Concept Not New or Recommended

Abstract

In Response: We appreciate Dr. Krensavage's interest in our proposed technique for easy fiberoptic intubation via a laryngeal mask airway (LMA). Our intention was to simplify the procedure and to increase the safety of this intubation technique. However, we believe that Dr. Krensavage has misunderstood our approach. We had two primary goals: removal of the LMA from the oropharynx and advancement of the endotracheal tube into the trachea under direct vision. Dr. Krensavage also seems to have misunderstood our message. Before testing our concept clinically, we wanted test a model, which, if successful, would provide insight into the strengths and limitations of our technique. Rather than taking "a step backward," we hoped to be moving toward advancing the airway management armamentarium. We would like to respond to Dr. Krensavage's specific comments. First, as mentioned in our letter, our approach was based on the use of a 49-cm endotracheal tube, not yet commercially available. To approximate this tube, we describe the joining together of two 5.5 endotracheal tubes, for which we used glue, to produce a primitive "cut-and-paste" prototype. We are not suggesting actually using two 5.5 endotracheal tubes with a connector for precisely the reasons that Dr. Krensavage cites, i.e., risk of separation of one or more parts of the apparatus, resulting in injury to the patient. We apologize that we did not describe our instrument adequately in our letter. To construct a functional prototype, we would work with an equipment manufacturer to design a single, 49-cm endotracheal tube (preferably 7.0) and a LMA with a tube wide enough to easily accommodate the 7.0 endotracheal tube. Second, an experienced clinician should be able to achieve fiberoptic intubation guided by the LMA within 20-30 s, making intermittent positive pressure ventilation sufficient for most patients. If a much slower intubation is anticipated, e.g., in cases involving a difficult airway or in a teaching setting, continuous positive pressure ventilation could be applied, as is common practice for prolonged fiberoptic procedures through endotracheal tubes. Because we are not advocating the use of our technique specifically for difficult airways, we do not see a conflict with the ASA algorithm. Third, we tested a 40-cm endotracheal tube and found its length insufficient to achieve one of our goals, the removal of the LMA from oropharynx. Although the Fastrach[registered sign] (Gensia Automedics, San Diego, CA) accommodates a wider endotracheal tube, it proved inadequate to allay one of our concerns, namely the occasional laryngeal trauma (swelling, bleeding) due to blind passage of an endotracheal tube, unless intubation is achieved under direct visualization with the aid of a fiberscope. Finally, we caution against recommendations for or against new or modified techniques before they are adequately investigated. This seems the antithesis of our scientific enterprise and truly a "step backward." Pekka O. Talke, MD Huong Nguyen, RN Department of Anesthesia; University of California, San Francisco; San Francisco, CA 94143-0648