Technique for Exchanging the King Laryngeal Tube for an Endotracheal Tube

Abstract

The King laryngeal tube (LT; Kingsystems, Noblesville, IN) is a supraglottic airway frequently used by prehospital providers, either as a first-line airway or as a rescue device after failed endotracheal intubation. When a patient arrives to the hospital with a King LT in place it needs to be replaced by a definitive airway, which typically occurs in the emergency department. This places emergency physicians in the precarious position of needing to remove a functioning airway to place an endotracheal tube (ETT). Many providers simply remove the King LT and intubate as usual, but this may have disastrous consequences if intubation is difficult or impossible (whether it be due to patient anatomy, trauma, emesis, or other factors). A safer scenario for the patient is to place the endotracheal tube before the King LT is removed. However, there is no standard technique for reliably exchanging the King LT for an ETT. Two techniques for placing an ETT with a King LT in place have been previously described. One technique is blind placement of a bougie (endotracheal tube introducer) through the King LT. However, this has been shown to be unpredictable. Lutes and Worman1 studied this technique on an airway task trainer and a human cadaver model and found a low success rate. They found that the bougie often encountered resistance at the level of the proximal balloon or lateral airway structures. In their single attempt on the cadaver model, the bougie actually penetrated the aryepiglottic fold. Another technique was described in two small case series. This technique involves placement of a tube exchange catheter or a wire through the King LT under flexible endoscopic guidance.2, 3 Both case series described high success rates (three out of three cases, nine out of 10 cases, respectively); however, this technique requires specialized equipment and is a complex process. Here, we describe a new technique that is simple and intuitive. The technique can be utilized with the King LT (reusable device), King LT-D (disposable device), or the King LTS-D (disposable device with gastric access capability). The technique uses equipment familiar to most emergency airway providers: a video laryngoscope, a bougie, a large syringe, suction, and an endotracheal tube. The key is that direct visualization of the glottis with the King LT in place is extremely difficult because the device occupies much of the oropharynx. However, it is relatively easy to visualize the glottis with video laryngoscopy and intubate using the video display. This technique also utilizes a bougie, which allows for better visualization of the glottis during the procedure, due to its smaller diameter compared to the ETT. The primary benefit of this technique is that intubation is completed with the King LT in place (with the balloons deflated). If endotracheal intubation around the King LT is unsuccessful, the balloons can simply be reinflated to resume ventilation and oxygenation. This novel technique is easy to learn and utilizes readily available airway equipment. Of note, in our institution, we perform this technique most often using the C-MAC video laryngoscope (Karl Storz, Tuttlingen, Germany), but have also performed it successfully using a GlideScope (Verathon Medical, Bothell, WA) with both standard Macintosh blades and hypercurved blades. The associated video (available as supporting information in the online version of this paper) reviews the specific details of this procedure. Institutional review board clearance for this video was obtained. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.