Impact of haematocrit on the accuracy of spot blood glucose measurements in dogs using two veterinary hand-held glucometers

Mariona R. Garcia^1*Nicholas Mann¹Marina Hernandez Perelló¹Valentina Silic¹Tim Sparks²Helen Titmarsh^1*

• ¹Wear Referrals Veterinary Specialist & Emergency Hospital, Bradbury, United Kingdom
• ²Waltham Petcare Science Institute, Melton Mowbray, United Kingdom

Anaemia is a common finding in critically ill dogs and understanding its potential impact on the accuracy of point-of-care glucometers is essential. In human medicine it is well reported that haematocrit can affect blood glucose measurements and influence clinical outcomes when measured using certain hand-held glucometers, whereas evidence in veterinary medicine is still scarce. This prospective case-control study included 72 client-owned dogs, 39 of which were anaemic. Haematocrit values were used to classify dogs between anaemic and non-anaemic categories. Whole blood glucose concentrations were measured using two new models of veterinary hand-held glucometers (G-PET PLUS® and AlphaTrak3®) and compared with the serum blood glucose measurements obtained with an automated wet biochemistry analyser. Agreement between the point-of-care blood glucose analysers and the reference method, as well as the effect of haematocrit on measurement accuracy were assessed. Both hand-held glucometers had a significant positive correlation with the wet biochemistry analyser (AlphaTrak3®: r = 0.664; 95% CI 0.502,0.78; G-PET PLUS®: r = 0.769; 95% CI 0.643, 0.855). However, when comparing the overall blood glucose results, there was a significant negative percentage bias (p <0.001) for both devices. Haematocrit reductions did not affect the degree of bias for AlphaTrak3®, and for the G-PET PLUS®, bias was also present in control patients and patients with a mild haematocrit reduction. Despite these statistical differences, clinical impact assessments of the results via specialist clinician questionnaires and Parkes error grid analysis, showed no change in clinical decision making or patient outcome, supporting cautious use of these devices in anaemic but normoglycaemic dogs when testing whole blood EDTA samples.