title: An evaluation of poor LMA CTrach views with a fibreoptic laryngoscope and the effectiveness of corrective measures.
abstract: BACKGROUND
  The LMA CTrach++ system has integrated fibreoptics to enable viewing of the glottis to aid tracheal intubation via a laryngeal mask conduit. Earlier evaluations of this system had shown high success rates of insertion, ventilation and tracheal intubation, but frequent difficulty or failure to view the glottis.
  
  
  METHODS
  We evaluated CTrach views in 100 patients. In 69 patients with partial or no views of the glottis, we evaluated the causes with the aid of an Olympus LF-DP fibreoptic laryngoscope passed through the CTrach. In those with poor views, we tested the effectiveness of simple corrective measures to improve the views and optimize CTrach placement. These included pushing the CTrach deeper in, partial withdrawal by 6 cm and reinsertion to correct epiglottic downfolding, withdrawal by 1 cm and applying forward lift to correct obstruction by the arytenoids, and complete removal to clean the fibreoptic ports followed by reinsertion when secretions were the problem.
  
  
  RESULTS
  Downfolding of the epiglottis caused poor views in 57 patients, which was correctable in 51. Obstruction of the view by the arytenoids occurred in seven patients and by secretions in five, all of which were correctable. With the Ctrach, we were able to ventilate the lungs in all patients, view the glottis in 94 and intubate the trachea in 97 patients.
  
  
  CONCLUSIONS
  Despite the ability to ventilate the lungs in all patients with the CTrach, poor initial views were very frequent, indicating suboptimal placement, although most poor views can be improved, leading to a high intubation success rate.
authors.affiliation: Department of Anaesthesia, Yong Loo Lin School of Medicine, National University of Singapore, Singapore. analiue@nus.edu.sg
authors.forename: E H C
authors.initials: EH
authors.lastname: Liu
authors.forename: R W L
authors.initials: RW
authors.lastname: Goy
authors.forename: F G
authors.initials: FG
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D002983:Clinical Competence; D004825:Epiglottis / Q000473:pathology; D004867:Equipment Design; D005260:Female; D005336:Fiber Optic Technology; D006801:Humans; D007442:Intubation, Intratracheal / Q000379:methods; D017214:Laryngeal Masks; D020704:Laryngoscopes; D008297:Male; D008875:Middle Aged; D012121:Respiration, Artificial