title: Tracheal tube-tip displacement in children during head-neck movement--a radiological assessment.
abstract: BACKGROUND
  Aims of this study were to assess the maximum displacement of tracheal tube tip during head-neck movement in children, and to evaluate the appropriateness of the intubation depth marks on the Microcuff Paediatric Endotracheal Tube regarding the risk of inadvertent extubation and endobronchial intubation.
  
  
  METHODS
  We studied children, aged from birth to adolescence, undergoing cardiac catheterization. The patients' tracheas were orally intubated and the tracheal tubes positioned with the intubation depth mark at the level of the vocal cords. The tracheal tube tip-to-carina distances were fluoroscopically assessed with the patient supine and the head-neck in 30 degrees flexion, 0 degrees neutral position and 30 degrees extension.
  
  
  RESULTS
  One hundred children aged between 0.02 and 16.4 yr (median 5.1 yr) were studied. Maximum tracheal tube-tip displacement after head-neck 30 degrees extension and 30 degrees flexion demonstrated a linear relationship to age [maximal upward tube movement (mm)=0 0.71 x age (yr)+9.9 (R(2)=0.893); maximal downward tube movement (mm)=0.83 x age (yr)+9.3 (R(2)=0.949)]. Maximal tracheal tube-tip downward displacement because of head-neck flexion was more pronounced than upward displacement because of head-neck extension.
  
  
  CONCLUSIONS
  The intubation depth marks were appropriate to avoid inadvertent tracheal extubation and endobronchial intubation during head-neck movement in all patients. However, during head-neck extension the tracheal tube cuff may become positioned in the subglottic region and should be re-adjusted when the patient remains in this position for a longer time.
authors.affiliation: Department of Anaesthesia, University Children's Hospital Zurich, Steinwiesstrasse 75, CH-8032 Zurich, Switzerland. markus.weiss@kispi.unizh.ch
authors.forename: M
authors.initials: M
authors.lastname: Weiss
authors.forename: W
authors.initials: W
authors.lastname: Knirsch
authors.forename: O
authors.initials: O
authors.lastname: Kretschmar
authors.forename: A
authors.initials: A
authors.lastname: Dullenkopf
authors.forename: M
authors.initials: M
authors.lastname: Tomaske
authors.forename: C
authors.initials: C
authors.lastname: Balmer
authors.forename: K
authors.initials: K
authors.lastname: Stutz
authors.forename: A C
authors.initials: AC
authors.lastname: Gerber
authors.forename: F
authors.initials: F
authors.lastname: Berger
mesh_terms: D000293:Adolescent; D000768:Anesthesia, General; D000886:Anthropometry; D006328:Cardiac Catheterization; D002648:Child; D002675:Child, Preschool; D005260:Female; D005547:Foreign Bodies / Q000209:etiology / Q000517:prevention & control; D019416:Head Movements; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007442:Intubation, Intratracheal / Q000009:adverse effects*; D008297:Male; D009038:Motion; D011859:Radiography; D014132:Trachea / Q000033:anatomy & histology / Q000000981:diagnostic imaging