Continuous GlucoseMonitor for Measurement of Blood Glucose Level (ContAssGlu)

• Eight hours measurement after initial referencing [ Time Frame: eight hours after initial referencing ] [ Designated as safety issue: Yes ]
  Agreement at point of care, i.e. agreement between the readings from the Continuous GlucoseMonitor taken eight hours after initial referencing and the measurement results from the RAPIDLab® 1265 blood gas analyser taken at the same time
  
  

• one and two (short) and three to eight (mid) deterioration [ Time Frame: one, two, three, four, five, six, seven and eight hours ] [ Designated as safety issue: Yes ]
  Short (one and two hour) and mid term (three to eight hour) deterioration in agreement, i.e. agreement between the readings from the Continuous GlucoseMonitor taken one and two and three, four, five, six, seven as well as eight hours after initial referencing and the measurement results from the RAPIDLab® 1265 blood gas analyser taken at the same time
  
  

The current standard for measuring blood glucose concentrations on ICU is to manually draw a blood sample from an arterial catheter and analyse the sample using a point of care blood gas analyser. This technique has several disadvantages as causes considerable blood loss and does not produce a continuous blood glucose profile and it is labour intensive (multiple samples over time are needed to follow the changes in blood glucose concentration). The monitoring system (Continuous GlucoseMonitor) based on the microdialysis technique has the advantage that not blood, but a physiological fluid such as saline is used as test medium. In brief, a physiological fluid, called the perfusate is continuously perfused through the microdialysis probe. At the membrane of the probe, glucose (as other low-molecular weight molecules) diffuses from the surrounding sample into the perfusate, now called dialysate, and is transported outside the probe for ex vivo monitoring.