Assessment of competency during orotracheal intubation in medical simulation

Comparison of Force Distribution during Laryngoscopy with the C-MAC D-BLADE and Macintosh-Style Blades: A Randomised Controlled Clinical Trial

Background: The geometry of a laryngoscope's blade determines the forces acting on the pharyngeal structures to a relevant degree. Knowledge about the force distribution along the blade may prospectively allow for the development of less traumatic blades. Therefore, we examined the forces along the blades experienced during laryngoscopy with the C-MAC D-BLADE and blades of the Macintosh style. We hypothesised that lower peak forces are applied to the patient's pharyngeal tissue during videolaryngoscopy with a C-MAC D-BLADE compared to videolaryngoscopy with a C-MAC Macintosh-style blade and direct laryngoscopy with a Macintosh-style blade. Beyond that, we assumed that the distribution of forces along the blade differs depending on the respective blade's geometry. Methods: After ethical approval, videolaryngoscopy with the D-BLADE or the Macintosh blade, or direct laryngoscopy with the Macintosh blade (all KARL STORZ, Tuttlingen, Germany), was performed on 164 randomly assigned patients. Forces were measured at six positions along each blade and compared with regard to mean force, peak force and spatial distribution. Furthermore, the duration of the laryngoscopy was measured. Results: Mean forces (all p < 0.011) and peak forces at each sensor position (all p < 0.019) were the lowest with the D-BLADE, whereas there were no differences between videolaryngoscopy and direct laryngoscopy with the Macintosh blades (all p > 0.128). With the D-BLADE, the forces were highest at the blade's tip. In contrast, the forces were more evenly distributed along the Macintosh blades. Videolaryngoscopy took the longest with the D-BLADE (p = 0.007). Conclusions: Laryngoscopy with the D-BLADE resulted in significantly lower forces acting on pharyngeal and laryngeal tissue compared to Macintosh-style blades. Interestingly, with the Macintosh blades, we found no advantage for videolaryngoscopy in terms of force application.

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.

Implementation of a Low-Cost 3D-Printed Feline Larynx Model for Veterinary Students

Endotracheal intubation (EI) in domestic cats is an important skill that veterinary students learn in order to perform anesthesia safely in this species. Implementing a 3D-printed larynx model (LaryngoCUBE) during the instruction process may improve student's learning of EI in felines. Twenty-two third-year students performed EI in cats with standard training (ST), and 16 students trained with the model (MT) the day before the laboratory. It was evaluated whether training with the model decreases the time and number of EI attempts, students' perceived difficulty performing EI using a visual analog score (VAS; 0 cm = very easy, 10 cm = extremely difficult; median [minimum-maximum]), and the incidence of failure to perform EI. The EI time on ST (58 [18-160] seconds) was longer, but not statistically different from MT (29 [13-120] seconds; p = .101). The number of EI attempts on ST (2 [1-3]) was higher than MT (1 [1-3]; p = .005). The VAS on the ST and MT were 4.5 (0.0-10.0) cm and 3.0 (0.2-10.0) cm, respectively (p = .029). The failure rate was 27% on the ST and 25% on the MT (p = 1.000). Students who practiced with a larynx model took fewer attempts to perform EI, tended to be faster, and found that EI was easier. However, the EI success rate in MT was not improved.

Design, development, and face validation of an intubation simulation device using real-time force data feedback

Objectives

To develop a novel laryngoscope device capable of dynamically measuring force and torque measurements in real-time during intubation and to explore the efficacy of such a device through a face validation simulation.

Methods

The torque sensor laryngoscope is designed for use during intubation and is modeled after a standard, single-use plastic laryngoscope. After device calibration, a face validation study was performed with intubation experts in the field. Quantitative data (intubation force metrics) and qualitative data (expert feedback on the device) were collected from three intubations using a Mac blade and three intubations with the Miller blade.

