Comparison of four manikins and fresh frozen cadaver models for direct laryngoscopic orotracheal intubation training

Four different models for simulation-based training of bronchoscopic procedures

BACKGROUND

Flexible bronchoscopy procedures require detailed anatomical knowledge and advanced technical skills. Simulation-based training offers a patient-safe training environment that can be more efficient than patient-based training. Physical models are cheaper than virtual reality simulators and allow trainees to be acquainted with the equipment used in the clinic. The choice of a physical model for training depends on the local context. The aim of this study was to compare four different bronchoscopy models for flexible bronchoscopy training.

METHODS

The BronchoBoy manikin, the Koken manikin, a human cadaver, and a preserved porcine lung were included in the study. Seven physicians experienced in bronchoscopy performed a bronchoscopic airway inspection, bronchoalveolar lavage (BAL), and tissue sampling on all four models with performance evaluated by observation and participant evaluation of models by questionnaire.

RESULTS

Nineteen segments were identified in all human anatomy models, and the only significant difference found was that only the Thiel embedded cadaver allowed all participants to enter RB1 with an instrument in the working channel (p = 0.001). The Thiel embedded cadaver and the BronchoBoy manikin had low fluid return on BAL (22 and 52 ml), whereas the Koken manikin and the preserved porcine lung had high return (132 and 134 ml), (p = 0.017). Tissue samplings were only completed in the preserved porcine lung and the Thiel embedded cadaver (p < 0.001).

CONCLUSIONS

An anatomically correct bronchoscopy is best simulated with the Koken manikin or the Thiel embedded cadaver. Bronchoalveolar lavage should be simulated with the Koken manikin or the preserved porcine lung. Tissue sampling procedures are best simulated using the Thiel embedded cadaver or the preserved porcine lung.

Comparison of Time to Intubation of a Double-Lumen Endobronchial Tube Utilizing C-MAC® Versus GlideScope® Versus Macintosh Blade: A Randomized Crossover Manikin Study

BACKGROUND

Macintosh blade direct laryngoscopy is widely used for endotracheal intubation. It may, however, provide an incomplete view of the glottis in patients with challenging airway anatomy. Consequently, various video laryngoscopes have been developed to enhance the visualization of the glottis and facilitate intubation. Yet, the effectiveness of these video laryngoscopes for intubation using a double-lumen endotracheal tube (DLT), which is longer, larger, and more rigid and has a linear configuration as opposed to the naturally semicircular curvature of a single-lumen endotracheal tube, remains uncertain. We hypothesized that video laryngoscopes would be more efficient for DLT intubation compared to the Macintosh blade in an adult manikin.

METHODS

Ninety-four anesthesia providers, comprising 67 residents, 15 fellows, and 12 attendings, attempted to intubate an adult manikin with normal airway anatomy (Laerdal, Wappingers Falls, NY, USA) using a 37 Fr left-sided DLT. Three different intubation devices were used: the C-MAC® video laryngoscope (Karl Storz GmbH & Co. KG, Tuttlingen, Germany), the GlideScope® video laryngoscope (Verathon Inc., Bothell, WA), and the Macintosh blade direct laryngoscope-were used. Each participant intubated a manikin once with each of the three devices. Participants were randomized via a crossover design with the order of devices determined by using a Latin square design. Time to intubation and the number of failed intubations (esophageal intubation) were compared across the three different devices.

RESULTS

Mean times to intubation for the C-MAC®, GlideScope®, and Macintosh blades were 18.57 ± 0.77, 36.26 ± 2.69, and 20.76 ± 0.96 seconds, respectively. There was a statistically significant difference (P<0.001) between the GlideScope® and the other two laryngoscopes. The times for C-MAC® and Macintosh blades were not significantly different. There were two instances of first-attempt failed intubation with the Macintosh.

CONCLUSION

Both the C-MAC® and the Macintosh blades proved more efficient in terms of time to DLT intubation in the manikin with normal airway anatomy, when compared to the GlideScope®. Considering the occurrence of first-attempt failed intubation, the C-MAC® was the most effective device among the three laryngoscopes for timely successful DLT intubation in the adult manikin. Further studies are needed to confirm these results in human subjects.

Technology-enhanced simulation in emergency medicine: Updated systematic review and meta-analysis 1991-2021

Background

Over the past decade, the use of technology-enhanced simulation in emergency medicine (EM) education has grown, yet we still lack a clear understanding of its effectiveness. This systematic review aims to identify and synthesize studies evaluating the comparative effectiveness of technology-enhanced simulation in EM.

Methods

We searched MEDLINE, EMBASE, PsycINFO, CINAHL, ERIC, Web of Science, and Scopus to identify EM simulation research that compares technology-enhanced simulation with other instructional modalities. Two reviewers screened articles for inclusion and abstracted information on learners, clinical topics, instructional design features, outcomes, cost, and study quality. Standardized mean difference (SMD) effect sizes were pooled using random effects.

Results

We identified 60 studies, enrolling at least 5279 learners. Of these, 23 compared technology-enhanced simulation with another instructional modality (e.g., living humans, lecture, small group), and 37 compared two forms of technology-enhanced simulation. Compared to lecture or small groups, we found simulation to have nonsignificant differences for time skills (SMD 0.33, 95% confidence interval [CI] -0.23 to 0.89, n = 3), but a large, significant effect for non-time skills (SMD 0.82, 95% CI 0.18 to 1.46, n = 8). Comparison of alternative types of technology-enhanced simulation found favorable associations with skills acquisition, of moderate magnitude, for computer-assisted guidance (compared to no computer-assisted guidance), for time skills (SMD 0.50, 95% CI -1.66 to 2.65, n = 2) and non-time skills (SMD 0.57, 95% CI 0.33 to 0.80, n = 6), and for more task repetitions (time skills SMD 1.01, 95% CI 0.16 to 1.86, n = 2) and active participation (compared to observation) for time skills (SMD 0.85, 95% CI 0.25 to 1.45, n = 2) and non-time skills (SMD 0.33 95% CI 0.08 to 0.58, n = 3).

Conclusions

Technology-enhanced simulation is effective for EM learners for skills acquisition. Features such as computer-assisted guidance, repetition, and active learning are associated with greater effectiveness.

Emergency Critical Skills Training for Pre-clinical Physician Assistant Students: Mixed Method Comparison of Training Method

INTRODUCTION

The fast-paced nature of physician assistant (PA) programs warrants an emphasis on high-fidelity, critical care skills training. Generally, manikins or task trainers are used for training and assessing. Soft-preserved cadavers provide a high-fidelity model to teach high-acuity, low-opportunity procedures; however, their effectiveness in PA pre-clinical training is not well understood.

OBJECTIVE

This study compared procedural competency of task trainer and soft-preserved cadaver trained pre-clinical PA (pcPA) students in completing tube thoracostomy, endotracheal intubation, intraosseous infusion, and needle thoracostomy.

METHODS

A randomized controlled study was conducted with pcPA students (n = 48) at a midwestern program. Participants were randomly assigned to cadaver trained (CT), task trainer (TT), or control group (CG). We assessed procedural competency using skill-specific rubrics and performed qualitative analysis of student comments regarding skill-specific procedural preparedness.

RESULTS

Intervention groups surpassed the control group on all skills. The CT students exhibited significantly higher procedural competency compared to TT-trained students in endotracheal intubation (p = 0.0003) and intraosseous infusion (p = 0.0041). Thematic analysis of student comments revealed pre-training students consistently felt unprepared and lacked confidence to perform needle thoracostomy, tube thoracostomy, and endotracheal intubation. Post-training perceptions, CT/TT, focused on preparedness and confidence. The CT group also consistently described the impact of realistic simulation.

CONCLUSION

High-fidelity training with soft-preserved cadavers may be the most effective way to prepare pcPA students to perform endotracheal intubation and intraosseous infusion. Student perspectives on procedural preparedness highlight the importance of multidimensional, realistic training methods.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40670-022-01575-0.

