Peripheral venous and arterial lactate agreement in septic patients in the emergency department: a pilot study

Lactate measurements are routinely used in sepsis for prognostication and for guiding treatment. Although venous lactate measurements have widely been used, most studies have used arterial lactate (A-LACT). The interchangeability between the measurements is debatable. This pilot study aimed to investigate whether an agreement exists between peripheral venous lactate (PV-LACT) and A-LACT with respect to sepsis in the Emergency Department (ED). PV-LACT lactate and A-LACT measurements were taken from a convenience sample of 37 patients presenting to a tertiary hospital ED between November 2010 and August 2011. The agreement between the paired measurements was assessed using Bland-Altman analysis. The mean difference between the measurements (venous-arterial) was 0.54 mmol/l, with 95% limits of agreement of -0.11 to 1.18 mmol/l. This pilot study demonstrates the potential use of PV-LACT as a substitute for A-LACT measurement in septic ED patients. However, further definitive investigation is needed to support widespread clinical adoption of peripheral venous lactate.