To the Editor:—Green and Beger  reported two cases in which malposition of the esophageal tracheal combitube (ETC) resulted in inability to ventilate a patient's lungs. As alternatives to tracheal intubation, devices such as the ETC and the laryngeal mask airway are used more frequently in clinical practice. Thus, verifying the proper placement of these devices becomes a source of legitimate concern.
We evaluated the effectiveness of the self-inflating bulb (SIB) in identifying the location of the ETC and facilitating its proper positioning in anesthetized patients.  In all patients studied, the SIB reliably identified either correct (43) or improper (3) positioning of the ETC. When the ETC is in proper position (Figure 1), a compressed SIB reinflates immediately when connected to the proximal lumen (which permits ventilation via pharyngeal perforations) and will remain compressed when connected to the distal lumen (which leads into the esophagus). In three patients, delayed reinflation (2–4 s) or absence of reinflation was noted when the compressed SIB was connected to the proximal lumen. This corresponded with the inability to ventilate adequately through either lumen. In these cases, slowly withdrawing the ETC 1–2 cm resulted in instantaneous reinflation of the SIB when retested, suggesting proper ETC positioning. Subsequent easy ventilation via the proximal lumen confirmed correct positioning. Based on our findings, we suggested a simple algorithm for use of the SIB to facilitate proper positioning of the ETC. .
The SIB has been shown to be a useful adjunct in differentiating between esophageal and tracheal intubation in anesthetized patients. [3–5] Its usefulness in assisting the correct positioning of other airway devices shows promise as well. Preliminary investigations at our institution suggest the SIB also may facilitate proper positioning of the laryngeal mask airway.  Although using the SIB in no way precludes the appropriate clinical assessment of adequate ventilation, i.e., bilateral breath sounds, we believe the ability of the SIB to facilitate the proper positioning of the ETC warrants its use.
Yaser Wafai, M.D., Edward A. Czinn, M.D., Attending Anesthesiologists, Illinois Masonic Medical Center, 836 West Wellington Avenue, Chicago, Illinois 60657; Clinical Assistant Professor of Anesthesiology, University of Illinois College of Medicine, Chicago, Illinois.
M. Ramez Salem, M.D., Chairman, Department of Anesthesiology, Illinois Masonic Medical Center; Clinical Professor of Anesthesiology, University of Illinois College of Medicine, Chicago, Illinois.
Anis Baraka, M.D., F.R.C.Anesth. (Hon), Professor and Chairman, Department of Anesthesiology, American University Hospital, Beirut, Lebanon.
(Accepted for publication February 10, 1995.)