Current and potential use of fresh frozen cadaver in surgical training and anatomical education

As surgical procedures continue to be more complex, the need for more effective training in anatomy has increased. The study of anatomy plays a significant role in the understanding of the human body as well as in basic and advanced clinical training. Among the different cadaver models, fresh frozen cadavers (FFCs) are known for their realistic tissue quality. The purpose of this article was to review and summarize the preparation procedures for and reported cases involving FFCs. PubMed, Scopus, Medline, and Web of Science were searched for relevant studies. The preparation procedures were divided into five steps: washing, irrigation, freezing, defrosting, and arterial infusion. Not all steps were reported to be mandatory, but omitting one or more could result in a loss of quality. FFCs were reported to be used for various purposes: undergraduate education, general surgery training, vascular surgery training, minimal access surgery (laparoscopic surgery) training, and microsurgery training. In all categories, expert opinions and statistical analyses indicated successful outcomes. The reasons for high satisfaction with FFCs included realistic texture, capability of reenacting actual operations, and accuracy of anatomical locations. The results also revealed the importance and advantages of the dissection courses in surgical training. Since the direct comparison between cadaver models is insufficient, future studies regarding this topic are deemed necessary. In addition, it would be advantageous to develop methods to improve FFC quality, or ideas to optimize this model for certain purposes.

Which Way Would You Slice It? Evaluation of 3 Educational Models for the Loop Drainage Technique

INTRODUCTION

Emergency department visits for cutaneous abscesses are increasing. It is important for healthcare professionals to be proficient in identifying and treating abscesses. Loop drainage technique (LDT) is a newer technique which has been described in several articles but limited resources for teaching have been studied. The objective of this study was to compare 3 models for learning and teaching the LDT.

METHODS

This was a prospective survey study of a convenience sample of emergency medicine residents at a large urban academic center. Residents volunteered to participate during a scheduled cadaver and simulation session. After a self-directed review of the LDT, each participant performed ultrasound visualization and then the LDT on 3 simulated abscesses: a cadaveric model, a commercial abscess pad, and a homemade phantom. Participants completed pre- and post-simulation surveys.

RESULTS

Of 57 residents, 28 participated in the 1-day simulation. The majority (57.1%, p < 0.009) preferred the cadaver model for learning the LDT, and 78.6% reported it to have the most realistic physical examination for an abscess (p = 0.001). Prior to participation, 0% of residents felt proficient performing LDT. After participation, 46.4% of residents felt proficient and 78.6% reported intent to use in clinical practice (p < 0.001).

CONCLUSIONS

Simulation is an effective educational tool for both learning new skills and improving procedural competency. Residents found cadavers provided the most realistic physical examination, and the majority preferred it for learning the LDT. However, cadavers are not always accessible, an important factor when considering various educational settings.

Re-creating reality: validation of fresh frozen full cadaver airway training with videolaryngoscopy and bougie FIRST strategy

Background

Tracheal intubation is the gold standard in emergency airway management. One way of measuring intubation quality is first pass success rate (FPSR). Mastery of tracheal intubation and maintenance of the skill is challenging for non-anesthesiologists. A combination of individual measures can increase FPSR. Videolaryngoscopy is an important tool augmenting laryngeal visualization. Bougie-first strategy can further improve FPSR in difficult airways. Standardized positioning maneuvers and manipulation of the soft tissues can enhance laryngeal visualization. Fresh frozen cadavers (FFC) are superior models compared to commercially manufactured manikins. By purposefully manipulating FFCs, it is possible to mimic the pre-hospital intubation conditions of helicopter emergency medical service (HEMS).

Methods

Twenty-four trauma surgeons (12 per Group, NOVICES: no pre-hospital experience, HEMS: HEMS physicians) completed an airway training course using FFCs. The FFCs were modified to match airway characteristics of 60 prospectively documented intubations by HEMS physicians prior to the study (BASELINE). In four scenarios the local HEMS airway standard (1: unaided direct laryngoscopy (DL), OLD) was compared to two scenarios with modifications of the intubation technique (2: augmented DL (bougie and patient positioning), 3: augmented videolaryngoscopy (aVL)) and a control scenario (4: VL and bougie, positioning by participant, CONTROL). FPSR, POGO score, Cormack and Lehane grade and duration of intubation were recorded. No participant had anesthesiological qualifications or experience in VL.

Results

The comparison between CONTROL and BASELINE revealed a significant increase of FPSR and achieved C&L grade for HEMS group (FPSR 100%, absolute difference 23%, p ≤ .001). The use of videolaryngoscopy, bougie, and the application of positioning techniques required significantly more time in the CONTROL scenario (HEMS group: mean 34.0 s (IQR 28.3–47.5), absolute difference to BASELINE: 13.0 s, p = .045). The groups differed significantly in the median number of real-life intubations performed in any setting (NOVICES n = 5 (IQR 0–18.75), HEMS n = 68 (IQR 37.25–99.75)). In the control scenario no significant differences were found between both groups. The airway characteristics of the FFC showed no significant differences compared to BASELINE.

Conclusion

Airway characteristics of a pre-hospital patient reference group cared for by HEMS were successfully reproduced in a fresh frozen cadaver model. In this setting, a combination of evidence based airway management techniques results in high FPSR and POGO rates of non-anesthesiological trained users. Comparable results (FPSR, POGO, duration of intubation) were achieved regardless of previous provider experience. The BOAH concept can therefore be used in the early stages of airway training and for skill maintenance.

Open vascular surgery training in the endovascular era: 5-year experience with cadaver laboratory

BACKGROUND

Vascular cadaver laboratory (CAD LAB) courses included vascular exposure techniques and simulations of open procedures. Aim of the study was to demonstrate the benefit of cadaver laboratory (CAD LAB) courses to improve trainees' experience in open surgical vascular procedures.

METHODS

Between 2014 and 2020, 162 vascular surgeons or medical trainees (mean age 28 years) participated in vascular CAD LAB courses in Italy and France. Outcomes were measured using the Linkert survey, performed pre- and post-course to evaluate self-efficacy/confidence, surgical experience and resident perception of the course with a range score from 0 to 5 for each point. Anatomical knowledge improvement was measured using a questionnaire with multiple answers pre- and post-course. The course was considered to have yielded a positive result if the post-course Linkert survey score increased by ≥2 points, or in the case of an increase of at least 30% above the baseline value of the multiple questionnaires.

RESULTS

Post-course questionnaires were positive for all outcomes evaluated. Participants' perception of the usefulness of the CAD LAB evaluation was 4.8 out of 5. For the vascular CAD LAB, participant anatomical knowledge improved overall from an average of 55% to 93% (P < .001), and self-efficacy/confidence improved from 2.3 to 4.5 out of 5 (P < .001). Regarding the different operative procedures, the greatest self-efficacy/confidence improvement was recorded in carotid endarterectomy and aortic procedures (+50% and +66% respectively; P < .001). The city location (Italy vs. France) did not affect the results.

CONCLUSIONS

CAD LAB courses were shown to be effective in increasing participants' self-efficacy, confidence, and anatomical knowledge in open vascular surgical procedures.

Anatomical Evaluation of Rat and Mouse Simulators for Laboratory Animal Science Courses

Simple Summary

Over the past decades simulators of rats and mice have been developed as initial training devices for prospective researchers involved in animal testing. By using these simulators, different techniques such as blood sampling can be be learned prior to working on live animals. As this has the potential to minimize stress and suffering of experimental animals, the use of simulators is demanded by European law. Nevertheless, only little is known about frequency of their use, their anatomical correctness and learning efficiency. With this in mind, a collaborative research project named “SimulRATor” was initiated to systematically evaluate existing rat and mouse simulators. Results will serve as the basis for the development of a new 3D-printed rat simulator with realistic anatomy. In the subproject presented here, simulators were evaluated by experts of the field in order to analyze their anatomical strengths and weaknesses. The evaluation showed, that the limbs and especially the heads were perceived as anatomically unrealistic. Therefore, the authors will focus on these body regions during the construction process by e.g. including movable limbs, and a lower jaw with a tongue. This might positively affect the learning process and outcome and thereby support animal welfare.

Abstract

According to the European Directive 63/2010/EU, education and training involving living rats and mice are classified as an animal experiment and demands the implementation of the 3Rs. Therefore, as a method of refinement, rat and mouse simulators were developed to serve as an initial training device for various techniques, prior to working on living animals. Nevertheless, little is known about the implementation, anatomical correctness, learning efficiency and practical suitability of these simulators. With this in mind, a collaborative research project called “SimulRATor” was initiated to systematically evaluate the existing rat and mouse simulators in a multi-perspective approach. The objective of the study presented here was to identify the anatomical strengths and weaknesses of the available rat and mouse simulators and to determine anatomical requirements for a new anatomically correct rat simulator, specifically adapted to the needs of Laboratory Animal Science (LAS) training courses. Consequently, experts of Veterinary Anatomy and LAS evaluated the anatomy of all currently available rat and mouse simulators. The evaluation showed that compared to the anatomy of living rats and mice, the tails were perceived as the most anatomically realistic body part, followed by the general exterior and the limbs. The heads were rated as the least favored body part.

