High- versus low-fidelity simulation training for emergency front of neck access: A prospective observational study in a Swiss anesthesiology department

Abstract

Background:

Emergency Front Of Neck Access techniques are an essential skill for anesthesiologists, enabling them to effectively manage the critical “can’t intubate, can’t oxygenate” scenarios. Current literature suggests minimal improvement in mortality associated with these scenarios due to their rarity and difficulty in providing adequate training. This study aims to evaluate whether high-fidelity training can outperform low-fidelity training in teaching Emergency Front Of Neck Access.

Methods:

We designed a prospective, single-blinded observational trial to assess the presumed superiority of high-fidelity training compared to low-fidelity training in teaching Emergency Front Of Neck Access to our anesthesiology department. The Performance Rating Scale (PRS) was the tool we employed to assess the participants’ performance during both scenarios. The primary outcome was the difference in PRS between the high- and low-fidelity training groups. The secondary outcomes were the correlation between PRS scores and the participants’ past clinical experience with Emergency Front Of Neck Access, the number of tracheostomies performed, and years of clinical service.

Results:

A total of 30 participants from our anesthesia department were enrolled. There was a statistically significant difference in Performance Rating Scale scores between high-fidelity and low-fidelity training. The low-fidelity group had a median score of 7 (range -7 to 9), while the high-fidelity group had a median score of -3 (range -11 to 11). None of the secondary outcomes reached statistical significance.

Conclusions:

Our findings suggest that the benefits of high-fidelity training may justify the additional costs associated with incorporating it into conventional airway management training.

Introduction

Airway management is a critical skill for anesthesiologists and is burdened with a high incidence of anesthesia-related morbidity and mortality, occurring in up to 1 in 22,000 cases according to NAP4.[1,2,3,4] Emergency cricothyrotomy is a life-saving procedure in ‘cannot ventilate, cannot intubate’ (CICV) scenarios, but it carries significant risks, including long-term complications such as hypoxic brain damage or death.[5,6,7,8]

Key issues contributing to adverse outcomes include the failure to recognise evolving CICV scenarios and delays in performing emergency Front Of Neck Access (eFONA), alongside nontechnical factors like poor communication and teamwork.[2,3,9,10,11,12,13,14]

Despite advances in airway management, the incidence of CICO remains steady at 0.2%.[15,16,17,18] Studies show that even experienced staff have a 25% failure rate in performing cricothyrotomies during simulations.[19,20]

Given the infrequency of real-life cricothyrotomies and the high-stress nature of the procedure, proper training is essential.[2,3,4,5] Simulations provide a safe and effective way to train for this procedure.[21,22,23,24,25] High-fidelity simulations, in particular, replicate the stress and urgency of real-life scenarios. The two most common techniques for eFONA are the “Scalpel-Bougie-Tube” (SBT) technique and the Melker Emergency Cricothyrotomy (MEC) technique. While there is no clear consensus on which is superior,[16,26,27,28] studies suggest that SBT is faster and easier to learn, though it may be more challenging in obese patients.[12,29,30,31] The American Society of Anesthesiologists (ASA) and the Difficult Airway Society (DAS) recommend the SBT technique as the first choice.

For the purposes of this study, only the SBT technique will be taught and evaluated, recalling that, as Crosby et al.[4] point out, the most important positive predictor is mastery of the technique.

In this study, we will focus on teaching and evaluating the SBT technique. While low-fidelity training may be sufficient for developing technical skills, it may not adequately prepare practitioners for the high-stress nature of emergency scenarios, potentially affecting outcomes. Therefore, we aim to test the hypothesis that low-fidelity training may not be enough for imparting adequate eFONA training.

Materials and Methods

Study design

We conducted a single-blinded, observational prospective study to investigate the transferability of the competence acquired during low-fidelity training to a high-fidelity scenario. The subjects involved in the study were not informed about its purpose, and the data gathered were used for evaluating simulations. The primary outcome was the difference in PRS scores between low-fidelity and high-fidelity training. The secondary outcomes were the correlation between PRS scores and the items listed in the precourse questionnaire [Table 1].

Table 1.

Precourse questionnaire

Age
Gender
Medical profession (doctor anesthesiologist, resident anesthesiologist, anesthesiology intwen, anesthesia nurse, anesthesia nurse in training)
Years of clinical practice in critical care
Country of specialist training
Number of Elective Tracheostomies Performed
Number of cricothyroidotomies performed
You have already done theoretical courses on FONA?
Have you already done practical courses on FONA?
If so, with what technique Melker Emergency Cricothyrotomy or SBT (scalpel-bougie-tube)
Do you think you have received adequate training during your specialist training?
From 1 to 5 how important do you think it is to learn how to correctly perform a FONA?
you think you are receiving adequate continuing education on eFONA?
How much confidence do you think you have when performing eFONA? (score from 1 to 10)
How far apart should the retraining be?
Would you be willing to perform an annual retraining to maintain skills?
Would you give us your consent to collect anonymous data about your performance during the high-fidelity simulation?

