Does Methemoglobin from Oxidized Hemoglobin-Based Oxygen Carrier (Hemoglobin Glutamer-200) Interfere with Lactate Measurement (YSI 2700 SELECT??? Biochemistry Analyzer)?

Abstract

In this study, we validated the accuracy of lactate measurements (YSI 2700 SELECT glucose/lactate analyzer) in the presence of methemoglobin from an oxidized bag of hemoglobin-based oxygen carrier (Met-HBOC), hemoglobin glutamer-200 (Oxyglobin; Biopure Corp). Different combinations of concentrated L-lactate solution, pooled canine plasma, and Plasmalyte A were added to 4 sample groups (1%, 10%, 20%, and 40% Met-HBOC [1.3 g/dL]) to yield linear increases in lactate concentration in consecutive samples. The mean difference between measured and calculated lactate was -5.1 mg/dL (1% Met-HBOC), -5.8 mg/dL (10% Met-HBOC), -4.6 mg (20% Met-HBOC), and -8.5 mg/dL (40% Met-HBOC). The root mean square error was 6.5 mg/dL, 7.4 mg/dL, 6.8 mg/dL, and 10.3 mg/dL, respectively. The Bland-Altman correlation (r) was r = -0.94 (P = 0.01), r = -0.91 (P < 0.001), r = -0.90 (P < 0.001), and r = -0.94 (P < 0.001), respectively, where r = 0 for perfect agreement between measured and calculated values. Results indicate that true lactate levels in the presence of Met-HBOC are underestimated when measured by an YSI 2700 analyzer independent of the amount of Met-HBOC present. When interpreting lactate concentrations from a patient with a HBOC present in plasma, underestimation of true lactate levels may occur unrelated to methemoglobin concentrations.

Differential sensitivities of pulmonary and coronary arteries to hemoglobin-based oxygen carriers and nitrovasodilators: Study in a bovine ex vivo model of vascular strips

“…Khan et al (2003) observed insignificant increase in methemoglobin in an opened bag HBOC over the course of one day of research. However, Moallempour et al (2009) and Osgood et al (2005) have reported that prolonged exposure of HBOC to air for months would result in the formation of methemoglobin up to 65–80%. Therefore, we took the following precautions in the handling of HBOC: a) withdrawing HBOC from the storage bag without injecting air into the bag, b) limiting the maximum duration for using a given bag to 1 week, and c) storing HBOC at 4°C.…”