An Evaluation of the Insertion and Function of a New Supraglottic Airway Device, the King LT ™, During Spontaneous Ventilation

A Retrospective Nationwide Comparison of the iGel and King Laryngeal Tube Supraglottic Airways for Out-of-Hospital Cardiac Arrest Resuscitation

INTRODUCTION

While various supraglottic airway devices are available for use during out-of-hospital cardiac arrest (OHCA) resuscitation, comparisons of patient outcomes by device are limited. In this study, we aimed to compare outcomes of OHCA patients who had airway management by emergency medical services (EMS) with the iGel or King-LT.

METHODS

We used the 2018-2021 ESO Data Collaborative public use research datasets for this retrospective study. All patients with non-traumatic OHCA who had iGels or King-LTs inserted by EMS were included. Our primary outcome was survival to discharge to home, and secondary outcomes included first-pass success, return of spontaneous circulation (ROSC), and prehospital rearrest. We examined the association between airway device and each outcome using two-level mixed effects logistic regression with EMS agency as the random effect, adjusted for standard Utstein variables and failed intubation prior to supraglottic airway insertion. Average treatment effects were calculated through propensity score matching.

RESULTS

A total of 286,192 OHCA patients were screened, resulting in 93,866 patients eligible for inclusion in this analysis. A total of 9,456 transported patients (59.8% iGel) had associated hospital disposition data. Use of the iGel was associated with greater survival to discharge to home (aOR:1.36 [1.06, 1.76]; ATE: 2.2%[+0.5, +3.8]; n = 7,576), first pass airway success (aOR:1.94 [1.79, 2.09]; n = 73,658), and ROSC (aOR:1.19 [1.13, 1.26]; n = 73,207) in comparison to airway management with the King-LT. iGel use was associated with lower odds of experiencing a rearrest (aOR:0.73 [0.67, 0.79]; n = 20,776). Among patients who received a supraglottic device as a primary airway, use of the iGel was not associated with significantly greater survival to discharge to home (aOR:1.26 [0.95, 1.68]). Among patients who received a supraglottic device as a rescue airway following failed intubation, use of the iGel was associated with greater odds of survival to discharge to home (aOR:2.16 [1.15, 4.04]).

CONCLUSION

In this dataset, use of the iGel during adult OHCA resuscitation was associated overall with better outcomes compared to use of the King-LT. Subgroup analyses suggested that use of the iGel was associated with greater odds of achieving the primary outcome than the King-LT when used as a rescue device but not when used as the primary airway management device.

Efficacy of Laryngeal Tube versus Bag Mask Ventilation by Inexperienced Providers

INTRODUCTION

Bag mask ventilation (BMV) and extraglottic devices (EGDs) are two common methods of providing rescue ventilation. BMV can be difficult to perform effectively, especially for inexperienced providers and in patients with difficult airway characteristics. There is some evidence that the laryngeal tube (LT) can be successfully placed by inexperienced providers to provide effective ventilation. However, it is unclear whether ventilation provided by LT is superior to that of BMV, especially in the hands of inexperienced airway providers. Therefore, we aimed to compare ventilation efficacy of inexperienced airway providers with BMV versus LT by primarily measuring tidal volumes and secondarily measuring peak pressures on a simulated model.

METHODS

We performed a crossover study first year emergency medicine residents and third and fourth year medical students. After a brief instructional video followed by hands on practice, participants performed both techniques in random order on a simulated model for two minutes each. Returned tidal volumes and peak pressures were measured.

RESULTS

Twenty participants were enrolled and 1200 breaths were measured, 600 per technique. The median ventilation volumes were 194 milliliters (mL) for BMV, and 387 mL for the laryngeal tube, with a median absolute difference of 170 mL (95% confidence interval [CI] 157-182 mL) (mean difference 148 mL [95% CI, 138-158 mL], p<0.001). The median ventilation peak pressures were 23 centimeters of water (cm H₂O) for BMV, and 30 cm H₂O for the laryngeal tube, with a median absolute difference of 7 cm H₂O (95% CI, 6-8 cm H2O) (mean difference 8 cm H₂O [95% CI, 7-9 cm H₂O], p<0.001).

CONCLUSION

Inexperienced airway providers were able to provide higher ventilation volumes and peak pressures with the LT when compared to BMV in a manikin model. Inexperienced providers should consider using an LT when providing rescue ventilations in obtunded or hypoventilating patients without intact airway reflexes. Further study is required to understand whether these findings are generalizable to live patients.

