Awake Cricothyrotomy: A Novel Approach to the Surgical Airway in the Tactical Setting

Success rate of prehospital emergency front-of-neck access (FONA): a systematic review and meta-analysis

BACKGROUND

Front-of-neck access (FONA) is an emergency procedure used as a last resort to achieve a patent airway in the prehospital environment. In this systematic review with meta-analysis, we aimed to evaluate the number and success rate of FONA procedures in the prehospital setting, including changes since 2017, when a surgical technique was outlined as the first-line prehospital method.

METHODS

A systematic literature search (PROSPERO CRD42022348975) was performed from inception of databases to July 2022 to identify studies in patients of any age undergoing prehospital FONA, followed by data extraction. Meta-analysis was used to derive pooled success rates. Methodological quality of included studies was interpreted using the Cochrane risk of bias tool, and rated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

RESULTS

From 909 studies, 69 studies were included (33 low quality; 36 very low quality) with 3292 prehospital FONA attempts described (1229 available for analysis). The crude median success rate increased from 99.2% before 2017 to 100.0% after 2017. Meta-analysis revealed a pooled overall FONA success rate of 88.0% (95% confidence interval [CI], 85.0-91.0%). Surgical techniques had the highest success rate at a median of 100.0% (pooled rate=92.0%; 95% CI, 88.0-95.0%) vs 50.0% for needle techniques (pooled rate=52.0%; 95% CI, 28.0-76.0%).

CONCLUSIONS

Despite being a relatively rare procedure in the prehospital setting, the success rate for FONA is high. A surgical technique for FONA appears more successful than needle techniques, and supports existing UK prehospital guidelines.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO CRD42022348975.

External penetrating laryngeal trauma caused by a metal fragment: A Case Report

BACKGROUND

Although external penetrating laryngeal trauma is rare in the clinic, such cases often result in a high mortality rate. The early recognition of injury, protection of the airway, one-stage laryngeal reconstruction with miniplates and interdisciplinary cooperation are important in the treatment of such patients.

CASE SUMMARY

A 58-year-old male worker sustained a penetrating injury in the left neck. After computed tomography scanning at a local hospital, he was transferred to our hospital, where he underwent tracheotomy, neck exploration, extraction of the foreign object, debridement and repair of the thyroid cartilage using titanium miniplates. An endo laryngeal stent was inserted, which was removed 12 days later. The patient recovered well and his voice rapidly improved after surgery.

CONCLUSION

Penetrating laryngeal trauma is uncommon. We successfully treated a patient with early laryngeal reconstruction and management by interdisciplinary cooperation.

Development of a Simulation Surgical Cricothyroidotomy Curriculum for Novice Providers: A Learning Curve Study

INTRODUCTION

Airway obstruction is the third most common cause of preventable death on the battlefield, accounting for 1%-2% of total combat fatalities. No previous surgical cricothyroidotomy (SC) studies have analyzed the learning curve required to obtain proficiency despite being studied in numerous other surgical technique training experiments. The aims of this study were to establish expert SC performance criteria, develop a novel standardized SC curriculum, and determine the necessary number of practice iterations required by a novice to reach this pre-determined performance goal.

MATERIALS AND METHODS

A standardized checklist and SC performance standards were established based on the performance of 12 board certified Military Health System surgeons with prior experience on performing a SC using a simulated trauma mannequin. Expert-level criteria were defined as a SC time to completion of 40 s or less and checklist score of at least 9/10, including all critical steps. Study subjects included 89 novice providers (54 active-duty first- and second-year medical students and 35 Navy corpsmen). Subjects received instruction on performing a SC using the principles of mastery learning and performed a final test of SC proficiency on a trauma mannequin within a realistic simulated MEDEVAC helicopter. The total number of subject practice attempts, checklist scores, and time to completion were measured and/or blindly scored. Learning curve and exponential plateau equations were used to characterize their improvement in mean time to SC completion and checklist scores.

