Continuous glucose monitors prove highly accurate in critically ill children

Introduction: Hyperglycemia is associated with increased morbidity and mortality in critically ill patients and strict glycemic control has become standard care for adults. Recent studies have questioned the optimal targets for such management and reported increased rates of iatrogenic hypoglycemia in both critically ill children and adults. The ability to provide accurate, real-time continuous glucose monitoring would improve the efficacy and safety of this practice in critically ill patients. The aim of our study is to determine if a continuous, interstitial glucose monitor will correlate with blood glucose values in critically ill children. Methods: We evaluated 50 critically ill children age 6 weeks to 16 years old with a commercially available continuous glucose monitor (CGM; Medtronic Guardian(R)). CGM values and standard blood glucose (BG) values were compared. During the study, no changes in patient management were made based on CGM readings alone. Results: Forty-seven patients had analyzable CGM data. A total of 1,555 CGM and routine BG measurements were compared using Clarke error grid and Bland-Altman analysis. For all readings, 97.9% were within clinically acceptable agreement. The mean absolute relative difference between CGM and BG readings was 15.3%. For the 1,555 paired CGM and BG measurements, there is a statistically significant linear relationship between CGM values and BG (P<.0001). A high degree of clinical agreement existed in three subpopulation analyses based on age, illness severity, and support measures. This included some of our smallest patients (that is, <12 months old), those who required vasopressors, and those who were treated for critical illness hyperglycemia. Conclusions: In one of the largest studies to date, in a highly vulnerable ICU population, CGM values have a clinically acceptable correlation with the BG values now used diagnostically and therapeutically. Our data contest the theoretical concerns posed by some regarding CGM use in the ICU. The existing medical evidence may now support a role for CGM devices in the identification and management of hyperglycemia in diverse ICU settings.