Results

Three experts (two anesthesiologists and one otolaryngologist) participated in the study. The mean maximum force exerted with the Mac blade was 24.5 N (95% confidence interval [CI], 22.3-26.8). The average force exerted was 13.6 N (95% CI, 11.7-15.5). The average total suspension time was 13.1 s (95% CI, 10.4-15.8). The average total impulse was 164.6 N·s (95% CI, 147.9-181.4). The mean maximum force exerted with the Miller blade was 31.6 N (95% CI, 26.4-36.8). The average force exerted was 15.8 N (95% CI, 13.8-17.9). The average total suspension time was 11.3 s (95% CI, 9.9-12.6). The average total impulse was 216.2 N·s (95% CI, 186.5-245.9). The mean maximum force (p = .0265) and total impulse (p = .009) were significantly higher in the Miller blade trials than in the Mac blade trials. Survey results found that this device, while bulky, intubated similarly to standard-use models and has potential as an intubation teaching tool.

Conclusion

The torque sensor laryngoscope can measure and display real-time intubation force metrics for multiple laryngoscope blades. Initial validation studies showed a significantly lower maximum force and total impulse when intubating with the Mac blade than with the Miller blade. Face validation survey results were positive and suggested the potential for this device as a teaching tool.

Level of Evidence

Level 5.

Developing a Profile of Procedural Expertise: A Simulation Study of Tracheal Intubation Using 3-Dimensional Motion Capture

BACKGROUND

Improving the assessment and training of tracheal intubation is hindered by the lack of a sufficiently validated profile of expertise. Although several studies have examined biomechanics of tracheal intubation, there are significant gaps in the literature. We used 3-dimensional motion capture to study pediatric providers performing simulated tracheal intubation to identify candidate kinematic variables for inclusion in an expert movement profile.

METHODS

Pediatric anesthesiologists (experienced) and pediatric residents (novices) were recruited from a pediatric institution to perform tracheal intubation on airway mannequins in a motion capture laboratory. Subjects performed 21 trials of tracheal intubation, 3 each of 7 combinations of laryngoscopic visualization (direct or indirect), blade type (straight or curved), and mannequin size (adult or pediatric). We used repeated measures analysis of variance to determine whether various kinematic variables (3-trial average for each participant) were associated with experience.

RESULTS

Eleven experienced and 15 novice providers performed 567 successful tracheal intubation attempts (9 attempts unsuccessful). For laryngoscopy, experienced providers exhibited shorter path length (total distance traveled by laryngoscope handle; 77.6 ± 26.0 cm versus 113.9 ± 53.7 cm; P = 0.013) and greater angular variability at the left wrist (7.4 degrees versus 5.5 degrees, P = 0.013) and the left elbow (10.1 degrees versus 7.6 degrees, P = 0.03). For intubation, experienced providers exhibited shorter path length of the right hand (mean = 61.1 cm versus 99.9 cm, P < 0.001), lower maximum acceleration of the right hand (0.19 versus 0.14 m/s, P = 0.033), and smaller angular, variability at the right elbow (9.7 degrees versus 7.9 degrees, P = 0.03).

CONCLUSIONS

Our study and the available literature suggest specific kinematic variables for inclusion in an expert profile for tracheal intubation. Future studies should include a larger sample of practitioners, actual patients, and measures of the cognitive and affective components of expertise.

An Intelligent Augmented Reality Training Framework for Neonatal Endotracheal Intubation

Neonatal Endotracheal Intubation (ETI) is a critical resuscitation skill that requires tremendous practice of trainees before clinical exposure. However, current manikin-based training regimen is ineffective in providing satisfactory real-time procedural guidance for accurate assessment due to the lack of see-through visualization within the manikin. The training efficiency is further reduced by the limited availability of expert instructors, which inevitably results in a long learning curve for trainees. To this end, we propose an intelligent Augmented Reality (AR) training framework that provides trainees with a complete visualization of the ETI procedure for real-time guidance and assessment. Specifically, the proposed framework is capable of capturing the motions of the laryngoscope and the manikin and offer 3D see-through visualization rendered to the head-mounted display (HMD). Furthermore, an attention-based Convolutional Neural Network (CNN) model is developed to automatically assess the ETI performance from the captured motions as well as identify regions of motions that significantly contribute to the performance evaluation. Lastly, augmented user-friendly feedback is delivered with interpretable results with the ETI scoring rubric through the color-coded motion trajectory that classifies highlighted regions that need more practice. The classification accuracy of our machine learning model is 84.6%.

