Open Access Open Badges Study protocol

Design of a prospective clinical study on the agreement between the Continuous GlucoseMonitor, a novel device for CONTinuous ASSessment of blood GLUcose levels, and the RAPIDLab® 1265 blood gas analyser: The CONTASSGLU study

Johannes B Zimmermann1*, Monika Lehmann2, Stefan Hofer1, Johannes Hüsing2, Catharina Alles1, Jens Werner3, Jürgen Stiller4, Wolfgang Künnecke5, Steffen Luntz2, Johann Motsch1 and Markus A Weigand6

Author affiliations

1 Department of Anaesthesiology, University Hospital Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Germany

2 Coordination Centre for Clinical Trials, Building 4410, Voßstraße 2, 69115, Heidelberg, Germany

3 Department of General-, Visceral-, and Transplantation Surgery, University Hospital Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Germany

4 Mechatronic AG, Wittichstraße 2, 64295, Darmstadt, Germany

5 TRACE Analytics GmbH, Richard-Wagner-Straße 1-2, 38106, Braunschweig, Germany

6 Department of Anaesthesiology and Operative Intensive Care, University Hospital Giessen and Marburg GmbH, Rudolf-Buchheim-Str. 7, 35392, Giessen, Germany

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Citation and License

BMC Anesthesiology 2012, 12:24  doi:10.1186/1471-2253-12-24

Published: 22 September 2012



Although a device is needed to continuously measure blood glucose levels within an intensive care setting, and several large-scale prospective studies have shown that patients might benefit from intensive insulin, potassium, or glucose therapy during intensive care, no devices are currently available to continuously assess blood glucose levels in critically ill patients. We conceived the study described here to evaluate the clinical use of the Continuous Glucose Monitor (CGM) performed via a central vein, and to determine the impact of phenomena, such as drift and shift, on the agreement between the CGM and a RAPIDLab® 1265 blood gas analyser (BGA).


In the CONTinuous ASSessment of blood GLUcose (CONTASSGLU) study, up to 130 patients under intensive care will be fitted with the CGM, an ex vivo device that continuously measures blood glucose and lactate levels. Readings from the device taken 8 h after initial placement and calibration will be compared with values measured by a BGA. For this study, we chose the BGA as it is an established standard point-of-care device, instead of the devices used in certified central laboratories. Nevertheless, we will also independently compare the results from the point-of-care BGA with those determined by a central laboratory-based device. Blood samples will be collected from each patient from the same site in which the CGM will measure blood glucose. Consequently, each participant will serve as their own control, and no randomisation is necessary. The 95% limits of agreement and the corresponding confidence intervals will be calculated and compared with a prespecified clinically acceptable relative difference of 20%.


Several attempts have been made to develop a device to continuously measure blood glucose levels within an intensive care setting or to use the devices that were originally designed for diabetes management, as several of these devices are already available. However, none of these devices were successful in intensive care settings. CONTASSGLU may well bridge this gap by confirming the ability of the CGM to continuously measure blood glucose levels in intensive care settings.

Trial registration NCT01580176

Agreement; Continuous; Monitor* (monitor~s~ing); Blood glucose [MeSH]; Lactate [MeSH]; Insulin [MeSH]; Potassium [MeSH]; Perioperative care [MeSH]; Critical care [MeSH]; Intensive care