Airway Manikin Research Articles

The Use of Video Laryngoscopy During Air Medical Transport

This study simulated intubation with direct laryngoscopy and with a GlideScope Ranger video laryngoscope using a standard Laerdal airway manikin in a medical helicopter under various conditions. We hypothesized that the intubation times would be greater using direct laryngoscopy compared with the GlideScope under all conditions. Twenty crew members of a single helicopter emergency medical service participated in the study. Participants intubated an airway manikin using both direct laryngoscopy and the GlideScope Ranger in varying conditions, including standing in a room with the lights on and off, in the helicopter while stationary on the ground and unbelted during both daytime and nighttime, and finally in the aircraft while in flight belted during both daytime and nighttime. A study investigator recorded the intubation times and independently confirmed tracheal placement of the endotracheal tube. For all 6 environments, the mean time for intubation was slightly greater using the GlideScope (18.7 seconds; 95% confidence interval, 17.4-20.0 seconds) compared with direct laryngoscopy (15.5 seconds; 95% confidence interval, 14.7-16.4). There was a statistically significant difference in times to intubation, in favor of direct laryngoscopy, in the settings of standing with the room lights on (P = 0.0013), on the ground in the helicopter unbelted during the daytime (P = 0.009), and in flight belted at nighttime (P = 0.0012), with the 3 other environments not reaching statistical significance. Using the GlideScope took more time to intubate compared with direct laryngoscopy in all tested environments. Although this difference in intubation times was statistically significant, it was not clinically significant, suggesting that both modalities may be comparable in nondifficult airways.

Rational comparison of tracheal intubation with direct and indirect laryngoscopes in a simulated trapped manikin

Editor, In a randomised controlled crossover trial on an airway manikin simulating a trapped patient, Wetsch et al.1 found that none of five indirect laryngoscopes, including the Glidescope Ranger video laryngoscope, Storz C-MAC video laryngoscope, Pentax AWS, Airtraq optical laryngoscope and McGrath Series 5 video laryngoscope outperformed the Macintosh laryngoscope for emergency intubation. In our view, however, there are several aspects of this study that need to be clarified. The design of this study merits comment. We noted that all participants were anaesthetists with extensive experience of intubation with a Macintosh laryngoscope in the operating room and in emergency conditions; 80% of them were also board certified as emergency physicians, and 44% were currently active as emergency physicians responding to calls at the scene of emergencies. According to the participants’ demographics, we concluded that all participants had managed difficult airways caused by various factors and achieved proficiency with intubation using a Macintosh laryngoscope in the different conditions. However, the authors should have further specified whether some of the participants had performed emergency intubations with a Macintosh laryngoscope in a truly trapped patient during first aid. In this study, it was also unclear why practising intubation with the tested devices on the simulated difficult airway scenario was not allowed prior to the study, although all the participants had almost no clinical experience with any of the five indirect laryngoscopes. Previous studies on patients or airway manikins with normal and difficult airways have shown that a learning curve is indeed required for any of the indirect laryngoscopes, although it is rapid and steep.2–4 Actually, experience and competence with any of the new airway devices are critical for their successful use, especially when there is a difficult airway.5 Before the initiation of this study, therefore, the authors should have attempted to define proficiency with the uses of the different laryngoscopes for intubation on the simulated difficult airway scenarios. In this respect, we completely agree with Behringer and Kristensen5 that for the results of a comparative airway management study to be valid, participants must be equally proficient with each airway device to avoid bias. Because all participants were experienced with direct laryngoscope but inexperienced with indirect laryngoscopes, the results of this study may be biased against indirect laryngoscopy. This may account for the main finding that indirect laryngoscopes did not outperform the direct laryngoscope for emergency intubation. That is, the conclusion of this study may only suggest that the peak of the learning curve of each indirect laryngoscope has not been achieved by all study participants.6 One reason is that, as with any airway device, experience and skill must be obtained before using an indirect laryngoscope. Special training for the device is not only needed, but also practising intubation with the device should be undertaken on patients with a normal airway before using it for more difficult airways. It is worth mentioning that most airway devices require a learning curve of around 20 to 30 attempts for acquisition of reasonable competency, but performance continues to improve even after 100 cases.7 An additional issue raised by this article1 is that the Airtraq was defined as a video laryngoscope. In fact, it is an optical laryngoscope that utilises mirrors and lenses to visualise the glottis through a curved optical channel that mimics the anatomical airway.8 The image is transmitted to a proximal viewfinder which allows the operator to visualise the larynx and the intubation.9 If a proprietary Airtraq video camera adaptor is attached to the proximal viewfinder for viewing the larynx and the intubation on a video monitor, it functions as a video laryngoscope with a remote screen. A manikin study shows that attachment of a video camera system can improve the ease of intubation with the Airtraq during chest compression.10 In the literature, both the optical and video laryngoscopes are often designated as indirect laryngoscopes because they achieve laryngeal exposure through indirect imaging, using video cameras or a series of mirrors and prisms.11 Acknowledgements Assistance with the study: none declared. Sources of funding: None of the authors had any financial support. Conflicts of interest: None of the authors has a potential conflict of interest concerning this letter.

