Evaluation of Four Point‐Of‐Care Glucose Meters in Alpacas

Abstract

Purpose: Hospitalized alpacas are often hyperglycemic requiring frequent blood glucose testing. Objectives: To compare the performance of 4 brands of glucometers with a laboratory-based analyzer (LCA) over a range of glucose concentrations in alpacas.Animals: Four healthy male alpacas. Methods: A 2-treatment cross-over study was utilized. The alpacas were given 0.4 U/kg of regular insulin intravenously and then 500 mg/kg of dextrose intravenously with a 1 week washout period between treatments. Blood samples were collected from 10 minutes before until 6 hours after drug administration. Glucose concentrations were measured in whole blood and plasma samples on 4 glucometers, and serum glucose was measured on an LCA.Results: Glucometer performance varied depending on whether glucose concentrations were measured in plasma or whole blood. Based on error grid analysis, the Precision Xtra and One Touch Ultra 2 glucometers were clinically acceptable for testing whole blood samples, whereas the Accu-Chek Aviva and Nova StatStrip Xpress glucometers were clinically acceptable for testing plasma samples in comparison with serum glucose concentrations determined by the LCA. All glucometers had systematic and proportional biases that varied based on sample type.Conclusions and Clinical Importance: Human-based glucometers in alpacas should be used cautiously, particularly at higher blood glucose concentrations. The blood sample type (plasma or whole blood) can alter meter performance when compared with serum glucose concentrations and potentially lead to errors in clinical decisions.Key words: Camelid; Glucometer; Hyperglycemia; Hypoglycemia; Insulin.A lpacas commonly experience hyperglycemia because of stress and a variety of disease states. Hyperglycemia in sick alpacas can persist for days until the primary medical condition resolves and normal metabolic feedback pathways reassert control. Alpacas have poor glucose tolerance and are relatively insulin resistant, which complicates medical management and the response to exogenous treatments.1,2 Hypoglycemia is less commonly observed in alpacas but can occur with a variety of conditions such as sepsis, inadequate nutrition in neonates, or insulin therapy.Veterinary hospitals that treat alpacas with these glycemic disorders use a variety of point-of-care (POC) glucometers designed for use in humans. Reports evaluating these glucometers in humans and animals have found variations in performance between meters and with disease states, medications, and sample types. 3,4 A currently available veterinary glucometer has been evaluated in alpacas but is not currently marketed for use in this species.5 Alpacas also have unique, elliptical red blood cells (RBC) that interfere with many table-top blood analyzers, but it is unknown whether there is an effect on POC glucometers. 6 The objective of this study was to compare 4 commercial POC glucometers against the gold standard of a laboratory chemistry analyzer (LCA) over a range of blood glucose concentrations in alpacas. To evaluate whet...

ASVCP guidelines: quality assurance for portable blood glucose meter (glucometer) use in veterinary medicine

“…Such assessment should be performed in each of the 3 diagnostically relevant glucose ranges, hypo‐, normo‐, and hyperglycemia . This is necessary because of the overwhelming evidence in the literature that PBGM performance varies across the glycemic range in human and veterinary studies. This assessment is even more important in veterinary medicine where there is currently no consensus regarding the range of hypo‐, normo‐, or hyperglycemia within which more error occurs, or whether the PBGM under‐ or overestimate the glucose concentration in that range .…”

Evaluation of Glucose Response to 3 Types of Insulin Using a Continuous Glucose Monitoring System in Healthy Alpacas

“…The POC glucometer used in this study had been previously evaluated and compared favorably to a laboratory chemistry analyzer . The POC glucometer was operated and calibrated according to the manufacturer's instructions.…”

“…After insulin treatment, if signs of hypoglycemia were observed (head tremors, excessive humming, and skittish behavior) or whole blood glucose was less than 20 mg/dL on the POC glucometer, the alpaca was to be administered an IV dextrose solution (5% solution) in a 60–100 mL bolus which was to be repeated if glucose remained less than 20 mg/dL or signs of hypoglycemia persisted. This dextrose dosage was used in a previous study and was adequate for increasing the glucose without causing hyperglycemia …”

“…In addition, by visually examining the layout of the data, systematic biases (mean difference) and proportional biases (positive or negative slope in the data) could be observed. Acceptance criteria were established based on a 3‐tier LOA . As the effects of a large LOA would be more critical at lower glucose concentrations, we required an LOA of ±10 mg/dL at POC glucose concentrations ≤60 mg/dL, but allowed an LOA of ±50 mg/dL at POC glucose concentrations ≥300 mg/dL for acceptable results.…”

“…Subcutaneously injected human long‐acting insulin (ultralente) depresses blood glucose for approximately 10 hours in alpacas, whereas the effects of IV regular insulin persist for approximately 45 minutes . Intravenous injection of regular insulin produced a nadir between 90 and 120 minutes, and depressed blood glucose for approximately 360 minutes …”