Comparison of a percutaneous device and the bougie-assisted surgical technique for emergency cricothyrotomy: an experimental study on a porcine model performed by air ambulance anaesthesiologists

[Ultrasound supported identification of the ligamentum conicum in teaching head and neck sonography]

OBJECTIVE

Upper airway obstructions are usually acute emergencies. Coniotomy is the last option to secure the airway and can be supported by sonography. The aim of this study was to establish a training program to teach these skills.

MATERIAL AND METHODS

The training consisted of theoretical training with an additional video presentation (10 minutes each) and practical training (45 minutes). Evaluations were completed before (T1) and after (T2) the training to measure prior experience and satisfaction with the training as well as subjective and objective competence levels. At T2, a practical test was also completed by n=113 participants. A standardized evaluation form was used to document the results of the practical test.

RESULTS

A large proportion of the participants had neither seen a coniotomy (64.6%) nor performed one independently (79.6%). Significant improvement (T1 to T2) was measured with regard to the subjective assessment of competence (p<0.001). The training received positive ratings for all items tested (scale ranges 1-2). During practical tests, the participants achieved an average of 89.2% of the possible points and needed a mean of 101 ±23 seconds to identify the conic ligament.

CONCLUSION

Structured training for sonographic identification of the conic ligament leads to significant improvement in the subjective assessment of competence and a high objective competence level in a short period of time. This type of training should be standardized in head and neck ultrasound training in the future.

Impact of simulation-based training on bougie-assisted cricothyrotomy technique: a quasi-experimental study

BACKGROUND

Cricothyrotomy is a lifesaving surgical technique in critical airway events. However, a large proportion of anesthesiologists have little experience with cricothyrotomy due to its low incidence. This study aimed to develop a multisensory, readily available training curriculum for learning cricothyrotomy and evaluate its training effectiveness.

METHODS

Seventy board-certificated anesthesiologists were recruited into the study. Participants first viewed an instructional video and observed an expert performing the bougie-assisted cricothyrotomy on a self-made simulator. They were tested before and after a one-hour practice on their cricothyrotomy skills and evaluated by a checklist and a global rating scale (GRS). Additionally, a questionnaire survey regarding participants' confidence in performing cricothyrotomy was conducted during the training session.

RESULTS

The duration to complete cricothyrotomy was decreased from the pretest (median = 85.0 s, IQR = 72.5-103.0 s) to the posttest (median = 59.0 s, IQR = 49.0-69.0 s). Furthermore, the median checklist score was increased significantly from the pretest (median = 30.0, IQR = 27.0-33.5) to the posttest (median = 37.0, IQR = 35.5-39.0), as well as the GRS score (pretest median = 22.5, IQR = 18.0-25.0, posttest median = 32.0, IQR = 31.0-33.5). Participants' confidence levels in performing cricothyrotomy also improved after the curriculum.

CONCLUSION

The simulation-based training with a self-made simulator is effective for teaching anesthesiologists to perform cricothyrotomy.

Anatomical morphometry for Cricothyrotomy puncture and incision

PURPOSE

Emergency surgical airway securing techniques include cricothyrotomy, puncture, and incision. While the instruments used for these methods vary in size, no index of laryngeal morphology exists to guide instrument selection. Therefore, we measured the morphology of the cricothyroid ligament in Japanese individuals and assessed its correlations with height.

METHODS

This retrospective study used 61 anatomical practice specimens. The cricothyroid ligament of the laryngeal area was dissected, and a frontal image was recorded. Next, images of the midsagittal sections of the larynx and trachea were recorded. The width and height of the cricothyroid ligament were measured from the frontal images, and the depth of the larynx and the angle to the lower edge of the cricothyroid plate were measured from the mid-sagittal cross-sectional images. The height was estimated from the tibial lengths of the specimens and statistically analyzed for correlations. 　 RESULTS: The width and depth were significantly greater in males. Overall, there was a slight correlation between the results of each laryngeal measurement and estimated height for all items.

CONCLUSION

The morphology of cricothyrotomy revealed that the width and depth of the laryngeal area varied according to sex. Moreover, the results also showed a correlation with the estimated height. Thus, it is important to predict the morphology of the laryngeal area and cricothyroid ligament by considering factors such as patient sex, weight, and height.

