Evaluation of four airway training manikins as simulators for inserting the LMA Classictm*

Low skill fibreoptic intubation using i-gel™ and air-Q™ in simulated difficult airways: A randomised study in manikin and in patients

Background:

Fibreoptic intubation via a supraglottic device (SAD) is ‘low skill fibreoptic intubation’ (LSFOI). ‘Standard’ second generation SADs (i-gelTM) have a gastric port. ‘Specialised’ second generation SADs (air-QTM) are designed to facilitate LSFOI and have wider ventilation ports. Our hypothesis was that performance of LSFOI differs between i-gelTM and air-QTM in a manikin with a simulated difficult airway.

Methods:

Our primary outcome was fibreoptic intubation success rate. Our secondary outcomes included SAD insertion and LSFOI times. A difficult airway was simulated by applying a hard cervical collar to a manikin. Anaesthetists performed LSFOI serially using both SADs in a random sequence. In the manikin study, 80 anaesthetists were recruited. To test the robustness of the conclusion from our manikin study, we repeated the study in 22 anaesthetised patients. Patients were fitted with the same cervical collar and randomly allocated to either devices. We used McNemar’s statistical test to analyse our primary outcome of successful intubations and paired nominal data. A Wilcoxon signed-ranks test was used to analyse nonparametric paired data and a Mann–Whitney U test was used for unpaired data analysis where appropriate. A p-value of <0.05 was considered statistically significant.

Results:

In the manikin study, the i-gelTM was superior to the air-QTM for successful tracheal intubation (98.8% vs 83.8%, respectively; p=0.002) and LSFOI times (34.0 s vs 36.0 s, respectively; p=0.012). In the patient study, LSFOI success rates were not significantly different between i-gelTM and air-QTM (100% vs 91.6%, respectively; p=0.545) but intubation times were shorter (52.5 s vs 60.0 s, respectively; p=0.036).

Conclusion:

In conclusion, we obtained LSFOI success rates for the i-gelTM or air-QTM of 98.8% and 83.8% respectively in a manikin; and 100% and 91.6% respectively in patients. It is in fact ‘low skill’ as many participants were successful despite no prior experience with LSFOI. The i-gelTM is superior for LSFOI compared with the air-QTM. This is despite being a ‘standard’ second generation SAD as compared to a ‘specialised’ second generation SAD (air-QTM).

Trial Registration:

The manikin and patient studies were conducted after being approved by the SingHealth Centralised Institutional Review Board (CRB reference number 2014/2039 and 2016/2069, respectively). The patient study was registered at ClinicalTrials.gov (ID: NCT02663843).

Comprehensive evaluation of manikin-based airway training with second generation supraglottic airway devices

Background

Supraglottic airway devices (SADs) are an essential second line tool during difficult airway management after failed tracheal intubation. Particularly for such challenging situations the handling of an SAD requires sufficient training. We hypothesized that the feasibility of manikin-based airway management with second generation SADs depends on the type of manikin.

Methods

Two airway manikins (TruCorp AirSim^® and Laerdal Resusci Anne^® Airway Trainer™) were evaluated by 80 experienced anesthesia providers using 5 different second generation SADs (LMA^® Supreme™ [LMA], Ambu^® AuraGain™, i-gel^®, KOO™-SGA and LTS-D™). The primary outcome of the study was feasibility of ventilation measured by assessment of the manikins' lung distention. As secondary outcome measures, oropharyngeal leakage pressure (OLP), ease of gastric tube insertion the insertion time, position and subjective assessments were evaluated.

Results

Ventilation was feasible with all combinations of SAD and manikin. By contrast, an OLP exceeding 10 cm H₂O could be reached with most of the SADs in the TruCorp but with the LTS-D only in the Laerdal manikin. Gastric tube insertion was successful in above 90% in the Laerdal vs 87% in the TruCorp manikin (P<0.009). Insertion times differed significantly between manikins. The SAD positions were better in the Laerdal manikin for LMA, Ambu, i-gel and LTS-D. Participant's assessments were superior in the Laerdal manikin for LMA, Ambu, i-gel and KOO-SGA.

Conclusions

Ventilation is possible with all combinations. However, manikins are variable in their ability to adequately represent additional functions of second generation SADs. In order to achieve the best performance during training, the airway manikin should be chosen depending on the SAD in question.

Optimizing education in difficult airway management: meeting the challenge

PURPOSE OF REVIEW

The last 2 decades have seen a vast change in the science and technology of airway management. As a result, there is an increasing need to equip anesthesiologists with the new knowledge and skills for the safe management of a difficult airway.

