title: An Analysis of Reliability and Accuracy of Muscle Thickness Ultrasonography in Critically Ill Children and Adults.
abstract: Muscle wasting starts already within the first week in critically patients and is strongly related to poor outcome. Nevertheless, the early detection of muscle wasting is difficult. Therefore, we investigated the reliability and accuracy of ultrasonography to evaluate skeletal muscle wasting in critically ill children and adults.
  
  
  
  This prospective observational study enrolled 30 sedated critically ill children and 14 critically ill adults. Two independent investigators made 210 ultrasonographical assessments of muscle thigh thickness. Inter- and intraobserver reliability and cutoff levels were calculated as a function of muscle thickness and the expected reduction in muscle size (predefined at 20% and 30%).
  
  
  
  Mean ± SD muscle thickness was 1.67 ± 0.55 cm in the pediatric and 2.10 ± 0.85 cm in the adult population. The median absolute interobserver variability was 0.07 cm (interquartile range [IQR], 0.04-0.20 cm) in the pediatric population and 0.05 cm (IQR, 0.03-0.09 cm) in the adult population. However, the absolute intraobserver accuracy had a 95% confidence interval of 0.43 cm in children and 0.22 cm in adults. Only a 30% decrease (0.50 cm) in muscle thickness can be detected in critically ill children.
  
  
  
  Although the interobserver variability is acceptable in the pediatric population, the intraobserver variability is too large with respect to the expected reduction in muscle thickness. In adults, ultrasonography may be a reliable tool for early detection of muscle mass wasting.
authors.affiliation: Department of Intensive Care Medicine, U Leuven-University of Leuven, University Hospitals Leuven, Leuven, Belgium.
authors.forename: Tom
authors.initials: T
authors.lastname: Fivez
authors.affiliation: Department of Intensive Care Medicine, U Leuven-University of Leuven, University Hospitals Leuven, Leuven, Belgium.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Hendrickx
authors.affiliation: Department of Intensive Care Medicine, U Leuven-University of Leuven, University Hospitals Leuven, Leuven, Belgium Department of Electrical Engineering-ESAT-SCD/iMINDS Medical Information Technologies, KU Leuven-University of Leuven, Leuven, Belgium.
authors.forename: Tom
authors.initials: T
authors.lastname: Van Herpe
authors.affiliation: Department of Intensive Care Medicine, U Leuven-University of Leuven, University Hospitals Leuven, Leuven, Belgium.
authors.forename: Dirk
authors.initials: D
authors.lastname: Vlasselaers
authors.affiliation: Department of Intensive Care Medicine, U Leuven-University of Leuven, University Hospitals Leuven, Leuven, Belgium.
authors.forename: Lars
authors.initials: L
authors.lastname: Desmet
authors.affiliation: Department of Intensive Care Medicine, U Leuven-University of Leuven, University Hospitals Leuven, Leuven, Belgium.
authors.forename: Greet
authors.initials: G
authors.lastname: Van den Berghe
authors.affiliation: Department of Intensive Care Medicine, U Leuven-University of Leuven, University Hospitals Leuven, Leuven, Belgium dieter.mesotten@med.kuleuven.be.
authors.forename: Dieter
authors.initials: D
authors.lastname: Mesotten
mesh_terms: D000368:Aged; D002648:Child; D002675:Child, Preschool; D016638:Critical Illness; D006801:Humans; D007223:Infant; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging*; D009133:Muscular Atrophy / Q000000981:diagnostic imaging*; D015588:Observer Variation; D011446:Prospective Studies; D015203:Reproducibility of Results; D014463:Ultrasonography
keywords: child; critical illness; skeletal muscle; ultrasonography; wasting syndrome