Scalpel cricothyrotomy versus punctured cricothyrotomy in the context of the CICO crisis. A systematic review and Meta-analysis

IMPORTANCE

The preferential use of a scalpel (SCT) or puncture techniques (PCT) for cricothyrotomy remains a controversial topic.

OBJECTIVE

We performed a systematic review and meta-analysis comparing puncture cricothyrotomy with scalpel cricothyrotomy using overall success rate, first-time success rate, and time taken to perform the procedure as the primary outcome together with complications as a secondary outcome.

EVIDENCE REVIEW

Pubmed databases, EMBASE databases, MEDLINE, Google Scholar, and Cochrane Central Register of Controlled Trials, from 1980 to October 2022.

FINDINGS

A total of 32 studies were included in the systematic review and meta-analysis. It also showed that PCT was close to SCT in terms of overall success rate (82.2% vs. 82.6%, Odd Ratios OR = 0.91, [95%CI: 0.52-1.58], p = 0.74) as well as first-performance success rate (62.9% vs. 65.3%, OR = 0.52, [0.22-1.25], p = 0.15). PCT does not compare favorably with SCT in terms of required time for the procedure (the mean time required for PCT versus SCT incision in the intervention groups was 0.34 standard deviations higher (Mean Difference MD = 17.12, [3.37-30.87], p = 0.01) as well as complications (21.4% vs. 15.1%, Relative Risk RR = 1.49, [0.80-2.77], p = 0.21).

CONCLUSIONS AND RELEVANCE

The results show that SCT has an advantage over PCT in terms of time required for the procedure, while there is no difference in overall success rate, first-time success rate after training, and complications. The superiority of SCT may be the result of fewer and more reliable procedural steps. However, the level of evidence is low (GRADE).

Anesthetic management of tracheal stent extraction using a double gum elastic bougie technique

Background

Tracheal stenosis is a life-threatening condition, and management of a patient with a risk of tracheal stenosis is challenging for anesthesiologists. In this report, we describe a method for airway management using two gum elastic bougie method when removing a tracheal stent via a tracheostomy orifice with a risk of airway restenosis.

Case presentation

A 71-year-old man had an enlarged squamous cell carcinoma of the lung invading the upper mediastinum that had caused severe stenosis of the trachea. Two months after diagnosis, a tracheal stent had been placed to maintain tracheal patency. One month after stent placement, acute respiratory failure was induced by upper airway obstruction caused by subglottic airway edema due to mechanical stimulation of the cranial end of the stent, and the patient was rescued by oral tracheal intubation. Tracheal stent extraction was scheduled to relieve the laryngeal edema. Since there was a risk of tracheal restenosis because of the possibility of accidental evulsion of the orally tracheal tube which intubated to secure an emergency airway and tracheal stent extraction, two gum elastic bougies were inserted through the oral tracheal tube and tracheostomy orifice to facilitate re-intubation. After extraction of the tracheal stent, airway openness was maintained and tracheostomy was completed without any complication.

Conclusion

Successful management of tracheal stent extraction was performed using a double gum elastic bougie technique.

Emergency cricothyrotomy in morbid obesity: comparing the bougie-guided and traditional techniques in a live animal model

BACKGROUND

Cricothyrotomy is a rare, time sensitive procedure that is more challenging to perform when anatomical landmarks are not easily palpated before the initial incision. There is a paucity of literature describing the optimal technique for cricothyrotomy in patients with impalpable airway structures, such as in morbid obesity. In this study, we used a live sheep model of morbid obesity to compare the effectiveness of two common cricothyrotomy techniques.

METHODS

We randomly assigned emergency medicine residents to perform one of two cricothyrotomy techniques on a live anesthetized sheep. To simulate the anterior soft tissue neck thickness of an adult with morbid obesity we injected 120 mL of a mixture of autologous blood and saline into the anterior neck of the sheep. The traditional technique (as described in the New England Journal Video titled "Cricothyroidotomy") used a Shiley tracheostomy tube and no bougie, and the bougie-guided technique used a bougie and a standard endotracheal tube. The primary outcome was the total procedure time; the secondary outcome was first attempt success.

