Relation between central venous, peripheral venous and arterial lactate levels in patients with sepsis in the emergency department

Background: Sepsis and multi-organ failure remain a major clinical problem with high morbidity and mortality worldwide. Lactate measurement remains part of the initial assessment and management of patients with sepsis. Although arterial blood is most commonly used for lactate measurement, there is increasing use of peripheral venous lactate for initial assessment and for monitoring of response to treatment in patients with sepsis. The aim of this study was to evaluate the relation between lactate levels measured from central line, peripheral vein and arterial line in patients treated for sepsis in the emergency department (ED). Methods: This prospective study enrolled 31 patients with diagnosis of sepsis who were evaluated and treated in the ED of a university hospital. During initial resuscitation, blood samples from the artery, peripheral vein and central vein (when available) were collected and lactate concentrations were measured. Correlation between lactate values from the three different locations was assessed using Pearson correlation. Bland-Altman plots were used to evaluate agreement between lactate measurements in different sampling locations. All patients were eventually admitted to the Internal Medicine Department ward or to the intensive care unit (ICU) for further treatment. Results: Our data showed strong, highly significant correlation between arterial and peripheral venous lactate levels (r = 0.880, P \u3c 0.0001), between arterial and central venous blood lactate (r = 0.898, P \u3c 0.0001) and between central and peripheral venous blood lactate (r = 0.941, P \u3c 0.0001). Conclusions: In this study we observed strong correlation between arterial, central vein and peripheral vein lactate concentrations in 31 patients assessed and treated for sepsis. We suggest that lactate measurement in peripheral venous blood could be used for screening and for monitoring response to therapy in sepsis patients. However, because this is a small study in only 31 patients and published data are limited, larger studies are needed in order to confirm the validity of our findings