title: Randomized, controlled trial of the double setup tracheal tube during fibreoptic orotracheal intubation under general anaesthesia.
abstract: BACKGROUND
  Impingement of the tracheal tube (ETT) on upper airway structures during railroading over the fibreoptic bronchoscope (FOB) occurs commonly. Potential complications of impingement include prolonged intubation time, leading to arterial desaturation, failed intubation and laryngeal trauma. The objective of this randomized, controlled trial was to assess the effect of the double setup ETT (a paediatric ETT is placed inside an adult ETT) on the incidence of impingement during orotracheal fibreoptic intubation.
  
  
  METHODS
  Two hundred patients were randomized to have a single ETT or double setup ETT. After induction of anaesthesia, fibreoptic orotracheal intubation was performed. The degree of impingement of the ETT during advancement over the FOB was assessed using a standardized scoring system based on the manoeuvres required to overcome the impingement.
  
  
  RESULTS
  The incidence of impingement was lower using the double setup ETT compared with the single ETT (18 vs 93%, P<0.001). The double setup ETT also reduced the incidence of impingement requiring more than a simple 90 degrees counterclockwise rotation to achieve intubation (3 vs 14%, P=0.01) and reduced the median intubation time (31 vs 35 s, P=0.046).
  
  
  CONCLUSIONS
  The double setup ETT is effective in reducing ETT impingement and in reducing intubation time. We did not find an association between ETT impingement and arterial desaturation.
authors.affiliation: Department of Anaesthetics, Royal Prince Alfred Hospital, Missenden Road, Camperdown 2050, New South Wales, Australia. andrewhjackson@hotmail.com
authors.forename: A H
authors.initials: AH
authors.lastname: Jackson
authors.forename: P
authors.initials: P
authors.lastname: Wong
authors.forename: B
authors.initials: B
authors.lastname: Orr
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000768:Anesthesia, General / Q000379:methods*; D001999:Bronchoscopy / Q000379:methods; D005260:Female; D006801:Humans; D007442:Intubation, Intratracheal / Q000295:instrumentation / Q000379:methods*; D007830:Larynx / Q000293:injuries; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D012399:Rotation; D013997:Time Factors; D014132:Trachea
chemical_list: D010100:Oxygen