A recent study published in British Journal of Anaesthesia highlighted the role of glucose monitoring in improving perioperative surveillance of dysglycaemia. Outside of the critical care environment, hyperglycemia after noncardiac surgery is rare.

The study aimed to determine the accuracy of glucose monitoring during noncardiac surgery.
At each prespecified time point in 118 participants (64/118 [54%] female; mean age: 66 [range: 51–89] yr; 25% with diabetes mellitus), comparison of paired blood (73% arterial) and continuous glucose monitoring glucose values was done. Patients undergoing noncardiac surgery who required at least 24 hours of hospital stay were prospectively enrolled. With reference values from arterial blood glucose measurements by amperometry, the real-time continuous glucose monitoring (Dexcom G7 sensor, placed in the upper outer arm) (Dexcom, San Diego, CA, USA) was determined. Overall mean difference between (bias) before surgery, 24 h after surgery (Bland–Altman analysis), and at the end of surgery was determined as the primary outcome. Mean absolute relative difference and surveillance error grid analyses were the secondary outcomes.

In the first 24 h after induction of anesthesia, the value was 0.38 mM (95% confidence interval [95% CI]: 0.23–0.53; n=340 paired readings), and the overall bias between continuous glucose monitoring and blood glucose from measurements at each of the three timepoints was found. From before the start of surgery (1.08 mM [95% CI: 0.87–1.29]; n=116) to 0.15 mM at the end of surgery (95% CI: −0.15 to 0.46; n=113), the bias decreased. From 12.0% to 18.3% the mean absolute relative difference ranged. More than 98% of continuous glucose monitoring values were within acceptable risk ranges, as demonstrated by error grid analyses.