We read with great interest the recent article of Drs. Rai et al.[1] regarding comparisonof a flexometallic tracheal tube with the intubating laryngeal mask (ILMA) tube, for nasotracheal fibreoptic intubation. The authors conclude that the incidence of impingement of the tracheal tube during nasotracheal fibreoptic intubation is significantly lower with the ILMA tube, than with the flexometallic tracheal tube. However, we believe it would be more appropriate to conclude that the ILMA tube is better only when the flexometallic tracheal tube is improperly oriented during passage. Drs. Rai et al. [1] reported that once the flexometallic tracheal tube was rotated anticlockwise by 90°, its success rate improved to 29 out of 30 patients. This was essentially the same as the success rate (30 out of 30 patients) of the ILMA tube. Why not simply start with the flexometallic tracheal tube rotated anticlockwise by 90°? This has been used during awake fibreoptic orotracheal intubation and has resulted in a higher success rate of intubation at the first attempt (100%), compared with the conventional tracheal tube orientation (60%) [2].

Rotation of the bevelled tracheal tube at random may reduce the difficulty in advancing a tracheal tube over a fibrescope, but 90°anticlockwise rotation should be effective in reducing impingement on the tracheal tube [3]. This manoeuvre was first suggested by Schwartz et al.[4]in 1989. Several studies have confirmed that 90° anticlockwise rotation of the tracheal tube may significantly decrease the likelihood of difficulty in advancing a tracheal tube over a fibrescope [4-7]. Maktabi et al. [8] recommend 90° anticlockwise rotation as the first step to overcome the problem. Ho et al. [9] and Wheeler et al. [10] also suggest that the firstrail roading attempt should only be made with the tracheal tube already turned in this direction. In our practice, the simple technique of rotating the bevelled tracheal tube anticlockwise by 90° during the first attempt along a fibrescope has become a routine part of fibreoptic intubation [11]. This study of Rai etal. [1] should help to popularize this important “trick”.

In the abstract, the authors conclude that compared with the ILMA tube, the incidence of potential laryngeal trauma from nasotracheal fibreoptic intubation is significantly greater with the flexometallic tracheal tube because of a higher incidence of impingement at the level of the glottis. However, we feel there is no evidence to support this conclusion in their results. This is concerning as it has been our experience that many readers do not read beyond the abstract of an article, and if so, this could inadvertently mislead a portion of the readers. It would perhaps be more informative to provide the difference between the two tracheal tubes with regards to the severity of epistaxis after the intubation, and the nasal pain, sore throat and dysphonia on the first postoperative day.

This study was performed in patients, who underwent electivedental or maxillofacial surgery, under general anaesthesia for whichnasotracheal intubation was indicated. However, we consider that because of anon-RAE contour design, the flexometallic tracheal tube or ILMA tube is not asuitable choice for nasotracheal intubation in order to optimise the surgicalapproach in the head and neck region, because vertical protrusion of thetracheal tube from the nostrils can often makes surgical procedures moredifficult, especially for the oral cavity and jaw surgery. Also, lack of thedistal curve does not allow the breathing system connection to be placed awayfrom the surgical field without use of special connector [11]. In addition, theILMA tube requires a higher cuff pressure [12], which, in our opinion, makes itless desirable, especially when the patient requires the nasotrachealintubation for a longer time.

F. S. Xue, J. H. Liu, X. Liao, Y.M. Zhang

Plastic SurgeryHospital, Chinese Academy of Medical Sciences and Peking Union Medical College,Beijing, People’s Republic of Chin 100144. E-mail: Fruitxue@yahoo.com.cn.

1.  Rai MR, Scott SH, Marfin AG, Popat MT, Pandit JJ. Acomparison of a flexometallic tracheal tube with the intubating laryngeal mask tracheal tube for nasotracheal fibreoptic intubation using the two-scope technique. Anaesthesia 2009; 64: 1303-6.

2  Sharma D, Bithal PK, Rath GP, Pandia MP. Effect of orientation of a standard polyvinyl chloride tracheal tube on success rates during awake flexible fibreoptic intubation. Anaesthesia 2006; 61: 845-8.

3.  Asai T, Shingu K. Difficulty in advancing a tracheal tube over a fibreoptic bronchoscope: incidence, causes and solutions. British Journal of Anaesthesia 2004; 92: 870-81.

4.  Schwartz D, Johnson C, Roberts J. A maneuver to facilitate flexible fiberoptic intubation. Anesthesiology 1989; 71: 470-1.

5.  Hughes S, Smith JE. Nasotracheal tube placement over the fibreoptic laryngoscope. Anaesthesia 1996; 51: 1026-8.

6.  Jones HE, Pearce AC, Moore P. Fibreoptic intubation.Influence of tracheal tube tip design. Anaesthesia 1993; 48: 672-4.

7.  Koga K, Asai T, Latto IP, Vaughan RS. Effect of size of a tracheal tube and the efficacy of the use of the laryngeal mask for fibrescope-aided tracheal intubation. Anaesthesia 1997; 52:131-5.

8.  Maktabi MA, Hoffman H, Funk G, From RP. Laryngeal trauma during awake fiberoptic intubation. Anesthesia and Analgesia 2002; 95: 1112-4.

9.  Ho AM, Chung DC, Karmakar MK. Is the Parker Flex-Tiptube really superior to the standard tube for fiberoptic orotracheal intubation? Anesthesiology 2003; 99: 1236.

10. Wheeler M, Dsida RM. Fiberoptic intubation: troubles with the "Tube"?. Anesthesiology 2003;99: 1236-7.

11. Xue FS, LiCW, Sun HT, Liu KP, Zhang GH, Xu YC, Liu Y, Yu L. The circulatory responses to fibreoptic intubation: a comparison of oral and nasal routes. Anaesthesia 2006;61: 639-45.

12.  Dorsch JA, Dorsch SE. Understanding anesthesia equipment, construction, care and complications. 4th ed. Baltimore: Williams& Wilkins, 1999: 563-564.

13. Brain AI, Verghese C, Addy EV,Kapila A. The intubating laryngeal mask. I: Development of a

       new device for intubation of the trachea. British Journal of Anaesthesia 1997; 79: 699-703.