To the Editor:-Extubation over an endotracheal tube changer (ETTC) is a method used to secure the airway in a patient with a known difficult intubation. Benumof describes, in detail, this procedure in his review of the management of the difficult adult airway. We found that, after extubation, the ETTC (Sheridan Catheter, Argyle, NY) becomes pliable and can be unintentionally removed from the trachea, even with careful use of the Seldinger technique. Therefore, we confirm the correct placement postextubation by using five criteria: (1) normal ETCO2tracing from the distal tip via a CO2analyzer, (2) audible exhalation through the ETTC, (3) injection of 20 ml air through the ETTC to confirm the lack of presence in the mouth, (4) inability of the patient to speak clearly, and (5) chest x-ray, when the patient is transferred to the intensive care unit (Figure 1).
Patients are able to tolerate the ETTC if 1 mg/kg lidocaine is given intravenously 2 min before tracheal extubation and if the distal end of the ETTC is placed in 2% lidocaine jelly. We transport these patients to the intensive care unit with the ETTC in place, because we are leaving the confines of the operating room, where anesthetic emergency airway equipment is available. Miller et al. reviewed postoperative tracheal extubation and noted that the "timing of the removal of the exchanger tube can be judged only on an individual basis but is usually permitted within one hour of extubation." We believe that the ETTC can be tolerated by the patient longer than 1 h, especially if airway competency postextubation has been questioned.
Andrew I. Topf, M.D., Department of Anesthesiology; Anthony Eclavea, CPT, MC, M.D., Department of Radiology, Tripler Army Medical Center, MCHK-DSA, 1 Jarrett White Road, Honolulu, Hawaii 96859-5000.
(Accepted for publication August 15, 1996.)