Hypercapnic acidosis in ARDS: A tolerated side effect or an important therapeutic modality?

Measurements and main results: The adjusted odds ratio and 95% confidence intervals (CI) for 28-day mortality rate associated with hypercapnic acidosis defined as day 1 pH <7.35 and PaCO2 >45 mm Hg were 0.14 (95% CI 0.03-0.70, p = .016) in the 12 mL/kg PBW tidal volume group and 1.18 (95% CI 0.59-2.35, p = .639) in the 6 mL/kg PBW tidal volume group. Other definitions of hypercapnic acidosis spanning a range of magnitudes suggest a dose-response association between hypercapnic acidosis and 28-day mortality in the 12 mL/kg PBW tidal volume group. None of our definitions of hypercapnic acidosis were associated with reduction in 28-day mortality in the 6 mL/kg PBW tidal volume group.