Intubation using VieScope vs. Video laryngoscopy in full personal protective equipment - a randomized, controlled simulation trial

BACKGROUND

VieScope is a new type of laryngoscope, with a straight, transparent and illuminated blade, allowing for direct line of sight towards the larynx. In addition, VieScope is disposed of after single patient use, which can avoid cross-contaminations of contagious material. This has gained importance especially when treating patients with highly contagious infectious diseases, such as during the SARS-CoV2 pandemic. In this context, VieScope has not been evaluated yet in a clinical study.

MATERIAL AND METHODS

This study compared intubation with VieScope to video-laryngoscopy (GlideScope) in normal and difficult airway in a standardized airway manikin in a randomized controlled simulation trial. Thirty-five medical specialists were asked to perform endotracheal intubation in full personal protective equipment (PPE). Primary endpoint was correct tube position. First-pass rate (i.e., success rate at the first attempt), time until intubation and time until first correct ventilation were registered as secondary endpoints.

RESULTS

For correct tracheal tube placement, there was no significant difference between VieScope and GlideScope in normal and difficult airway conditions. VieScope had over 91% fist-pass success rate in normal airway setting. VieScope had a comparable success rate to GlideScope in difficult airway, but had a significantly longer time until intubation and time until ventilation.

CONCLUSION

VieScope and GlideScope had high success rates in normal as well as in difficult airway. There was no unrecognized esophageal intubation in either group. Overall time for intubation was longer in the VieScope group, though in an acceptable range given in literature. Results from this simulation study suggest that VieScope may be an acceptable alternative for tracheal intubation in full PPE.

TRIAL REGISTRATION

The study was registered at the German Clinical Trials Register www.drks.de (Registration date: 09/11/2020; TrialID: DRKS00023406 ).

Enhanced Experiential Learning in Airway Management: Surgical Modification of Cadavers

INTRODUCTION

Failure of airway management remains a significant source of morbidity and mortality. Advanced airway management has been addressed effectively by simulation-based training. However, simulation of difficult airways in manikins is limited by the pre-set conditions provided by the manufacturer. Life-like conditions in the form of the softness of the tissue and true anatomy as seen in cadaver models are needed to create simulated models with a closer resemblance to real patients. The goal of this study was to determine the feasibility of simulating difficult airway from submandibular abscess in cadaver models by surgical modification of the cadaver heads for use in enhanced experiential learning of the management of difficult airways.

METHODS

The cadaver heads were modified surgically to simulate a submandibular abscess. The models were used in an airway course where participants provided feedback on the realistic nature of the model and its benefits for difficult airway training. The ease of tracheal intubation of the models with the assistance of video laryngoscopy was assessed.

RESULTS

The modified cadavers were acceptable in simulating difficult airway as demonstrated by the feedback from the participants. All participants (100% [95% confidence interval = 89.1%-100%]) found the models to be realistic and beneficial for difficult airway training. A good proportion (56.3%) felt that the intubation technique was made easier with the video laryngoscopy.

CONCLUSIONS

Cadavers can be modified to simulate pathologies associated with difficult airways. These models can be used to enhance experiential learning and the management of difficult airways.

Improving the quality of training paramedics by means of cadavers - a pilot study

BACKGROUND

Paramedics are authorised to perform emergency procedures, including trauma assessment according to global standards. The aim of the study was to answer the question whether the use of cadavers in teaching practical competencies to medical rescue students, in the field of trauma assessment, is necessary as a supplement to learning in simulated conditions with the use of mannequins.

METHODS

Research included several stages. The first stage was conduction of classes for 27 students in the field of rapid trauma assessment, in accordance with the guidelines of the International Trauma Life Support. In the second stage, a plan of a test in which students had to perform an analogous procedure of rapid trauma assessment, but with the use of cadavers, human unfixed specimens, was prepared. The Delphi method was used to develop and approve checklists, as well as a scale to assess the global correctness of identification of head, torso and limb injuries by medical rescue students.

RESULTS

The identification rate was 76.54% in the head area, 67.90% in the torso area, while in the limb area it equalled 44.45%. A significant difference in scores, compared to the examination performed on a mannequin, was observed (Wilcoxon = 4.541; p = 0.000). The most difficult to make a correct diagnosis were injuries related to a fracture of the proximal end of the femur and a dislocated wrist (only 18.52% of correct answers). The students highly rated the usefulness of the examination, by awarding it an average of 4.76 points (SD ± 0.56) on the Likert scale (0-5).

CONCLUSIONS

The study shows that the use of cadavers to teach practical competencies in the field of trauma assessment to medical rescue students can be an effective supplement to simulated learning. Students could feel the difference between the human body and the mannequin. More research is needed to assess whether realistic simulation translates into objective endpoints, such as the effectiveness of diagnosis in the examination of trauma patients. However, it should be remembered that the introduction of this teaching method is expensive and requires adequate base, as well as the compliance with a number of formal requirements.

The Usefulness of Saturated Salt Solution Embalming Method for Oral Surgical Skills Training: A New Cadaveric Training Model for Bone Harvesting

The purpose of this study was to assess the usefulness of saturated salt solution-embalmed cadavers for oral surgical skills training related to bone graft harvesting. Two half-day surgical skills training workshops were held at the Tokyo Medical University utilizing eight cadavers embalmed with the saturated salt solution. A total of 22 participants including oral surgeons, residents, and dentists attended the workshop. Surgical training consisted of six procedures related to intraoral and extraoral bone harvesting. The participants were surveyed to assess self-confidence levels for each surgical procedure before and after completion of each workshop. The Wilcoxon signed-rank test was used to compare the differences between each median score before and after the workshop. There were statistically significant increases in the self-assessed confidence scores in bone harvesting procedures for the zygomatic bone (P = 0.003), maxillary tuberosity (P = 0.002), and other sites (P < 0.001). The anatomical features of saturated salt solution-embalmed cadavers were also examined. The textures of the oral mucosa and skin were similar to those of living individuals. The structure of bone tissues was well-preserved and the hardness was realistic. Consequently, all procedures were performed with sufficient realism. The saturated salt solution method has a relatively low cost of preparation and storage, and almost no odor. The authors suggest that saturated salt solution-embalmed cadavers could provide a new model for oral surgical skills training in bone harvesting.

Suitability and realism of the novel Fix for Life cadaver model for videolaryngoscopy and fibreoptic tracheoscopy in airway management training

Background

Videolaryngoscopy is increasingly advocated as the standard intubation technique, while fibreoptic intubation is broadly regarded as the ‘gold standard’ for difficult airways. Traditionally, the training of these techniques is on patients, though manikins, simulators and cadavers are also used, with their respective limitations. In this study, we investigated whether the novel ‘Fix for Life’ (F4L) cadaver model is a suitable and realistic model for the teaching of these two intubation techniques to novices in airway management.

Methods

Forty consultant anaesthetists and senior trainees were instructed to perform tracheal intubation with videolaryngoscopy and fibreoptic tracheoscopy in four F4L cadaver models. The primary outcome measure was the verbal rating scores (scale 1–10, higher scores indicate a better rating) for suitability and for realism of the F4L cadavers as training model for these techniques. Secondary outcomes included success rates of the procedures and the time to successful completion of the procedures.

Results

The mean verbal rating scores for suitability and realism for videolaryngoscopy was 8.3 (95% CI, 7.9–8.6) and 7.2 (95% CI, 6.7–7.6), respectively. For fibreoptic tracheoscopy, suitability was 8.2 (95% CI, 7.9–8.5) and realism 7.5 (95% CI, 7.1–7.8). In videolaryngoscopy, 100% of the procedures were successful. The mean (SD) time until successful tracheal intubation was 34.8 (30.9) s. For fibreoptic tracheoscopy, the success rate was 96.3%, with a mean time of 89.4 (80.1) s.

Conclusions

We conclude that the F4L cadaver model is a suitable and realistic model to train and teach tracheal intubation with videolaryngoscopy and fibreoptic tracheoscopy to novices in airway management training.