The Development and Preliminary Evaluation of a Proposed New Scoring System for Videolaryngoscopy

Clear documentation of anaesthetic technique, difficulties and complications is an essential part of good anaesthetic practice, particularly in the area of airway management. The current convention of describing intubation using a videolaryngoscope only in terms of a Cormack and Lehane score is at best unhelpful and at worst dangerous. In an attempt to address the inadequacy of a Cormack and Lehane score to describe videoscopic intubation, we propose a three part scoring system: view, ease and device - the 'Fremantle Score'. Preliminary evaluation of this system in a diverse group of anaesthetists utilising four available videolaryngoscopes in a simulated normal and difficult airway manikin has demonstrated that the system is easy to use, easy to understand and relevant. In three of the eight device and manikin combinations studied, the videolaryngoscopic view correlated with the ease of intubation. This highlights the need for an alternative tool to describe intubation with a videolaryngoscope. We consider this development of a specific videoscopic scoring system a first step in better describing intubation by a videolaryngoscope and improving patient care.

External laryngeal manipulation does not improve the intubation success rate by novice intubators in a manikin study

BackgroundExternal laryngeal manipulation (ELM) is a technique used in cases of poor glottic view in direct laryngoscopy. Studies investigating ELM in the pediatric population are lacking. The objective of this study was to examine if use of ELM by inexperienced intubators improves the success rate of pediatric intubation. MethodsWe conducted a randomized, controlled, manikin study comparing intubation using ELM (study subjects) with standard intubation (controls). Study participants were paramedic students. Each participant performed 1 intubation attempt on 3 different pediatric airway manikins, independently. If an optimal Cormack-Lehane glottic view (CLGV) of more than 2 has been obtained, study subjects were previously instructed to perform the intubation using ELM; controls were instructed to continue with standard intubation. Outcome measures were single-attempt intubation success rate, preintubation CLGV, and duration of intubation. ResultsThe study group included 13 subjects who performed 39 intubations. In 19 intubations, CLGV of more than 2 had been obtained; and ELM was used. The control group included 14 subjects who performed 42 intubations. In 20 intubations, CLGV of more than 2 was obtained. Median CLGV score improved from 3.5 before ELM to 2 when ELM was used. However, no difference was found between the groups in intubation success rate (10/19 vs 14/20, P = .43); and the duration of intubation was significantly shorter in controls (25.8 vs 37.8 seconds, P < .007). ConclusionsIn this pediatric manikin study, ELM performed by novice intubators improved laryngeal view, but lengthened the duration of intubation and did not improve intubation success rate.

Ergonomics of novices and experts during simulated endotracheal intubation

Endotracheal Intubation (ETI) is an airway procedure commonly used to secure the airway for a variety of medical conditions. Proficiency in ETI procedures requires significant clinical experience and insufficient data currently exists describing the physical ergonomics of successful direct laryngoscopy. The research objectives of this study were to examine how ETI time, error and practitioner biomechanics varied among clinical experience levels and hospital bed heights. The participant population included novice and expert personnel, differentiated by their exposure to ETI procedures. Participants used a standard laryngoscope and blade to perform ETI trials on an airway manikin trainer at predesigned hospital bed heights. Participants were evaluated based on ETI time and accuracy, as well as wrist postures and muscle utilization. Hospital bed height did not affect task completion time, error rates or muscle utilization. Expert participants exhibited less ulnar deviation and forearm supination during task trials, as well as a higher utilization of the bicep brachii and anterior deltoid muscles. Expert grasped instrumentation differently, requiring less wrist manipulation required to achieve ideal instrument positions. By encouraging ergonomic best-practices in hand and arm postures during ETI training, the opportunity exists to improve patient safety and reduce the learning curve associated with ETI procedures.

