title: Accuracy of a novel noninvasive transdermal continuous glucose monitor in critically ill patients.
abstract: Stress hyperglycemia and hypoglycemia are associated with increased morbidity and mortality in the critically ill. Intermittent, random blood glucose (BG) measurements can miss episodes of hyper- and hypoglycemia. The purpose of this study was to determine the accuracy of the Symphony® continuous glucose monitor (CGM) in critically ill cardiac surgery patients. Fifteen adult cardiac surgery patients were evaluated immediately postoperatively in the intensive care unit. Prelude® SkinPrep prepared the skin and a sensor was applied to 2 test sites on each subject to monitor interstitial fluid glucose. Reference BG was sampled at 30- to 60-minute intervals. The skin at the test sites was inspected for adverse effects. Accuracy of the retrospectively analyzed CGM data relative to reference BG values was determined using continuous glucose-error grid analysis (CG-EGA) and mean absolute relative difference (MARD). Using 570 Symphony CGM glucose readings paired with reference BG measurements, CG-EGA showed that 99.6% of the readings were within zones A and B. BG measurements ranged from 73 to 251 mg/dL. The MARD was 12.3%. No adverse device effects were reported. The Symphony CGM system is able to safely, continuously, and noninvasively monitor glucose in the transdermal interstitial fluid of cardiac surgery intensive care unit patients with accuracy similar to that reported with other CGM systems. Future versions of the system will need real-time data analysis, fast warm-up, and less frequent calibrations to be used in the clinical setting.
authors.affiliation: Departments of Surgery/Anesthesiology, Tufts Medical Center and Tufts University School of Medicine, Boston, MA, USA.
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Saur
authors.affiliation: Departments of Surgery/Anesthesiology, Tufts Medical Center and Tufts University School of Medicine, Boston, MA, USA.
authors.forename: Michael R
authors.initials: MR
authors.lastname: England
authors.affiliation: Echo Therapeutics, Inc, Philadelphia, PA, USA.
authors.forename: Wayne
authors.initials: W
authors.lastname: Menzie
authors.affiliation: Departments of Surgery/Anesthesiology, Tufts Medical Center and Tufts University School of Medicine, Boston, MA, USA.
authors.forename: Ann Marie
authors.initials: AM
authors.lastname: Melanson
authors.affiliation: Echo Therapeutics, Inc, Philadelphia, PA, USA.
authors.forename: My-Quyen
authors.initials: MQ
authors.lastname: Trieu
authors.affiliation: Echo Therapeutics, Inc, Philadelphia, PA, USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Berlin
authors.affiliation: Echo Therapeutics, Inc, Philadelphia, PA, USA.
authors.forename: James
authors.initials: J
authors.lastname: Hurley
authors.affiliation: Echo Therapeutics, Inc, Philadelphia, PA, USA.
authors.forename: Keith
authors.initials: K
authors.lastname: Krystyniak
authors.affiliation: The Epsilon Group, Charlottesville, VA, USA.
authors.forename: Gail L
authors.initials: GL
authors.lastname: Kongable
authors.affiliation: Departments of Surgery/Anesthesiology, Tufts Medical Center and Tufts University School of Medicine, Boston, MA, USA Snasraway@tuftsmedicalcenter.org.
authors.forename: Stanley A
authors.initials: SA
authors.lastname: Nasraway
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015374:Biosensing Techniques / Q000295:instrumentation*; D001786:Blood Glucose / Q000032:analysis*; D016638:Critical Illness; D005260:Female; D006801:Humans; D006943:Hyperglycemia / Q000097:blood; D007003:Hypoglycemia / Q000097:blood; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D015203:Reproducibility of Results
chemical_list: D001786:Blood Glucose
keywords: biosensor; continuous glucose; diabetes; intensive care; tight glycemic; transdermal