Automated Assessment of Neonatal Endotracheal Intubation Measured by a Virtual Reality Simulation System

Manual assessment from experts in neonatal endotracheal intubation (ETI) training is a time-consuming and tedious process. Such subjective, highly variable, and resource-intensive assessment method may not only introduce inter-rater/intra-rater variability, but also represent a serious limitation in many large-scale training programs. Moreover, poor visualization during the procedure prevents instructors from observing the events occurring within the manikin or the patient, which introduces an additional source of error into the assessment. In this paper, we propose a physics-based virtual reality (VR) ETI simulation system that captures the entire motions of the laryngoscope and the endotracheal tube (ETT) in relation to the internal anatomy of the virtual patient. Our system provides a complete visualization of the procedure, offering instructors with comprehensive information for accurate assessment. More importantly, an interpretable machine learning algorithm was developed to automatically assess the ETI performance by training on the performance parameters extracted from the motions and the scores rated by experts. Our results show that the leave-one-out-cross-validation (LOOCV) classification accuracy of the automated assessment algorithm is 80%, which indicates that our system can reliably conduct a consistent and standardized assessment for ETI training.

A Physics-based Virtual Reality Simulation Framework for Neonatal Endotracheal Intubation

Neonatal endotracheal intubation (ETI) is a complex procedure. Low intubation success rates for pediatric residents indicate the current training regimen is inadequate for achieving positive patient out-comes. Computer-based training systems in this field have been limited due to the complex nature of simulating in real-time, the anatomical structures, soft tissue deformations and frequent tool interactions with large forces which occur during actual patient intubation. This paper addresses the issues of neonatal ETI training in an attempt to bridge the gap left by traditional training methods. We propose a fully interactive physics-based virtual reality (VR) simulation framework for neonatal ETI that converts the training of this medical procedure to a completely immersive virtual environment where both visual and physical realism were achieved. Our system embeds independent dynamics models and interaction devices in separate modules while allowing them to interact with each other within the same environment, which offers a flexible solution for multi-modal medical simulation scenarios. The virtual model was extracted from CT scans of a neonatal patient, which provides realistic anatomical structures and was parameterized to allow variations in a range of features that affect the level of difficulty. Moreover, with this manikin-free VR system, we can capture and visualize an even larger set of performance parameters in relation to the internal geometric change of the virtual model for real-time guidance and post-trial assessment. Lastly, validation study results from a group of neonatologists are presented demonstrating that VR is a promising platform to train medical professionals effectively for this procedure.

Pecha Kucha with Part-Task Training Improves Airway Management in Fresh Frozen Cadavers: A Case-Control Observational Study

OBJECTIVE

The objective of this study was to ascertain whether the addition of part-task training as a step in Pecha Kucha for fiberoptic tracheal intubation increases the success rate and reduces the complication rate.

SUBJECTS AND METHODS

The residents of the Department of Anesthesiology were initially included in an orientation program. We used the Pecha Kucha method for the presentation of teaching fiberoptic intubation skills. Afterwards the participants were trained in Laerdal® airway management and each participant performed tracheal intubation using the Aintree catheter. The participants were divided into two groups. Group 1 (n = 9) received part-task training and group 2 (n = 9) received whole-task training. The tracheal intubation performances of participants were evaluated on fresh frozen cadavers. The number of interventions, incidence of complications, success rate, and optimization maneuver requirements were recorded.

RESULTS

Eighteen residents aged between 27 and 33 years were included. All were junior residents with less than 2 years of experience. There was no significant difference in terms of duration of tracheal intubation, complication rates, and optimization maneuvers between the study groups. Six participants could not place the tracheal tube in the last section. The success rates for the part-task group during Aintree and tracheal tube placement were 100 and 66.7%, respectively, whereas the rates were 55.6 and 44.4%, respectively, in whole-task group (p < 0.05).

CONCLUSION

In addition to the Pecha Kucha method in fiberoptic intubation training, simulation-based part-task training appears to increase the success rate and to reduce the complication rate on fresh frozen cadavers.

Teaching Endotracheal Intubation Using a Cadaver Versus a Manikin-based Model: a Randomized Controlled Trial

INTRODUCTION

The optimal method to train novice learners to perform endotracheal intubation (ETI) is unknown. The study objective was to compare two models: unembalmed cadaver vs simulation manikin.

METHODS

Fourth-year medical students, stratified by baseline ETI experience, were randomized 1:1 to train on a cadaver or simulation manikin. Students were tested and video recorded on a separate cadaver; two reviewers, blinded to the intervention, assessed the videos. Primary outcome was time to successful ETI, analyzed with a Cox proportional hazards model. Authors also compared percentage of glottic opening (POGO), number of ETI attempts, learner confidence, and satisfaction.

RESULTS

Of 97 students randomized, 78 were included in the final analysis. Median time to ETI did not differ significantly (hazard ratio [HR] 1.1; 95% CI [confidence interval], 0.7-1.8): cadaver group = 34.5 seconds (interquartile ratio [IQR]: 23.3-55.8) vs manikin group = 35.5 seconds (IQR: 23.8-80.5), with no difference in first-pass success (odds ratio [OR] = 1; 95% CI, 0.1-7.5) or median POGO: 80% cadaver vs 90% manikin (95% CI, -14-34%). Satisfaction was higher for cadavers (median difference = 0.5; p = 0.002; 95% CI, 0-1) as was change in student confidence (median difference = 0.5; p = 0.03; 95% CI, 0-1). Students rating their confidence a 5 ("extremely confident") demonstrated decreased time to ETI (HR = 4.2; 95% CI, 1.0-17.2).

CONCLUSION

Manikin and cadaver training models for ETI produced similar time to ETI, POGO, and first-pass success. Cadaver training was associated with increased student satisfaction and confidence; subjects with the highest confidence level demonstrated decreased time to ETI.

Impact of Quantitative Feedback via High-Fidelity Airway Management Training on Success Rate in Endotracheal Intubation in Undergraduate Medical Students-A Prospective Single-Center Study

Endotracheal intubation is still the gold standard in airway management. For medical students and young professionals, it is often difficult to train personal skills. We tested a high-fidelity simulator with an additional quantitative feedback integration to elucidate if competence acquisition for airway management is increased by using this feedback method. In the prospective trial, all participants (n = 299; 4th-year medical students) were randomized into two groups—One had been trained on the simulator with additional quantitative feedback (n = 149) and one without (n = 150). Three simulator measurements were considered as quality criteria—The pressure on the upper front row of teeth, the correct pressure point of the laryngoscope spatula and the correct depth for the fixation of the tube. There were a total of three measurement time points—One after initial training (with additional capture of cognitive load), one during the exam, and a final during the follow-up, approximately 20 weeks after the initial training. Regarding the three quality criteria, there was only one significant difference, with an advantage for the control group with respect to the correct pressure point of the laryngoscope spatula at the time of the follow-up (p = 0.011). After the training session, the cognitive load was significantly higher in the intervention group (p = 0.008) and increased in both groups over time. The additional quantitative feedback of the airway management trainer brings no measurable advantage in training for endotracheal intubation. Due to the increased cognitive load during the training, simple airway management task training may be more efficient for the primary acquisition of essential procedural steps.

Comparison of forces acting on maxillary incisors during tracheal intubation with different laryngoscopy techniques: a blinded manikin study

Dental trauma is a common complication of tracheal intubation. As existing evidence is insufficient to validly assess the impact of different laryngoscopy techniques on the incidence of dental trauma, the force exerted onto dental structures during tracheal intubation was investigated. An intubation manikin was equipped with hidden force sensors in all maxillary incisors. Dental force was measured while 104 anaesthetists performed a series of tracheal intubations using direct laryngoscopy with a Macintosh blade, and videolaryngoscopy with a C-MAC^® , or the hyperangulated GlideScope^® or KingVision^® laryngoscopes in both normal and difficult airway conditions. A total of 624 tracheal intubations were analysed. The median (IQR [range]) peak force of direct laryngoscopy in normal airways was 21.1 (14.0-32.8 [2.3-127.6]) N and 29.3 (17.7-44.8 [3.3-97.2]) N in difficult airways. In normal airways, these were lower with the GlideScope and KingVision hyperangulated laryngoscopes, with a reduction of 4.6 N (p = 0.006) and 10.9 N (p < 0.001) compared with direct laryngoscopy, respectively. In difficult airways, these were lower with the GlideScope and KingVision hyperangulated laryngoscopes, with a reduction of 9.8 N (p < 0.001) and 17.6 N (p < 0.001) compared with direct laryngoscopy, respectively. The use of the C-MAC did not have an impact on the median peak force. Although sex of anaesthetists did not affect peak force, more experienced anaesthetists generated a higher peak force than less experienced providers. We conclude that hyperangulated videolaryngoscopy was associated with a significantly decreased force exerted on maxillary incisors and might reduce the risk for dental injury in clinical settings.

