Engagement of the Median Glossoepiglottic Fold and Laryngeal View During Emergency Department Intubation.

STUDY OBJECTIVE: When using a standard geometry laryngoscope, experts recommend engaging the hyoepiglottic ligament-a ligament deep to the vallecula not visible to the intubator. The median glossoepiglottic fold (hereafter termed midline vallecular fold) is a superficial mucosal structure, visible to the intubator, that lies in the midline of the vallecula. We aimed to determine whether engaging the midline vallecular fold with a standard geometry blade tip during orotracheal intubation improved laryngeal visualization. METHODS: We reviewed laryngoscopic videos from intubations by emergency physicians using standard geometry video laryngoscopes over a 2-year period. Two reviewers watched each video and recorded whether the blade tip engaged the midline vallecular fold (obscured the fold with the blade tip) and the best modified Cormack-Lehane grade and percent of glottic opening obtained. We compared laryngeal views in the presence and absence of fold engagement. RESULTS: We analyzed 183 discrete laryngoscopic episodes, including 113 instances in which the midline vallecular fold was engaged and 70 instances in which the fold was not engaged. The proportion with a Cormack-Lehane grade 1 or 2a was higher with fold engagement (96%) than without (87%) (absolute difference 9% [95% confidence interval (CI) 1 to 18%]). Ordinal logistic regression demonstrated that midline vallecular fold engagement was associated with a more favorable Cormack-Lehane grade (odds ratio 2.1 [95% CI 1.1 to 4.2]). The median percent of glottic opening score was 95% (interquartile range 90 to 100%) with fold engagement and 95% (65 to 100%) without engagement (median difference 0% [95% CI 0 to 5%]). CONCLUSION: Engaging the midline vallecular fold with the laryngoscope blade tip during orotracheal intubation when using a standard geometry blade was associated with improved laryngeal visualization.

The High-Risk Airway.

The high-risk airway is a common presentation and a frequent cause of anxiety for emergency physicians. Preparation and planning are essential to ensure that these challenging situations are managed successfully. Difficult airways typically present as either physiologic or anatomic, each type requiring a specialized approach. Primary physiologic considerations are oxygenation, hemodynamics, and acid-base, whereas anatomic difficulty is overcome using proper positioning and skilled laryngoscopy to ensure success. It is essential to be comfortable performing alternative techniques to address varying presentations. Ultimately, competence in airway management hinges on consistent training, deliberate practice, and a dedication to excellence.

Early Self-Proning in Awake, Non-intubated Patients in the Emergency Department: A Single ED's Experience During the COVID-19 Pandemic.

OBJECTIVE: Prolonged and unaddressed hypoxia can lead to poor patient outcomes. Proning has become a standard treatment in the management of patients with ARDS who have difficulty achieving adequate oxygen saturation. The purpose of this study was to describe the use of early proning of awake, non-intubated patients in the emergency department (ED) during the COVID-19 pandemic. METHODS: This pilot study was carried out in a single urban ED in New York City. We included patients suspected of having COVID-19 with hypoxia on arrival. A standard pulse oximeter was used to measure SpO2 . SpO2 measurements were recorded at triage and after 5 minutes of proning. Supplemental oxygenation methods included non-rebreather mask (NRB) and nasal cannula. We also characterized post-proning failure rates of intubation within the first 24 hours of arrival to the ED. RESULTS: Fifty patients were included. Overall, the median SpO2 at triage was 80% (IQR 69 to 85). After application of supplemental oxygen was given to patients on room air it was 84% (IQR 75 to 90). After 5 minutes of proning was added SpO2 improved to 94% (IQR 90 to 95). Comparison of the pre- to post-median by the Wilcoxon Rank-sum test yielded P = 0.001. Thirteen patients (24%) failed to improve or maintain their oxygen saturations and required endotracheal intubation within 24 hours of arrival to the ED. CONCLUSION: Awake early self-proning in the emergency department demonstrated improved oxygen saturation in our COVID-19 positive patients. Further studies are needed to support causality and determine the effect of proning on disease severity and mortality.

Clinical Cadavers as a Simulation Resource for Procedural Learning.

