Fiberoptic Wire-Guided Transoral and Through the LMA Intubation Technique Using Modified Gum Elastic Bougie

To the Editor: Transoral wire-guided endotracheal intubation is possible, however, very few reports exist in the literature (1). Most reports (2,3) describe the use of guidewire in the pediatric population for managing difficult intubation, but under certain circumstances, the guidewire intubation could be lifesaving. For example, this technique could offer an alternative mechanism in the event of loss of airway control to promptly reintubate patients while switching endotracheal tubes, during percutaneous bedside tracheostomy or difficult fiberoptic bronchoscopy-guided intubation (4). A number of solutions have been offered to solve the problem with flexible bronchoscope (FOB)-guided switching of Laryngeal Mask Airway (LMA) with a conventional endotracheal tube (ETT), especially the problem of removing the LMA/Fastrach LMA over the ETT (6). Most tubes are too short to allow for the removal of the LMA without risking extubation. The LMA also restricts the size and type of the ETT that could be placed through it (5). Wire-guided switching of ETT tubes for an LMA offers a promising alternative. Unfortunately, there is currently no reliable introducer guide available that can be used to accomplish wire-guided intubation. Here we describe a technique that is particularly useful in accomplishing FOB guided through the LMA (or LMA Fastrach) intubation that is inserted during the management of inadvertent difficult intubation. This technique not only overcomes all the problems cited but offers the choice of switching the LMA for a wide variety of endotracheal tubes, including double lumen tubes of the appropriate size. A 5F 60-cm Tracheal Tube Introducer (TTI) (SIMS Portex Inc., Keene, NH) or its disposable version (Sun Med, Largo, FL) is modified by perforating the distal tip of the introducer with a 16-gauge needle and cutting away the proximal 1 cm (Fig. 1). A 0.35-mm diameter stiff guidewire with softer distal tip that is at least 140 cm is preferred. Depending on the clinical situation, the guidewire could be placed into the trachea either through the suction port of FOB or through an endotracheal tube already in place. Next, the FOB is removed leaving the guidewire in the trachea. A repeat FOB to reconfirm the guidewire placement is recommended especially when this technique is utilized during the course of switching an ETT for a LMA. Next, a well-lubricated modified TTI is gently threaded over the guidewire into the trachea. While threading, one should ensure that the wire remains stationary while the TTI is being pushed distally into the trachea. The TTI is introduced to the desired depth and the guidewire is removed. Following this, the desired well-lubricated endotracheal tube is threaded over the TTI into the trachea. Sometimes resistance is encountered while threading the ETT over the TTI, a problem that is easily overcome by switching to either a well-lubricated regular reinforced ETT or the specialized reinforced ETT with modified tip (supplied with the Fastrach LMA) (7). If this technique is used while switching an ETT for a LMA, then after the TTI has been placed in the trachea, the LMA is gently removed leaving the TTI in place. The desired ETT tube is then threaded over the modified TTI and secured into position. The guidewire and the gum-elastic bougie are easy to procure and modify and most anesthesia providers are familiar with threading an ETT over the TTI. We have used this technique successfully at our institution on multiple occasions while managing inadvertent difficult intubation at induction. Consequently, the guidewire and modified gum-elastic bougie are routinely stocked in our operating room difficult-airway cart.Figure 1.: Photograph shows the relationship of various components used during wire-guided intubation using a modified Tracheal Tube Introducer (TTI). A, Flex-tip guidewire; B, the distal tip of TTI; C, tracheal tube.Govind R. Rajan, MD Department of Anesthesiology VA Medical Center St. Louis, MO [email protected] or [email protected]