title: 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.
authors.affiliation: *Department of Anesthesiology, David Geffen School of Medicine at University of California Los Angeles; †Charles R. Drew University of Medicine and Science, Martin Luther King Jr./Drew Medical Center, Los Angeles, California; and ‡Department of Clinical Studies, University of Pennsylvania School of Veterinary Medicine, Philadelphia.
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Osgood
authors.forename: Jonathan S
authors.initials: JS
authors.lastname: Jahr
authors.forename: Poonam
authors.initials: P
authors.lastname: Desai
authors.forename: Jessica
authors.initials: J
authors.lastname: Tsukamoto
authors.forename: Bernd
authors.initials: B
authors.lastname: Driessen
mesh_terms: D000818:Animals; D001802:Blood Substitutes / Q000737:chemistry*; D004285:Dogs; D006454:Hemoglobins; D006861:Hydrogen Peroxide / Q000737:chemistry; D019344:Lactic Acid / Q000097:blood*; D008706:Methemoglobin / Q000737:chemistry*; D016877:Oxidants / Q000737:chemistry; D010092:Oximetry
chemical_list: D001802:Blood Substitutes; D006454:Hemoglobins; D016877:Oxidants; C402601:hemoglobin glutamer-200; D019344:Lactic Acid; D008706:Methemoglobin; D006861:Hydrogen Peroxide