Accuracy of Continuous Glucose Monitoring in Patients With Diabetes. A Prospective Observational Study

Validation of the Accuracy of Continuous Glucose Monitoring Using the Dexcom G7 in Patients With Diabetes in Situations With Circulatory Impairment. A Prospective Observational Study

The goal of this observational study is to investigate the accuracy of the continuous glucose monitoring (CGM) compared to standard point-of-care (POC) blood glucose measurements in patients with diabetes in patients who during their hospital admission can experience circulatory impairment.

The main questions it aims to answer are:

• Do CGM measurements have a decreased accuracy compared to standard blood glucose measurements in periods with circulatory impairment?

Participants will be asked to wear a blinded CGM device (Dexcom G7, Dexcom Inc.) during their stay in the hospital but will receive standard care of their diabetes. The CGM device will be worn for up to 10 days.

This is a prospective observational study on patients living with diabetes who a) undergo surgery at the Department of Vascular Surgery, Rigshospitalet, Denmark and the Surgical Department and Department of Orthopedic Surgery and Traumatology, Bispebjerg and Frederiksberg Hospital, Denmark, or b) are admitted to the intensive care unit (ICU) at Bispebjerg and Frederiksberg Hospital with circulatory impairment.

The study aim is to investigate the accuracy of the Dexcom G7 CGM in patients with diabetes undergoing surgery and in patients at the ICU with circulatory impairment. The glucose readings will be compared to standard practice with POC blood glucose measurements.

Included patients will be asked to wear the CGM device Dexcom G7 for up 10 days.

The study will include 60 patients

This study is part of an overall project that aims to investigate the use of CGM and continuous wireless monitoring of vital signs in patients with diabetes undergoing major surgery. Using this technology, postoperative complications including dysglycaemia can potentially be detected and treated earlier thus improving the perioperative care.

Inclusion Criteria:

• Medical history with diabetes mellitus requiring antidiabetic drugs
• Age ≥18 years
• Surgery with estimated surgery time ≥45 minutes with expected stay for at least one night in hospital postoperatively OR
• Admission to the ICU with Circulatory impairment defined as need of vasopressors to maintain a mean arterial pressure (MAP) ≥65 mmHg and peripheral perfusion index <1.5

Exclusion Criteria:

• Local skin symptoms including infection at the posterior aspect of the upper arm that does not allow the sensor to be placed on an unaffected skin area
• Contraindications to skin puncture (arteriovenous fistula for dialysis, post-mastectomy lymphoedema etc)
• Known allergy to plaster used in the CGM device