Elevated lactate levels and impaired lactate clearance during extracorporeal life support (ECLS) are associated with poor outcome in cardiac surgery patients

Abstract

The use of extracorporeal life support (ECLS) as part of cardio-circulatory support has increased rapidly in recent years. Severe hyperlactatemia is not uncommon in this group of patients. Lactate peak concentrations and lactate clearance have already been identified as independent marker for mortality in critical ill patients without mechanical device support. The aim of this study was to determine a supposed correlation between the variables lactate peak concentration and clearance in the blood and mortality in the ECLS context. Therefore, a total of 51 cardiac surgery ICU patients with ECLS therapy were included in this retrospective, clinical observational study (survivors n = 23; non-survivors n = 28). Lactate measurement was performed before, during and after ECLS therapy. Further, common ICU scores (SAPSII, SOFA, TISS28), the rates of transfusion and the different vasopressor therapies will be compared. Significant elevated peak lactate levels and poor lactate clearance were associated with higher mortality during ECLS therapy (p < 0.001). Deceased patients had higher SAPSII scores (p < 0.001), received more transfusions (p < 0.001) and presented with higher rates of epinephrine (p < 0.001). In conclusion, hyperlactatemia during ECLS therapy is a time sensitive emergency. Lactate cannot be cleared in all patients. Reversible causes should be explored and treated. In cases where the cause is irreversible, the prognosis of elevated lactate concentrations and reduced clearance is very poor.