Comparison of a Novel Cadaver Model (Fix for Life) With the Formalin-Fixed Cadaver and Manikin Model for Suitability and Realism in Airway Management Training

BACKGROUND

Manikins are widely used in airway management training; however, simulation of realism and interpatient variability remains a challenge. We investigated whether cadavers embalmed with the novel Fix for Life (F4L) embalmment method are a suitable and realistic model for teaching 3 basic airway skills: facemask ventilation, tracheal intubation, and laryngeal mask insertion compared to a manikin (SimMan 3G) and formalin-fixed cadavers.

METHODS

Thirty anesthesiologists and experienced residents ("operators") were instructed to perform the 3 airway techniques in 10 F4L, 10 formalin-fixed cadavers, and 1 manikin. The order of the model type was randomized per operator. Primary outcomes were the operators' ranking of each model type as a teaching model (total rank), ranking of the model types per technique, and an operator's average verbal rating score for suitability and realism of learning the technique on the model. Secondary outcomes were the percentages of successfully performed procedures per technique and per model (success rates in completing the respective airway maneuvers). For each of the airway techniques, the Friedman analysis of variance was used to compare the 3 models on mean operator ranking and mean verbal rating scores.

RESULTS

Twenty-seven of 30 operators (90%) performed all airway techniques on all of the available models, whereas 3 operators performed the majority but not all of the airway maneuvers on all models for logistical reasons. The total number of attempts for each technique was 30 on the manikin, 292 in the F4L, and 282 on the formalin-fixed cadavers. The operators' median total ranking of each model type as a teaching model was 1 for F4L, 2 for the manikin and, 3 for the formalin-fixed cadavers (P < .001). F4L was considered the best model for mask ventilation (P = .029) and had a higher mean verbal rating score for realism in laryngeal mask airway insertion (P = .043). The F4L and manikin did not differ significantly in other scores for suitability and realism. The formalin-fixed cadaver was ranked last and received lowest scores in all procedures (all P < .001). Success rates of the procedures were highest in the manikin.

CONCLUSIONS

F4L cadavers were ranked highest for mask ventilation and were considered the most realistic model for training laryngeal mask insertion. Formalin-fixed cadavers are inappropriate for airway management training.

Soiled airway tracheal intubation and the effectiveness of decontamination by paramedics (SATIATED): a randomised controlled manikin study

Introduction:

Vomiting and regurgitation are commonly encountered in out-of-hospital cardiac arrest (OHCA), with a reported incidence of 20–30%. This is of concern since patients who have suffered an OHCA are already in extremis. If standard suctioning techniques are not sufficient to maintain a clear airway and provide ventilation, then these patients will die, irrespective of the quality of chest compressions and the timeliness of defibrillation. This study aimed to determine whether a short teaching session of the suction assisted laryngoscopy and airway decontamination (SALAD) technique improved paramedics’ ability to successfully intubate a contaminated airway.

Methods:

A modified airway manikin with the oesophagus connected to a reservoir of ‘vomit’, and a bilge pump capable of propelling the vomit up into the oropharynx, was used to simulate a soiled airway. The intervention consisted of a brief SALAD training session with a demonstration and opportunity to practice. Participants were randomly allocated into two groups: AAB, who made two pre-training intubation attempts and one post-training attempt, and ABB, who made one pre-training and two post-training attempts, to adjust for improvement in performance due to repetition.

Results:

In this manikin study, following a brief SALAD training session, more paramedics were able to intubate a soiled airway on their first attempt, compared to those without training (90.2% vs. 53.7%, difference of 36.6%, 95% CI 24–49.1%, p < 0.001). In addition, the mean difference in time taken to perform a successful intubation between groups was statistically significant for attempts 1 and 2 (mean difference 11.71 seconds, 95% CI 1.95–21.47 seconds, p = 0.02), but not attempts 1 and 3 (mean difference –2.52 seconds, 95% CI –11.64–6.61 seconds, p = 0.58). This result is likely to be confounded by the use of tracheal suction, which only occurred in the post-training attempts and added additional time to the intubation attempts. There was no statistically significant difference in success rates on the third attempt between AAB and ABB (89.0% vs. 86.6%, difference 2.4%, 95% CI 7.6–12.4%, p = 0.63).

Conclusion:

In this study, the use of the SALAD technique significantly improved first attempt success rates when paramedics were intubating a simulated soiled airway.

Development and Utilization of 3D Printed Material for Thoracotomy Simulation

Medical simulation is a widely used training modality that is particularly useful for procedures that are technically difficult or rare. The use of simulations for educational purposes has increased dramatically over the years, with most emergency medicine (EM) programs primarily using mannequin-based simulations to teach medical students and residents. As an alternative to using mannequin, we built a 3D printed models for practicing invasive procedures. Repeated simulations may help further increase comfort levels in performing an emergency department (ED) thoracotomy in particular, and perhaps this can be extrapolated to all invasive procedures. Using this model, a simulation training conducted with EM residents at an inner city teaching hospital showed improved confidence. A total of 21 residents participated in each of the three surveys [(1) initially, (2) after watching the educational video, and (3) after participating in the simulation]. Their comfort levels increased from baseline after watching the educational video (9.5%). The comfort level further improved from baseline after performing the hands on simulation (71.4%).

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.

Comparison of the GlideScope® with the Macintosh Laryngoscope in Endotracheal Intubation during Uninterrupted Mechanical Chest Compression: A Randomised Crossover Manikin Study

Background

The GlideScope® (GS) has been shown to improve the first-attempt success rate of endotracheal intubation during continuous mechanical chest compressions compared with the conventional Macintosh laryngoscope (ML) in inexperienced hands. Yet, its value for operators with experience of emergency airway management has remained uncertain. We set out to compare their performance in the hands of experienced operators in a manikin receiving continuous mechanical chest compressions delivered by LUCAS®.

Method

This was a randomised crossover study. Thirty-five emergency physicians and intensivists performed intubation using GS and ML in 3 different scenarios: (1) normal airway without chest compressions; (2) normal airway with uninterrupted mechanical chest compressions; and (3) normal airway with cervical spine (C-spine) immobilisation and uninterrupted mechanical chest compressions. The sequence of scenarios and devices used were randomised. The primary outcome was the first-attempt success rate of intubation. Other data including demographics, the time required for successful intubation, complications during intubation, the visual analog scale of perceived difficulty of intubation and the preference on devices in each scenario were also collected and analyzed.

Results

In scenario 1, the first-attempt success rate with both laryngoscopes was 100%. In scenario 2, there was a higher first-attempt success rate with ML but it was not statistically significant (GS 97.14% vs ML 100%, p=1.00). In scenario 3, one participant failed to intubate in the first attempt with each of the laryngoscopes (GS 97.14% vs ML 97.14%, p=0.754). More dental compression was noted with GS but the difference was not statistically significant (GS 42.86% vs ML 22.86%, p=0.126). Overall, the median time for intubation with GS was significantly longer in all 3 scenarios (Scenario 1: GS 18.5s; interquartile range [IQR] 13.8 -22.2s vs ML 11.2s, IQR 9.5-14.2s, p<0.001; Scenario 2: GS 18.7s, IQR 13.1-25.2s vs ML 13.4s, 10.3-15.8s, p<0.001; Scenario 3: GS 20.8s, IQR 16.5-29.2s vs ML 14.0s, IQR 10.5-18.0s, p<0.001). More participants preferred GS in scenario 3, while ML remained the device of choice in the other two scenarios. Conclusion: GS is not superior to ML in terms of the first-attempt success rate of intubation and it takes significantly longer to intubate for experienced operator. Yet more participants prefer its use when the C-spine motion is limited. Further studies are warranted to explore its role in trauma resuscitation. (Hong Kong j.emerg.med. 2016;23:159-167)

Comparison of intubation devices in level C personal protective equipment: A cadaveric study

BACKGROUND

With the advancement of chemical, biological and nuclear warfare and the reemergence of infectious diseases, the possibility of intubating in personal protective equipment has become increasingly more real to the emergency physician. Human cadaveric models have been found to simulate real world conditions better than mannequins. The aim of the study was to determine the first pass success rate and average time to successful intubation while wearing Personal Protective Equipment (PPE). Secondarily, subjects were asked to rank their choice of a primary and back up device, as well as the most common encountered barriers using PPE.

METHODS

Emergency medicine residents and pre-hospital providers were enrolled in a double randomized sequence to either intubation with direct laryngoscopy (DL), video laryngoscopy (VL), or the Supraglottic Airway Laryngopharyngeal Tube (SALT) in a cadaveric model while wearing level C PPE or without PPE.

