Comparison of Force During the Endotracheal Intubation of Commercial Simulation Manikins

Background  Medical simulation allows clinicians to safely practice the procedural skill of endotracheal intubation. Applied force to oropharyngeal structures increases the risk of patient harm, and video laryngoscopy (VL) requires less force to obtain a glottic view. It is unknown how much force is required to obtain a glottic view using commercially available simulation manikins and if variability exists. This study compares laryngoscopy force for a modified Cormack-Lehane (CL) grade I view in both normal and difficult airway scenarios between three commercially available simulation manikins. Methods Experienced clinicians (≥2 years experience) were recruited to participate from critical care, emergency medicine, and anesthesia specialties. A C-MAC size 3 VL blade was equipped with five force resistor reading (FSR) sensors (four concave surfaces, one convex), measuring resistance (Ohms) in response to applied pressure (1-100 Newtons). The study occurred in a university simulation lab. Using a randomized sequence, 49 physicians performed intubations on three manikins (Laerdal SimMan 3GPlus, Gaumard Hal S3201, CAE Apollo) in normal and difficult airway scenarios. The outcomes were sensor mean pressure, peak force, and CL grade. Summary statistics were calculated. Generalized estimating equations (GEEs) conducted for both scenarios assessed changes in pressure measured in three manikins while accounting for correlated responses of individuals assigned in random order. Paired t-test assessed for the in-manikin difference between scenarios. STATA/BE v17 (R) was used for analysis; results interpreted at type I error alpha is 0.05.  Results Participants included 49 experienced clinicians. Mean years' experience was 4(±6.6); median prior intubations were 80 (IQR 50-400). Mean individual sensor pressure varied within scenarios depending on manikin (p<0.001). Higher mean forces were used in difficult scenarios (603.4±128.9, 611.1±101.4, 467.5±72.4 FSR) than normal (462.5±121.9, 596.0±90.5, 290.6±63.2 FSR) for each manikin (p<0.001). All manikins required more peak force in the difficult scenario (p<0.03). The highest mean forces (Laerdal, CAE, difficult scenario) were associated with the higher frequency of grade 2A views (p<0.001). The Gaumard manikin was rated most realistic in terms of force required to intubate. Conclusion Commercially available high-fidelity manikins had significant variability in laryngoscopy force in both normal and difficult airway scenarios. In difficult airway scenarios, significant variability existed in CL grade between manikin brands. Experienced clinicians rated Gaumard Hal as the most realistic force applied during endotracheal intubation.

Evaluation of an Innovative Bleeding Cricothyrotomy Model

Objectives

Emergency medicine (EM) residents are required to perform a cricothyrotomy during training as per the Accreditation Council for Graduate Medical Education (ACGME) guidelines. Cricothyrotomy is a rare procedure, comprising 0.45% of emergency department airway management procedures. Procedural competence in utilizing a realistic trainer is of utmost importance. We have developed a cricothyrotomy trainer using a fused deposition modeling (FDM) three-dimensional (3D) printer and innovative bleeding tissue to enhance fidelity. We aim to evaluate the trainer’s realism.

Methods

Implementation occurred during a difficult airway educational lab for EM residents in April 2018. Participants completed anonymous written surveys after performing a cricothyrotomy on the trainer. The survey evaluated the realism of the trainer and compared it to other available models by utilizing five-point visual analog scales (VAS). The participants rated their comfort level in performing the procedure pre- and post-educational lab on a five-point VAS. Demographic data included postgraduate year, prior clinical cricothyrotomy experience as a primary operator versus as an assistant, and previous trainer experience. The survey included open-response suggestions for trainer improvement. 

Results

Forty-three EM residents completed the survey (82.7%, 43/52). The mean realism rating of the trainer was 3.81 (95% CI = 3.54-4.1). The participants reported previous training on cadaver (62.8%, 27/43), porcine (46.5%, 20/43), and manikin (67.4%, 29/43) models prior to using this trainer. The bleeding cricothyrotomy trainer was rated higher than other models (4.45, 95% CI = 4.28-4.63). Participants noted improved comfort with performing the cricothyrotomy after the educational lab (average improvement of 1.23±0.75). Participants specifically commented on the realism of the bleeding and skin texture; however, they also recommended a reduction in the size of the cricothyroid membrane space. 

Conclusion

The innovative bleeding cricothyrotomy trainer has greater fidelity and reported superiority when compared to other commonly used nonbleeding models. This trainer provides a more advanced platform to teach an infrequent yet critical procedural skill to emergency medicine residents.

