Development and evaluation of a formula to correct blood glucose concentration measurements in hemodiluted and hemoconcentrated feline blood samples tested by use of a veterinary point-of-care glucometer.

Abstract

OBJECTIVE: To determine the effect of PCV on blood glucose concentration measurements in feline blood samples tested with a point-of-care (POC) glucometer and to develop and evaluate a correction formula that adjusts POC glucometer-measured blood glucose concentration (POCgluc) for a given PCV. DESIGN: Experimental and prospective study. SAMPLE: Blood samples from 4 healthy and 16 hospitalized cats. PROCEDURES: Heparinized blood samples from healthy cats were processed into packed RBCs and plasma. Packed RBCs were resuspended with plasma to achieve PCVs ranging from 0% to 87%. Duplicate PCV and POCgluc measurements were obtained for each suspension. Plasma glucose concentration as measured by a clinical laboratory biochemical analyzer (LABgluc) was assessed; results were compared with the POCgluc. A formula to correct POCgluc measurements for PCV was developed. Blood samples from hospitalized cats were used to evaluate the formula. RESULTS: For each healthy cat, LABgluc values were similar for all PCVs; the mean difference between POCgluc and LABgluc at PCVs outside a range of 35% to 55% was significant. Mean differences between POCgluc and LABgluc were 24.3 and 41.5 mg/dL, whereas mean differences between corrected POCgluc and LABgluc were 3 and 25.9 mg/dL for samples from healthy and hospitalized cats, respectively. Correlation between corrected POCgluc and LABgluc was stronger than that between POCgluc and LABgluc for samples from healthy and hospitalized cats. CONCLUSIONS AND CLINICAL RELEVANCE: The POCgluc did not reflect LABgluc in hemodiluted or hemoconcentrated feline blood samples. Use of a correction formula appeared to reduce this error. Additional studies are needed to evaluate the frequency with which this correction formula might prevent clinical errors. (2019;254:1180-1185).