Deobald, Gayle R.

The use of high-dose vitamin C in cancer care has offered promising results for some patients. However, the intravenous (IV) doses used for these patients can reach concentrations that interfere with some strip-based glucose meters. We characterized the impact of vitamin C interference, from standard to the very high doses used for some cancer protocols, using three different hospital-use glucose meters. For two of the three devices tested, increasing concentrations of ascorbic acid caused false elevations in the glucose measurements. The third glucose meter did not provide inaccurate results, regardless of the vitamin C concentration present. Rather, above a certain threshold, the device generated error messages and no results could be obtained.

Background: More stringent accuracy guidelines for hospital-use glucose meters have recently been published, but it remains unclear whether glucose meters can meet these accuracy guidelines when measurement is performed on critically ill patients with fresh whole blood samples. Materials and Methods: We performed a retrospective evaluation of a conventional (Roche Diagnostics [Indianapolis, IN] AccuChek ® Inform) and a newer-generation (Nova Biomedical [Waltham, MA] StatStrip ® ) glucose system by comparing paired (drawn within 5 min of each other) whole blood glucose meter and laboratory serum glucose values obtained from intensive care unit (ICU) patients. We also performed a prospective evaluation of the accuracy of the Nova StatStrip. Results: The median (interquartile range) bias between Roche AccuChek Inform and serum laboratory glucose measurements was 11 (6–18) mg/dL, compared with a median bias between the Nova StatStrip and serum glucose measurements of 1 (−5 to 5) mg/dL. StatStrip met International Organization for Standardization 15197 and Clinical and Laboratory Standards Institute (CLSI) POCT12-A3 accuracy guidelines using both retrospective and prospective datasets. Conclusions: The newer-generation (StatStrip) glucose meter met more stringent CLSI POCT12-A3 accuracy criteria because of reduced bias compared with the previous-generation device. Reduced glucose meter bias led to fewer insulin dosing discrepancies when the insulin dose determined from serum glucose was compared with that determined from the glucose meter value using the institutional glycemic control protocol.