Accuracy and reliability of continuous blood glucose monitor in post-surgical patients

Background: The STG-22™ is the only continuous blood glucose monitoring system currently available. The aim of this study is to determine the accuracy and reliability of the STG-22™ for continuously monitoring blood glucose level in post-surgical patients. Methods: Fifty patients scheduled for routine surgery were studied in surgical intensive care unit (ICU) of a university hospital. After admission to the ICU, the STG-22™ was connected to the patients. An attending physician obtained blood samples from a radial arterial catheter. Blood glucose level was measured using the ABL™800FLEX immediately after blood collection at 0, 4, 8, and 16 h post-admission to the ICU (total of 200 blood glucose values). Results: The correlation coefficient (R²) was 0.96. In the Clarke error grid, 100% of the paired measurements were in the clinically acceptable zone A and B. The Bland and Altman analysis showed that bias±limits of agreement (percent error) were 0.04(0.7)±0.35(6.3) mmol (mg/dl) (7%), -0.11(-2)±1.22(22) (15%) and -0.33(-6)±1.28(23) (10%) in hypoglycemia (<70(3.89) mmol (mg/dl), normoglycemia (3.89(70)-10(180) mmol (mg/dl), and hyperglycemia (>10(180) mmol (mg/dl), respectively. Conclusions: The STG-22™ can be used for measuring blood glucose level continuously and measurement results are consistent with intermittent measurement (percentage error within 15%). Therefore, the STG-22™ is a useful device for monitoring in blood glucose level in the ICU for 16 h.