Randomised study to the efficacy and safety of Continuous Glucose Monitoring by subcutaneous measurement compared to frequent point of care measurement by Accu-Chek in critically ill patients (RESCUE)

The Van den Berghe-studies in 2001 and 2006 showed an improved outcome for
critically ill patients with strict glucose regulation. However, in a recent
meta-analysis, benefit of strict glucose regulation was not found. Moreover,
strict glycaemic control increases the risk of hypoglycaemia (NICE-SUGAR
trial). Another study found that intensive glucose control increased mortality
among adults in the Intensive Care Unit. This could be caused by hypoglycaemia.
These days it is common to use a higher blood glucose target in critically ill
adults.
The ICU of the Onze Lieve Vrouwe Gasthuis implemented a computerized guideline
for glucose regulation of critically ill patients. The guideline recommends the
timing between glucose measurements and the administration of insulin doses.
The recommended interval varies between 15 minutes and six hours, depending on
stability of arterial blood glucose concentration. Arterial blood samples are
analyzed by AccuChek . The AccuChek uses the enzyme glucose dehydrogenase and
an amperometric end-point to measure glucose. The AccuChek-Inform has been
tested in critically ill patients before. A mean number of 10 bloodsamples are
taken per patient per day.

Continuous Glucose Monitoring Systems (CGMS) may have the potential for strict
regulation without the dangers of hypoglycemia. The continuous feedback may
lead to the prevention of variation and swings in glucose levels and may reduce
the risk of hypoglycaemia compared to an interval point-of-care glucose meter.
Moreover, the use of CGMS may decrease workload for the nurses, since less
glucose measurements have to be performed. In addition, CGMS will reduce the
frequency and quantity of blood loss, because the only need for a blood sample
is to calibrate the system. Other advantages may be:
- cost reduction
- better knowledge of glucose levels in critically ill patients
- early detection of hypglycemia

To compare the efficiency and safety of Continuous subcutaneous glucose
monitoring compared to our standard care (bloodsamples obtained from an
arterial or venous bloodsample and measured by the AccuChek.

Randomised open label study.

The risk for paticipants is judged to be minor. The insertion and wearing of
the sensors is minimally invasive. The Freestyle Navigator is a miniature
electrochemical sensor placed in the subcutaneous adipose tissue.

In total a maximum of 20 arterial or venous bloodsamles of 1.5 ml will be
obtained besides standard care samples. The bloodsamples will be obtained from
an intra arterial or intravenous catheter. Insertion of these catheters are
standard care on the ICU.The arterial line is routinely in situ for routine
blood sampling and continuous monitoring of blood pressure.

Continiuous glucose montinoring on the ICU has several advantages compared to
point-of-care glucose measurement. The first is early detection of
hypoglycaemia. The Freestyle Navigatior CGM system is equipped with an alarm
function to indicate hyper- and hypoglycemia.

The second advantage is a limitation of blood loss by sampling. In patients
receiving intensive insulin therapy, frequent determination of blood glucose is
needed. The point-of-care measurement needs blood to be drawn for every glucose
determination. (1.5 ml). Continuous glucosemonitoring with the Freestyle
Navigator does not require additional bloodsamples, only when the glucose level
is under or above the target range, or to calibrate the system. (which is at a
maximum of twice daily)