How I Do IT: Making Awake Airway Examinations Safer, Cheaper, and Easily Accessible

Transnasal tracheoscopy (TNT) is a commonly-employed technique to visualize the larynx, trachea, and mainstem bronchi in an office setting [1]. Topical anesthesia is typically delivered via a nebulizer or through the working channel of a distal chip endoscope with high levels of patient tolerance [2]. However, the delivery of nebulized lidocaine during the COVID-19 era raised concerns about infectious disease transmission [3]. Also, working channel endoscopes and their associated proprietary video towers are expensive. Further, the towers are cumbersome to find or use in hospital settings such as the ICU, PACU, or a patient ward. We have devised a novel technique for TNT to anesthetize the larynx and trachea without a nebulizer or a working channel. This technique reduces infectious disease risk from a nebulizer, is inexpensive, and is easily employed in office and all hospital settings. The patient sits upright and sitting forward in an Otolaryngology examination chair. If the patient is inpatient and on a hospital bed, raising the back of the bed is recommended; when the patient is supine or semi-supine, then the pharynx and larynx are more closely approximated, which limits access of the endoscope. Ten to Fourteen French (FR) red rubber catheters, with the proximal end trimmed for a tight attachment to a 10-cc syringe, are used to anesthetize the supraglottis and glottis for this procedure. First, oxymetazoline and 4% lidocaine spray are applied to each nasal cavity via a syringe with a disposable atomizing tip. Adequate levels of decongestion and topical anesthesia are achieved within a couple of minutes. Nasal pledgets with these medications can be delivered into the more patent nasal cavity if desired. Then nasal pledgets are removed if they were initially placed, and the flexible laryngoscope is delivered into one nasal cavity. A classic flexible fiberoptic laryngoscope or a more modern distal chip flexible laryngoscope will work best. At this point, our protocol is for a thorough exam of the nasopharynx, base of tongue, supraglottis, glottis, and visualized post-cricoid region. Once the primary assessment has been performed, the laryngoscope is then withdrawn to the nasopharynx and a 12 FR (sizes from 10 to 14 FR can be used) red rubber catheter is passed through the contralateral nasal cavity into the nasopharynx. If the patient has a large septal deviation preventing the passage of the red rubber catheter, it can be inserted through the same nasal passage used as the laryngoscope. Once the red rubber catheter can be visualized in the nasopharynx, it is slowly advanced until it is sitting just above the epiglottis. Then a 10 mL slip-tip syringe is filled with 0.25 mL of 4% lidocaine and 9.75 mL of air, and the tip snugly placed into the proximal end of the red rubber catheter. The ample amount of air in the syringe assures that the lidocaine is pushed through the catheter. This first delivery is directed into either vallecula and helps gently prepare the epiglottis and its surrounding area for the light touch of the red rubber catheter. The patient does not need to phonate for this initial drip. After the first drip, the red rubber catheter can be advanced next to the laryngeal surface of the epiglottis and should be hovering 1–2 cm above the glottis. At this point, a similar procedure is performed in which 0.25 mL drips of 4% lidocaine are delivered onto the glottis while the patient is holding prolonged phonation, a “laryngeal gargle” The tip of the red rubber catheter can be best directed toward the center of the endolarynx by a special maneuver—the patient tilts their chin up, turns their head toward the side with the red rubber catheter in it, and says “eh” as in the sound of the word egg. This triad directs and stabilizes the catheter towards the center of the endolarynx. Typically, the initial drips will cause the patient to cough, and they will only be able to hold phonation for a few seconds, but this should improve with each subsequent aliquot. Topical anesthesia will typically take anywhere from 3 to 5 laryngeal gargles until the supraglottis and glottis are adequately anesthetized. The beginnings of pooling of saliva in the piriform sinuses are a helpful indicator that an adequate anesthesia level has been achieved. The red rubber catheter is removed and the patient returns to normal respirations. The laryngoscope can then be advanced to, and ultimately through, the true vocal folds. Once the subglottis is visualized, the laryngoscope should be kept in the middle of the trachea to avoid stimulation thereof. At this point, the patient will typically be able to tolerate having the scope passed all the way to the carina with minimal irritation. Once the airway has been examined down to the carina and the mainstem bronchi, the laryngoscope can be removed. The patient is instructed not to eat or drink anything for the next 60 min to avoid the risk of aspiration due to anesthesia of the sensory nerves of the larynx and pharynx. This study is covered by institutional review board approval (UW HS-IRB 2013–0751). This procedure is regularly performed on a weekly basis at our institution by faculty, fellows, and Otolaryngology residents. The “red rubber TNT” has been performed in a standard office setting, in the Emergency Department, during inpatient consultations, in the pre- and post-operative holding areas and in the ICU. There have been no reported cases of needing to abort the exam due to patient intolerance. Potential complications of this technique include nasal trauma, mucosal injury, airway edema, vasovagal response, or laryngospasm. However, none of these was encountered in our experience. This technique has been successfully used to evaluate the airway in adult patients aged 18–90 years across diverse clinical settings, including the Post Anesthesia Care Unit (PACU), emergency department, inpatient consults, and outpatient clinic. Since the beginning of the COVID-19 pandemic, the residents and faculty at our institution have been unable to use nebulized lidocaine for anesthesia of the supraglottis and glottis due to changes in protocol from the COVID-19 pandemic. When no channeled endoscope was available for application of topical anesthetic, we used this technique. Throughout this time period, there has been significant success in examining the airway via the red rubber method. Notably, there have been several documented scenarios in which residents have been approached by our anesthesia colleagues in the preoperative surgical area due to concerns about a difficult airway in patients with previous tracheostomies or prolonged intubations. In these scenarios, a quick red rubber TNT was performed safely and effectively to ensure that there was no distal obstruction in the subglottis or trachea that may precipitate an intraoperative airway emergency. Also, the red rubber TNT method was used for patients with aggressive thyroid malignancies where there was concern about possible tracheal involvement or invasion. A thorough examination of the airway can be an invaluable and lifesaving tool for the Otolaryngologist. In this article, we present a method that was developed to examine the airway during the COVID-19 pandemic that has played an integral role in the health and safety of our patients. Additionally, this procedure did not incur any additional cost, as the red rubber catheter required is widely available and typically costs only a few dollars. The overall cost of the materials used to examine this portion of the airway is significantly less than a channeled endoscope, which can cost tens of thousands of dollars, including the proprietary video tower, and vastly less expensive than a trip to the operating room for a similar airway exam. Although not quantified, the technique did not result in any noticeable increase in procedure time compared to channeled scope exams, given their similar workflow. Furthermore, many of the skills needed for this exam are already part of an Otolaryngologist's toolkit and therefore it is an easy exam to learn and perform with minimal additional training needed. At our Otolaryngology department, red rubber catheters are frequently used for tracheoesophageal punctures and other in-office procedures. Not only is this a method that can be seamlessly and efficiently done in the clinic, it can also be easily adapted to use in the emergency department or on the inpatient unit. Being able to examine the subglottis and trachea at the bedside can help in diagnosing potentially life-threatening pathology such as subglottic stenosis, tracheal stenosis, invasive malignancies, vascular anomalies, or post-tracheostomy sequelae. Having this ability can and will help efficiently and safely examine these patients so that plans can be implemented prior to going to the operating room (Video 1). The authors declare no conflicts of interest.