Nasotracheal intubation in a difficult airway using the Storz C-MAC Videolaryngoscope, the Boedeker Bougie endotracheal introducer, and the Boedeker curved forceps.

Airway management has multiple indications for nasotracheal intubation. In this study, we focus on its indication in difficult airways. This work describes a modified procedure of nasotracheal intubation using the new Storz CMAC® Videolaryngoscope, the malleable Boedeker Bougie and the curved Boedeker Forceps in the intubation of a difficult airway manikin.

Comparison of different video laryngoscopes for emergency intubation in a standardized airway manikin with immobilized cervical spine by experienced anaesthetists. A randomized, controlled crossover trial

BackgroundThe aim of the present study was to evaluate whether different video laryngoscopes (VLs) facilitate endotracheal intubation (ETI) faster or more secure than conventional laryngoscopy in a manikin with immobilized cervical spine. MethodsAfter local ethics board approval, a standard airway manikin with cervical spine immobilization by means of a standard stiff collar was placed on a trauma stretcher. We compared times until glottic view, ETI, cuff block and first ventilation were achieved, and verified the endotracheal tube position, when using Macintosh laryngoscope, Glidescope Ranger, Storz C-MAC, Ambu Pentax AWS, Airtraq, and McGrath Series5 VLs in randomized order. Wilcoxon signed-rank test and McNemar's test were used for statistical analysis; p<0.05 was considered as significant. ResultsTwenty-three anaesthetists (mean age 32.1±4.9 years, mean experience in anaesthesia of 6.9±4.8 years) routinely involved in the management of multitrauma patients participated. The primary study end point, time to first effective ventilation, was achieved fastest when using Macintosh laryngoscope (21.0±7.6s) and was significantly slower with all other devices (Airtraq 33.2±23.9s, p=0.002; Pentax AirwayScope 32.4±14.9s, p=0.001; Storz C-MAC 34.1±23.9s, p<0.001; McGrath Series5 101.7±108.3s, p<0.001; Glidescope Ranger 46.3±59.1s, p=0.001). Overall success rates were highest when using Macintosh, Airtraq and Storz C-MAC devices (100%), and were lower in Ambu Pentax AWS and Glidescope Ranger (87%, p=0.5) and in McGrath Series5 device (72.2%, p=0.063). ConclusionWhen used by experienced anaesthesiologists, video laryngoscopes did not facilitate endotracheal intubation in this model with an immobilized cervical spine in a faster or more secure way than conventional laryngoscopy. However, data was gathered in a standardized model and further studies in real trauma patients are desirable to verify our findings.

Success rates and endotracheal tube insertion times of experienced emergency physicians using five video laryngoscopes

No randomised controlled trial has yet compared different video laryngoscopes in respect of the success rates and the time taken to achieve endotracheal intubation in trapped car accident victims. The aim of the present study was to evaluate whether five video laryngoscopes facilitate tracheal intubation more quickly or more securely than conventional laryngoscopy. Prospective, controlled, randomised crossover trial. An airway manikin was placed on the driver's seat of a compact car. Access was possible only through the opened driver's door. Twenty-five experienced anaesthetists. Tracheal intubation in a simulated trapped patient using video laryngoscopes in a typical out-of-hospital setting. Times to achievement of a view of the glottis, tracheal intubation, cuff inflation, first ventilation and tracheal tube position were compared using a standard Macintosh laryngoscope or Glidescope Ranger, Storz C-MAC, Ambu-Pentax AWS, Airtraq and McGrath Series 5 video laryngoscopes in a randomised order. Wilcoxon signed-rank test and McNemar test were used for statistical analysis. A P value of less than 0.05 was considered statistically significant. Twenty-five anaesthetists (35.1 ± 7.3 years; 16 male, nine female) with an intubation experience of 374 ± 96 intubations per year and an experience of 9.1 ± 7.3 years participated. Glottic view, tracheal intubation, cuff inflation and first ventilation were achieved most rapidly with the Macintosh laryngoscope, although the Airtraq and Pentax AWS video laryngoscopes were not significantly slower. Times were significantly longer when the Glidescope Ranger, McGrath Series 5 or Storz C-MAC video laryngoscopes were used (P < 0.05), failure to place the endotracheal tube correctly was significantly commoner with the McGrath Series 5 than with the Macintosh (P = 0.031). When attempting to intubate a trapped car accident victim, video laryngoscopes provide a better view of the glottis, but some delay tracheal intubation significantly. The devices with a tube guide (Airtraq and Ambu Pentax AWS) enable tracheal intubation to be achieved significantly faster and with a lower failure rate than devices without a tube guide. No video laryngoscope outperformed direct laryngoscopy with a Macintosh laryngoscope in this simulation study.

