Serial Lactate Measurements as a Prognostic Tool in Venovenous Extracorporeal Membrane Oxygenation Support

Abstract

Serial lactate measurements over time or lactate clearance has been reported to be clinically reliable for risk stratification in different pathologic conditions ranging from sepsis to trauma, but no data are so far available on the behavior of lactate during venovenous extracorporeal membrane oxygenation (VV-ECMO) support in refractory adult acute respiratory distress syndrome (ARDS). We assessed lactate values during VV-ECMO support and the prognostic role of lactate clearance at 6, 24, and 72 hours after ECMO start in 126 consecutive patients with refractory ARDS treated with VV-ECMO. Survivors showed a progressive, significant decrease in lactate values throughout the study period, whereas nonsurvivors exhibited a progressive increase. Lactate values (measured before ECMO initiation, as well as 6 and 24 hours after) were independently associated with intensive care unit (ICU) death. A significantly higher lactate clearance was observed for survivors at 72 hours after ECMO start than for nonsurvivors. At logistic regression analysis, lactate clearance at 72 hours after ECMO start was an independent predictor of ICU death (odds ratio 0.988, 95% confidence interval [CI]: 0.995 to 0.982, p= 0.001) (together with age, body mass index, and Sequential Organ Failure Assessment). At receiver operating characteristic curve analysis, lactate clearance at 72 hours after ECMO start cutoff value of-16% had a sensitivity of 68% and a specificity of 63% (area under the curve= 0.67, 95% CI: 0.57 to 0.77, p= 0.002). Lactate (measured before ECMO initiation, as well as 6 and 24 hours after) is a prognostic factorin patients with refractory ARDS treated with VV-ECMO, and lactate clearance at 72 hours after ECMO initiation helps in the risk stratification of these patients, being independently associated with death.