RECENT FINDINGS

In addition to knowledge and expertise, human factors and nontechnical skills (NTS), including situational awareness, communication and team work, play an important role during difficult airway management and contribute to the outcome. Didactic sessions are useful to impart knowledge. Self-learning, interactive discussions, simulation and debriefing are important tools for teaching and training in difficult airway management. Manikin training and simulation enable development of technical as well as NTS without subjecting patients to risk and allow multiple training sessions of relatively uncommon scenarios. Guidelines are useful teaching tools, whereas cognitive tools such as the Vortex approach may be useful during a difficult airway.

SUMMARY

There is need for research on difficult airway management and optimized training methods. Research is also required to determine the barriers to adoption of guidelines and strategies to ensure widespread dissemination and implementation of guidelines and best practices for difficult airway management.

Comparison of the Macintosh laryngoscope and blind intubation via the iGEL for Intubation With C-spine immobilization: A Randomized, crossover, manikin trial

INTRODUCTION

Endotracheal intubation (ETI) using a Macintosh laryngoscope (MAC) requires the head to be positioned in a modified Jackson position, slightly reclined and elevated. Intubation of trauma patients with an injured neck or spine is therefore difficult, since the neck usually cannot be turned or is already immobilized in order to prevent further injury. The iGEL supraglottic airway seems optimal for such conditions due to its blind insertion without the need of a modified Jackson position.

METHODS

Prospective, randomized, crossover study in 46 paramedics. Participants performing standard intubation and blind intubation via iGEL supraglottic airway device in three airway scenarios: Scenario A - normal airway; Scenario B - manual inline cervical immobilization, performed by an independent instructor; scenario C: cervical immobilization using a standard Patriot cervical extraction collar.

RESULTS

In Scenario A, nearly all participants performed ETI successfully both with MAC and iGEL (100% vs. 95.7%). The time to intubation (TTI) using the MAC and iGEL amounted to 19 [IQR, 18-21]s vs. 12 [IQR, 11-13]s (P<0.001). Head extension angle as well as tooth compression were significantly better with the iGEL compared to the MAC (P<0.001). In scenario B and C, the results with the iGEL were significantly better than with MAC for all analyzed variables (TTI, success of first intubation attempt, head extension angle, tooth compression and VAS scores).

CONCLUSION

We showed that blind intubation with the iGEL supraglottic airway was superior to ETI performed by paramedics in a simulated cervical immobilization scenario in a manikin in terms of success rate, time to definite tube placement, head extension angle, tooth compression, and rating.

Inherent variability in airway characteristics of simulation manikins: is it time we standardised assessments of crisis management skills?

Introduction

Learning of simulation-based crisis management skills involves technologically advanced manikins and use of automated scenarios. Progressions in preprogrammed scenarios require finite task completion such as successful airway intubations for achieving optimal learning outcomes aligned to curricular goals. The study was set to explore the existing variability among various simulation manikins in use at our institute for undergraduate medical education.

Methods

56 final-year undergraduate students, who had received prior training in airway management skills, performed intubations on each of the 5 different manikins (56×5=280 intubations). The manikins used were the Human Patient Simulator (HPS), iStan & Emergency Care Simulator (ECS) from CAE Healthcare and Mega Code Kelly (MCK) and Airway Trainer (AWTR) from Laerdal. The students’ performances were compared for success rates, ease of intubation, grade of laryngeal visualisation and presence of tooth injury on the manikins, Data from the intubations were cross-tabulated and evaluated by general estimating equation analysis using the Poisson model.

Results

iStan had the higher rates of failure to intubate (64.3%). iStan (62.5%) and HPS (57.1%) had statistically significant teeth injury (p<0.0001) compared to other manikins. HPS and AWTR had the least difficult grades of laryngeal visualisation (Cormack Lehane grades 1 and 2), while the most difficult grade of visualisation (Cormack Lehane grades 3 and 4) was reported in ECS (44.6%).

Conclusions

Each of the high-technology manikins used in automated scenarios for crisis management teaching and learning has heterogeneity in airway features. Since frequent airway management is a critical component of simulation scenarios, this can affect student performance when these manikins are used for formative and summative high-stakes assessments.

