ΔPrs) under mechanical ventilation and worse outcome has never been studied specifically in chest trauma patients. The objective of the present study was to assess in cases of chest trauma the relationship between ΔPrs and severity of acute respiratory distress syndrome (ARDS) or death and length of stay.

A retrospective analysis of severe trauma patients (ISS > 15) with chest injuries admitted to the Trauma Centre from January 2010 to December 2018 was performed. Patients who received mechanical ventilation were included in our analysis. Mechanical ventilation parameters and ΔPrs were recorded during the stay in the intensive care unit. Association of ΔPrs with mortality and outcomes was specifically studied at the onset of ARDS (ΔPrs_-ARDS) by receiver operator characteristic curve analysis, Kaplan-Meier curves, and multivariate analysis.

Among the 266 chest trauma patients studied, 194 (73%) developed ARDS. ΔPrs was significantly higher in the ARDS group versus in the no ARDS group (11.6 ± 2.4 cm H₂O vs. 10.9 ± 1.9 cm H₂O, p = 0.04). Among the patients with ARDS, no difference according to the duration of mechanical ventilation was found between the high ΔPrs group (ΔPrs_-ARDS > 14 cm H₂O) and the low ΔPrs group (ΔPrs_-ARDS ≤ 14 cm H₂O), (p = 0.75). ΔPrs_-ARDS was not independently associated with the duration of mechanical ventilation (hazard ratio [HR], 1.006; 95% CI, 0.95-1.07; p = 0.8) or mortality (HR, 1.07; 95% CI, 0.9-1.28; p = 0.45). High mechanical power (≥ 12 J/min) was associated with a lower time for weaning of mechanical ventilation in Kaplan-Meier curves but not in multivariate analysis (HR, 0.98; 95% CI, 0.94-1.02; p = 0.22).

A high ΔPrs_-ARDS was not significantly associated with an increase in mechanical ventilation duration or mortality risk in ARDS patients with chest trauma in contrast with medical patients.