Use of the Self-Inflating Bulb with the Esophageal Tracheal Combitube Registered Trademark

Abstract

In Response: We appreciate the response to our study demonstrating the effectiveness of the self-inflating bulb (SIB) for verification of proper placement of the Esophageal Tracheal Combitube Trademark (ETC) [1]. Certainly packaging the ETC with a SIB and an algorithm for its use would be helpful, especially if the ETC were used in nonanesthestizing locations where capnography is usually unavailable. Although our work was neither sponsored by nor performed in collaboration with Sheridan Catheter Corporation, the manufacturer is aware of the benefits of the SIB and the algorithm, since this information has been presented in scientific exhibits at various meetings.* *The Self-I nflating Bulb in Differentiating Esophageal from Tracheal Intubation: Annual Meeting of the American Society of Anesthesiologists, Washington, DC, October 1993; 47th Annual New York State Society of Anesthesiologist's, Post-Graduate Assembly PGA, New York, December 1993; 68th Clinical and Scientific Congress of the International Anesthesia Research Society, Orlando, March 1994. The Esophageal Tracheal Combitube: 48th Annual New York State Society of Anesthesiologist's Post-Graduate Assembly PGA, New York, December 1994 and the 69th Clinical and Scientific Congress of the International Anesthesia Research Society, Honolulu, HI, March 1995. The original algorithm was based on our controlled study of 56 ETC intubations in 46 patients. Dr. Haridas states that, in order to reduce the chance of the ETC being used incorrectly by his anesthesia staff, he has modified our algorithm. That raises several important points that we would like to address. Obviously familiarity with the design and function of the ETC is required to appropriately use the ETC. The two lumens of the ETC have been alternately described as esophageal and tracheal, proximal and distal, No. 1 and No. 2, blue and clear, and longer and shorter. Any or all of these descriptors are designed to permit easier identification and proper use of the ETC. Whether someone prefers using one nomenclature over another is not a critical issue and does not affect the basic concept of our algorithm. The suggestion of inflating the distal cuff immediately after insertion of the ETC prior to verification of its placement with the SIB is unnecessary. All previous articles on the use of the ETC recommended inflation of the pharyngeal balloon and subsequently the distal cuff [2]. We have previously shown that cuff inflation or deflation does not affect the performance of the SIB in differentiating esophageal from tracheal intubation [3]. The same has been demonstrated regarding the reliability of the SIB in differentiating tracheal from esophageal placement of an ETC with a deflated distal cuff [1]. Verification of ETC placement with the SIB prior to inflation of both cuffs is a quick maneuver, requiring only 2 to 4 s to attach a SIB to the distal lumen, and thus concern over regurgitation and aspiration during this period should be a nonissue. Finally, inflation of the distal cuff prior to identifying ETC location can be undesirable. Although the ETC almost always enters the esophagus during blind placement, tracheal placement is still a possibility. With a 13-mm external diameter, the ETC (with deflated distal cuff) may fit snugly into the trachea in some patients, especially females. Inflation of the distal cuff may then lead to injury to the vocal cords or trachea under these circumstances. As outlined in our algorithm, absence of reinflation when the compressed SIB is connected to the distal lumen is indicative of esophageal placement [1]. However, the suggested modification of our algorithm recommends ventilation through the proximal lumen rather than immediate attachment of the SIB to the proximal lumen to both confirm ETC location and assess airway patency. We believe that airway patency of the proximal lumen should be confirmed prior to initiation of ventilation through that lumen, and again this can be performed by the SIB in a few seconds. Attempting to ventilate in the presence of an obstructed airway can lead to leakage around an underinflated pharyngeal balloon and to insufflation of the stomach in the presence of an overinflated balloon when high airway pressures are applied. The value of an algorithm depends on its simplicity of understanding, ease of use, and continuity in the progression from step to step. Dividing the algorithm into two parts, "ETC POSITION CHECK" and "AIRWAY PATENCY CHECK," unnecessarily interrupts the continuity of the algorithm and increases the number of steps. Yaser Wafai, MD M. Ramez Salem, MD Ninos J. Joseph, BS Edward A. Czinn, MD Robert Paulissian, MD Department of Anesthesiology, Illinois Masonic Medical Center, Chicago, IL 60657