title: Bedside ultrasound is a practical and reliable measurement tool for assessing quadriceps muscle layer thickness.
abstract: BACKGROUND
  Critically ill patients commonly experience skeletal muscle wasting that may predict clinical outcome. Ultrasound is a noninvasive method that can measure muscle quadriceps muscle layer thickness (QMLT) and subsequently lean body mass (LBM) at the bedside. However, currently the reliability of these measurements are unknown. The objectives of this study were to evaluate the intra- and interreliability of measuring QMLT using bedside ultrasound.
  
  
  METHODS
  Ultrasound measurements of QMLT were conducted at 7 centers on healthy volunteers. Trainers were instructed to perform measurements twice on each patient, and then a second trainee repeated the measurement. Intrarater reliability measured how consistently the same person measured the subject according to intraclass correlation (ICC). Interrater reliability measured how consistently trainer and trainee agreed when measuring the same subject according to the ICC.
  
  
  RESULTS
  We collected 42 pairs of within operator measurements with an ICC of .98 and 78 pairs of trainer-to-trainee measurements with an ICC of .95. There were no statistically significant differences between the trainer and trainee results (trainer and trainee mean = -0.028 cm, 95% CI = -0.067 to -0.011, P = .1607).
  
  
  CONCLUSIONS
  Excellent intra- and interrater reliability for ultrasound measurements of QMLT in healthy volunteers was observed when performed by a range of providers with no prior ultrasound experience, including dietitians, nurses, physicians, and research assistants. This technique shows promise as a method to evaluate LBM status in ICU or hospital settings and as a method to assess the effects of nutrition and exercise-based interventions on muscle wasting.
authors: Brigham and Women's Hospital, Boston, MA, USA.
authors: Maggie
authors: M
authors: Tillquist
authors: University of Alberta, Edmonton, AB, Canada.
authors: Demetrios J
authors: DJ
authors: Kutsogiannis
authors: University of Colorado School of Medicine, Aurora, CO, USA.
authors: Paul E
authors: PE
authors: Wischmeyer
authors: University Hospital, University of Strasbourg, Strasbourg, France.
authors: Christine
authors: C
authors: Kummerlen
authors: Kingston General Hospital, Kingston, ON, Canada.
authors: Roger
authors: R
authors: Leung
authors: University of Alberta, Edmonton, AB, Canada.
authors: Daniel
authors: D
authors: Stollery
authors: University of Alberta, Edmonton, AB, Canada.
authors: Constantine J
authors: CJ
authors: Karvellas
authors: Erasme University Hospital, Brussels, Belgium.
authors: Jean-Charles
authors: JC
authors: Preiser
authors: UT Health Science Center of Houston, Houston, TX, USA.
authors: Nora
authors: N
authors: Bird
authors: UT Health Science Center of Houston, Houston, TX, USA.
authors: Rosemary
authors: R
authors: Kozar
authors: Kingston General Hospital, Kingston, ON, Canada dkh2@queensu.ca.
authors: Daren K
authors: DK
authors: Heyland
mesh_terms: D000328:Adult; D001823:Body Composition; D001825:Body Fluid Compartments; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D052097:Quadriceps Muscle / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D014463:Ultrasonography; D055815:Young Adult
keywords: critical care; muscle layer thickness; muscle wasting; ultrasound
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