Capillary and Venous Lactate Agreement: a pilot prospective observational study.

BACKGROUND: Blood lactate is a marker of patient illness severity. Capillary lactate (CAP-LACT) measurement can potentially improve patient screening; however, it has poor evidence of clinical utility. AIM: We aimed to investigate agreement between CAP-LACT and peripheral venous lactate (PV-LACT). METHODS: We performed a prospective observational pilot study of 99 patients requiring lactate measurement. Paired CAP-LACT and PV-LACT was recorded. Agreement was determined by Bland-Altman analysis. RESULTS: Bias was 0.2 mmol/L, with 95% limits of agreement from -1.9 to 2.3. CONCLUSIONS: CAP-LACT has poor agreement with PV-LACT. Further research is needed to improve its potential clinical utility.