"See one, do one, teach one" remains an unofficial, unsanctioned framework for procedural skill learning in medicine. Appropriately, medical educators have sought alternative simulation venues for students to safely learn their craft. With the end goal of ensuring competence, educational programming will require the use of valid simulation with appropriate fidelity. While cadavers have been used for teaching anatomy for hundreds of years, more recently they are being repurposed as a "high-fidelity" procedural skill learning simulation resource. Newly deceased, previously frozen, and soft-preserved cadavers, such as those used in Baltimore and Halifax, produce clinical cadavers with high physical and functional fidelity that can serve as simulators for performing many high-acuity procedures for which there is otherwise limited clinical or simulation opportunities to practice. While access and cost may limit the use of cadavers for simulation, there are opportunities for sharing resources to provide an innovative procedural learning experience using the oldest of medical simulation assets, the human body.

Airway management outside the operating room: how to better prepare.

Airway management outside the operating room is associated with increased risks compared with airway management inside the operating room. Moreover, airway management-whether in the intensive care unit, emergency department, interventional radiology suite, or general wards-often requires mastery of not only the anatomically difficult airway but also the physiologically and situationally difficult airway. The 2015 Difficult Airway Society Guidelines encourage the airway team to "stop and think". This article provides a practical review of how that evidence applies during emergency airway management outside of the operating room. To counter the challenges of airway management outside the operating room, we offer a mnemonic that combines both technical and non-technical insights summarized using the seven letters of the word PREPARE (P: pre-oxygenate/position; R: reset/resist; E: examine/explicit; P: plan A/B; A: adjust/attention; R: remain/review; E: exit/explore). We hope it can unite potentially disparate personnel with a structure that allows them to make acute decisions, coordinate action, and communicate unequivocally. This multidisciplinary publication also hopes to encourage common understanding and language between anesthesiologists and non-anesthesiologists about the perils of airway management outside the operating room and the importance of airway teamwork.

The Cric-Key™ and Cric-Knife™: a combined tube-introducer and scalpel-hook open cricothyrotomy system.

The author describes a cricothyrotomy system that consists of two devices that, packaged together, are labeled the Control-Cric™ system. The Cric-Key™ was invented to verify tracheal location during surgical airway procedures?without the need for visualization, aspiration of air, or reliance on clinicians? fine motor skills. The Cric-Knife™ combines a scalpel with an overlying sliding hook to facilitate a smooth transition from membrane incision to hook insertion and tracheal control. In a recent test versus a traditional open technique, this system had a higher success rate and was faster to implement.

Preoxygenation and prevention of desaturation during emergency airway management.

Patients requiring emergency airway management are at great risk of hypoxemic hypoxia because of primary lung pathology, high metabolic demands, anemia, insufficient respiratory drive, and inability to protect their airway against aspiration. Tracheal intubation is often required before the complete information needed to assess the risk of periprocedural hypoxia is acquired, such as an arterial blood gas level, hemoglobin value, or even a chest radiograph. This article reviews preoxygenation and peri-intubation oxygenation techniques to minimize the risk of critical hypoxia and introduces a risk-stratification approach to emergency tracheal intubation. Techniques reviewed include positioning, preoxygenation and denitrogenation, positive end expiratory pressure devices, and passive apneic oxygenation.

The complexities of tracheal intubation with direct laryngoscopy and alternative intubation devices.

Intubation research on both direct laryngoscopy and alternative intubation devices has focused on laryngeal exposure and not the mechanics of actual endotracheal tube delivery or insertion. Although there are subtleties to tracheal intubation with direct laryngoscopy, the path of tube insertion and the direct line of sight are relatively congruent. With alternative intubation devices, this is not the case. Video or optical elements in alternative intubation devices permit looking around the curve of the tongue, without a direct line of sight to the glottic opening. With these devices, laryngeal exposure is generally the simple part of the procedure, and conversely, tube delivery to the glottic opening and advancement into the trachea are sometimes not straightforward. This article presents the mechanical and optical complexities of endotracheal tube insertion in both direct laryngoscopy and alternative devices. An understanding of these complexities is critical to facilitate rapid tracheal intubation and to minimize unsuccessful attempts.

Use of a battery-operated needle driver for intraosseous access by novice users: skill acquisition with cadavers.