[Statement of the Austrian Society for Anesthesiology, Resuscitation and Intensive Care Medicine (ÖGARI) on the use of laryngeal tubes by ambulancemen and paramedics]

Due to an increasing number of severe complications reported during the prehospital application of laryngeal tubes, the Austrian Society for Anesthesiology, Resuscitation and Intensive Care Medicine (ÖGARI) is prompted to formulate a respective statement. With regard to the current training situation and the applicable laws, ÖGARI recommends to convert the "Emergency Competence for Endotracheal Intubation (NKI)" for emergency paramedics into an "Emergency Competence for Extraglottic Airway Management, (NK-EGA)". Training should include at least 40 h of theoretical instruction, hands-on training on the manikin to secure mastery of the methodology and at least 20 successful applications under clinically elective conditions in adult patients under direct medical supervision. Here, depending on local conditions, both laryngeal mask and laryngeal tube can be used. In the prehospital environment, the device must be used which has been trained as mentioned above. Only 2nd generation EGA should be used. After successful EGA placement timely cuff pressure monitoring and gastric suction should be performed. The use of an EGA by ambulance-men cannot be recommended; these have to be limited to bag-mask ventilation.

Design and implementation of the Resuscitation Outcomes Consortium Pragmatic Airway Resuscitation Trial (PART)

Airway management is an important component of resuscitation from out-of-hospital cardiac arrest (OHCA). The optimal approach to advanced airway management is unknown. The Pragmatic Airway Resuscitation Trial (PART) will compare the effectiveness of endotracheal intubation (ETI) and Laryngeal Tube (LT) insertion upon 72-h survival in adult OHCA. Encompassing United States Emergency Medical Services agencies affiliated with the Resuscitation Outcomes Consortium (ROC), PART will use a cluster-crossover randomized design. Participating subjects will include adult, non-traumatic OHCA requiring bag-valve-mask ventilation. Trial interventions will include (1) initial airway management with ETI and (2) initial airway management with LT. The primary and secondary trial outcomes are 72-h survival and return of spontaneous circulation. Additional clinical outcomes will include airway management process and adverse events. The trial will enroll a total of 3000 subjects. Results of PART may guide the selection of advanced airway management strategies in OHCA.

Comparison of Airway Management Methods in Entrapped Patients: A Manikin Study

INTRODUCTION

Endotracheal intubation remains one of the most challenging skills in prehospital care. There is a minimal amount of data on the optimal technique to use when managing the airway of an entrapped patient. We hypothesized that use of a blindly placed device would result in both the shortest time to airway management and highest success rate.

METHODS

A difficult airway manikin was placed in a cervical collar and secured upside down in an overturned vehicle. Experienced paramedics and prehospital registered nurses used four different methods to secure the airway: direct laryngoscopy, digital intubation, King LT-D, and CMAC video laryngoscopy. Each participant was given three opportunities to secure the airway using each technique in random order. A study investigator timed each attempt and confirmed successful placement, which was determined upon inflation of the manikin's lungs. Intubation success rates were analyzed using a general estimating equations model to account for repeated measures and a linear mixed effects model for average time.

RESULTS

Twenty-two prehospital providers participated in the study. The one-pass success rate for the King LT-D was significantly higher than direct laryngoscopy (OR 0.048, CI 0.006-0.351, p < 0.01) and digital intubation (OR 0.040, CI 0.005-0.297, p < 0.01). However, there was no statistical difference between the one-pass success rate of the King LT-D and CMAC video laryngoscopy (OR 0.302, 95% CI 0.026-3.44, p = 0.33). The one-pass median placement time of the King LT-D (22 seconds, IQR 17-26) was significantly lower (p < 0.001) than direct laryngoscopy (60 seconds, IQR 42-75), digital intubation (38 seconds, IQR 26-74), and the CMAC (51 seconds, IQR 43-76).

CONCLUSIONS

In this study, while the King LT-D offered the quickest airway placement, success rates were not significantly greater than intubation using the CMAC video laryngoscope. Intubation using direct laryngoscopy and digital intubation were less successful and took more time. Use of a blindly placed device or a video laryngoscope may provide the best avenues for airway management of entrapped patients.

Overinflation of a King LT Extraglottic Airway Device Mimicking Ludwig's Angina

In this report, we describe the case of a young female with Down syndrome who presented to the anesthesia service after pulseless electrical activity arrest with a King LT(S)-D extraglottic airway device in situ. She had multiple predictors of difficult intubation, including what appeared to be a submental mass consistent with Ludwig's angina. She went on to receive an urgent tracheotomy because of those predictors but had full resolution of the submental mass on removal of the extraglottic airway device, which had been overinflated at the time of insertion. We outline the various techniques to establish a definitive airway with an extraglottic device in place.

