A recent study in JAMA had shown that you could substitute serial lactate levels for measurement of ScvO2 in EGDT and do just as well.
Now a paper in the American Journal of Respiratory and Critical Care Medicine has looked at lactate guided therapy in a little different way. Here are the main points:
Overall, for patients with lactate levels greater than 3 meq/l, lactate guided therapy in the first 8 hours improved mortality.
In this study, in contrast to the JAMA study, lactate monitoring was an adjunct to ScvO2 monitoring rather than a substitute.
Treatment differences driven by the lactate monitoring consisted of more fluids and vasodilators.
Despite lower mortality in the lactate group, lactate clearance didn't differ between the groups. At first glance that's odd. It may merely mean that investigators caring for patients in the lactate group had one more “vital sign” to alert them to provide more aggressive and physiologically appropriate therapy.
The investigators interviewed in Medscape, noting some patients who met ScvO2 goals yet still had elevated lactates, posited a microcirculatory defect and gave vasodilators such as nitroglycerine. (Remember, though, in such patients, the non-hypoxic causes of hyperlactatemia such as drugs, e.g. metformin, and liver disease).