Novice And Expert Muscle Utilization And Wrist Postures During Simulated Endotrachial Intubation - A Pilot Study

Endotracheal Intubation (ETI) is an airway procedure commonly used to secure the airway for a variety of medical conditions. Endotracheal tube placement is most commonly performed under direct vision of the glottis with the use of a standard laryngoscope and blade. Proficiency in ETI procedures requires significant clinical experience and insufficient data currently exists describing the physical ergonomics of successful direct laryngoscopy. The research objectives of this study were to examine how ETI time, error and practitioner biomechanics varied among clinical experience levels and hospital bed heights. The participant population included novice and expert subgroups recruited from the University of Nebraska Medical Center, and the department of Emergency Medicine. Using a standard laryngoscope handle and blade, participants performed ETI trials on an airway manikin trainer at a minimum and maximum bed height. Participants were evaluated based on ETI completion time, endotracheal tube placement, wrist...

A simulated severe difficult airway does not alter the intubation performance with the SensaScope: a prospective randomised manikin study

Prospective randomised controlled study. Operation unit in a tertiary academic university hospital in a central European city. Period of the study was springtime and summer 2010. Twenty-four anaesthesiologists with various levels of professional experience were allocated to intubate an airway manikin either with the SensaScope (group S) or with the conventional Macintosh 3 laryngoscope (group L). Each participant performed three consecutive intubations with normal anatomy followed by three intubations with difficult anatomy. The airway difficulty was simulated by inflation of the manikin's tongue base with 40 ml of air. The times taken to view the larynx and to insert the tracheal tube were noted. The resulting tube position and the occurrence of dental damage were recorded. Those planned in the protocol. In normal anatomy, the laryngeal view (group L 5.9 ± 4.2 s vs. group S 9.2 ± 3.5 s) and intubation (group L 13.4 ± 7.6 s vs. group S 23.3 ± 8.6 s) was more rapidly obtained with conventional laryngoscopy (values presented as mean ± SD). In difficult anatomy, only the SensaScope permitted successful laryngeal view (group L impossible vs. group S 9.9 ± 4.8 s) and tracheal intubation (group L impossible vs. group S 23.4 ± 8.8 s). The latter always enabled correct tracheal tube position, whereas with laryngoscopy alone either oesophageal intubation or aborted attempts resulted. In the difficult airway setting, the frequency of simulated tooth damage was also significantly higher with conventional laryngoscopy (group L 26 of 36 vs. group S 6 of 36). The SensaScope performed fairly well in normal intubation anatomy, although its use was more complex than with conventional laryngoscopy and it required a slightly longer time. In the difficult airway setting, the SensaScope performed as well as in normal anatomy, whereas intubation by direct laryngoscopy proved to be impossible. The SensaScope enables the user to overcome severe airway difficulties caused by large tissue masses at the level of the tongue base or mouth floor.

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

BackgroundAlternatives 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.MethodsTwenty 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.ResultsIn 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.ConclusionsThe 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.

A paramedic study comparing the use of the Airtraq®, Airway Scope and Macintosh laryngoscopes in simulated prehospital airway scenarios*

In a randomised, cross-over study, we compared the use of the Airtraq , Airway Scope and Macintosh laryngoscopes by paramedics for tracheal intubation in three simulated prehospital scenarios. Fifty-four paramedics were invited to take part. When evaluated in a difficult airway manikin, median IQR [range] time to intubation with the Airtraq (21 (16-37 [6-80] s) and Airway Scope (16 (5-75 [12-23] s) was shorter than that with the Macintosh laryngoscope (39 (25-54 [7-120] s; p < 0.0001). The success rate within 30 s was greater with the Airtraq (61%) and Airway Scope (93%) than with the Macintosh laryngoscope (22%; p < 0.0001). When used for a standard intubation and in the sitting position, we found minimal differences among the three laryngoscopes. We conclude that the Airway Scope and Airtraq have significant advantages over the Macintosh laryngoscope and that of the two, the Airway Scope is the more effective device to use in the prehospital environment.

