Methods: We studied a nested cohort of 115 patients from two tertiary intensive care units (ICUs) within a large multicenter randomized controlled trial treated with lower intensity (LI) or higher intensity (HI) CRRT.
Results: Levels of metabolic acidosis at randomization were similar [base excess (BE) of −8 ± 8 vs. −8 ± 7 mEq/l; p = 0.76]. Speed of BE correction did not differ between the two groups. However, the HI group had a greater increase in MAP from baseline to 24 h (7 ± 3 vs. 0 ± 3 mmHg; p < 0.01) and a greater decrease in norepinephrine dose (from 12.5 to 3.5 vs. 5 to 2.5 μg/min; p < 0.05). The correlation (r) coefficients between absolute change in MAP and norepinephrine (NE) dose versus change in BE were 0.05 and −0.37, respectively.
Conclusions: Overall, LI and HI CRRT have similar acid–base effects in patients with acidosis. However, HI was associated with greater improvements in MAP and vasopressor requirements (clinical trial no. NCT00221013).