Accuracy of continuous glucose monitoring during noncardiac surgery: a prospective, blinded observational multicentre cohort study
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Background
Hyperglycaemia after noncardiac surgery is rarely detected outside of the critical care environment, yet occurs commonly and is associated with excess complications including infections and myocardial injury. Systematic, prospectively collected data regarding the accuracy of continuous glucose monitoring commenced immediately before surgery and throughout the early perioperative period are lacking.
Methods
We prospectively enrolled patients aged >50 yr undergoing noncardiac surgery who required at least 24 h of hospital stay. We used real-time continuous glucose monitoring (Dexcom G7 sensor, placed in the upper outer arm) (Dexcom, San Diego, CA, USA) with reference values from arterial blood glucose measurements by amperometry. The primary outcome was the overall mean difference (bias) before surgery, at end of surgery, and 24 h after surgery (Bland–Altman analysis). Secondary outcomes included the mean absolute relative difference and surveillance error grid analyses.
Results
We compared paired blood (73% arterial) and continuous glucose monitoring glucose values at each prespecified timepoint in 118 participants (64/118 [54%] female; mean age: 66 [range: 51–89] yr; 25% with diabetes mellitus). The overall bias between continuous glucose monitoring and blood glucose from measurements at each of the three timepoints in the first 24 h after induction of anaesthesia was 0.38 mM (95% confidence interval [95% CI]: 0.23–0.53; n=340 paired readings). Bias decreased 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). Mean absolute relative difference ranged from 12.0% to 18.3%. Error grid analyses found that >98% continuous glucose monitoring values were within acceptable risk ranges.
Conclusions
The accuracy of state-of-the-art continuous glucose monitoring is sufficient for perioperative use and could enhance perioperative surveillance of dysglycaemia.
Clinical trial registration
ISRCTN46862025.
Hyperglycaemia after noncardiac surgery is rarely detected outside of the critical care environment, yet occurs commonly and is associated with excess complications including infections and myocardial injury. Systematic, prospectively collected data regarding the accuracy of continuous glucose monitoring commenced immediately before surgery and throughout the early perioperative period are lacking.
Methods
We prospectively enrolled patients aged >50 yr undergoing noncardiac surgery who required at least 24 h of hospital stay. We used real-time continuous glucose monitoring (Dexcom G7 sensor, placed in the upper outer arm) (Dexcom, San Diego, CA, USA) with reference values from arterial blood glucose measurements by amperometry. The primary outcome was the overall mean difference (bias) before surgery, at end of surgery, and 24 h after surgery (Bland–Altman analysis). Secondary outcomes included the mean absolute relative difference and surveillance error grid analyses.
Results
We compared paired blood (73% arterial) and continuous glucose monitoring glucose values at each prespecified timepoint in 118 participants (64/118 [54%] female; mean age: 66 [range: 51–89] yr; 25% with diabetes mellitus). The overall bias between continuous glucose monitoring and blood glucose from measurements at each of the three timepoints in the first 24 h after induction of anaesthesia was 0.38 mM (95% confidence interval [95% CI]: 0.23–0.53; n=340 paired readings). Bias decreased 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). Mean absolute relative difference ranged from 12.0% to 18.3%. Error grid analyses found that >98% continuous glucose monitoring values were within acceptable risk ranges.
Conclusions
The accuracy of state-of-the-art continuous glucose monitoring is sufficient for perioperative use and could enhance perioperative surveillance of dysglycaemia.
Clinical trial registration
ISRCTN46862025.
Date Issued
2025-10-01
Date Acceptance
2025-05-28
Citation
British Journal of Anaesthesia, 2025, 135 (4), pp.912-919
ISSN
0007-0912
Publisher
Elsevier
Start Page
912
End Page
919
Journal / Book Title
British Journal of Anaesthesia
Volume
135
Issue
4
Copyright Statement
© 2025 The Author(s). Published by Elsevier Ltd on behalf of British Journal of Anaesthesia. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).
License URL
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/40707283
PII: S0007-0912(25)00410-6
Subjects
Anesthesiology
complications
glucose monitoring
hyperglycaemia
HYPERGLYCEMIA
Life Sciences & Biomedicine
noncardiac surgery
perioperative care
Science & Technology
Publication Status
Published
Coverage Spatial
England
Date Publish Online
2025-07-24