STUDY OBJECTIVES: We determine skill acquisition and performance by using a battery-operated, intraosseous needle driver in cadavers. METHODS: This was a prospective study of the EZ-IO, a battery-operated intraosseous needle driver (Vidacare Corp). Operators received a 5-minute presentation (with 1 insertion demonstration) and then performed 3 tibial insertions on a cadaver. Insertion time was measured from skin placement until stylet removal. Another participant recorded the time and determination of "success." Success required stable bone position and infusion of fluid without extravasation. After testing, operators completed a questionnaire including ease of use (1 to 5; 1=very difficult, 5=very easy), speed versus central line (faster, same, slower), ease of use versus a central line (easier, same, harder), and willingness to use the device in future cardiac arrest situations (yes, maybe, no). RESULTS: Operators included 42 emergency medicine attending physicians, 13 other physicians, 31 emergency medicine residents, and 13 nonphysicians (emergency medical services, etc). None had previous experience with the EZ-IO, and 80 of 99 (80.8%) had never placed an intraosseous needle. Two hundred eighty-nine of 297 insertions (97.3%) were successful. Success rates for the first, second, and third insertion were 96.9%, 94.9%, and 100%, respectively. Median insertion time was 6 seconds (range 3 to 25 seconds), with interquartile range 5 to 8 seconds. The mean ease of use rating was 4.8 (95% confidence interval 4.70 to 4.90). All operators subjectively rated the device faster and easier than a central line; 98 of 99 (99%) expressed willingness to use the device in a cardiac arrest. CONCLUSION: The EZ-IO requires minimal training, is easy to use, and is fast. Skill acquisition is rapid, with a high success rate on the initial insertion after a brief training session and a single demonstration.

Light intensity of curved laryngoscope blades in Philadelphia emergency departments.

STUDY OBJECTIVE: Laryngoscopy and tracheal intubation requires laryngeal exposure and illumination. The objective of this study is to assess variation in laryngoscope lights across different emergency departments (EDs). METHODS: A convenience sample of 3 Mac #4 blade and handle pairs in each of 17 Philadelphia area EDs was tested with a digital light meter to derive the median lux at the distal tip. For each blade tested, we characterized blade design (American, English, or German) and light type (fiber-illuminated versus conventional bulb-on-blade) and measured light-to-tip distance. RESULTS: A total of 50 blades and handle pairs were tested (one ED had only 2 Mac #4 blades). American designs were the most common (38/50), followed by English (6/50) and German (3/50) designs. Three blades had hybrid design features and acrylic light-conducting fibers. Median luminance varied from 11 lux to 5,627 lux. The glass fiber-illuminated blades (n=13) produced greater luminance (median 1,205 lux; interquartile range [IQR] 726 to 2,176 lux) than bulb-on-blade designs (median 689 lux; IQR 290 to 906 lux). German fiber-illuminated blades produced the highest luminance (median 1,937 lux; IQR 1,453 to 3,782 lux). English bulb-on-blade designs produced more luminance (median 915 lux; IQR 745 to 1270 lux) than American (median 689 lux; IQR 269 to 807 lux). German and English blades had shorter light-to-tip distances (median 51 mm and 47 mm, respectively) than American blades (65 mm). CONCLUSION: Curved laryngoscope blades in different EDs have marked variation in light intensity. The contribution of luminance to laryngoscopy performance warrants investigation.

Stylet bend angles and tracheal tube passage using a straight-to-cuff shape.

