The EU funded project CLINICIP (Closed Loop Insulin Infusion for Critically Ill Patients) aims to develop a low-risk monitoring and control device which allows maintaining metabolic control in intensive care units. A system will be developed comprising three subsystems: a body interface for the delivery of biofluids, biosensors for the determination of glucose concentration in these biofluids and an adaptive control algorithm that generates advice and thus represents a decision support system with respect to insulin infusion rate to establish glycaemic control in critically ill patients. Within a closed loop system, intensified insulin treatment will make use of the calculations leading to external regulation of glucose.

It is the aim of this study to evaluate the correlation between arterial blood glucose concentrations and interstitial fluid glucose concentrations in post surgery patients in the Intensive Care Unit (ICU). Interstitial fluid glucose concentrations are based on microdialysis in subcutaneous adipose tissue and calculated using the ionic reference technique.

This trial includes a screening visit (V1) and a monitoring visit (V2) and follow-up assessment. Visit 1 will be performed before performance of surgery to obtain informed consent and to assess patient eligibility. At Visit 2 monitoring visit after surgery) arterial blood glucose values will be monitored and subcutaneous sampling of ISF with microdialysis for glucose determination will be performed. Visit 2 will last from admittance to the ICU for 48 hours. In a follow-up assessment, two weeks after the end of visit 2, further clinical relevant data for the two week period after visit 2 will be collected.

Inclusion Criteria:

• Signed informed consent obtained before any trial-related activities.
• Planned surgery and post-surgery stay in the ICU.
• Study day inclusion criteria: Increased blood glucose levels at admission to the ICU ( > 120 mg/dL; > 6.7 mM)
• Age of patients in the range from 18 to 90 years.

Exclusion Criteria:

• Known or suspected allergy against insulins.
• Mental incapacity, unwillingness or language barriers precluding adequate understanding or co-operation.
• Any disease or condition which the Investigator or the treating physician feels would interfere with the trial or the safety of the patient.

Patients with a blood glucose level of more than 120 mg/dl (6.7mM) at admission to the ICU after surgery