RESULTS

23 residents were included, 11 assigned to the bougie-guided technique and 12 to the traditional technique. After injection of blood and saline, the median depth from skin to cricothyroid membrane was 3.0 cm (IQR 2.5-3.4 cm). The median time for the bougie technique was 118 s (IQR 77-200 s) compared to 183 s (IQR 134-270 s) for the traditional technique (median difference 62 s, 95% CI 10-144 s). Success on the first attempt occurred in 7/11 (64%) in the bougie group and 6/12 (50%) in the traditional technique group.

CONCLUSION

In this study, which simulated morbid obesity on a living animal model complete with active hemorrhage and time pressure caused by extubation before the procedure, the bougie-guided technique was faster than the traditional technique using a tracheostomy tube without a bougie.

Organic vs. Inorganic Tracheobronchial Airway Foreign Body Aspiration: Does Type/Duration Matter?

OBJECTIVE

We sought to determine the time course of clinical and histologic differences between aspirated inorganic and organic foreign bodies.

STUDY DESIGN

In-vivo.

METHODS

Twenty Sinclair miniature swine (Sus scrofa domesticus) were divided into two groups-inorganic or organic foreign bodies. Either an organic (peanut) or an inorganic (Lego) foreign body was placed within a bronchus and left for 3, 5, 7, 14 or 21 days. The airway was reassessed at the predetermined endpoint at which time endoscopic, gross, and histopathological findings were documented. Specimens were scored with a pathologic scoring system to assess injury severity from the foreign body.

RESULTS

Foreign bodies were successfully placed in all 20 swine. Two animals required early euthanasia due to respiratory compromise. The foreign body was identified grossly in eight (40%) animals. An additional three (15%) had microscopic evidence suggestive of a previous foreign body of an undetermined duration. There was no difference in injury severity between organic and inorganic foreign bodies. The 3-day group had injuries limited to the bronchial lining, whereas the longer duration groups had bronchial and adjacent lung parenchymal involvement. There was no difference in injury severity between days 5 and 21.

CONCLUSIONS

Airway foreign bodies initially cause bronchial damage. After 5 days, the foreign body causes lung parenchymal changes. There was no difference in airway lesion severity between organic and inorganic foreign bodies.

LEVEL OF EVIDENCE

N/A Laryngoscope, 131:490-495, 2021.

Percutaneous vs surgical emergency cricothyroidotomy: An experimental randomized crossover study on an animal-larynx model

BACKGROUND

Airway management is a paramount clinical skill for the anaesthesiologist. The Emergency Cricothyroidotomy (EC) constitutes the final step in difficult airway algorithms securing a patent airway via a front-of-neck access. The main distinction among available techniques is whether the procedure is surgical and scalpel-based or percutaneous and needle-based.

METHODS

In an experimental randomized crossover trial, using an animal larynx model, we compared two EC techniques; the Rapid Four Step Technique and the Melker Emergency Cricothyrotomy Kit®. We assessed time expenditure and success rates among 20 anaesthesiologists and related this to previous training, seniority and clinical experience with EC.

RESULTS

All participants achieved successful airway access with both methods. Average time to successful airway access for scalpel-based EC was 54 (±31) seconds and for percutaneous EC 89 (±38) seconds, with 35 (95% CI: 14-57) seconds time difference, P = .003. Doctors with recent (<12 months) EC training performed better compared to the non-training group (37 vs 61 seconds, P = .03 for scalpel-based EC, and 65 vs 99 seconds, P = .02 for percutaneous EC). We found no differences according to clinical seniority or previous real-life EC experience.

CONCLUSIONS

Our study demonstrated that anaesthesiologists achieved successful airway access on an animal experimental model with both EC methods within a reasonable time frame, but the scalpel-based EC is performed more promptly. Recent EC training affected the time expenditure positively, while seniority and clinical EC experience did not. EC procedures should be regularly trained for.

Airway Management for Trauma Patients

Trauma airway management is a critical skill for medical providers supporting combat casualties since it is an integral component of damage control resuscitation and surgery. This clinical practice guideline presents methods for optimizing the airway management of patients with traumatic injury in the operational medical treatment facility environment. The guidelines represent the knowledge and experience of 10 co-authors from 3 allied countries representing Emergency Medicine, Surgery and Anesthesia.

