Clinical Use of Continuous Glucose Monitoring in Critically Ill Pediatric Patients with Diabetic Ketoacidosis

BACKGROUND: The use of continuous glucose monitoring (CGM) in pediatric patients with diabetic ketoacidosis (DKA) remains investigational, and data on its accuracy in pediatric intensive care units (PICU) are limited. This study evaluated the accuracy of three CGM devices in pediatric patients with DKA in the PICU. METHODS: We compared 399 matched pairs of CGM and point-of-care capillary glucose (POC) values and grouped patients based on whether they changed their CGM sensor during their PICU stay. RESULTS: Eighteen patients with a mean age of 10.98 ± 4.20 years were included, with three patients in the sensor change group. The overall mean absolute relative difference (MARD) was 13.02%. The Medtronic Guardian Sensor 3 (n = 331), Dexcom G6 (n = 41), and Abbott FreeStyle Libre 1 (n = 27) showed MARD values of 13.40%, 11.12%, and 11.33%, respectively. The surveillance error grid (SEG), Bland–Altman plot, and Pearson's correlation coefficient demonstrated satisfactory clinical accuracy of the CGM devices (SEG zones A and B, 98.5%; mean difference, 15.5 mg/dL; Pearson's correlation coefficient [r(2)], 0.76, P < 0.0001). MARD was significantly lower in subjects who did not experience a sensor change (11.74% vs. 17.31%, P = 0.048). Also, a statistically significant negative correlation was found between serum bicarbonate levels and POC–CGM values (r = −0.34, P < 0.001). CONCLUSIONS: The severity of DKA has a major effect on reducing the accuracy of the CGM, especially during the first several days in the intensive care unit. The reduced accuracy appears to be related to acidosis, as reflected in the serum bicarbonate levels.