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Perioperative fully closed-loop insulin delivery in patients undergoing elective surgery: an open-label, randomised controlled trial

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posted on 26.07.2022, 00:10 authored by David Herzig, Simon Suhner, Jonathan Roos, Daniel Schürch, Luca Cecchini, Christos T Nakas, Salome Weiss, Alexander Kadner, Gregor J Kocher, Dominik P Guensch, Malgorzata E Wilinska, Andreas Raabe, Klaus A Siebenrock, Guido Beldi, Beat Gloor, Roman Hovorka, Andreas P Vogt, Lia Bally


Introduction: Perioperative management of glucose levels remains challenging. We aimed to assess whether fully closed-loop subcutaneous insulin delivery would improve glycaemic control compared with standard insulin therapy in insulin-requiring patients undergoing elective surgery.

Research Design and Methods: We did a single-centre, open-label, randomised controlled trial. Patients with diabetes (other than type 1) undergoing elective surgery were recruited from different surgery units and randomized using a minimisation schedule (stratified by HbA1c and daily insulin dose) to fully closed-loop insulin delivery with faster-acting insulin aspart (closed-loop group) or standard insulin therapy according to local clinical practice (control group). Study treatment was administered from hospital admission to discharge (for a maximum of 20 days). The primary endpoint was the proportion of time with sensor glucose in the target range (5.6-10.0 mmol/L).

Results: Forty-five patients were enrolled and assigned to the closed-loop (n=23) or the control group (n=22). One patient (closed-loop group) withdrew from the study before surgery and was not analysed. Participants underwent abdominal (57%), vascular (23%), orthopaedic (9%), neuro- (9%) or thoracic (2%) surgery. The mean proportion of time that sensor glucose was in the target range was 76.7±10.1% in the closed-loop and 54.7±20.8% in the control group (mean difference 22.0 percentage points [95% CI: 11.9-32.0%; p<0.001]). No episodes of severe hypoglycaemia (<3.0 mmol/L) or hyperglycaemia with ketonaemia nor any study-related adverse events occurred in either group.

Conclusion: In the context of mixed elective surgery, the use of fully closed-loop subcutaneous insulin delivery improves glucose control, without a higher risk of hypoglycaemia.


The study was funded by the Swiss Helmut Horten Foundation and the Swiss Foundation of Anaesthesiology and Intensive Care. Dexcom provided product support (CGM equipment). Company representatives had no role in study design, data collection, data analysis, data interpretation, or writing of the report.