Necessity to depict difficult neck anatomy for training of cricothyroidotomy: A pilot study evaluating two surgical devices on a new hybrid training model

BACKGROUND

Everyone dealing with airway emergencies must be able to accomplish cricothyroidotomy, which cannot be trained in real patients. Training models are necessary.

OBJECTIVE

To evaluate the suitability of a hybrid training model combining synthetic and porcine parts to depict variable neck anatomy.

DESIGN

Model-based comparative trial.

SETTING

Armed Forces Hospital Ulm, Germany, August 2018.

INTERVENTION

On four anatomical neck variations (long slim/long obese/short slim/short obese) we performed two surgical approaches to cricothyroidotomy (SurgiCric II vs. ControlCric).

PARTICIPANTS

Forty-eight volunteers divided into two groups based on their personal skill level: beginners group and proficient performers group.

MAIN OUTCOME MEASURES

Time to completion was recorded for each procedure. Once the operator had indicated completion, the correct anatomical tube placement was confirmed by dissection and structures were inspected for complications. Primary outcomes were successful tracheal placement of an airway tube and time needed to achieve a patent airway. Secondary outcome was assessment of complications.

RESULTS

Overall, 384 procedures were performed. Median time to completion was 74 s. In total, 284 procedures (74%) resulted in successful ventilation. Time to completion was longer in short obese than in long slim and the risk of unsuccessful procedures was increased in short obese compared with long slim. Even if ControlCric resulted in faster completion of the procedure, its use was less successful and had an increased risk of complications compared with SurgiCric II. Proficient performers group performed faster but had an increased risk of injuring the tracheal wall compared with beginners group.

CONCLUSION

Participants had difficulties in performing cricothyroidotomy in obese models, but various and difficult anatomical situations must be expected in airway management and therefore must be taught. A new hybrid model combining porcine and synthetic materials offers the necessary conditions for the next step in training of surgical airway procedures.

TRIAL REGISTRATION

The study was performed without human tissue or living animals, and was therefore exempted from ethical review by the University of Ulm Ethical Committee, Germany (Chairperson Prof Dr C. Lenk) on 9 August 2018. Hence a protocol number was not attributed.

Perfecting practice: a protocol for assessing simulation-based mastery learning and deliberate practice versus self-guided practice for bougie-assisted cricothyroidotomy performance

BACKGROUND

Simulation-based medical education (SBME) is a cornerstone for procedural skill training in residency education. Multiple studies have concluded that SBME is highly effective, superior to traditional clinical education, and translates to improved patient outcomes. Additionally it is widely accepted that mastery learning, which comprises deliberate practice, is essential for expert level performance for routine skills; however, given that highly structured practice is more time and resource-intensive, it is important to assess its value for the acquisition of rarely performed technical skills. The bougie-assisted cricothyroidotomy (BAC), a rarely performed, lifesaving procedure, is an ideal skill for evaluating the utility of highly structured practice as it is relevant across many acute care specialties and rare - making it unlikely for learners to have had significant previous training or clinical experience. The purpose of this study is to compare a modified mastery learning approach with deliberate practice versus self-guided practice on technical skill performance using a bougie-assisted cricothyroidotomy model.

METHODS

A multi-centre, randomized study will be conducted at four Canadian and one American residency programs with 160 residents assigned to either mastery learning and deliberate practice (ML + DP), or self-guided practice for BAC. Skill performance, using a global rating scale, will be assessed before, immediately after practice, and 6 months later. The two groups will be compared to assess whether the type of practice impacts performance and skill retention.

DISCUSSION

Mastery learning coupled with deliberate practice provides systematic and focused feedback during skill acquisition. However, it is resource-intensive and its efficacy is not fully defined. This multi-centre study will provide generalizable data about the utility of highly structured practice for technical skill acquisition of a rare, lifesaving procedure within postgraduate medical education. Study findings will guide educators in the selection of an optimal training strategy, addressing both short and long term performance.

Emergency front-of-neck airway by ENT surgeons and residents: A dutch national survey

Objectives

ENT surgeons and anesthesiologists work closely together in managing challenging airway cases. Sharing knowledge, experiences, and expectations interdisciplinary is essential in order to facilitate decision‐making and adequate management in emergency front‐of‐neck airway cases.

Methods

A survey was performed, to analyze level of experience, technique of preference, training, knowledge of material and protocols, and self‐efficacy scores of Dutch ENT surgeons and residents in performing an urgent or emergency front‐of‐neck airway.