CPR using the lifeline ARM mechanical chest compression device: a randomized, crossover, manikin trial

INTRODUCTION

European Resuscitation Council as well as American Heart Association guidelines for cardiopulmonary resuscitation (CPR) stress the importance of uninterrupted and effective chest compressions (CCs). Manual CPR decreases in quality of CCs over time because of fatigue which impacts outcome. We report the first study with the Lifeline ARM automated CC device for providing uninterrupted CCs.

METHODS

Seventy-eight paramedics participated in this randomized, crossover, manikin trial. We compared the fraction of effective CCs between manual CPR and automated CPR using the ARM.

RESULTS

Using the ARM during resuscitation resulted in a higher percentage of effective CCs (100/min [interquartile range, 99-100]) compared with manual CCs (43/min [interquartile range, 39-46]; P<.001). The number of effective CCs decreased less over time with the ARM (P<.001), more often reached the required depth of 5 cm (97% vs 63%, P<.001), and more often reached the recommended CC rate (P<.001). The median tidal volume was higher and hands-off time was lower when using the ARM.

CONCLUSION

Mechanical CCs in our study adhere more closely to current guidelines than manual CCs. The Lifeline ARM provides more effective CCs, more ventilation time and minute volume, less hands-off time, and less decrease in effective CCs over time compared with manual Basic Life Support and might therefore impact outcome.

Reliability of manikin-based studies: an evaluation of manikin characteristics and their impact on measurements of ventilatory variables

Findings from manikin-based studies on ventilation are commonly directly extrapolated to clinical practice. The aim of this study was to determine how the use of manikins affects measurements of ventilatory variables. We connected a lung simulator to a manikin, which was then ventilated at different inspiratory flows. We defined three experimental models to compare measurements of ventilatory variables between the mechanical ventilator and the lung simulator. Even when no leakage occurred, significant tidal volume deviations were observed; from a mean (SD) of 21 (2) ml to 49 (9) ml, and from 40 (4) ml to 88 (5) ml for invasive and non-invasive ventilation, respectively (p < 0.001). Significant peak pressure deviations from 0.7 (0.1) cmH2 O to 10.6 (0.3) cmH2 O were also recorded during non-invasive ventilation (p < 0.001). Evaluation of manikin resistance and airway dead space may be essential to limit study bias. We suggest a recalibration of the recorded data if comparisons are made between different tests performed at different inspiratory flows.

Evaluation of airway management associated hands-off time during cardiopulmonary resuscitation: a randomised manikin follow-up study

INTRODUCTION

Airway management is an important component of cardiopulmonary resuscitation (CPR). Recent guidelines recommend keeping any interruptions of chest compressions as short as possible and not lasting more than 10 seconds. Endotracheal intubation seems to be the ideal method for establishing a secure airway by experienced providers, but emergency medical technicians (EMT) often lack training and practice. For the EMTs supraglottic devices might serve as alternatives.

METHODS

40 EMTs were trained in a 1-hour standardised audio-visual lesson to handle six different airway devices including endotracheal intubation, Combitube, EasyTube, I-Gel, Laryngeal Mask Airway and Laryngeal tube. EMTs performances were evaluated immediately after a brief practical demonstration, as well as after 1 and 3 months without any practice in between, in a randomised order. Hands-off time was pair-wise compared between airway devices using a repeated-measures mixed-effects model.

RESULTS

Overall mean hands-off time was significantly (p<0.01) lower for Laryngeal tube (6.1s; confidence interval 5.2-6.9s), Combitube (7.9s; 95% CI 6.9-9.0s), EasyTube (8.8s; CI 7.3-10.3s), LMA (10.2s; CI 8.6-11.7s), and I-Gel (11.9s; CI 10.2-13.7s) compared to endotracheal intubation (39.4s; CI 34.0-44.9s). Hands-off time was within the recommended limit of 10s for Combitube, EasyTube and Laryngeal tube after 1 month and for all supraglottic devices after 3 months without any training, but far beyond recommended limits in all three evaluations for endotracheal intubation.

CONCLUSION

Using supraglottic airway devices, EMTs achieved a hands-off time within the recommended time limit of 10s, even after three months without any training or practice. Supraglottic airway devices are recommended tools for EMTs with lack of experience in advanced airway management.

Difficult airway simulator intubation success rates using Commission on Accreditation of Medical Transport systems training standards

OBJECTIVES

This study was undertaken to evaluate difficult airway simulator intubation success rates using Commission on Accreditation of Medical Transport Systems (CAMTS) initial and maintenance intubation training standards on transport-RN novice intubators over a 1-year period.