The prehospital management of traumatic brain injury

Traumatic brain injury (TBI) is an important cause of death and disability, particularly in younger populations. The prehospital evaluation and management of TBI is a vital link between insult and definitive care and can have dramatic implications for subsequent morbidity. Following a TBI the brain is at high risk for further ischemic injury, with prehospital interventions targeted at reducing this secondary injury while optimizing cerebral physiology. In the following chapter we discuss the prehospital assessment and management of the brain-injured patient. The initial evaluation and physical examination are discussed with a focus on interpretation of specific physical examination findings and interpretation of vital signs. We evaluate patient management strategies including indications for advanced airway management, oxygenation, ventilation, and fluid resuscitation, as well as prehospital strategies for the management of suspected or impending cerebral herniation including hyperventilation and brain-directed hyperosmolar therapy. Transport decisions including the role of triage models and trauma centers are discussed. Finally, future directions in the prehospital management of traumatic brain injury are explored.

Critical airway skills and procedures

Airway management is a critical procedure and essential skill necessary for all physicians working in the emergency department. Optimal resuscitative treatment of medical and trauma patients often revolves around timely and effective airway interventions that can be challenging in the acute setting, especially in critical patients. Time-honored airway techniques and procedures combined with recent advances in rapid sequence intubation, video laryngoscopy, and further advanced airway techniques now offer emergency clinicians a wide range of exciting new options for improving this crucial component of acute care and management.

Emergency Airway Placement by EMS Providers: Comparison between the King LT Supralaryngeal Airway and Endotracheal Intubation

Introduction:

The ever-present risk of mass casualties and disaster situations may result in airway management situations that overwhelm local emergency medical services (EMS) resources. Endotracheal intubation requires significant user education/training and carries the risk of malposition. Furthermore, personal protective equipment (PPE) required in hazardous environments may decrease dexterity and hinder timely airway placement. Alternative airway devices may be beneficial in these situations.

Objective:

The objective of this study was to evaluate the time needed to place the King LT Supralaryngeal Airway compared to endotracheal intubation when performed by community EMS personnel with and without PPE.

Methods:

Following training, 47 EMS personnel were timed placing both endotracheal tubes and the King LT supralaryngeal airway in a simulator mannikin. The study participants then repeated this exercise wearing PPE.

Results:

The EMS personnel wearing PPE took significantly longer to place an endotracheal tube than they did without protective equipment (53.4 seconds and 39.5 seconds, p <0.002). The time to place the King LT was significantly faster than the placement of the endotracheal tube without protective equipment (18.4 seconds and 39.5 seconds, respectively, p<0.00003). There also were statistically significant differences between the time required to place the King LT and endotracheal tube in EMS personnel wearing protective equipment (19.7 seconds and 53.4 seconds, p <0.000007).

Conclusions:

The King LT Supralaryngeal Airway device may be advantageous in prehospital airway management situations involving multiple patients or hazardous environments. In this study, its insertion was faster than endotracheal intubation when performed by community EMS providers.

Design and implementation of an educational program in advanced airway management for anesthesiology residents

Education and training in advanced airway management as part of an anesthesiology residency program is necessary to help residents attain the status of expert in difficult airway management. The Accreditation Council for Graduate Medical Education (ACGME) emphasizes that residents in anesthesiology must obtain significant experience with a broad spectrum of airway management techniques. However, there is no specific number required as a minimum clinical experience that should be obtained in order to ensure competency. We have developed a curriculum for a new Advanced Airway Techniques rotation. This rotation is supplemented with a hands-on Difficult Airway Workshop. We describe here this comprehensive advanced airway management educational program at our institution. Future studies will focus on determining if education in advanced airway management results in a decrease in airway related morbidity and mortality and overall better patients' outcome during difficult airway management.

King Airway Use by Air Medical Providers

BACKGROUND

In cases of difficult or failed endotracheal intubation (ETI), alternate airways are designed to provide adequate oxygenation and ventilation until a definitive airway can be established. The King Laryngeal Tube Disposable (LTD) is a new superglottic alternate airway.

OBJECTIVE

To describe the use, rates of success, and outcomes of the King airway by highly skilled prehospital providers.

METHOD

In this retrospective analysis, we examined prehospital King airway use by a large regional air medical service for the period from March 2006 to December 2006. Rescuers used alternate airways after three unsuccessful ETI attempts or in situations of anticipated ETI difficulty. We identified clinical characteristics, described airway difficulties, and determined the success of airway placement. Where available, we evaluated the hospital course and outcomes.

RESULTS

Of 575 ETI, alternate airways were used in 27 cases, including 26 King airway placements (4.5%, 95% CI: 3.0-6.6%). All were successfully placed; 24 required one attempt, and two required more than one attempt. No immediate complications were observed. No prehospital surgical airways were performed. Follow-up data were available for 15 of 26 patients. Five patients were in cardiac arrest and did not survive to hospital admission. Many of the patients required specialized efforts from anesthesia or surgery for definitive airway management with 40% (4/10) requiring emergent tracheostomy.

