The association between higher driving pressure and higher mortality in patients with pneumonia without acute respiratory distress syndrome.

PURPOSE: Recent studies reported that driving pressure has been associated with increased mortality in acute respiratory distress syndrome (ARDS) patients. We aimed to explore the association between 28-day mortality and driving pressure in patients with severe pneumonia without ARDS. METHODS: In total, 207 non-ARDS patients with severe pneumonia were enrolled. Serial driving pressures were recorded daily for either 21 days or until ventilator support was no longer required. The relationships between all variables and 28-day mortality were analyzed using binary logistic regression analyses. RESULTS: Non-survivors (56 patients) demonstrated high incidences of shock (55.4% vs. 24.5%, p < 0.001), acute renal failure (55.4% vs. 31.1%, p = 0.001), gastrointestinal bleeding (21.4% vs. 9.9%, p = 0.029), thrombocytopenia (53.6% vs. 23.2%, p < 0.001), jaundice (12.5% vs. 1.3%, p = 0.002), and driving pressure on Day 1 (19.9 ± 4.1 vs. 17.4 ± 4.5 cmH2O, p = 0.001). The ratio of arterial partial pressure of oxygen to fraction of inspired oxygen was lower in non-survivors than in survivors (281.5 ± 139.3 vs. 376.2 ± 211.9, p = 0.002). Regression analysis revealed that driving pressure was an independent factor associated with 28-day mortality (odds ratio, 1.110; 95% confidence interval, 1.013-1.217). CONCLUSION: Driving pressure was associated with 28-day mortality in patients with severe pneumonia without ARDS.