title: Effects of pH, lactate, hematocrit and potassium level on the accuracy of continuous glucose monitoring (CGM) in pediatric intensive care unit.
abstract: BACKGROUND
  Continuous glucose monitoring (CGM) originally was developed for diabetic patients and it may be a useful tool for monitoring glucose changes in pediatric intensive care unit (PICU). Its use is, however, limited by the lack of sufficient data on its reliability at insufficient peripheral perfusion. We aimed to correlate the accuracy of CGM with laboratory markers relevant to disturbed tissue perfusion.
  
  
  METHODS
  In 38 pediatric patients (age range, 0-18 years) requiring intensive care we tested the effect of pH, lactate, hematocrit and serum potassium on the difference between CGM and meter glucose measurements. Guardian® (Medtronic®) CGM results were compared to GEM 3000 (Instrumentation laboratory®) and point-of-care measurements. The clinical accuracy of CGM was evaluated by Clarke Error Grid -, Bland-Altman analysis and Pearson's correlation. We used Friedman test for statistical analysis (statistical significance was established as a p < 0.05).
  
  
  RESULTS
  CGM values exhibited a considerable variability without any correlation with the examined laboratory parameters. Clarke, Bland-Altman analysis and Pearson's correlation coefficient demonstrated a good clinical accuracy of CGM (zone A and B = 96%; the mean difference between reference and CGM glucose was 1,3 mg/dL, 48 from the 780 calibration pairs overrunning the 2 standard deviation; Pearson's correlation coefficient: 0.83).
  
  
  CONCLUSIONS
  The accuracy of CGM measurements is independent of laboratory parameters relevant to tissue hypoperfusion. CGM may prove a reliable tool for continuous monitoring of glucose changes in PICUs, not much influenced by tissue perfusion, but still not appropriate for being the base for clinical decisions.
authors.affiliation: First Department of Pediatrics, Semmelweis University, Budapest, Hungary. marics.gabor@gmail.com.
authors.forename: Gábor
authors.initials: G
authors.lastname: Marics
authors.affiliation: Bethesda Children's Hospital, Budapest, Hungary. matyasszajko@gmail.com.
authors.forename: Levente
authors.initials: L
authors.lastname: Koncz
authors.affiliation: First Department of Pediatrics, Semmelweis University, Budapest, Hungary. katalin.eitler@gmail.com.
authors.forename: Katalin
authors.initials: K
authors.lastname: Eitler
authors.affiliation: First Department of Pediatrics, Semmelweis University, Budapest, Hungary. vataibarbara@hotmail.com.
authors.forename: Barbara
authors.initials: B
authors.lastname: Vatai
authors.affiliation: First Department of Pediatrics, Semmelweis University, Budapest, Hungary. bogis.zenasi@gmail.com.|Department of Anaesthesiology and Intensive Therapy, Semmelweis University, Budapest, Hungary. bogis.zenasi@gmail.com.
authors.forename: Boglárka
authors.initials: B
authors.lastname: Szénási
authors.affiliation: First Department of Pediatrics, Semmelweis University, Budapest, Hungary. david.zakarias@yahoo.com.
authors.forename: David
authors.initials: D
authors.lastname: Zakariás
authors.affiliation: Bethesda Children's Hospital, Budapest, Hungary. borbala.mikos@gmail.com.
authors.forename: Borbála
authors.initials: B
authors.lastname: Mikos
authors.affiliation: First Department of Pediatrics, Semmelweis University, Budapest, Hungary. korner.anna@med.semmelweis-univ.hu.
authors.forename: Anna
authors.initials: A
authors.lastname: Körner
authors.affiliation: First Department of Pediatrics, Semmelweis University, Budapest, Hungary. toth-heyn.peter@med.semmelweis-univ.hu.
authors.forename: Péter
authors.initials: P
authors.lastname: Tóth-Heyn
mesh_terms: D000293:Adolescent; D001786:Blood Glucose / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D003422:Critical Care / Q000592:standards; D016638:Critical Illness; D005260:Female; D006400:Hematocrit; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007223:Infant; D015278:Intensive Care Units, Pediatric / Q000592:standards; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D008991:Monitoring, Physiologic / Q000592:standards*; D019095:Point-of-Care Systems / Q000592:standards*; D011188:Potassium / Q000097:blood*; D015203:Reproducibility of Results
chemical_list: D001786:Blood Glucose; D019344:Lactic Acid; D011188:Potassium