Lactate levels in arterial and venous blood may be correlated but not equivalent

[...]the authors adjusted initial lactate, time between lactate values, initial systolic blood pressure, fluid volume, and use of vasopressors in their multivariable analysis. [...]if prolonging the time limit to 6 hours, the relative lactate reduction in the study of Jansen et al [5] would be (1-0.83) * 100%=48.8% rather than 20%. [...]we do not believe that it is appropriate to cite this reference as argument to support the view without elaborating the difference in the meaning of lactate reduction in the 2 studies. [...]we appreciate Lokhandwala et al for their innovative and meaningful work, but further validation should be performed before any rigorous conclusions can be made.