RESULTS

First pass success rate was 96% without PPE and 58% while wearing PPE when all devices were considered (p≤0.001). Time to intubation while wearing PPE was 35.0s while no PPE was 22.2s (p=0.012). While wearing PPE both DL and VL were found to allow for a faster intubation as compared to the SALT (23.0s and 18.8s; p=0.002 and p=0.006 respectively). No statistical difference was noted in intubations without PPE. Participants indicated the most common barrier to successful intubation included visibility while wearing hoods (73.7%). Furthermore, 52.6% of participants indicated they would choose DL as the primary method to intubate with if wearing PPE while 47.4% would choose VL.

CONCLUSION

There is a statistically significant difference in first pass success and time to successful intubation while wearing and not wearing PPE in human cadaveric models.

Does end-tidal capnography confirm tracheal intubation in fresh-frozen cadavers?

BACKGROUND

Life-like end-tidal capnography (ETCO₂) waveforms have been demonstrated in recently deceased and fresh-frozen cadavers following tracheal intubation, offering potential for high fidelity airway simulation training. As the mechanism for carbon dioxide production is not fully understood, it is possible that oesophageal intubation may also generate a capnograph. Our aim was to measure ETCO₂ levels following (1) oesophageal and (2) tracheal intubation in fresh-frozen cadavers, and to observe the size, shape and duration of any capnographic waveform.

METHODS

Four fresh frozen cadavers underwent oesophageal intubation by an emergency medicine specialist with confirmation by a second specialist. Hand ventilation with room air via a self-inflating resuscitation bag was provided at 12 breaths per minute for 2 min or until ETCO₂ was zero for 10 consecutive breaths. ETCO₂ and waveform morphology were examined and video recorded. The oesophagus was then extubated and the process was repeated for tracheal intubation.

RESULTS

In no case was oesophageal ETCO₂ detected. For two cadavers, life-like ETCO₂ waveforms were achieved immediately after tracheal intubation, with maximum ETCO₂ achieved by the second breath. In these cases waveform morphology was normal and persistent.

CONCLUSIONS

Cadaveric oesophageal intubation did not result in a capnography waveform, simulating live patients. When present, ETCO₂ following tracheal intubation showed normal morphology which was sustained for 2 min. However, ETCO₂ was not present following tracheal intubation in all cadavers. These results represent instrumentation on the cadavers for the first time after thawing and further work should assess the repeatability of the findings with subsequent intubations.

A novel fresh cadaver model for education and assessment of joint aspiration

OBJECTIVES

The objective of this study was to describe a novel cadaver model and to determine the utility of this model for teaching and assessing students in performing knee, elbow, and wrist arthrocentesis.

METHODS

Third year medical students were evaluated while performing arthrocentesis during a fresh cadaver training sessions.

RESULTS

Sixty-three participants were included in this analysis. There was statistically significant improvement between the pre- and post-test analysis in all aspects assessed in our study of elbow, knee and wrist arthrocentesis.

CONCLUSIONS

The use of fresh cadavers for the education and assessment of arthrocenteses is an effective training model.

Suitability of a preserved human cadaver model for the simulation of facemask ventilation, direct laryngoscopy and tracheal intubation: a laboratory investigation

BACKGROUND

Using fresh or formalin-embalmed cadavers has not been generally accepted for the purposes of teaching airway management. We investigated whether cadavers 'preserved according Thiel's embalming method' (PATEM) are suitable for the simulation of facemask ventilation and tracheal intubation by direct laryngoscopy.

METHODS

This observational cluster sampling, controlled simulation study, included eight PATEM cadavers and eight manikins in two clusters. Twenty experienced anaesthetists were randomly assigned to execute 80 facemask ventilations and 80 tracheal intubations in both groups. The ease of facemask ventilation was the primary endpoint. The secondary endpoint was the composite outcomes of laryngoscopy and tracheal intubation.

RESULTS

The success rate at the first attempt at mask ventilation was 74% (59/80 attempts) on cadavers and 41% (33/80 attempts) on manikins (P<0.0001). Twenty one subjects received an oral airway in both groups and succeeded in facemask ventilation 20 times on cadavers and four times on manikins (P=0.004). Two-handed technique mask ventilation was required 24 times on manikins and once on cadavers (P=0.0016). In one attempt on a manikin the mask ventilation was impossible. Poor laryngeal view (Cormack-Lehane grade 3) occurred 14 times among cadavers (17.5%) and once in manikins (1.25%) (P=0.007), whereas difficulties in tracheal intubation were encountered 16 times in cadavers (20%) vs 17 times in manikins (21.25%) (P=0.84). In a subjective evaluation the participants preferred the cadaver model over the manikins (P<0.0001).

CONCLUSIONS

PATEM cadavers were better suited for facemask ventilation and provided a more realistic environment for laryngoscopy and tracheal intubation than the studied manikins.

Introducing a Fresh Cadaver Model for Ultrasound-guided Central Venous Access Training in Undergraduate Medical Education

Introduction

Over the past decade, medical students have witnessed a decline in the opportunities to perform technical skills during their clinical years. Ultrasound-guided central venous access (USG-CVA) is a critical procedure commonly performed by emergency medicine, anesthesia, and general surgery residents, often during their first month of residency. However, the acquisition of skills required to safely perform this procedure is often deficient upon graduation from medical school. To ameliorate this lack of technical proficiency, ultrasound simulation models have been introduced into undergraduate medical education to train venous access skills. Criticisms of simulation models are the innate lack of realistic tactile qualities, as well as the lack of anatomical variances when compared to living patients. The purpose of our investigation was to design and evaluate a life-like and reproducible training model for USG-CVA using a fresh cadaver.

Methods

This was a cross-sectional study at an urban academic medical center. An 18-point procedural knowledge tool and an 18-point procedural skill evaluation tool were administered during a cadaver lab at the beginning and end of the surgical clerkship. During the fresh cadaver lab, procedure naïve third-year medical students were trained on how to perform ultrasound-guided central venous access of the femoral and internal jugular vessels. Preparation of the fresh cadaver model involved placement of a thin-walled latex tubing in the anatomic location of the femoral and internal jugular vein respectively.

Results

Fifty-six third-year medical students participated in this study during their surgical clerkship. The fresh cadaver model provided high quality and lifelike ultrasound images despite numerous cannulation attempts. Technical skill scores improved from an average score of 3 to 12 (p<0.001) and procedural knowledge scores improved from an average score of 4 to 8 (p<0.001).

Conclusion

The use of this novel cadaver model prevented extravasation of fluid, maintained ultrasound-imaging quality, and proved to be an effective educational model allowing third-year medical students to improve and maintain their technical skills.

History and future of human cadaver preservation for surgical training: from formalin to saturated salt solution method

Traditionally, surgical training meant on-the-job training with live patients in an operating room. However, due to advancing surgical techniques, such as minimally invasive surgery, and increasing safety demands during procedures, human cadavers have been used for surgical training. When considering the use of human cadavers for surgical training, one of the most important factors is their preservation. In this review, we summarize four preservation methods: fresh-frozen cadaver, formalin, Thiel's, and saturated salt solution methods. Fresh-frozen cadaver is currently the model that is closest to reality, but it also presents myriad problems, including the requirement of freezers for storage, limited work time because of rapid putrefaction, and risk of infection. Formalin is still used ubiquitously due to its low cost and wide availability, but it is not ideal because formaldehyde has an adverse health effect and formalin-embalmed cadavers do not exhibit many of the qualities of living organs. Thiel's method results in soft and flexible cadavers with almost natural colors, and Thiel-embalmed cadavers have been appraised widely in various medical disciplines. However, Thiel's method is relatively expensive and technically complicated. In addition, Thiel-embalmed cadavers have a limited dissection time. The saturated salt solution method is simple, carries a low risk of infection, and is relatively low cost. Although more research is needed, this method seems to be sufficiently useful for surgical training and has noteworthy features that expand the capability of clinical training. The saturated salt solution method will contribute to a wider use of cadavers for surgical training.

Comparison of Preloaded Bougie versus Standard Bougie Technique for Endotracheal Intubation in a Cadaveric Model

INTRODUCTION

We compared intubating with a preloaded bougie (PB) against standard bougie technique in terms of success rates, time to successful intubation and provider preference on a cadaveric airway model.

METHODS

In this prospective, crossover study, healthcare providers intubated a cadaver using the PB technique and the standard bougie technique. Participants were randomly assigned to start with either technique. Following standardized training and practice, procedural success and time for each technique was recorded for each participant. Subsequently, participants were asked to rate their perceived ease of intubation on a visual analogue scale of 1 to 10 (1=difficult and 10=easy) and to select which technique they preferred.