As a prerequisite to the course, participants were asked to complete a questionnaire to collect their personal data, professional experience, past training in eFONA, preferred eFONA technique, and perceived competency [Table 1]. A specific consent to participate in the study was also obtained.

Participants were recruited from specialized anesthesia nurses, interns, residents, attending anesthesiologists, and consultant anesthesiologists working in the Ospedale Regionale di Lugano’s anesthesiology department, Switzerland. The course began with a 20-minute lecture covering key literature related to eFONA, the necessary theoretical basis for performing the SBT technique (outlines of airway anatomy, indications, national and international guidelines, procedural steps, and considerations for the technical execution), and the basic epidemiological information concerning CICV. Finally, a video demonstrating the procedure was presented.

The second part of the study consisted of 15 minutes dedicated to low-fidelity ‘hands on’ teaching of the SBT technique. A ratio of 4 trainees per 1 tutor was guaranteed. The simulator used was a low-fidelity model of the neck specially designed to practice cricothyrotomy maneuvers (TruCric Surgical Cricothyrotomy Trainer).

Following this phase, participants were tested and evaluated by applying the PRS. The items of the PRS and their relative score are displayed in Table 2. The PRS is a scoring system designed to assess competency in eFONA, taking into account factors such as speed of execution, incidence of periprocedural complications, and confirmation of correct airway device placement. We modified the scoring system in order to assure that a score of ≥ 5, the predefined threshold for a successful eFONA, was attainable only with a properly secured airway in under 120 seconds, two fundamental goals that increase the likelihood of a favorable outcome.

Table 2.

Performance Rating Scale (PRS)

Procedural Step	Successful	Unsuccessful
Airway was secured	-3 (NO)	+3 (YES)
Time to complete the procedure (≤120 sec)	-2 (NO)	+2 (YES)
Number of attempts	-1 (≥2 attempts)	+1 (1 attempt)
Anatomical landmark identification	-1	+1
Tracheal stabilization (with nondominant hand)	-1	+1
Confirmation of correct placement	-1	+1
Injury to the pars membranacea	-1 (no)	+1 (yes)
Proper fastening of the endotracheal tube	-1	+1
	Total:	-11/+11

In the final step, the participants were subjected to high-fidelity simulation that enacted a CICO scenario and were evaluated again using the PRS. Each participant assumed the role of a leader, performing the maneuver in a high-stress scenario to closely simulate real-life CICO situations. Participants awaiting their turn to perform the simulation were not shown the ongoing simulation; only those who had already participated could view it remotely. This was to minimize the potential confounding effects of providing additional training that could not be measured by observing colleagues.

A short debriefing was held at the end of the simulation.

The successful transferability of the competence acquired during low-fidelity training to a high-fidelity scenario was defined a high-fidelity PRS score of ≥5.

The PRS values of both scenarios were stored for future evaluation of competence maintenance.

At the end of the high-fidelity scenario, the participants were asked to complete a postcourse questionnaire.

Statistical analysis

Data were transcribed into a Microsoft Excel 365 spreadsheet for preliminary organization, and statistical analyses were conducted using RStudio (version 4.3). Descriptive statistics summarized the demographic and clinical characteristics of the sample, with continuous variables presented as medians and interquartile ranges (IQR) or means and standard deviations (SD), while categorical variables were described using frequencies and percentages.

The normality of continuous variables was assessed using the Shapiro–Wilk test. For variables that did not meet the assumption of normality, nonparametric methods were employed. The primary outcome, the Performance Rating Score (PRS), was compared between low-fidelity and high-fidelity conditions using the Wilcoxon signed-rank test. Effect sizes were calculated using the rank-biserial correlation (r) to quantify the magnitude of differences observed.

For categorical outcomes, differences between the two fidelity conditions were analyzed using Fisher’s exact test. Additionally, Spearman’s rank correlation coefficient was utilized to evaluate the relationships among years of experience, perceived confidence, and PRS, given the ordinal nature of the confidence variable and the non-normal distribution of PRS. A significance level of P < 0.05 was established for all statistical tests.

Ethical approval was not necessary for this study as it adhered to local legislation and institutional guidelines.

Results

We consecutively enrolled 35 participants registered from April 2024 to May 2024. Five participants were excluded from the study for missing data during the low fidelity trial.

The sample consisted of 30 participants with an average age of 42 years (SD = 8.08). The age distribution ranged from 30 to 55 years. The Shapiro–Wilk test indicated that the age variable was normally distributed, with a P value of 0.053. Gender distribution showed 46.7% (14/30) of participants identified as male and 53.3% (16/30) as female.