Intubation through the LMA-Supreme™: A Pilot Study of Two Techniques in a Manikin

The LMA-Supreme is a single-use disposable laryngeal mask that combines features of several laryngeal mask airways in one device. The primary aim of our study was to compare ease of use and operator preference for fibreoptic-aided intubation through the LMA-Supreme using an Aintree Intubating Catheter or Arndt Airway Exchange Catheter Set. Twenty participants experienced in fibreoptic-aided intubation performed a total of 40 intubations on an AirSim airway manikin through a #4 LMA-Supreme. Intubation using the Arndt Airway Exchange Catheter Set was easier than with the Aintree Intubating Catheter. Half of the participants preferred Aintree Intubating Catheter-assisted intubation, citing fewer steps and faster performance as the reasons. All 20 (100%) Arndt Airway Exchange Catheter Set-assisted intubations and 18/20 (90%) of Aintree Intubating Catheter-assisted intubations were successful. Aintree Intubating Catheter and Arndt Airway Exchange Catheter Set-assisted intubations can be performed quickly, successfully and with minimal difficulty through the LMA-Supreme by experienced operators. While the Arndt Airway Exchange Catheter may be easier the Aintree Intubating Catheter is faster.

Learning fibreoptic intubation with a virtual computer program transfers to ‘hands on’ improvement

Fibreoptic intubation is an essential skill in anaesthesiology that is challenging to learn in the clinical setting. The goal of this study was to evaluate 'virtual fibreoptic intubation' (VFI) software as an adjunct to the traditional fibreoptic intubation teaching. After informed consent, 42 undergraduate medical students were randomized into two groups. The 'control group' was taught conventionally by an expert bronchoscopist with a 1 h lecture. In addition to the didactic lecture by the expert, the 'VFI group' was given the VFI CD-ROM, and students self-trained with the software until they felt competent performing a virtual fibreoptic bronchoscopy on the normal patient models. Students were evaluated 2 weeks later on their first orotracheal fibreoptic intubation of an airway manikin. The primary endpoint was success, as evaluated by a staff anaesthesiologist blinded to the group of teaching. Fibreoptic intubation ability was the secondary endpoint. The fibreoptic intubation success rate was significantly higher in the VFI group than in the control group (81 versus 52%, P < 0.05). Among 10 failures in the control group, nine were due to oesophageal intubation as compared with only one out of four in the VFI group. Among four failures in the VFI group, three were because of taking longer than 4 min as compared with only one out of 10 in the control group. The VFI group tended towards better ability in the procedural skills of fibreoptic intubation than the control group. Self-training in fibreoptic intubation with the VFI software may improve the acquisition of fibreoptic intubation skills.

A comparison of the I-gel supraglottic airway as a conduit for tracheal intubation with the intubating laryngeal mask airway: A manikin study

Background Insertion of a supraglottic airway and tracheal intubation through it may be indicated in resuscitation scenarios where conventional laryngoscopy fails. Various supraglottic devices have been used as conduits for tracheal intubation, including the intubating laryngeal mask airway (ILMA), the Ctrach™ laryngeal mask and the I-gel supraglottic airway. Methods A prospective study with 25 participants evaluated the success rate of blind intubation (using a gum-elastic bougie, an Aintree intubating catheter (AIC) and designated tracheal tube) and fibrescope-guided tracheal intubation (through the intubating laryngeal mask airway and the I-gel supraglottic airway) on three different airway manikins. Results Twenty-five anaesthetists performed three intubations with each method on each of three manikins. The success rate of the fibrescope-guided technique was significantly higher than blind attempts ( P < 0.0001) with both devices. For fibreoptic techniques, there was no difference found between the ILMA and I-gel ( P > 0.05). All blind techniques were significantly more successful in the ILMA group compared to the I-gel ( P < 0.0001 for bougie, Aintree catheter and tracheal tube, respectively). Conclusions The results of this study show that, in manikins, fibreoptic intubation through both ILMA and I-gel is a highly successful technique. Blind intubation through the I-gel showed a low success rate and should not be attempted.

