The prevalence of diabetes and hyperglycaemia in surgical patients is rising and associated with grater complication rates, length of stay and mortality rates. Suboptimal glucose management in the perioperative setting remains a major barrier to optimal surgical care. While there are guidelines to manage perioperative diabetes care, implementation is challenging and inconsistent, in part due to a stretched workforce, involvement of several disciplines and clinical teams and shortcomings in clinical training and knowledge. Closed-loop glucose control represents an emerging diabetes treatment modality that autonomously adjusts insulin delivery according to continuously measured glucose levels. The use of fully automated closed-loop insulin delivery may represent an easy-to-adopt approach for safe and effective perioperative diabetes management.

Inclusion Criteria:

• Written informed consent
• The subject is aged 18 years or over
• Diagnosis of type 2 diabetes using standard diagnostic practice (37)
• The subject is planned for an elective abdominal, thoracic or cardiovascular surgery at the University Hospital Bern expected to last ≥2 hours
• The subject requires treatment with subcutaneous insulin as part of the perioperative glucose management
• The subject is literate in German
• The subject is willing to wear study devices 24/7

Exclusion Criteria:

• Physical or psychological condition likely to interfere with the normal conduct of the study and interpretation of the study results as judged by the investigator
• Known or suspected allergy to insulin
• Type 1 diabetes
• Pregnancy, planned pregnancy, or breast feeding
• Medically documented allergy towards the adhesive (glue) of plasters or unable tolerate tape adhesive in the area of sensor placement
• Lack of safe contraception for female participants of childbearing potential for the entire study duration (medically reliable method of contraception are considered oral, injectable, or implantable contraceptives, intrauterine contraceptive devices, or any other methods judged as sufficiently reliable by the investigator in individual cases).
• Serious skin diseases located at places of the body, which potentially are possible to be used for localisation of the glucose sensor
• Illicit drug abuse or prescription drug abuse
• Incapacity to give informed consent
• Droplet/airborne isolation precautions
• Participation in another clinical trial that interferes with the interpretation of the study results