Development of a Novel Ultrasound-guided Peritonsillar Abscess Model for Simulation Training

Introduction

Peritonsillar abscess (PTA) is the most common deep space infection of the head and neck presenting to emergency departments.1 No commercial PTA task trainer exists for simulation training. Thus, resident physicians often perform their first PTA needle aspiration in the clinical setting, knowing that carotid artery puncture and hemorrhage are serious and devastating complications. While several low-fidelity PTA task trainers have been previously described, none allow for ultrasound image acquisition.6-9 We sought to create a cost-effective and realistic task trainer that allows trainees to acquire both diagnostic ultrasound and needle aspiration skills while draining a peritonsillar abscess.

Methods

We built the task trainer with low-cost, replaceable, and easily cleanable materials. A damaged airway headskin was repurposed to build the model. A mesh wire cylinder attached to a wooden base was fashioned to provide infrastructure. PTAs were simulated with a water and lotion solution inside a water balloon that was glued to the bottom of a paper cup. The balloon was fully submerged with ordnance gelatin to facilitate ultrasound image acquisition, and an asymmetric soft palate and deviated uvula were painted on top after setting. PTA cups were replaced after use. We spent eight hours constructing three task trainers and used 50 PTA cups for a total cost <$110.

Results

Forty-six emergency medicine (EM) residents performed PTA needle aspirations using the task trainers and were asked to rate ultrasound image realism, task trainer realism, and trainer ease of use on a five-point visual analog scale, with five being very realistic and easy. Sixteen of 46 (35%) residents completed the survey and reported that ultrasound images were representative of real PTAs (mean 3.41). They found the model realistic (mean 3.73) and easy to use (mean 4.08). Residents rated their comfort with the drainage procedure as 2.07 before and 3.64 after practicing on the trainer.

Conclusion

This low-cost, easy-to-construct simulator allows for ultrasound image acquisition while performing PTA needle aspirations and is the first reported of its kind. Educators from EM and otolaryngology can use this model to educate inexperienced trainees, thus ultimately improving patient safety in the clinical setting.

A novel and inexpensive ballistic gel phantom for ultrasound training

BACKGROUND

Ultrasonography use is increasing in emergency departments, and ultrasound education is now recommended in resident training. Ultrasound phantoms are used in many institutions for training purposes. The purpose of this study is to describe an inexpensive and simple method to create ultrasound-imaging models for the purpose of education and practice using clear ballistic gel.

METHODS

Clear ballistic gel is used to simulate tissue for firing practice and other military evaluations.

RESULTS

The transparent and durable ultrasound phantom we produced was clear and contained four vessel lumens. The images obtained using the phantom were of high quality and compared well to normal sonographic anatomy.

CONCLUSIONS

The clear ballistic brand gel is unique because it is inexpensive, does not dry out, does not decay, is odorless, and is reusable. The ultrasound images obtained using the phantom are realistic and useful for ultrasound education.

Intensive laparoscopic training course for surgical residents: program description, initial results, and requirements

INTRODUCTION

The Department of Surgery at the University of Arizona has created an intensive laparoscopic training course for surgical residents featuring a combined simulation laboratory and live swine model. We herein report the essential components to design and implement a rigorous training course for developing laparoscopic skills in surgical residents.

MATERIALS AND METHODS

At our institution, we developed a week-long pilot intensive laparoscopic training course. Six surgical residents (ranging from interns to chief residents) participate in the structured, multimodality course, without any clinical responsibilities. It consists of didactic instruction, laboratory training, practice in the simulation laboratory, and performance (under the direction of attending laparoscopic surgeons) of surgical procedures on pigs. The pigs are anesthetized and attended by veterinarians and technicians, and then euthanized at the end of each day. Three teams of two different training-level residents are paired. Daily briefing, debriefing, and analysis are performed at the close of each session. A written paper survey is completed at the end of the course.

RESULTS

This report describes the results of first 36 surgical residents trained in six courses. Preliminary data reveal that all 36 now feel more comfortable handling laparoscopic instruments and positioning trocars; they now perform laparoscopic surgery with greater confidence and favor having the course as part of their educational curriculum.

CONCLUSION

A multimodality intensive laparoscopic training course should become a standard requirement for surgical residents, enabling them to acquire basic and advanced laparoscopic skills on a routine basis.