TY - JOUR T1 - Stability of Whole Blood Lactate Specimens at Room Temperature Versus Slushed Ice Conditions JF - Respiratory Care DO - 10.4187/respcare.08023 SP - respcare.08023 AU - Gerald S Zavorsky AU - Samuel Gasparyan AU - Nicholas S Stollenwerk AU - Rebecca A Brooks Y1 - 2020/09/01 UR - http://rc.rcjournal.com/content/early/2020/09/01/respcare.08023.abstract N2 - BACKGROUND: There are limited data on lactate stability in whole blood. The purpose of this study was to determine whole blood lactate stability at room temperature and in slushed ice conditions.METHODS: An equal number of arterial and venous samples were obtained from 202 subjects hospitalized for various pathophysiological conditions. Whole blood lactate concentration was measured over 5 different times spanning 80–90 min in a blood gas lab at a major hospital center. Samples were stored at room temperature (22–24°C) or in slushed ice conditions (0.1–0.2°C) before analysis.RESULTS: The mean increase in lactate concentration was 0.001 mmol/L/min in samples on slushed ice over 90 min. However, at room temperature conditions, the mean increase in lactate concentration was 0.008 mmol/L/min regardless of whether the sample was arterial or venous. An increase in whole blood lactate concentration of ≥ 0.4 mmol/L occured after 45 min at room temperature, with 5% of all whole blood specimens demonstrating a meaningful change at ≤ 20 min. The ≥ 0.4 mmol/L change in whole blood lactate is considered significant based on the College of American Pathologists instrument peer-group standards.CONCLUSIONS: Considering that a change in whole blood lactate concentration of ≥ 0.4 mmol/L is unacceptable instrument peer-group variation as defined by the College of American Pathologists, ice is no longer needed to stabilize whole blood lactate specimens when the draw time to analyze time is < 45 min. Samples remain stable even at 90 min when left on ice. ER -