Driving Pressure and Hospital Mortality in Patients Without ARDS A Cohort Study

BACKGROUND: Driving pressure (Delta P) is associated with mortality in patients with ARDS and with pulmonary complications in patients undergoing general anesthesia. Whether Delta P is associated with outcomes of patients without ARDS who undergo ventilation in the ICU is unknown. Our objective was to determine the independent association between Delta P and outcomes in mechanically ventilated patients without ARDS on day 1 of mechanical ventilation. METHODS: This was a retrospective analysis of a cohort of 622 mechanically ventilated adult patients without ARDS on day 1 of mechanical ventilation from five ICUs in a tertiary center in the United States. The primary outcome was hospital mortality. The presence of ARDS was determined using the minimum daily PaO2 to FIO2 (PF) ratio and an automated text search of chest radiography reports. The data set was validated by first testing the model in 543 patients with ARDS. RESULTS: In patients without ARDS on day 1 of mechanical ventilation, Delta P was not independently associated with hospital mortality (OR, 1.01; 95% CI, 0.97-1.05). The results of the primary analysis were confirmed in a series of preplanned sensitivity analyses. CONCLUSIONS: In this cohort of patients without ARDS on day 1 of mechanical ventilation and within the limits of ventilatory settings normally used by clinicians, Delta P was not associated with hospital mortality. This study also confirms the association between Delta P and mortality in patients with ARDS not enrolled in a trial and in hypoxemic patients without ARDS.