To the Editor:—
We read with great interest the article by Johnson et al. 1
in which the right arytenoid inhibited the advancement of the endotracheal tube (ETT) into the trachea during awake fiberoptic orotracheal intubation. We have been observing the process of oral fiberoptic intubation during general anesthesia with the use of the similar double-fiberscope technique and reported a case in which the right arytenoid cartilage prevented the ETT passage and the tube rotation solved the problem.2
This problem often occurs not only during awake fiberoptic intubation but during general anesthesia. Moreover, we experienced a case in which the ETT threaded over the fiberscope displaced the right arytenoid markedly despite gentle tube advancement (fig. 1
). In this case, the operator could not feel the resistance until the ETT displaced the arytenoid markedly because the laryngeal tissues were soft, floppy, and relaxed. Therefore, we agree with the authors that this problem can lead to serious laryngeal injury and should be solved.
To avoid this problem, the authors recommend that the fiberscope should be placed in the center of the larynx before tube advancement. However, in usual intubation situations, the fiberscope itself cannot be seen, and the position relative to the larynx cannot be identified. The fiberscope position may be changed during tube advancement. When the ETT cannot be passed into the trachea, the operator cannot identify whether the fiberscope is placed in the center. Therefore, it would be difficult to control the fiberscope position in the center of the larynx. For successful intubation, we should carefully consider other factors (i.e.
, the size and type [design] of the ETT,3,4
the fiberscope size,5
and the sleeve for the fiberscope6,7
) before the intubation procedure. In any case, the ETT should be rotated at the first tube advancement.
Finally, regarding the study method, when the nasally placed second fiberscope for observation of the intubation procedure is positioned in the center against the larynx, it may be difficult for the operator to introduce the fiberscope for intubation in the center. If the fiberoptic view for observation is obtained from the left or right side, the intubating fiberscope position looks near another side. It seems to be difficult to identify the “true” fiberscope position.
Kazuyoshi Aoyama, M.D.,*
Ichiro Takenaka, M.D.
*Nippon Steel Yawata Memorial Hospital, Kitakyushu, Japan. firstname.lastname@example.org
1. Johnson DM, From AM, Smith RB, From RP, Maktabi MA: Endoscopic study of mechanisms of failure of endotracheal tube advancement into the trachea during awake fiberoptic orotracheal intubation. Anesthesiology 2005; 102:910–4
2. Aoyama K, Takenaka I, Sata T, Shigematsu A: Use of the fibrescope-video camera system for difficult tracheal intubation. Br J Anaesth 1996; 77:662–4
3. Brull SJ, Wiklund R, Ferris C, Connelly NR, Ehrenwerth J, Silverman DG: Facilitation of fiberoptic orotracheal intubation with a flexible tracheal tube. Anesth Analg 1994; 78:746–8
4. Greer JR, Smith SP, Strang T: A comparison of tracheal tube tip designs on the passage of an endotracheal tube during oral fiberoptic intubation. Anesthesiology 2001; 94:729–31
5. Hakala P, Randell T: Comparison between two fiberscopes with different diameter insertion cords for fibreoptic intubation. Anaesthesia 1995; 50:735–7
6. Ayoub CM, Rizk MS, Yaacoub CI, Baraka AS, Lteif AM: Advancing the tracheal tube over a flexible fiberoptic bronchoscope by a sleeve mounted on the insertion cord. Anesth Analg 2003; 96:290–2
7. Aoyama K, Yasunaga E, Takenaka I: Another sleeve for fiberoptic tracheal intubation. Anesth Analg 2003; 97:1205–6
© 2006 American Society of Anesthesiologists, Inc.