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.

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.

Ergonomic Challenges Inherent in Neonatal Resuscitation

Neonatal resuscitation demands that healthcare professionals perform cognitive and technical tasks while working under time pressure as a team in order to provide efficient and effective care. Neonatal resuscitation teams simultaneously process and act upon multiple data streams, perform ergonomically challenging technical procedures, and coordinate their actions within a small physical space. An understanding and application of human factors and ergonomics science broadens the areas of need in resuscitation research, and will lead to enhanced technologies, systems, and work environments that support human limitations and maximize human performance during neonatal resuscitation.

Biomechanical profiles of tracheal intubation: a mannequin-based study to make an objective assessment of clinical skills by expert anesthesiologists and novice residents

BACKGROUND

Tracheal intubation (TI) is a key medical skill used by anesthesiologists and critical care physicians in airway management in operating rooms and critical care units. An objective assessment of dexterity in TI procedures would greatly enhance the quality of medical training. This study aims to investigate whether any biomechanical parameters obtained by 3D-motion analysis of body movements during TI procedures can objectively distinguish expert anesthesiologists from novice residents.

METHODS

Thirteen expert anesthesiologists and thirteen residents attempted TI procedures on an airway mannequin using a Macintosh laryngoscope. Motion capturing technology was utilized to digitally record movements during TI procedures. The skill with which experts and novices measured biomechanical parameters of body motions were comparatively examined.

RESULTS

The two groups showed similar outcomes (success rates and mean time needed to complete the TI procedures) as well as similar mean absolute velocity values in all 21 body parts examined. However, the experts exhibited significantly lower mean absolute acceleration values at the head and the left hand than the residents. In addition, the mean-absolute-jerk measurement revealed that the experts commanded potentially smoother motions at the head and the left hand. The Receiver Operating Characteristic (ROC) curves analysis demonstrated that mean-absolute-acceleration and -jerk measurements provide excellent measures for discriminating between experts and novices.

CONCLUSIONS

Biomechanical parameter measurements could be used as a means to objectively assess dexterity in TI procedures. Compared with novice residents, expert anesthesiologists possess a better ability to control their body movements during TI procedures, displaying smoother motions at the selected body parts.

A Continuous Quality Improvement Airway Program Results in Sustained Increases in Intubation Success

INTRODUCTION

Airway management is a critical skill for air medical providers, including the use of rapid sequence intubation (RSI) medications. Mediocre success rates and a high incidence of complications has challenged air medical providers to improve training and performance improvement efforts to improve clinical performance.

OBJECTIVES

The aim of this research was to describe the experience with a novel, integrated advanced airway management program across a large air medical company and explore the impact of the program on improvement in RSI success.

METHODS

The Helicopter Advanced Resuscitation Training (HeART) program was implemented across 160 bases in 2015. The HeART program includes a novel conceptual framework based on thorough understanding of physiology, critical thinking using a novel algorithm, difficult airway predictive tools, training in the optimal use of specific airway techniques and devices, and integrated performance improvement efforts to address opportunities for improvement. The C-MAC video/direct laryngoscope and high-fidelity human patient simulation laboratories were implemented during the study period. Chi-square test for trend was used to evaluate for improvements in airway management and RSI success (overall intubation success, first-attempt success, first-attempt success without desaturation) over the 25-month study period following HeART implementation.

RESULTS

A total of 5,132 patients underwent RSI during the study period. Improvements in first-attempt intubation success (85% to 95%, p < 0.01) and first-attempt success without desaturation (84% to 94%, p < 0.01) were observed. Overall intubation success increased from 95% to 99% over the study period, but the trend was not statistically significant (p = 0.311).

CONCLUSIONS

An integrated advanced airway management program was successful in improving RSI intubation performance in a large air medical company.

Claims for compensation after injuries related to airway management: a nationwide study covering 15 years

BACKGROUND

Securing the airway is one of the most important responsibilities in anaesthesia. Injuries related to airway management can occur. Analysis from closed claims can help to identify patterns of injury, risk factors and areas for improvement.

