Manual versus Automated moNitoring Accuracy of GlucosE II (MANAGE II)

Abstract

BackgroundIntravascular continuous glucose monitoring (CGM) may facilitate glycemic control in the intensive care unit (ICU). We compared the accuracy of a CGM device (OptiScanner®) with a standard reference method.MethodsAdult patients who had blood glucose (BG) levels >150 mg/dl and required insertion of an arterial and central venous catheter were included. The OptiScanner® was inserted into a multiple-lumen central venous catheter. Patients were treated using a dynamic-scale insulin algorithm to achieve BG values between 80 and 150 mg/dl. The BG values measured by the OptiScanner® were plotted against BG values measured using a reference analyzer. The correlation between the BG values measured using the two methods and the clinical relevance of any differences were assessed using the coefficient of determination (r 2) and the Clarke error grid, respectively; bias was assessed by the mean absolute relative difference (MARD). Three different standards of glucose monitoring were used to assess accuracy. Glycemic control was assessed using the time in range (TIR). Six indices of glycemic variability were calculated.ResultsThe analysis included 929 paired samples from 88 patients, monitored for a total of 2584 hours. Reference BG values ranged between 60 and 484 mg/dl. The r 2 value was 0.89. The percentage of BG values within zones A and B of the Clarke error grid was 99.9%; the MARD was 7.7%. Using the ISO 15197 standard and Food and Drug Administration and consensus standards, respectively, 80.4% of measurements were within 15 mg/dl and 88.2% within 15% of reference values, 40% of measurements were within 7 mg/dl and 72.5% within 10% of reference values, and 65.2% of measurements were within 10 mg/dl and 82.7% within 12.5% of reference values. The TIR was slightly lower with the OptiScanner® than with the reference method. The J-index, standard deviation and maximal glucose change were the indices of glycemic variability least affected by the measurement device.ConclusionsBased on the MARD, the performance of the OptiScanner® is adequate for use in ICU patients. Because recent standards for accuracy were not met, the OptiScanner® should not be used as a sole monitor. The assessment of glycemic variability is influenced by the time interval between BG determinations.Trial registrationClinicaltrials.gov NCT01720381. Registered 31 October 2012.

Continuous glucose monitoring in the ICU: clinical considerations and consensus

“…Yet, despite more than $700 million spent by the industry on developing CGM devices, they remain largely experimental in the ICU and although several have FDA approval for use in noncritically ill patients, the only device that received FDA approval for critically ill patients is not marketed and is not in clinical use. Only one device is currently in clinical use in Europe [ 53 ].…”

“…Many of the devices reported in peer-reviewed literature (using different probe location sites and measurement techniques) fail to meet the mean absolute relative difference (MARD) point accuracy standard adopted by a previous consensus panel [ 54 ]. One exception is the Optiscanner® (OptiScan Biomedical Corporation, Hayward, CA, USA), which has been reported to have MARD < 10% [ 53 , 55 ], although other consensus requirements for CGM devices were not met or not reported. Importantly, comparisons, including MARD and Clark error grids, are based on evaluation of differences in values at a single time point, and do not take the trend factor into account.…”

Glycemic Effects of a Low‐Carbohydrate Enteral Formula Compared With an Enteral Formula of Standard Composition in Critically Ill Patients: An Open‐Label Randomized Controlled Clinical Trial

“…Moreover, in our study, we used continuous instead of intermittent glucose measurements. Glycemic metrics are differently affected by measurement frequency, although it seems that there is a good correlation between both continuous and intermittent measurements in terms of variability indices …”

Accuracy of Blood Glucose Measurement and Blood Glucose Targets

“…51 Several BGM "systems" exist, from nurse-driven insulin administration based on intermittent measurements to fully autonomous computer-controlled looped systems, fed by near-continuous measurements. [52][53][54][55][56] In the original Leuven studies, an intuitive paper-based algorithm was used by the ICU nurses. This was later converted into a computer-based algorithm to calculate the most optimal insulin or glucose dose to achieve normoglycemia.…”