title: Selection of an appropriate left-sided double-lumen tube size for one-lung ventilation among Asians.
abstract: BACKGROUND
  Selecting an appropriate size double-lumen tube (DLT) for one-lung ventilation has always been a challenge as most choose it based on experience or using the existing guidelines based on gender and height.
  
  
  OBJECTIVE
  The aim of this study was to determine if the appropriate choice of this tube could be based on the patients' height, weight, tracheal diameter (TD), or the left main stem bronchus diameter (LMBD) and also to determine the relationship between height and depth of insertion among Asians.
  
  
  METHODS
  This was a retrospective review of 179 patients who were intubated with a left-sided DLT and also had a posterior-anterior view of a digital chest radiograph for tracheal and left main bronchus diameter measurements. Additional data collected included patients' demographics and DLT size used.
  
  
  RESULTS
  There were 123 (68.7%) males and 56 (31.3%) females with an overall mean age of 33.3 ± 16.3 years. Majority of the males (48.8%) used a size 39 Fr while females (46.4%) used a 35 Fr. There were weak correlations between DLT size with height (male: R2 = 0.222; female: R2 = 0.193), DLT size with weight (male: R2 = 0.109; female: R2 = 0.211), DLT size with TD (male: R2 = 0.027); female: R2 = 0.016), and DLT size with LMBD (male: R2 = 0.222; female: R2 = 0.193). There was a good correlation between depth of DLT inserted with patient's height for both genders.
  
  
  CONCLUSIONS
  The appropriate size of the left-sided DLT could not be predicted based on patients' height, weight, tracheal or left main bronchus diameter alone in Asians; however, the depth of insertion of the tube was dependent on the height in both genders.
authors.affiliation: Department of Anaesthesiology and Intensive Care, Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur, Malaysia.
authors.forename: Siti Salwani
authors.initials: SS
authors.lastname: Ideris
authors.affiliation: Department of Anaesthesiology and Intensive Care, Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur, Malaysia.
authors.forename: Muhamad Rahimi
authors.initials: MR
authors.lastname: Che Hassan
authors.affiliation: Department of Surgery, Cardiothoracic Unit, Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur, Malaysia.
authors.forename: Mohd Ramzisham
authors.initials: MR
authors.lastname: Abdul Rahman
authors.affiliation: Department of Anaesthesiology and Intensive Care, Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur, Malaysia.
authors.forename: Joanna Su Min
authors.initials: JS
authors.lastname: Ooi
mesh_terms: D000328:Adult; D001208:Asia; D001827:Body Height; D001835:Body Weight; D001837:Body Weights and Measures; D001980:Bronchi; D005260:Female; D006801:Humans; D008297:Male; D061810:One-Lung Ventilation / Q000295:instrumentation*; D012737:Sex Factors; D014132:Trachea