Prognostic Value of Blood Lactate and Lactate Clearance in Refractory Cardiac Arrest Treated by Extracorporeal Life Support.

Abstract

During cardiac arrest (CA) resuscitation, an 'ischaemia-reperfusion' syndrome occurs leading to multiorgan failure reflected by an increase in blood lactate. Blood lactate is a diagnosis and prognosis biomarker in extracorporeal life support (ECLS), but its kinetic appears more informative to assess a patient's outcome. The aim of the present study was to describe the prognostic value of blood lactate and lactate clearance (LC) 3 (H3) and 6 h (H6) after the initiation of ECLS in the treatment of refractory CA. Patients admitted to the intensive care unit for refractory CA were included. Lactate measurements were performed at the initiation of ECLS (H0) and at H3 and H6 upon the initiation of ECLS. LC was measured from 0 to 3 h (LC03), 0 to 6 h (LC06) and 3 to 6 h (LC36). The primary endpoint was in-hospital mortality within 28 days. Sixty-six patients were enrolled in the study. Lactate levels were higher in deceased patients. Increased mortality was observed with increasing levels of lactate at H3 and H6 and with decreasing LC03. Using logistic regression, an association was observed between mortality and lactate at H3 with an odds ratio (OR) of 1.21 (95% confidence interval (CI) 1.05-1.42); LC03, OR of 0.93 (95% CI 0.87-0.99) and LC06, OR of 0.96 (95% CI 0.92-0.99). Blood lactate and LC within the first 3 h of ECLS in refractory CA are associated with mortality. LC is a more relevant parameter than blood lactate, taking into account both the production and elimination of lactate. We suggest to preferentially use LC to assess the patient's outcome.