title: [Endotracheal tube selection in children: which is the better predictor for the selection, tracheal internal diameter in X-ray photograph or age-based formula?].
abstract: BACKGROUND
  Age-based formula has been widely used to predict the appropriate size of the endotracheal tube in children. Tracheal internal diameter in X-ray photograph is reported to show higher correlation with a correct tube than age. In our institution, X-ray photographs were stored as digital images, enabling us to measure tracheal internal diameters more accurately than conventional X-ray films. Therefore, we investigated whether tracheal size in digital X-ray photograph is a better predictor for the tube selection than age.
  
  
  METHODS
  We reviewed data from children aged 1 to 8 years for the past 5 years. The data included age, tracheal internal diameter at 6th cervical (C6), 2nd thoracic vertebrae (T2) in X-ray photograph and selected tube size. The tube size was estimated by the age-based formula or on the basis of tracheal size.
  
  
  RESULTS
  The endotracheal tube size correlated significantly with the age, and tracheal internal diameter at C6 or T2 in X-ray photograph (correlation coefficients P=0.898, 0.653, and 0.771 respectively; P<0.0001). The tube size predicted by the age allowed appropriate intubation in 62.2%, but that by the tracheal size at C6 and T2 in 42.8% and 43.7% respectively.
  
  
  CONCLUSIONS
  The age-based formula is more reliable and appropriate to decide the size of endotracheal tube for children than the tracheal size.
authors.affiliation: Division of Anesthesiology, Yamanashi Prefectural Central Hospital, Kofu.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Furuya
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Nomura
authors.forename: Genya
authors.initials: G
authors.lastname: Kuroiwa
authors.forename: Fumimasa
authors.initials: F
authors.lastname: Tamaki
authors.forename: Satomi
authors.initials: S
authors.lastname: Suzuki
authors.forename: Akihiko
authors.initials: A
authors.lastname: Nonaka
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Abe
authors.forename: Takashi
authors.initials: T
authors.lastname: Matsukawa
mesh_terms: D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D007442:Intubation, Intratracheal / Q000295:instrumentation* / Q000379:methods*; D011237:Predictive Value of Tests; D011856:Radiographic Image Enhancement; D012044:Regression Analysis; D014132:Trachea / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*