Perioperative Fully Closed-loop versus Usual Care Glucose Management in Adults Undergoing Major Abdominal Surgery – A Two-centre Randomised Controlled Trial

Objective: To assess the efficacy and safety of fully closed-loop (FCL) compared with usual care (UC) glucose control in patients experiencing major abdominal surgery-related stress hyperglycaemia. Summary Background Data: Major abdominal surgery-related stress and periprocedural interventions predispose to perioperative hyperglycaemia, both in diabetes and non-diabetes patients. Insulin corrects hyperglycaemia effectively, but its safe use remains challenging. Methods: In this two-centre randomised controlled trial, we contrasted subcutaneous FCL with UC glucose management in patients undergoing major abdominal surgery anticipated to experience prolonged hyperglycaemia. FCL (CamAPS HX, Dexcom G6, mylife YpsoPump 1.5x) or UC treatment was used from hospital admission to discharge (max 20 d). Glucose control was assessed using continuous glucose monitoring (masked in the UC group). The primary outcome was the proportion of time with sensor glucose values in target range 5.6-10.0 mmol/L. Results: Thirty-seven surgical patients (54% pancreas, 22% liver, 19% upper gastrointestinal, 5% lower gastrointestinal), of whom 18 received FCL and 19 UC glucose management, were included in the analysis. Mean±SD percentage time with sensor glucose in target range was 80.1±10.0% in the FCL and 53.7±19.7% in the UC group ( P <0.001). Mean±SD glucose was 7.5±0.5 mmol/L in the FCL and 9.1±2.4 mmol/L in the UC group ( P =0.015). Time in hypoglycaemia (<3.0 mmol/L) was low in either group. No study-related serious adverse events occurred. Conclusions: The FCL approach resulted in significantly better glycaemic control compared to UC management, without increasing the risk of hypoglycaemia. Automated glucose-responsive insulin delivery is a safe and effective strategy to minimise hyperglycaemia in complex surgical populations.