CONCLUSION

In this series of critically ill patients, air medical providers successfully used the King airway as an alternate airway device. Definitive airway management was complicated and required specialized efforts from surgery and anesthesia.

Advanced trauma life support, 8th edition, the evidence for change

The American College of Surgeons Committee on Trauma's Advanced Trauma Life Support Course is currently taught in 50 countries. The 8th edition has been revised following broad input by the International ATLS subcommittee. Graded levels of evidence were used to evaluate and approve changes to the course content. New materials related to principles of disaster management have been added. ATLS is a common language teaching one safe way of initial trauma assessment and management.

A pilot study of the King LT supralaryngeal airway use in a rural Iowa EMS system

INTRODUCTION

In 2003, the King Laryngeal Tube (LT) received FDA approval for US sales. Prehospital systems in urban setting have begun evaluating and adopting the LT for clinical airway management. However, it is not routinely approved by State EMS Boards for use by all prehospital providers. Given the LT's simple design there may be benefit to using this tool for airway management in all levels of prehospital providers. This pilot study reviews cases where the King LT was used in a rural Iowa county EMS system.

METHODS

In 2006, the Iowa Department of Public Health / Bureau of EMS approved a 12 month pilot evaluating the King LT by all levels of EMS providers in a rural county EMS system. Following a didactic and competency training session on using the King LT, the providers were instructed to continue airway management per usual protocol but were allowed to use the King LT as a first line airway tool if they felt indicated. Successful placement of airway devices used were determined by colourimetric end-tidal CO2, chest auscultation and rise as well as vital sign and skin colour improvement. Review of the data was approved by the University of Iowa Institution Review Board (IRB).

RESULTS

During the 12-month pilot period, the King LT was used in 13 patients with a mean age of 60.7 years (24-81). All patients had cardiopulmonary or traumatic arrest. The King LT was successfully placed on the first attempt in all but one case. The King LT was placed following endotracheal intubation failure in 6/13 (46.1%) cases and in 3/13 (23.1%) of cases of Combitube attempt / failure.

CONCLUSIONS

This small pilot project emphasizes the need for additional rapid airway management tools given the demonstrated ETI failures. The authors believe the King LT has significant potential to impact prehospital airway management as a primary airway device or backup to other failed strategies. Further study is necessary to evaluate the LT's efficacy compared to current strategies.

How Would Minimum Experience Standards Affect the Distribution of Out-of-Hospital Endotracheal Intubations?

STUDY OBJECTIVE

Out-of-hospital endotracheal intubation is a complex intervention. One strategy for improving the quality of a complex intervention is to limit the procedure to practitioners or agencies that meet minimum procedure experience standards. The system-level influence of such limits is unknown. We seek to determine how minimum endotracheal intubation experience standards influence the number and distribution of out-of-hospital endotracheal intubations.

METHODS

We used 2003 Pennsylvania statewide emergency medical services (EMS) data. We included endotracheal intubations that could be attributed to a valid rescuer, EMS agency, and minor civil division. We calculated the total number of endotracheal intubations performed across the state. We calculated the absolute and relative changes in total, cardiac arrest, nonarrest, pediatric, and trauma endotracheal intubation when the procedure was limited to on-scene rescuers meeting minimum endotracheal intubation experience standards, ranging from zero to 20 annual endotracheal intubations. We evaluated the same relationships when the procedure was limited to EMS agencies meeting minimum endotracheal intubation experience standards, ranging from zero to 200 annual endotracheal intubations. We evaluated these relationships with line plots and geographic information system maps.

RESULTS

During the study period there were 11,771 endotracheal intubations (7,854 cardiac arrest, 3,917 non-arrest, 1,325 trauma and 561 pediatric endotracheal intubations). Limiting endotracheal intubations to rescuers with at least 3, 5, 10, and 15 endotracheal intubations per year would result in relative endotracheal intubation reductions of 12%, 32%, 79%, and 93%, respectively. Limiting endotracheal intubations to EMS agencies with at least 20, 30, 50, 100, and 150 endotracheal intubations per year would result in relative endotracheal intubation reductions of 15%, 27%, 41%, 65%, and 73%, respectively. Cardiac arrest endotracheal intubations would exhibit the largest absolute reduction.

CONCLUSION

Minimum endotracheal intubation experience standards would result in absolute and relative reductions in total and subgroup endotracheal intubations. These findings provide vital perspectives about the system-wide organization of out-of-hospital airway management.