Participants had an average of 12.82 years of experience in airway management (SD = 8.26), with a range from 0 to 27 years. When examining the number of tracheostomies performed, participants reported a median of 1.5. The number of cricothyroidotomy was considerably lower, with an average of 0.53 (SD = 1.20) and a median of 0.

Confidence and perceived adequacy

Considering training experiences, 40% (12/30) and 33% (10/30) reported having undergone theoretical and practical courses, respectively; between participants who underwent practical courses, 80% (8/10) practice Melker cricothyrotomy technique. Additionally, 40% of participants felt that their specialized training was adequate, and 40% considered their continuous education sufficient, with an overall agreement of its importance in continuous training programs (96.7%, 29/30, gave an importance of 5 out of 5 points).

Perceived confidence levels among participants varied, with a median confidence rating of 3 on a 10-point scale. Most participants (96.7%) believed that annual practice was adequate for maintaining their skills.

Performance Rating Score analysis

The low-fidelity PRS had a median score of 7, with a range from -7 to 9, while the high-fidelity PRS had a median score of -3, with a range from -11 to 11. Both distributions were non-normal, as indicated by the Shapiro–Wilk tests (P < 0.001 and P = 0.014, respectively).

A Wilcoxon signed-rank test was used to compare the PRS between low-fidelity and high-fidelity conditions. The results indicated a statistically significant difference between the two conditions (V = 354, P < 0.001), with a large effect size (r = -0.63), suggesting that performance was notably different between the two fidelity conditions [Figure 1].

Figure 1.

PRS low vs high fidelity; PRS: Performance Rating Scale

Moreover, we assessed the difference for every aspect of the overall PRS evaluation, assessing the significance between low- and high-fidelity simulation using Fisher test [Figure 2]. We found statistically significantly worse outcomes in the high-fidelity group in the following areas: airway securement (P < 0.001), time to complete the maneuver exceeding 120 seconds (P < 0.001), and the number of attempts greater than 1 (P = 0.020). There were no significant differences in other aspects, including the identification of anatomical landmarks, tracheal stabilization, verification of tube position, damage to the pars membranacea, and tube securement.

Figure 2.

Single components of PRS score in low and high fidelity; PRS: Performance Rating Scale

Correlational analyses

The relationship between years of experience and confidence was examined using Spearman’s correlation, given the ordinal nature of the confidence variable. The Spearman correlation coefficient was 0.33 (P = 0.074), indicating a positive but not statistically significant relationship.

For the relationship between years of experience and low-fidelity PRS, the Spearman correlation was -0.16 (P = 0.389), and for high-fidelity PRS, it was -0.22 (P = 0.237). Neither relationship was statistically significant, suggesting that years of experience did not strongly correlate with PRS in either fidelity condition.

The relationship between perceived confidence and PRS showed a Spearman correlation of -0.25 (P = 0.186) for low-fidelity PRS and 0.02 (P = 0.907) for high-fidelity PRS, indicating no significant correlation.

When gender was considered, the Spearman correlation between gender and low-fidelity PRS was -0.28 (P = 0.130) and that between gender and high-fidelity PRS was -0.19 (P = 0.311). Again, these relationships were not statistically significant.

Discussion

Our current study prospectively investigated how low-fidelity training and high-fidelity training affect the performance of a low incidence and highly stressful procedure such as eFONA.

There was a statistically significant difference between the high- and low-fidelity PRS scores. Specifically, the low fidelity had a median score of 7 (-7 to 9), while the high-fidelity group had a median score of -3, (-11 to 11). None of the secondary outcomes were statistically significant.

The primary outcome confirms our initial hypothesis that low-fidelity training is an effective tool for teaching and practicing the technical skill required of eFONA since it allows the participant to repeatedly rehearse the technique with minimal distractions, such as the monitor’s alarms or interactions with the support staff. However, once the scenario closely mirrors the clinical reality of an airway emergency, the success rate of the procedure drastically drops to worrisome levels. It is our belief that this decline in performance is mostly due to the lacking nontechnical skills required to properly handle the psychological stress experienced during high-fidelity scenarios. Factors such as anxiety, inadequate communication techniques, lack of familiarity with the equipment, and environmental noise, especially alarms, contribute to sensory overload and diminished performance. Our study thus supports the need to include nontechnical skills in the competencies taught during eFONA training.

It is interesting to note that less than half of participants reported having received theoretical training in eFONA and even fewer underwent specific practical training. These results are in line with the existing literature and highlight the need for improved eFONA training for anesthesia practitioners since there is always a risk of CICO when attempting to secure an airway.

Among those who received practical training, Melker technique was the most commonly taught. This technique bears many similarities to the elective percutaneous tracheostomy technique often employed in the intensive care unit. We believe that since most of our participants are specialized in both anesthesia and critical care medicine, they were taught Malker’s approach instead of SBT in the hope of leveraging on the transferability of the skill, even if some guidelines do not support it.

