title: Optimal depth of insertion of left-sided double-lumen endobronchial tubes cannot be predicted from body height in below average-sized adult patients.
abstract: OBJECTIVE
  The optimal depth of insertion of left-sided double-lumen endobronchial tubes is strongly correlated with body height in average-sized adults. However, this relationship has not been studied in below average-sized adult patients. We investigated whether or not there is a clinically useful relationship in below average-sized adult patients.
  
  
  METHODS
  One hundred and ninety six consecutive adult patients undergoing thoracic surgery under one-lung anaesthesia (body height < or = 155 cm) were included in this study. Left-sided double-lumen tubes were inserted under the guidance of a fibre-optic bronchoscope. Optimal depth was defined as the proximal surface of the bronchial cuff positioned just below the carina.
  
  
  RESULTS
  There was a statistically significant positive correlation between body height and the optimal depth of insertion (r = 0.61, P < 0.0001); however, the correlation coefficient was low. The actual optimal depth of insertion of one patient was even 4.5 cm shorter than that obtained from the equation.
  
  
  CONCLUSIONS
  Although there was a statistically significant correlation between body height and the optimal depth of insertion of left sided double lumen tubes in adult patients of short stature (< or = 155 cm), clinical application of the equation is not warranted and these tubes should be inserted under direct vision with a fibre-optic bronchoscope.
authors.affiliation: Fukuoka University School of Medicine, Department of Anesthesiology, Japan. hh037555@fukuoka-u.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Yasumoto
authors.forename: K
authors.initials: K
authors.lastname: Higa
authors.forename: K
authors.initials: K
authors.lastname: Nitahara
authors.forename: S
authors.initials: S
authors.lastname: Shono
authors.forename: T
authors.initials: T
authors.lastname: Hamada
mesh_terms: D000368:Aged; D000768:Anesthesia, General; D001827:Body Height / Q000502:physiology*; D001980:Bronchi / Q000033:anatomy & histology* / Q000502:physiology; D001999:Bronchoscopy; D005260:Female; D006801:Humans; D007442:Intubation, Intratracheal / Q000379:methods*; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D011237:Predictive Value of Tests