RESULTS

47 participants with variable experience intubating were enrolled at an emergency medicine intern airway course. The success rate of all groups for both techniques was equal (95.7%). The range of times to completion for the standard bougie technique was 16.0-70.2 seconds, with a mean time of 29.7 seconds. The range of times to completion for the PB technique was 15.7-110.9 seconds, with a mean time of 29.4 seconds. There was a non-significant difference of 0.3 seconds (95% confidence interval -2.8 to 3.4 seconds) between the two techniques. Participants rated the relative ease of intubation as 7.3/10 for the standard technique and 7.6/10 for the preloaded technique (p=0.53, 95% confidence interval of the difference -0.97 to 0.50). Thirty of 47 participants subjectively preferred the PB technique (p=0.039).

CONCLUSION

There was no significant difference in success or time to intubation between standard bougie and PB techniques. The majority of participants in this study preferred the PB technique. Until a clear and clinically significant difference is found between these techniques, emergency airway operators should feel confident in using the technique with which they are most comfortable.

The impact of a cadaver-based airway lab on critical care fellows' direct laryngoscopy skills

This study sought to determine the impact of a cadaver-based airway lab on critical care medicine fellows' direct laryngoscopy skills and hypothesised that fellows can improve their self-reported percentage of glottic opening (POGO) scores in cadaver models to achieve POGO scores similar to that of expert faculty. Nineteen fellows attended an airway management skills laboratory utilising five modified cadavers. Initial fellow POGO (POGOi) visualised was recorded at the onset with direct laryngoscopy. Maximum fellow POGO score with optimised direct laryngoscopy was recorded after two additional hours of teaching and also during a testing phase several days later. Data was assessed for significant differences between trainee POGO scores at each time interval and between trainee POGO scores and expert scores. A departmental procedural database was utilised to examine success rates of intubation as a clinical correlation. Fellows' mean POGOi scores, averaged across all five specimens, were significantly lower than both their maximum POGO scores and their testing phase POGO scores. Mean POGOi scores for fellows, averaged over all five cadavers, were lower than the instructors' POGOi scores. There was no difference between fellows' and instructors' mean maximum POGO or mean testing phase POGO scores. Clinical success rates of intubation were over 98%. A short training session using modified cadavers can be utilised to teach new critical care medicine fellows additional techniques for airway management and assist them in obtaining higher POGO scores, similar to those of expert instructors. Success rates of clinical intubations were favourable in the wake of this training.

Saturated salt solution method: a useful cadaver embalming for surgical skills training

This article evaluates the suitability of cadavers embalmed by the saturated salt solution (SSS) method for surgical skills training (SST). SST courses using cadavers have been performed to advance a surgeon's techniques without any risk to patients. One important factor for improving SST is the suitability of specimens, which depends on the embalming method. In addition, the infectious risk and cost involved in using cadavers are problems that need to be solved. Six cadavers were embalmed by 3 methods: formalin solution, Thiel solution (TS), and SSS methods. Bacterial and fungal culture tests and measurement of ranges of motion were conducted for each cadaver. Fourteen surgeons evaluated the 3 embalming methods and 9 SST instructors (7 trauma surgeons and 2 orthopedists) operated the cadavers by 21 procedures. In addition, ultrasonography, central venous catheterization, and incision with cauterization followed by autosuture stapling were performed in some cadavers. The SSS method had a sufficient antibiotic effect and produced cadavers with flexible joints and a high tissue quality suitable for SST. The surgeons evaluated the cadavers embalmed by the SSS method to be highly equal to those embalmed by the TS method. Ultrasound images were clear in the cadavers embalmed by both the methods. Central venous catheterization could be performed in a cadaver embalmed by the SSS method and then be affirmed by x-ray. Lungs and intestines could be incised with cauterization and autosuture stapling in the cadavers embalmed by TS and SSS methods. Cadavers embalmed by the SSS method are sufficiently useful for SST. This method is simple, carries a low infectious risk, and is relatively of low cost, enabling a wider use of cadavers for SST.

Reconsidering fidelity in simulation-based training

In simulation-based health professions education, the concept of simulator fidelity is usually understood as the degree to which a simulator looks, feels, and acts like a human patient. Although this can be a useful guide in designing simulators, this definition emphasizes technological advances and physical resemblance over principles of educational effectiveness. In fact, several empirical studies have shown that the degree of fidelity appears to be independent of educational effectiveness. The authors confronted these issues while conducting a recent systematic review of simulation-based health professions education, and in this Perspective they use their experience in conducting that review to examine key concepts and assumptions surrounding the topic of fidelity in simulation.Several concepts typically associated with fidelity are more useful in explaining educational effectiveness, such as transfer of learning, learner engagement, and suspension of disbelief. Given that these concepts more directly influence properties of the learning experience, the authors make the following recommendations: (1) abandon the term fidelity in simulation-based health professions education and replace it with terms reflecting the underlying primary concepts of physical resemblance and functional task alignment; (2) make a shift away from the current emphasis on physical resemblance to a focus on functional correspondence between the simulator and the applied context; and (3) focus on methods to enhance educational effectiveness using principles of transfer of learning, learner engagement, and suspension of disbelief. These recommendations clarify underlying concepts for researchers in simulation-based health professions education and will help advance this burgeoning field.

[Proposed difficult airway teaching methodology. Presentation of an interactive fresh frozen cadaver model]

BACKGROUND AND OBJECTIVE

The aim of this paper is to present a methodology based on the use of fresh-frozen cadavers for training in the management of the airway, and to evaluate the degree of satisfaction among learning physicians.

MATERIAL AND METHODS

About 6 fresh-frozen cadavers and 14 workstations were prepared where participants were trained in the different skills needed for airway management. The details of preparation of the cadavers are described. The level of satisfaction of the participant was determined using a Likert rating scale of 5 points, at each of the 14 stations, as well as the overall assessment and clinical usefulness of the course.

RESULTS

The mean overall evaluation of the course and its usefulness was 4.75 and 4.9, out of 5, respectively. All parts of the course were rated above 4 out of 5. The high level of satisfaction of the course remained homogeneous in the 2 editions analysed. The overall satisfaction of the course was not finally and uniquely determined by any of its particular parts.

CONCLUSION

The fresh cadaver model for training physicians in techniques of airway management is a proposal satisfactory to the participant, and with a realism that approaches the live patient.

Paramedic intubation: patient position might matter

OBJECTIVE

Paramedics often intubate in challenging environments. We evaluated whether patient position might affect prehospital intubation success rates utilizing a cadaver model.

METHODS

The study was conducted in two phases: a cross-sectional survey and an experimental model in which paramedics were asked to demonstrate intubation skills on cadavers in three positions. New York State certified paid and volunteer paramedics and critical care emergency medical technicians were recruited from multiple agencies. To assess past experience, participants self-reported the number of patients they attempted to intubate in the previous 12 months and the patient positions in which they attempted those intubations. Participants attempted to intubate nonembalmed cadavers in a controlled environment in three positions: on the floor, on a low stretcher to simulate the patient care compartment of an ambulance, and on an elevated stretcher. Paramedics were allowed a maximum of three intubation attempts of one minute each per cadaver. Endotracheal tube placement was verified by a single attending emergency physician using direct visualization.

RESULTS

Self-reports of intubation attempts in the previous 12 months indicated that participants had attempted to intubate a mean of 6.4 patients per paramedic. Self-reported positions of patient intubations were 57% on the floor, 33% in the ambulance, 7% on a stretcher of unspecified height, and 3% in some other position. During the study, 84 paramedics performed 251 intubations on 42 cadavers. First-attempt and cumulative first- and second-attempt success rates were 77.4 and 89.3% for the floor position, 74.7 and 94.0% for the low stretcher (ambulance) position, and 86.9 and 96.4% for the elevated stretcher position, respectively. First attempt success was higher in the elevated stretcher position compared to the low stretcher position (OR = 2.25, 95% CI 1.01-5.00). No other position contributed to greater odds of ETI success either on the first or second attempt.

CONCLUSIONS

Endotracheal intubation success was higher with the cadaver positioned on an elevated stretcher compared to a low stretcher. Paramedics must be aware of patient position when performing prehospital intubation.