Results

Within one year (January 2014–2015), 25.7% of the 257 respondents had performed an urgent or emergency front‐of‐neck airway. Of all reported emergency front‐of‐neck airways (N = 30), 80% were managed by tracheotomy. In future emergency front‐of‐neck airway cases, 74% stated cricothyrotomy would be their technique of preference. The majority would choose an uncuffed large‐bore cannula technique. Post‐academic hands‐on training was attended by 42% of respondents. Self‐efficacy scores were highest for surgical tracheotomy, and higher when trained or experienced. In case of an emergency scenario, 8.6% would not perform a front‐of‐neck airway themselves. The main reasons for reluctance to start in general were lack of experience and lack of training. Reported items for improvement were mainly the development of a protocol and training.

Conclusion

The chance of encountering an airway emergency scenario requiring front‐of‐neck airway is realistic. There is inconsistency between advised technique, technique of preference and technique actually performed by ENT surgeons. This study shows that there is both a need and desire for improvement in training and organization of care. Interdisciplinary guidelines and education is needed and could eventually safe lives.

Level of evidence

5

Cricothyroidotomy In Situ Simulation Curriculum (CRIC Study): Training Residents for Rare Procedures

INTRODUCTION

Technical skill acquisition for rare procedures can be challenging given the few real-life training opportunities. In situ simulation (ISS), a training technique that takes place in the actual workplace, is a promising method to promote environmental fidelity for rare procedures. This study evaluated a simulation-based technical skill curriculum for cricothyroidotomy using deliberate practice, followed by an ISS evaluation session.

METHODS

Twenty emergency medicine residents participated in a two-part curriculum to improve cricothryoidotomy performance. A pretest established participant baseline technical skill. The training session consisted of two parts, didactic teaching followed by deliberate practice using a task-training manikin. A posttest consisted of an unannounced, high-fidelity ISS, during an emergency department shift. The primary outcome was the mean performance time between the pretest and posttest sessions. Skill performance was also evaluated using a checklist scale and global rating scale.

RESULTS

Cricothyroidotomy performance time improved significantly from pretest to posttest sessions (mean difference, 59 seconds; P < 0.0001). Both checklist and global rating scales improved significantly from the pretest to the posttest with a mean difference of 1.82 (P = 0.002) and 6.87 (P = 0.0025), respectively. Postcourse survey responses were favorable for both the overall curriculum experience and the unannounced ISS.

CONCLUSIONS

This pilot study demonstrated that unannounced ISS is feasible and can be used to effectively measure cricothyroidotomy performance among EM residents. After a two-part training session consisting of didactic learning and deliberate practice, improved cricothyroidotomy skill performance was observed during an unannounced ISS in the emergency department. The integration of ISS in cricothyroidotomy training represents a promising approach; however, further study is needed to establish its role.

A Randomized Comparison of Bougie-Assisted and TracheoQuick Plus Cricothyrotomies on a Live Porcine Model

Objectives

Cricothyrotomy is a rescue procedure in “cannot intubate, cannot oxygenate” scenarios where other methods of nonsurgical airway management have failed. We compared 2 cuffed cricothyrotomy sets, bougie-assisted cricothyrotomy (BACT) and novel percutaneous TracheoQuick Plus, on a live porcine model in a simulated periarrest situation.

Methods

Thirty-four anesthetized minipigs were randomly allocated into two groups: BACT technique (n = 17) and TracheoQuick Plus (n = 17). The primary outcome was duration of cricothyrotomy while secondary outcomes were total success rate, number of attempts, location of incision, changes in heart rate, oxygen saturation, and the incidence of complications.

Results

BACT was significantly faster than TracheoQuick Plus cricothyrotomy, with a median time of 69 sec (IQR 56–85) versus 178 sec (IQR 152–272). The total success rate was without difference. 94% of BACT was performed successfully on the first attempt, while in the TracheoQuick Plus group, it was only 18% (P < 0.001). Trauma to the posterior tracheal wall was observed once in the BACT group and 5 times in the TracheoQuick Plus group. Oxygen saturation was significantly higher in the BACT group both during and after the procedure.

Conclusions

BACT is superior to TracheoQuick Plus cricothyrotomy on a live animal model.

