Evaluation of the impact of icodextrin metabolite interference on the accuracy of hospital based glucose meters

Abstract

<h3>Background</h3> Accurate glucose measurement is an essential requirement for tight glucose control, especially in critical care environments.¹ Oligomeric forms of maltose that are metabolites of the icodextrin glucose polymer used to maintain the osmotic gradient across the peritoneal membrane in peritoneal-dialysis patients has been shown to result in overestimation of blood glucose values in several point-of-care (POC) glucose analysers with harmful consequences to patients.^2,3 However, the extent of this interference or its impact on intravenous or subcutaneous insulin dosing is not well documented with the current POC glucose measurement methods. <h3>Method</h3> In this study we compared the analytical interference produced by three Icodextrin metabolites on venous whole blood specimens on five glucometers and in a POC blood-gas analyser. The values obtained were compared with the plasma values, from the same venous whole blood samples, analysed by the hexokinase reference (HK) method. Precision (within run accuracy) and bias were determined for all methods. <h3>Results</h3> All three metabolites showed clinically significant interference (>10% change) with glucose measurement in three of five glucometers but no significant interference was observed on the blood-gas analyser or the HK methods. The precision was acceptable for most meters (CV <5%) while there were variable degrees to which the meters correlated with the HK method (ADA-1996 consensus suggest total analytical error <5%). <h3>Conclusion</h3> Interference with the three icodextrin metabolites and correlation to plasma reference method values are the main variables that differentiate the methods. Methods that correlate with the laboratory reference method and have minimal interference with other glucose polymers are preferred for safe glycaemic control in patients using icodextrin for peritoneal dialysis or exposed to metabolites of icodextrin.