METHODS

Twelve transport nurses were blinded to and randomly assigned five or six of 64 different difficult airway simulator scenarios. Intubation success rates were measured 1 month before training, 1 month after training, and 1 year later, following CAMTS initial and maintenance intubation standards. Outcome measurements included first attempt intubation rate, overall intubation success rate, number of attempts to intubation, time per attempt, time to intubation, and time between attempts. During the study, participants received no additional training or opportunities to intubate.

RESULTS

First-attempt intubation rates significantly improved (P 5 .022) from 19% 1 month before training to 36% 1 month after training, but did not significantly change (P > .999) 1 year later following CAMTS maintenance standards (34%). Mean cumulative success rates did not significantly improve after four attempts or after 3.5 minutes. The overall mean time per attempt and time between attempts declined with subsequent intubation attempts.

CONCLUSIONS

Using initial and maintenance CAMTS standards, simulator difficult airway intubation success rates are low in novice intubators. Our results suggest that one intubation/quarter may be enough to maintain difficult airway intubation success rates. Training significantly improves intubation rates. Little advantage occurs in intubation rates after four attempts or 3.5 minutes.

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.

Hands-off time during insertion of six airway devices during cardiopulmonary resuscitation: a randomised manikin trial

INTRODUCTION

Cardiopulmonary resuscitation (CPR) guidelines recommend limiting interruptions of chest compressions because prolonged hands-off (i.e., non-compression) time compromises tissue perfusion. 2010 European Resuscitation Council guidelines suggest that chest compressions should be paused less than 10 s during airway device insertion.

METHODS

With approval of the local ethics committee of the Medical University of Vienna and written informed consent, we recruited 40 voluntary emergency medical technicians, none of whom had advanced airway management experience. After a standardised audio-visual lecture and practical demonstration, technicians performed airway management with each six airway devices (endotracheal tube, Combitube, EasyTube, laryngeal tube, Laryngeal Mask Airway, and I-Gel) during on-going chest compressions in a randomised sequence on a Resusci Anne Advanced Simulator. Data were analysed using a mixed-effects model accounting for the repeated measurements and pair-wise comparisons among the airway devices.

RESULTS

The hands-off time associated with airway management using an endotracheal tube (including all intubation attempts) was 48 s (95% confidence interval: 43-53). The hands-off time for airway management using a laryngeal tube was 8.4 (3.4-16.4) s, Combitube 10.0 (4.9-15.1) s, EasyTube 11.4 (6.4-16.4) s, LMA 13.3 (8.2-18.3) s and for I-Gel 15.9 (10.8-20.9) s. Hands-off time was significantly longer with the conventional endotracheal tube than with any of the other airway systems. Only a third of the technicians successfully inserted an endotracheal tube whereas all of them successfully positioned each supraglottic device.

CONCLUSION

Supraglottic devices appear to be a reasonable emergency airway management strategy, even for inexperienced personnel.

Evaluation of a single-use intubating videoscope (Ambu aScope ™) in three airway training manikins for oral intubation, nasal intubation and intubation via three supraglottic airway devices

We compared the Ambu aScope™ with a conventional fibrescope in two simulated settings. First, 22 volunteers performed paired oral and nasal fibreoptic intubations in three different manikins: the Laerdal Airway Trainer, Bill 1 and the Airsim (a total of 264 intubations). Second, 21 volunteers intubated the Airway Trainer manikin via three supraglottic airways: classic and intubating laryngeal mask airways and i-gel (a total of 66 intubations). Performance of the aScope was good with few failures and infrequent problems. In the first study, choice of fibrescope had an impact on the number of user-reported problems (p=0.004), and user-assessed ratings of ease of endoscopy (p<0.001) and overall usefulness (p<0.001), but not on time to intubate (p=0.19), or ease of railroading (p=0.72). The manikin chosen and route of endoscopy had more consistent effects on performance: best performance was via the nasal route in the Airway Trainer manikin. In the second study, the choice of fibrescope did not significantly affect any performance outcome (p=0.3), but there was a significant difference in the speed of intubation between the devices (p=0.02) with the i-gel the fastest intubation conduit (mean (SD) intubation time i-gel 18.5 (6.8) s, intubating laryngeal mask airway = 24.1 (11.2) s, classic laryngeal mask airway = 31.4 (32.5) s, p=0.02). We conclude that the aScope performs well in simulated fibreoptic intubation and (if adapted for untimed use) would be a useful training tool for both simulated fibreoptic intubation and conduit-assisted intubation. The choice of manikin and conduit are also important in the success of such training. This manikin study does not predict performance in humans and a clinical study is required.