The usefulness of 3-dimensional virtual simulation using haptics in training orotracheal intubation

Objectives. Airway control is the most critical treatment. The most common and basic method of endotracheal intubation is orotracheal intubation. To perform accurate and rapid tracheal intubation, appropriate education and training are required. We developed the virtual simulation program utilizing the 3-dimensional display and haptic device to exercise orotracheal intubation, and the educational effect of this program was compared with that of the mannequin method. Method. The control group used airway mannequin and virtual intubation group was trained with new program. We videotaped both groups during objective structured clinical examination (OSCE) with airway mannequin. The video was reviewed and scored, and the rate of success and time were calculated. Result. The success rate was 78.6% in virtual intubation group and 93.3% in control group (P = 0.273). There was no difference in overall score of OSCE (21.14 ± 4.28 in virtual intubation group and 23.33 ± 4.45 in control group, P = 0.188), the time spent in successful intubation (P = 0.432), and the number of trials (P > 0.101). Conclusion. The virtual simulation with haptics had a similar effect compared with mannequin, but it could be more cost effective and convenient than mannequin training in time and space.

Technology-enhanced simulation in emergency medicine: a systematic review and meta-analysis

OBJECTIVES

Technology-enhanced simulation is used frequently in emergency medicine (EM) training programs. Evidence for its effectiveness, however, remains unclear. The objective of this study was to evaluate the effectiveness of technology-enhanced simulation for training in EM and identify instructional design features associated with improved outcomes by conducting a systematic review.

METHODS

The authors systematically searched MEDLINE, EMBASE, CINAHL, ERIC, PsychINFO, Scopus, key journals, and previous review bibliographies through May 2011. Original research articles in any language were selected if they compared simulation to no intervention or another educational activity for the purposes of training EM health professionals (including student and practicing physicians, midlevel providers, nurses, and prehospital providers). Reviewers evaluated study quality and abstracted information on learners, instructional design (curricular integration, feedback, repetitive practice, mastery learning), and outcomes.

RESULTS

From a collection of 10,903 articles, 85 eligible studies enrolling 6,099 EM learners were identified. Of these, 56 studies compared simulation to no intervention, 12 compared simulation with another form of instruction, and 19 compared two forms of simulation. Effect sizes were pooled using a random-effects model. Heterogeneity among these studies was large (I(2) ≥ 50%). Among studies comparing simulation to no intervention, pooled effect sizes were large (range = 1.13 to 1.48) for knowledge, time, and skills and small to moderate for behaviors with patients (0.62) and patient effects (0.43; all p < 0.02 except patient effects p = 0.12). Among comparisons between simulation and other forms of instruction, the pooled effect sizes were small (≤ 0.33) for knowledge, time, and process skills (all p > 0.1). Qualitative comparisons of different simulation curricula are limited, although feedback, mastery learning, and higher fidelity were associated with improved learning outcomes.

CONCLUSIONS

Technology-enhanced simulation for EM learners is associated with moderate or large favorable effects in comparison with no intervention and generally small and nonsignificant benefits in comparison with other instruction. Future research should investigate the features that lead to effective simulation-based instructional design.

Parametrically adjustable intubation mannequin with real-time visual feedback

INTRODUCTION

Training for direct laryngoscopy relies heavily on practice with patients. The necessity for human practice might be supplanted to some extent by an intubation mannequin with accurate airway anatomy, a realistic "feel" during laryngoscopy, the capacity to model many patient configurations, and a means to provide feedback to trainees and instructors. The goals of this project were (1) to build and evaluate an airway simulator with realistic dimensions and haptic sensation that could undergo a range of adjustments in several features that affect laryngoscopy difficulty and (2) to develop a system for displaying information on laryngoscopy force and motion in real time.

METHODS

The prototype was an existing 2-dimensional (2D) airway model that closely approximated cephalometric measurements of head, neck, and airway anatomy from the dental and surgical literature. The 2D model was extended in a third dimension by adding layers along the coronal axis. An off-the-shelf airway model provided the tongue, pharynx, larynx, and trachea. Adjustability was built into the face, jaw, mouth, teeth, and spine components. A feedback system was constructed with a force- and motion-sensing laryngoscope and motion sensors incorporated in the mannequin head, jaw, and larynx. Anatomic accuracy was assessed by measuring model dimensions. Realism was evaluated by measuring laryngoscopy force and motion compared with laryngoscopy in patients.

RESULTS

The extruded 2.5-dimensional model maintained a close conformity to the anatomic measurements present in the original 2D model. The model could be adjusted through multiple settings for face length, jaw length and tension, mouth opening, and dental condition. The laryngoscopy trajectory had a similar shape to laryngoscopy trajectories in patients, but force was greater, on the order of 50 N, compared with roughly 30 N in patients. The movement of the laryngoscope through the mannequin airway could be displayed in real time during the procedure, establishing a means for feedback.

CONCLUSIONS

The model incorporates novel features that could aid in developing mastery of the laryngoscopy procedure. Further work is needed to investigate how adjustability and feedback impact the value of laryngoscopy practice on mannequins.

Education in airway management

In airway management, poor judgment, education and training are leading causes of patient morbidity and mortality. The traditional model of medical education, which relies on experiential learning in the clinical environment, is inconsistent and often inadequate. Curriculum change is underway in many medical organisations in an effort to correct these problems, and airway management is likely to be explicitly addressed as a clinical fundamental within any new anaesthetic curriculum. Competency-based medical education with regular assessment of clinical ability is likely to be introduced for all anaesthetists engaged in airway management. Essential clinical competencies need to be defined and improvements in training techniques can be expected based on medical education research. Practitioners need to understand their equipment and diversify their airway skills to cope with a variety of clinical presentations. Expertise stems from deliberate practice and a desire constantly to improve performance with a career-long commitment to education.

A Comparison of the Forces Applied to a Manikin during Laryngoscopy with the Glidescope® and Macintosh Laryngoscopes

The force applied during laryngoscopy can cause local tissue trauma and can induce cardiovascular responses and cervical spine movement in susceptible patients. Previous studies have identified numerous operator and patient factors that influence the amount of force applied during intubation. There are few studies evaluating the effect of different laryngoscope blades and no study involving video laryngoscopes. In this study we measured the forces using two laryngoscopic techniques. Three FlexiForce Sensors® (A201-25, Tekscan, Boston, MA, USA) were attached to the concave blade surface of a Macintosh and a GlideScope® laryngoscope. Experienced anaesthetists performed Macintosh and GlideScope intubations on the Laerdal® Airway Management Trainer manikin. Compared to Macintosh intubations, the GlideScope intubations had equal or superior views of the glottis with 55%, 58% and 66% lower median peak, average and impulse forces applied to the tongue base. The distal sensor registered the most force in both devices and the force distribution pattern was similar between the devices. The findings suggest that the GlideScope requires less force for similar or better laryngoscopic views, at least in a manikin model.

Airway management in simulated restricted access to a patient--can manikin-based studies provide relevant data?

Background

Alternatives to endotracheal intubation (ETI) are required when access to the cranial end of the patient is restricted. In this study, the success rate and time duration of standard intubation techniques were compared with two different supraglottic devices. Two different manikins were used for the study, and the training effect was studied when the same manikin was repeatedly used.

Methods

Twenty anaesthesiologists from the Air Ambulance Department used iGEL^™, laryngeal tube LTSII^™ and Macintosh laryngoscopes in two scenarios with either unrestricted (scenario A) or restricted (scenario B) access to the cranial end of the manikin. Different manikins were used for ETI and placement of the supraglottic devices. The technique selected by the physicians, the success rates and the times to completion were the primary outcomes measured. A secondary outcome of the study was an evaluation of the learning effect of using the same manikin or device several times.

Results

In scenario A, all anaesthesiologists secured an airway using each device within the maximum time limit of 60 seconds. In scenario B, all physicians secured the airway on the first attempt with the supraglottic devices and 16 (80%) successfully performed an ETI with either the Macintosh laryngoscope (n = 13, 65%) or with digital technique (n = 3, 15%). It took significantly longer to perform ETI (mean time 28.0 sec +/- 13.0) than to secure an airway with the supraglottic devices (iGel™: mean 12.3 sec +/- 3.6, LTSII™: mean 10.6 sec +/- 3.2). When comparing the mean time required for the two scenarios for each supraglottic device, there was a reduction in time for scenario B (significant for LTSII^™: 12.1 versus 10.6 seconds, p = 0.014). This may be due to a training effect using same manikin and device several times.

Conclusions

The amount of time used to secure an airway with supraglottic devices was low for both scenarios, while classic ETI was time consuming and had a low success rate in the simulated restricted access condition. This study also demonstrates that there is a substantial training effect when simulating airway management with airway manikins. This effect must be considered when performing future studies.