RESULTS

Mean pre-test knowledge scores for the entire group were 11.8 ± 3.1 out of 24 points. Total mean practice learning plateaued at checklist scores of 9.9/10 after 7 iterations and at a mean completion time of 30.4 s after 10 iterations. During the final test performance in the helicopter, 67.4% of subjects achieved expert-level performance on the first attempt. All subjects achieved expert-level performance by the end of two additional attempts. While a significantly larger proportion of medical students (79.9%) successfully completed the helicopter test on the first attempt compared to corpsmen (54.3%), there were no statistically significant differences in mean SC completion times and checklist scores between both groups (P > 0.05). Medical students performed a SC only 1.3 s faster and scored only 0.16 points higher than corpsmen. The effect size for differences were small to negligible (Cohen's d range 0.18-0.33 for SC completion time; Cohen's d range 0.45-0.46 for checklist scores).

CONCLUSION

This study successfully defined SC checklist scores and completion times based on the performance of experienced surgeons on a simulator. Using these criteria and the principles of mastery learning, novices with little knowledge and experience in SC were successfully trained to the level of experienced providers. All subjects met performance targets after training and overall performance plateaued after approximately seven iterations. Over two-thirds of subjects achieved the performance target on the first testing attempt in a simulated helicopter environment. Performance was comparable between medical student and corpsmen subgroups. Further research will assess the durability of maintaining SC skills and the timing for introducing refresher courses after initial skill acquisition.

Prehospital Emergency Cricothyrotomy in Dogs Part 1: Experiences With Commercial Cricothyrotomy Kits

The surgical cricothyrotomy (CTT) has been recommended for emergency front of neck airway access (eFONA) during a cannot intubate, cannot oxygenate scenario for military working dogs (MWD) and civilian law enforcement working dogs (operational K9s). In prehospital and austere environments, combat medics and emergency medical service providers are expected to administer emergency medical care to working dogs and may only have emergency airway kits designed for humans at their disposal. The objective of this article is to provide a detailed description of the application of such devices in cadaver dogs and highlight potential alterations to manufacturer guidelines required for successful tube placement. The kits evaluated included the Portex® PCK, Melker universal cricothyrotomy kit and H&H® emergency cricothyrotomy kit. A novel technique for awake cricothyrotomy in the dog is also described, which can also be considered for in-hospital use, together with the open surgical method described for the H&H® kit. To the authors' knowledge, this is the first publication documenting and providing instruction on the application of commercial cricothyrotomy kits in dogs.

Battlefield Medicine: Anesthesia and Critical Care in the Combat Zone

The US Military Joint Trauma System has been developed to mitigate the harsh conditions under which medical providers care for combat casualties and provide continuity of care from the battlefield to US medical centers. We review the components of this system with emphasis on combat trauma care under fire and the role of the anesthesiologist and intensivist in this continuum of care. An important link in the chain of survival is the Air Force Critical Care Aeromedical Transport Team, which provides critical care while transporting casualties from the theater to higher levels of care outside the war zone and home.

Definitive Management of a Traumatic Airway: Case Report

Maxillofacial and neck trauma from penetrating injuries present unique challenges for anesthesia providers and surgeons. In the austere conditions of a combat setting these challenges may be amplified due to limited resources and injury severity. Currently there is a lack of evidence and consensus on how to best manage a traumatized airway in this situation. The authors of this paper present the successful emergency management of a traumatized airway from a severe maxillofacial and neck-penetrating wound. A stepwise team approach using strong communication and a global mental model facilitated definitive airway management in this case allowing for safe transport to definitive care.

An Experience of Improvised Laryngoscopy

Airway management in the wilderness runs the gamut from basic airway support to endotracheal intubation. Fortunately, direct laryngoscopy is a seldom called upon skill in expedition medicine. However, the medical skills required during a mission or expedition are never truly known in advance. Improvisation during evolving medical events is a mainstay of expedition medicine education and practice. It is unlikely, given constraints of weight and size of expedition medical kits, that a conventional laryngoscope would find its way into a standard "go bag." Faced with the real but rare event of needing to intubate a patient in an austere environment, how can improvisation be used? Multiple ideas for improvised laryngoscopes can be found in the wilderness medicine literature, but which, if any, of these devices have true clinical utility? To this end, participants of a recent Wilderness Medical Society preconference in medical elements of light search and rescue were given the opportunity to devise and construct their own improvised laryngoscopes and attempt intubation of a training mannequin. Participants with varying degrees of intubating experience improvised effective laryngoscopes from provided materials and successfully intubated an airway mannequin.