Evaluation of four manikins as simulators for teaching airway management procedures specified in the Difficult Airway Society guidelines, and other advanced airway skills

Ten volunteers evaluated the performance of four currently available manikins: Airway Management Trainer, Airway Trainer, Airsim and Bill 1 as simulators for the 16 procedures described in the Difficult Airway Society Guidelines (DAS techniques) and eight other advanced airway techniques (non-DAS techniques), by scoring and ranking each manikin and procedure. Manikin performance was unequal (p < 0.0001 for both SCORE and RANK data for both DAS and non-DAS techniques). Post hoc analysis ranked the manikins for DAS techniques as: 1st Laerdal, 2nd Trucorp, 3rd equal VBM and Ambu. For non-DAS techniques, the ranking was: 1st equal Laerdal and Trucorp, 3rd equal VBM and Ambu. The power to discriminate for individual procedures was considerably lower but for 15 of 16 DAS techniques and 6 of 8 non-DAS techniques, manikin performance differed significantly. Post hoc tests showed significant performance differences between individual manikins for 10 DAS procedures, with the Laerdal manikin performing best.

Evaluation of four airway training manikins as patient simulators for the insertion of single use laryngeal mask airways

We evaluated the performance of four manikins: Airsim(trade mark), Bill 1, Airway Management Trainer and Airway Trainer, as simulators for insertion of single-use laryngeal mask airways and the reusable LMA Classic. Sixteen volunteer anaesthetists inserted each laryngeal mask airway into each manikin twice. Insertions were scored for ease of insertion, clinical and fibreoptic position, and lung ventilation (maximum score 10). Scores < 7 were classified 'poor' and < 5 'failure'. We analysed manikin and laryngeal mask airway performance. Poor insertion rate was 15% (range 9-21%) and was lowest for the VBM manikin (p = 0.02). Insertion failure rate was 2.6% and did not differ significantly between manikins (p = 0.2). Overall manikin performance was significantly different (p < 0.0001). The VBM manikin scored best, with all other manikins equivalent. The VBM manikin performed significantly better for three individual laryngeal mask airways. Overall performance differences of laryngeal mask airways were statistically significant (p < 0.001) but individual comparisons were not. Silicone devices performed better than PVC devices (p < 0.05) Devices with and without grilles performed similarly. All manikins were adequate. The VBM manikin performed best overall and for several individual laryngeal mask airways. The methodology is useful for future evaluations of devices, both manikins and supraglottic airways. Further human clinical research is required.

Evaluation of four airway training manikins as patient simulators for the insertion of eight types of supraglottic airway devices*

We evaluated the performance of four currently available manikins: Airway Management Trainer (Ambu, UK), Airway Trainer (Laerdal, Norway), Airsim (Trucorp, Ireland), 'Bill 1' (VBM, Germany), with eight supraglottic airway devices: Airway Management Device, Cobra Perilaryngeal Airway, Combitube, i-Gel, Laryngeal Tube, Laryngeal Tube Disposable, Laryngeal Tube Suction II and Streamlined Liner of the Pharynx Airway. Ten anaesthetists inserted each supraglottic airway device twice into each manikin. Each insertion was scored and ranked. Manikin score and rank data showed statistically significant overall performance differences. Post hoc analysis showed the Trucorp manikin performed best, followed by the Laerdal manikin. No one manikin performed best for all individual supraglottic airway devices. The Trucorp manikin performed adequately for all supraglottic airway devices. Comparing supraglottic airway devices, i-Gel insertion was significantly the easiest. Our results show that manikin performance for supraglottic airway device insertion is unequal, which has implications for selecting manikins for supraglottic airway device training and for manikin studies assessing performance of supraglottic airway devices.

Simulators for use in anaesthesia

There are many simulators available for use in anaesthetic-related education and research. Those who wish to purchase a simulator or to establish a simulation facility face a daunting task in understanding the differences between simulators. Recent reviews have focused on narrower areas of simulation, such as airway management or basic life support, or on the application of simulators. It would be difficult to deal in detail with every simulator ever made for anaesthesia, but in the present review we cover the spectrum of currently available anaesthetic simulators, provide an overview of different types of simulator, and discuss a selection of simulators of particular interest, including some of historical significance and some examples of 'home made' simulators. We have found no common terminology amongst authors for describing or classifying simulators, and propose a framework for describing (or classifying) them that is simple, clear and applicable to any simulator.