LOGIC-Insulin Algorithm-guided Versus Nurse-directed Blood Glucose Control During Critical Illness

Critical illness typically causes elevated blood glucose concentrations, which have been associated with increased mortality. Strictly normalizing these blood glucose levels by intensive insulin therapy, called tight glycemic control, decreased morbidity and mortality in well-controlled single-center clinical studies. However, multi-center pragmatic trials failed to reproduce those effects, proving that the implementation of tight glycemic control in daily clinical practice is rather difficult.

A computerized algorithm, amongst others, may help the nurses in the titration of insulin to reach normal blood glucose levels and to avoid the particularly worrisome hypoglycemia.

The LOGIC-1 study is a single blinded randomized controlled trial. On admission patients will be randomly assigned to either tight glycemic control (80-110 mg/dL) by the computerized LOGIC-Insulin 3.0 algorithm or to tight glycemic control (80-110 mg/dL) by the nurse-directed protocol. Written informed consent will be asked from the patient in the case of elective surgery requiring post-operative ICU-admission. Proxy informed consent from the closest family member will be asked when the patient was admitted to the ICU in emergency. As blood glucose control by itself is essential in the management of critical illness, random allocation will be done on admission and written informed consent from the closest family member can be deferred to a maximum of 24 hours after randomization. The patient or family member can at all times withdraw from the trial without impact on his treatment. Allocation will be done in blocks (block size is unknown to the care givers responsible for treatment allocation), stratified into cardiac surgery and other reasons for ICU admission, by central computer randomization.

The time window for the study will be 14 days starting from admission to the ICU or when one of the following stop criteria will be met:

• Withdrawal of the informed consent
• Patient starts eating or drinking sugar containing liquids
• Patient is discharged from the ICU (including ICU deaths)
• Removal of arterial line or central venous line

Under the following conditions the study investigator/treating physician will be contacted and, if necessary, patients will be switched from LOGIC-Insulin to nurse-directed blood glucose control:

• Recurrent severe hypoglycemia (<40 mg/dL)
• Refractory hyperglycemia
• Any change in condition that compromises the safety of the patient, as judged by the investigator or treating physician

The common strategy for blood glucose control in both groups involves blood glucose measurements from arterial blood by a blood gas analyzer and the administration of insulin through a central line with a syringe pump.

Inclusion criteria

• Aged 18 years or more
• Admitted to the ICU
• Already receiving or needing insulin infusion for blood glucose control

Exclusion criteria

• Not critically ill (eating, not mechanically ventilated)
• Pregnant or breastfeeding
• Previous inclusion into the trial
• Included in other trial
• Moribund
• Diabetes coma
• No arterial line available