Emergency Surgical Airways Following Activation of a Difficult Airway Management Team in Hospitalized Critically Ill Patients: A Case Series

INTRODUCTION

An emergency surgical airway (ESA) is widely recommended for securing the airway in critically ill patients who cannot be intubated or ventilated. Little is known of the frequency, clinical circumstances, management methods, and outcomes of hospitalized critically ill patients in whom ESA is performed outside the emergency department or operating room environments.

METHODS

We retrospectively reviewed all adult patients undergoing ESA in our intensive care units (ICUs) and other hospital units from 2008 to 2012 following activation of our difficult airway management team (DAMT).

RESULTS

Of 207 DAMT activations for native airway events, 22 (10.6%) events culminated in an ESA, with 59% of these events occurring in ICUs with the remainder outside the ICU in the context of rapid response team activations. Of patients undergoing ESA, 77% were male, 63% were obese, and 41% had a history of a difficult airway (DA). Failed planned or unplanned extubations preceded 61% of all ESA events in the ICUs, while bleeding from the upper or lower respiratory tract led to ESA in 44% of events occurring outside the ICU. Emergency surgical airway was the primary method of airway control in 3 (14%) patients, with the remainder of ESAs performed following failed attempts to intubate. Complications occurred in 68% of all ESAs and included bleeding (50%), multiple cannulation attempts (36%), and cardiopulmonary arrest (27%). Overall hospital mortality for patients undergoing ESA was 59%, with 38% of deaths occurring at the time of the airway event.

CONCLUSION

An ESA is required in approximately 10% of DA events in critically ill patients and is associated with high morbidity and mortality. Efforts directed at early identification of patients with a difficult or challenging airway combined with a multidisciplinary team approach to management may reduce the overall frequency of ESA and associated complications.

Great variation between ICU physicians in the approach to making end-of-life decisions

INTRODUCTION

End-of-life (EOL) decision-making in the intensive care unit (ICU) is difficult, but is rarely practiced in simulated settings. We wanted to explore different strategies ICU physicians use when making EOL decisions, and whether attitudes towards EOL decisions differ between a small-group simulation setting and a large-group plenary setting.

METHODS

The study took place during a Scandinavian anaesthesiology and intensive care conference. The simulated ICU patient had a cancer disease with a grave prognosis, had undergone surgery, suffered from severe co-morbidities and had a son present demanding all possible treatment. The participants were asked to make a decision regarding further ICU care. We presented the same case scenario in a plenary session with voting opportunities.

RESULTS

In the simulation group (n = 48), ICU physicians used various strategies to come to an EOL decision: patient-oriented, family-oriented, staff-oriented and regulatory-oriented. The simulation group was more willing than the plenary group (n = 47) to readmit the patient to the ICU if the patient again would need respiratory support (32% vs. 8%, P < 0.001). Still, fewer participants in the simulation group than in the plenary group (21% vs. 38%, P = 0.019) considered the patient's life expectancy of living an independent life to be over 10%.

CONCLUSION

There was great variation between ICU physicians in the approach to making EOL decisions, and large variations in their life expectancy estimates. Participants in the simulation group were more willing to admit and readmit the patient to the ICU, despite being more pessimistic towards life expectancies. We believe simulation can be used more extensively in EOL decision-making training.

Development of a standard operating procedure and checklist for rapid sequence induction in the critically ill

INTRODUCTION

Rapid sequence induction (RSI) of critically ill patients outside of theatres is associated with a higher risk of hypoxia, cardiovascular collapse and death. In the prehospital and military environments, there is an increasing awareness of the benefits of standardised practice and checklists.

METHODS

We conducted a non-systematic review of literature pertaining to key components of RSI preparation and management. A standard operating procedure (SOP) for in-hospital RSI was developed based on this and experience from large teaching hospital anaesthesia and critical care departments.

RESULTS

The SOP consists of a RSI equipment set-up sheet, pre-RSI checklist and failed airway algorithm. The SOP should improve RSI preparation, crew resource management and first pass intubation success while minimising adverse events.

CONCLUSION

Based on the presented literature, we believe the evidence is sufficient to recommend adoption of the core components in the suggested SOP. This standardised approach to RSI in the critically ill may reduce the current high incidence of adverse events and hopefully improve patient outcomes.