Less than half of the participants believed they received adequate training during their residency, and a similar number of participants stated that they receive adequate continuous education on eFONA. These data further support our hypothesis that participants may feel and actually be competent in performing the technical aspect of SB; however, when faced with the added difficulty of managing all the nontechnical skills, they may fail to complete the scenario. Therefore, specific nontechnical skills training should be considered when designing an eFONA training program.

Airway management is a fundamental skill that every anesthetist must master in order to administer general anesthesia and secure the airway during both in-hospital and out-of-hospital emergencies. A significant percentage of anesthesia-related morbidity and mortality is caused by inadequate airway management.[1,2,3,4] The National Audit Project 4 in the UK reported that the incidence of major complications related to unanticipated difficult airway management is at least one in 22,000 cases.[2,3] Recent work confirms an elevated rate of serious adverse events such as hypoxic brain damage or death in this cohort of patients.[5,6]

Analysis of these adverse events related to failed airway management showed that the failure to recognize an evolving scenario as CICO and the inability to access the airway quickly through emergency front-of-neck access (eFONA) via cricothyrotomy are significant issues.[2,3,9,10,11,12,13,14] Another significant element is related to nontechnical skills: Inadequate communication and suboptimal teamwork dynamics seem to contribute to the morbidity in this context.[9]

Despite considerable improvements in airway management over the past decade, the incidence of CICO (estimated 0.2%[15,39]) has not decreased over the years.[16,17,18] A survey conducted from 2011 to 2015 in the Houston Emergency and Urgent Care Department reported an incidence rate of cricothyrotomy of 0.5%.[32] According to the NEAR III investigators, approximately 0.31% of the patients who were candidates for intubation underwent eFONA,[19] whereas in the COVID population, the need for an emergent surgical access was 0.22%.[20]

The performance of medical and nursing staff in emergency cricothyrotomy evaluated through low-fidelity and high-fidelity simulations, measured with the PRS, shows that the failure rate in performing cricothyrotomies is by no means low even in experienced staff (about 25%).[2,33] In line with the report of the National Confidential Enquiry into Patient Outcome and Death (NCEPOD) “Tracheostomy care: on the right trach” and the DAS recommendations regarding adequate training to deal with the emergency CVCO scenario to all critical care personnel, we consider specific training in emergent cricothyrotomy to be essential.[29,34] The critical nature of this scenario is related to the rarity of the procedure and to the high stress levels perceived by the operators. Field training during routine clinical care not only is risky for the patients but also does not provide enough practice and procedural knowledge.[2,5]

A proven alternative instrument to train invasive medical procedures while ensuring the safety of both operators and patients is simulation-based training.[21,22,23,24,25] The literature includes several studies that have employed low-fidelity simulations due to their ease of organization and lower cost. However, high-fidelity training is gaining popularity since it allows for a better enactment of the high stress environment during the performance of eFONA.

The “Scalpel-Bougie-Tube” technique (SBT) and the Melker Emergency Cricothyrotomy (MEC) technique are the two primary approaches for emergency front-of-neck access.[40]

Although the available literature does not establish a clear superiority between these techniques,[40] SBT can be considered the fastest and most reliable in securing the airway.[30,35] It is recommended as the first choice by the American Society of Anesthesiologists (ASA) in their 2016 guidelines and by the Difficult Airway Society (DAS) in their 2015 and 2018 guidelines.[29,30,36,37,38] The 2022 FLAVA (The Fondation Latine des Voies Aériennes) guidelines by the Swiss Latin Airway Society identify SBT as the preferred approach for eFONA as it is the easiest and quickest technique to secure the airway. MEC is classified as a second choice, appropriate only for personnel with significant experience. The most recent ASA 2022 guidelines suggest identifying a preferred approach in the case of CICO, considering the second approach only in selected cases or if the first-choice approach is not feasible.[30]

The major limitation of our study is the sample size of the participants. We acknowledge this problem, but by training our entire department, we believe we can offer an interesting insight into our clinical practice and preparedness, with success rates comparable to those reported in the literature.

A strength of our study is that each participant was tested immediately with both high- and low-fidelity simulations, with no significant time lag between the two types. Additionally, these results will act as a benchmark to justify further training and retraining of our anesthesia staff, enabling us to define the timeframe for optimal skill retention.

Conclusions

Our study suggests that low-fidelity training is an adequate tool for teaching the basic procedural aspect of eFONA but fails to adequately prepare an anesthesiologist for a CICO scenario, where nontechnical skills and environmental stressors significantly hinder the efficient execution of eFONA. High-fidelity training may be the best approach for teaching eFONA as it addresses both the technical and nontechnical aspects of this life saving procedure, mimicking as closely as possible a real-life scenario.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.