 CORRESPONDENCE Anesthesiology 2003; 98:1293 © 2003 American Society of Anesthesiologists, Inc. Lippincott Williams & Wilkins, Inc. Use of the Cook Airway Exchange Catheter ® to Facilitate Fiberoptic Intubation: Are We Trying to Solve a Problem That We Created? To the Editor:—In their report, Ayoub et al. 1 found that advancing the endotracheal tube (ETT) into the trachea over the fiberoptic broncho- scope (FOB) fails in about one third of patients. They also found that by inserting a Cook Airway Exchange Catheter ® (Cook Critical Care, Bloomington, IN) (CAEC) alongside the FOB, tracheal intubation was successfully accomplished in these patients. They concluded that the presence of the FOB and the CAEC together inside the lumen of the ETT minimized the size of the cleft along the ETT bevel (created by the OD of the FOB and the internal diameter of the ETT), therefore decreasing the likelihood of impingement on the arytenoids cartilages and enhancing the chances of passing the ETT into the trachea. Before this technique becomes an accepted practice, we would like to forward the following comments. First, the authors’ reported 32% failure rate of advancing the ETT over the FOB is unusually high. Had the authors used an appropriate fiberoptic intubation technique, their failure rate would have been extremely low. They used a FOB with an OD of 3.8 mm and ETTs with internal diameters of 7.5 and 8.0 mm. We believe that the great disparity in these diameters contributed to their high incidence of failure in passing the ETT over the FOB. Second, we feel that the authors were biased in their comparison of the success rate using the FOB alone (despite its small diameter) versus the combined use of the FOB and the CAEC. They compared one attempt to advance the ETT over the FOB with up to three attempts when the CAEC was used. If only the first attempts of both techniques were compared, the success rate of using the FOB alone would have been higher (68%) than using both the FOB and the CAEC (9 of 16, or 56%). Third, it is not clear how the authors directed the CAEC through the cords into the trachea. Because the FOB was already in the trachea, it could not have been used to visualize and direct the CAEC toward the cords. For the CAEC to pass through the cords under vision, its tip should be distal to the tip of the FOB. Withdrawing the FOB from the trachea until its tip lies in the pharynx and aligning the CAEC alongside the FOB to introduce both as a unit through the cords is time consum- ing, carries no guarantee for a successful attempt, and leaves the airway unprotected in the process. Blind insertion of the CAEC with the expectation that it will find its way through the cords can cause, literally, what the authors were trying to avoid, that is, trauma making further attempts at ETT placement more difficult. Fourth, from our experience and the experience of others, difficulty in passing the ETT over the FOB is rarely encountered. 2 The use of a proper technique is the best prophylaxis against failure of ETT ad- vancement over a FOB. Using the largest FOB that fits easily inside an appropriate size ETT, using the jaw thrust maneuver (to decrease the posterior pharyngolaryngeal angle), applying generous lubrication, and placing the ETT in warm water to make it more pliable can ensure almost no failure in ETT advancement. 2 In the rare situation when the ETT cannot be advanced, a gentle 90-degree counterclockwise rotation can be successfully utilized. 3 Introducing another device adjacent to the FOB during intubation can be time consuming, can cause trauma to the airway, and most importantly, should not be an alternative to the use of an appropriate fiberoptic intubation technique. Mohammad I. El-Orbany, M.D.,* Katarzyna Klimas-Osolkowski, M.D., M. Ramez Salem, M.D. Advocate Illinois Masonic Medical Center, Chicago, Illinois. ninos-j.joseph@advocatehealth.com References 1. Ayoub CM, Lteif AM, Rizk MS, Abu Jalad NM, Hadi U, Baraka AS: Facilitation of passing the endotracheal tube over the flexible frberoptic bronchoscope using a Cook® airway exchange catheter. ANESTHESIOLOGY 2002; 96:1517– 8 2. Ovassapian A, Wheeler M: Fiberoptic endoscopy-aided techniques, Airway Management. Edited by Benumof JL. St. Louis, Mosby, 1996, pp 282–319 3. Schwartz D, Johnson C, Roberts J: A maneuver to facilitate flexible fiber- optic intubation. ANESTHESIOLOGY 1989; 71:470 –1 (Accepted for publication November 4, 2002.) Anesthesiology 2003; 98:1293 © 2003 American Society of Anesthesiologists, Inc. Lippincott Williams & Wilkins, Inc. In Reply:—Thank you for referring to me the letter of Drs. El- Orbany, Klimas-Osolkowski, and Salem. We agree with Dr. El-Orbany et al. that the difference between the OD of the fiberoptic broncho- scope (FOB)(3.8 mm) and the ID of the endotracheal tube (ETT) (7.5– 8 mm) contributed to the high incidence of failure in advancing the ETT over the FOB. However, in our department and in many other institutions, the 3.8 mm FOB may be the only available size. In order to solve this problem, multiple maneuvers have been suggested to facil- itate the advancement of the ETT, such as 90-degree anticlockwise rotation and designing different tube tips. 1 Moreover, we have de- signed a removable conical polyvinyl chloride sleeve to sheath the insertion cord of the FOB, which increases its size from 3.8 mm to 5.5 mm; the use of this sleeve technique increases the incidence of suc- cessful advancement from the first attempt to 96%. 2 Our report shows that failure from the first attempt when using the FOB alone amounts to 32%. It is only in these failed attempts that we introduced the Cook Airway Exchange Catheter ® (Cook Critical Care, Bloomington, IN), which increased the success rate up to 9 of 16 from the first attempt. Also, as mentioned in our manuscript, when the ETT tube failed to pass over the FOB to the trachea, the FOB was not withdrawn, and the tip of the ETT tube was kept in close proximity to the glottis, which facilitated the introduction of the Cook Airway Exchange Catheter ® from the first attempt. In conclusion, we agree with Dr. El-Orbany et al. that the use of a proper technique is the best prophylaxis against the failure of ETT advancement over the FOB. However, we can still encounter failure to advance the tube over the FOB despite the use of a larger FOB or a smaller tube size, the application the jaw thrust maneuver, generous lubrication, and 90-degree counterclockwise rotation. It is this situa- tion that the introduction of Cook Airway Exchange Catheter ® can centralize the tube in front of the glottis and facilitate advancement. Chakib M. Ayoub, M.D.,* Antoine M. Lteif, M.D., Marwan S. Rizk, M.D., Naji M. Abu Jalad, M.D., Ussama Hadi, M.D., Anis S. Baraka, M.D., F.R.C.A. American University of Beirut, Beirut, Lebanon. chakib.ayoub@aub.edu.lb References 1. Baraka A, Rizk M, Muallem M, Bizri SH, Ayoub C: Posterior-beveled versus lateral- beveled tracheal tube for fiberoptic intubation. Can J Anesthesia 2002; 49:889 –90 2. Ayoub CM, Rizk M, Yaacoub Ch, Baraka A, Lteif A: Advancing the tracheal tube over a flexible fiberoptic bronchoscope by a sleeve mounted on the insertion cord. Anesth Analg 2003; 96:290 –2 (Accepted for publication November 4, 2002.) Anesthesiology, V 98, No 5, May 2003 1293 Downloaded from http://pubs.asahq.org/anesthesiology/article-pdf/98/5/1293/407160/0000542-200305000-00039.pdf by guest on 16 November 2021