Performance of the Dexcom G6 Continuous Glucose Monitoring System During Cardiac Surgery Using Hypothermic...

Area of Science:

• Medical Devices
• Cardiovascular Surgery
• Endocrinology

Background:

• Continuous glucose monitoring (CGM) systems are vital for diabetes management.
• Extreme physiological conditions, such as those during cardiac surgery with hypothermic extracorporeal circulation (ECC), can impact CGM accuracy.
• The Dexcom G6 sensor's performance in such demanding surgical environments requires thorough evaluation.

Purpose of the Study:

• To assess the accuracy and reliability of the Dexcom G6 continuous glucose monitoring sensor during cardiac surgery involving hypothermic extracorporeal circulation (ECC).
• To compare Dexcom G6 readings with a reference blood glucose meter under these specific surgical conditions.

Main Methods:

• The study involved 16 subjects undergoing cardiac surgery with hypothermic ECC, including 11 with deep hypothermic circulatory arrest (DHCA).
• Dexcom G6 sensor glucose values were compared against arterial blood glucose measurements obtained from an Accu-Chek Inform II meter.
• Statistical analysis included calculating mean absolute relative difference (MARD) and assessing performance against Clarke error grid and ISO 15197:2013 standards.

Main Results:

• Intrasurgery, the mean absolute relative difference (MARD) between Dexcom G6 and reference values was 23.8%.
• Accuracy was reduced during extracorporeal circulation (MARD 29.1%) and immediately after deep hypothermic circulatory arrest (MARD 41.6%), with a notable negative bias.
• While 86.3% of readings fell within acceptable Clarke error grid zones A or B, only 41.0% met the ISO 15197:2013 criteria during surgery. Post-surgery, MARD improved to 15.0%.

Conclusions:

• Cardiac surgery utilizing hypothermic extracorporeal circulation (ECC) presents significant challenges to the accuracy of the Dexcom G6 continuous glucose monitoring sensor.
• Sensor performance appears to be compromised during the intraoperative period, particularly following deep hypothermic circulatory arrest.
• Despite intraoperative limitations, the Dexcom G6 sensor shows potential for recovery and acceptable accuracy in the postsurgical phase.