OBJECTIVES: Malleable stylets improve maneuverability and control during tube insertion, but after passage through the vocal cords the stiffened tracheal tube may impinge on the tracheal rings, preventing passage. The goal of this study was to assess insertion difficulty with styletted tubes of different bend angles. METHODS: Tube passage was assessed with four different bend angles (25 degrees, 35 degrees, 45 degrees, and 60 degrees) using straight-to-cuff-shaped tubes. In two separate airway procedure classes, 16 operators in each class (32 total) placed randomly ordered styletted tubes of the different angles into eight cadavers (16 total). Operators subjectively graded the ease of tube passage as no resistance, some resistance, or impossible to advance. RESULTS: No resistance was reported in 69.1% (177/256) at 25 degrees, in 63.7% (163/256) at 35 degrees, in 39.4% (101/256) at 45 degrees, and in 8.9% (22/256) at 60 degrees. Tube passage was impossible in 2.3% of insertions (6/256) at 25 degrees, in 3.5% (9/256) at 35 degrees, in 11.3% (29/256) at 45 degrees, and in 53.9% (138/256) at 60 degrees. The odds ratios of impossible tube passage for 35 degrees, 45 degrees, and 60 degrees vs. 25 degrees were 1.52 (95% confidence interval [CI] = 0.55 to 4.16), 5.32 (95% CI = 2.22 to 12.71), and 48.72 (95% CI = 21.35 to 111.03), respectively. CONCLUSIONS: Bend angles beyond 35 degrees with straight-to-cuff styletted tracheal tubes increase the risk of difficult and impossible tube passage into the trachea. The authors did not compare different stylet stopping points, stylets of different stiffness, or tracheal tubes with different tip designs, all variables that can affect tube passage.

Design rationale and intended use of a short optical stylet for routine fiberoptic augmentation of emergency laryngoscopy.

Patient safety in emergency airway management has traditionally relied upon prediction of difficult laryngoscopy and alternative intubation devices. Unfortunately, screening tests for difficult laryngoscopy have poor predictive value, and alternative devices are often not suitable for emergency airways. RSI performed with hit or miss repetitive laryngoscopy followed by delayed deployment of rarely used rescue devices is inherently hazardous. First pass success with laryngoscopy should be a benchmark of quality and patient safety in emergency airway management. By making a commitment to minimally modify practice and expand our skill set, fiberoptic augmentation of every laryngoscopy can promote patient safety through the avoidance of repetitive laryngoscopy and esophageal intubation. This article presents the design rationale and intended use of a new short optical stylet for the routine augmentation of emergency direct laryngoscopy.

Laryngeal view during laryngoscopy: a randomized trial comparing cricoid pressure, backward-upward-rightward pressure, and bimanual laryngoscopy.

STUDY OBJECTIVE: External cricoid and thyroid cartilage manipulations are commonly taught to facilitate laryngeal view during intubation. We compare the laryngeal views during laryngoscopy with 4 manipulations (no manipulation, cricoid pressure, backward-upward-rightward pressure [BURP], and bimanual laryngoscopy) to determine the method that optimizes laryngeal view. METHODS: This was a randomized intervention study involving emergency physicians participating in airway training courses from December 2003 to November 2004. Direct laryngoscopies were performed with curved blades on fresh, non-fixed cadavers by using each of the 4 methods. The percentage of glottic opening (POGO), a validated scoring scale, was recorded for each laryngoscopy. Scores for bimanual laryngoscopy were recorded before the assistant applied external pressure. RESULTS: A total of 1,530 sets of comparative laryngoscopies were performed by 104 participants. One thousand one hundred eighteen of 1,530 sets (73%) had POGO scores less than 100 with no manipulation. Compared to no manipulation, mean POGO scores with bimanual laryngoscopy improved by 25 (95% confidence interval [CI] 23 to 27); mean POGO score improvement with cricoid pressure and BURP were 5 (95% CI 3 to 8) and 4 (95% CI 1 to 7), respectively. POGO scores with bimanual laryngoscopy were higher compared to cricoid pressure (mean difference 20, 95% CI 17 to 22) and BURP (mean difference 21, 95% CI 19 to 24). Among laryngoscopies with no manipulation in which the POGO score greater than 0 (n=1,434), laryngeal view worsened in 60 cases (4%, 95% CI 3% to 5%) with bimanual laryngoscopy, in 409 cases (29%, 95% CI 26% to 31%) with cricoid pressure, and in 504 cases (35%, 95% CI 33% to 38%) with BURP. CONCLUSION: Using a cadaver model, we found pressing on the neck during curved blade laryngoscopy greatly affects laryngeal view. Overall, bimanual laryngoscopy improved the view compared to cricoid pressure, BURP, and no manipulation. Cricoid pressure and BURP frequently worsen laryngoscopy. These data suggest bimanual laryngoscopy should be considered when teaching emergency airway management.