METHODS

All claims to The Norwegian System of Compensation to Patients from 1 January 2001 to 31 December 2015 within the medical specialty of anaesthesiology were studied. Data were extracted from this database for patients and coded by airway management procedures.

RESULTS

Of 400 claims for injuries related to airway management, 359 were classified as 'non-severe' and 41 as 'severe'. Of the severe cases, 37% of injuries occurred during emergency procedures. Eighty-one claims resulted in compensation, and 319 were rejected. A total of €1,505,344 was paid to the claimants during the period. Claims of dental damage contributed to a numerically important, but financially modest, proportion of claims. More than half of the severe cases were caused by failed intubation or a misplaced endotracheal tube.

CONCLUSION

Anaesthesia procedures are not without risk, and injuries can occur when securing the airway. The most common injury was dental trauma. Clear patterns of airway management that resulted in injuries are not apparent from our data, but 37% of severe cases were related to emergency procedures which suggest the need for additional vigilance. Guidelines for difficult intubation situations are well established, but adherence to such guidelines varies. Good planning of every general anaesthesia should involve consideration of possible airway problems and assessment of pre-existing poor dentition.

Validation of a difficult endotracheal intubation simulator designed for use in anaesthesia training

There is a need for a validated endotracheal intubation trainer that has variable difficulty settings for the training and assessment of medical practitioners. In this study three anatomical modifications were retrofitted to a commercial manikin and then validated. These modifications included restricted movements of the mandible as well as changes to the upper incisors. A total of 130 participants comprising specialists, trainees and medical students volunteered for this study. Validity was tested using randomised between-groups comparison of the time taken to intubate the manikin on all settings. Overall, and at each setting, there was a significant difference between the times to intubation among the three levels of experience (P <0.001). Novices were more than 12 times more likely to fail than experts (odds ratio [OR] 12.4, 95% confidence intervals [CI] 3.8, 41.8, P <0.001). The median time to intubation for all three groups changed significantly between settings 1 (easiest) and 4 (most difficult), novice 18 seconds (CI 8.9, 27.1, P <0.001), intermediate 15 seconds (CI 6.5, 23.5, P=0.001), and expert 9 seconds (CI 0.4, 17.6, P=0.04). The novice group was significantly different from the expert group at all attempts (P <0.002), and from the intermediates at all attempts apart from the third (P=0.055). The time for the novice and intermediate groups improved significantly by the fourth attempt, novice 15 seconds (CI 5.4, 24.6, P=0.002) and intermediate 10 seconds (CI 1.0, 19.0, P=0.03). Other aspects of validity were also satisfied during this study. A high degree of validity was established for these modifications, which can be retrofitted to an existing manikin and then used for teaching or assessment.

A comparison of the transillumination-assisted technique versus midline approach technique in novices: a prospective randomized controlled trial about the Bonfils intubation fiberscope

Background

The present study aimed to compare the safety and efficacy for novices to conduct intubation with the Bonfils intubation fiberscope (BIF) using the transillumination-assisted or midline approach technique in patients with normal airways.

Methods

In this prospective randomized control study, 10 trainees were assigned to the transillumination-assisted technique group (T group) or the midline approach technique group (R group). Each trainee was required to conduct intubation in 50 patients. The primary outcome was intubation time. The secondary outcomes were success rate (%), number of attempts, and complications.

Results

Among the cases of successful intubation, the intubation time was not significantly different between the two groups (P > 0.05). The overall success rate of intubation was not significantly different between the two groups (P > 0.05). The intubation success rates at the first, second, and third attempts as well as the average intubation times were similar between the two groups (P > 0.05), but in patients receiving successful intubation at the second attempt, the intubation time was longer in the T group (P = 0.0006). The incidences of dry throat, sore throat, and hoarseness were higher in the T group (all P < 0.05).

Conclusions

For patients with a normal airway, the transillumination-assisted technique was unlikely to increase the success rate of intubation with the BIF compared with the midline approach technique, but led to more complications.

Trial registration

ChiCTR-INR-16009967, retrospectively registered on November 22, 2016

Electronic supplementary material

The online version of this article (doi:10.1186/s12871-017-0322-6) contains supplementary material, which is available to authorized users.