In humans, it has been found that Hct affects the performance of blood glucometers.1–6 An increase in Hct results in a decrease in measured glucose concentration,5,6 and glucometers become progressively more inaccurate as Hct increases.3 A decrease in Hct also may result in an increase in measured glucose concentrations for some glucometers.1
Handheld POC glucometers are widely used in veterinary hospitals for measurement and monitoring of blood glucose concentrations. Greyhounds have a naturally high Hct,7 and given the reported inaccuracy of POC glucometers in humans, it is possible that glucometer results may be misinterpreted by veterinarians during examination of racing Greyhounds. Similarly, abnormal results for measurement of blood glucose concentrations in critically ill dogs8 and anemic dogs may be misinterpreted. The accuracy of glucometer measurements is paramount to the management of diabetic and hypoglycemic patients that also may have abnormal Hcts. It is important to evaluate POC glucometers in the species in which they are used because glucometers may provide results that differ from those for a laboratory standard or from those of other POC glucometers, and results may differ at extremes of blood glucose concentration or Hct.
The purpose of the study reported here was to compare measurements of canine blood glucose concentrations obtained by use of 2 POC glucometers against a reference method and to assess the impact of Hct on glucose concentration. A portable glucometer developed for use in humans and a handheld glucometer specifically developed for veterinary use were evaluated.
K EDTA, 1.6 mg of EDTA/1 mL of blood, catalogue No. 47.556, Sarstedt Haematology, Newton, NC.
Glucose FH/1.3, catalogue No. 41.1394.005, Sarstedt Haematology, Newton, NC.
Ascensia Elite XL, Bayer, Elkhart, Ind.
AlphaTrak, Abbott Laboratories, Abbott Park, Ill.
Rx Daytona autoanalyzer, Randox Laboratories, Crumlin, Northern Ireland.
Advia 120, Siemens Diagnostics, Deerfield, Ill.
Advia 2120, Siemens Medical Solutions Diagnostics GmbH [Dx], Erfurt, Germany.
GraphPad Prism, version 5.01, GraphPad Software, San Diego, Calif.
Karon BS, Griesmann L, Scott BS, et al. Evaluation of the impact of hematocrit and other interference on the accuracy of hospital-based glucose meters. Diabetes Technol Ther 2008; 10: 111–120.
Ghys T, Goedhuys W, Spincemaille K, et al. Plasma-equivalent glucose at the point-of-care: evaluation of Roche Accu-Chek Inform® and Abbott Precision PCx® glucose meters. Clin Chim Acta 2007; 386: 63–68.
Hussain K, Sharief N. The inaccuracy of venous and capillary blood glucose measurement using reagent strips in the newborn period and the effect of haematocrit. Early Hum Dev 2000; 57: 111–121.
Rao LV, Jakubiak F, Sidwell JS, et al. Accuracy evaluation of a new glucometer with automated hematocrit measurement and correction. Clin Chim Acta 2005; 356: 178–183.
Holtzinger C, Szelag E, DuBois JA, et al. Evaluation of a new POCT bedside glucose meter and strip with hematocrit and interference corrections. Point Care 2008; 7: 1–6.
Tang Z, Lee JH, Louie RF, et al. Effects of different hematocrit levels on glucose measurements with handheld meters for point of care testing. Arch Pathol Lab Med 2000; 124: 1135–1140.
Shiel RE, Brennan SF, O'Rourke LG. Hematologic values in young pretraining healthy Greyhounds. Vet Clin Pathol 2007; 36: 274–277.
Torre DM, de Laforcade AM, Chan DL. Incidence and clinical relevance of hyperglycemia in critically ill dogs. J Vet Intern Med 2007; 21: 971–975.
Kilpatrick ES, Rumley AG, Myin H. The effect of variations in hematocrit, mean cell volume and red cell count on reagent strip tests for glucose. Ann Clin Biochem 1993; 30: 485–487.
Tang Z, Du X, Louise R, et al. Effects of drugs on glucose measurements with handheld glucose meters and a postable glucose analyzer. Am J Clin Pathol 2000; 113: 75–86.
Kimberley M, Vespa H, Caudill S, et al. Variability among five over-the-counter blood glucose monitors. Clin Chim Acta 2006; 364: 292–297.
Püntmann I, Wosnoik W, Haeckel R. Comparison of several point-of-care testing (POCT) glucometers with an established laboratory procedure for the diagnosis of type 2 diabetes using the discordance rate. Clin Chem Lab Med 2003; 41: 809–820.
Hollis AR, Dallap Schaer BL, Boston RC, et al. Comparison of the Accu_Check Aviva point-of-care glucometer with blood gas and laboratory methods of analysis of glucose measurement in equine emergency patients. J Vet Intern Med 2008; 22: 1189–1195.
Persons EL. Studies on red blood cell diameter III. The relative diameter of immature (reticulocytes) and adult red blood cells in health and anemia, especially in pernicious anemia. J Clin Invest 1929; 7: 615–629.
Meinkoth JH, Clinkenbeard KD. Normal hematology of the dog. In: Feldman BF, Zinkl JG, Jain NC, eds. Schalm's veterinary hematology. 5th ed. Philadelphia: Lippincott Williams & Wilkins, 2000; 1057–1063.