Success Rate of Orotracheal Intubation via GlideScope®versus Direct Laryngoscopy in Manikin-Only–Trained Medical Personnel

Success Rate of Orotracheal Intubation <i>via</i> GlideScope®<i>versus</i> Direct Laryngoscopy in Manikin-Only–Trained Medical Personnel

Rigid fibrescope Bonfils: use in simulated difficult airway by novices

BackgroundThe Bonfils intubation fibrescope is a promising alternative device for securing the airway. We examined the success rate of intubation and the ease of use in standardized simulated difficult airway scenarios by physicians. We compared the Bonfils to a classical laryngoscope with Macintosh blade.Methods30 physicians untrained in the use of rigid fibrescopes but experienced in airway management performed endotracheal intubation in an airway manikin (SimMan, Laerdal, Kent, UK) with three different airway conditions. We evaluated the success rate using the Bonfils (Karl Storz, Tuttlingen, Germany) or the Macintosh laryngoscope, the time needed for securing the airway, and subjective rating of both techniques.ResultsIn normal airway all intubations were successful using laryngoscope (100%) vs. 82% using the Bonfils (p < 0.05). In the scenario "tongue oedema" success rate using the Macintosh laryngoscope was 67% and 83% using the Bonfils. In the scenario "decreased cervical range of motion with jaw trismus", success rate using the Macintosh laryngoscope was 84% vs. 76%. In difficult airway scenarios time until airway was secured did not differ between the two devices. Use of Bonfils was rated "easier" in both difficult airway scenarios.ConclusionThe Bonfils can be successfully used by physicians unfamiliar with this technique in an airway manikin. The airway could be secured with at least the same success rate as using a Macintosh laryngoscope in difficult airway scenarios. Use of the Bonfils did not delay intubation in the presence of a difficult airway. These results indicate that intensive special training is advised to use the Bonfils effectively in airway management.

Comparison of Video Laryngoscopy Technologies

Indirect laryngoscopy allows practitioners to “see around the corner” of a patient's airway during intubation. Inadequate airway management is a major contributor to patient injury, morbidity and mortality. The purpose of the present study was to evaluate the video quality of commercially available video laryngoscopy systems. A team of four investigators at the University of Nebraska at Omaha and the Peter Kiewit Institute performed intubation simulations using a number of video laryngoscopy systems. Testing was done with a Laerdal Difficult Airway Manikin (Laerdal Medical Corp., Wappingers Falls, NY) in a setting that simulated difficult airways, adverse lighting conditions and various system configurations (e.g., maximizing screen contrast, minimizing screen brightness, maximizing screen color hue, etc.). Systems included the STORZ C-MACTM (KARL STORZ Endoscopy, Tuttlingen, Germany), a prototype developed by STORZ (a McIntosh #3 video blade with USB connectivity to an ultra mobile PC; “UMPC”) and a GlideScope® Portable GUL (Verathon Inc., Bothell, WA). Equipment was evaluated based on investigator's perceptions of the color (“C”), clarity (“L”) and brightness (“B”) of the image onscreen for each of the systems. Perceptions were given one of three possible ratings: High=3, Moderate=2 or Low=1. Statistics were performed using a two-tailed Wilcoxon Rank Sum test for independent samples. A summary of the results of the testing are shown below (shown as “Mean±Standard Deviation”): • C-MAC–L=2.13±0.99, C=1.75±0.89, B=2.5±0.93, Total=6.38±2.5 • GlideScope®–L=2.38±0.92, C=1.38±0.52, B=2.38±0.92, Total=6.13±1.96 • UMPC–L=1.88±0.83, C=1.75±1.04, B=1.88±0.83, Total=5.5±2.2 Testing showed that there were no significant differences between image clarity, color, brightness or overall score of any of the tested systems (α=0.05). Since there were no significant differences in video quality between the three systems, the choice of system falls to user preference, which can vary from person to person, and qualitative analysis of features that are outside the scope of this study. Investigators plan to evaluate additional video laryngoscopy solutions in an effort to create a platform-agnostic video laryngoscopy suite. Funding by KARL STORZ Endoscopy. Investigators were blinded to funding source until after testing was completed. The authors wish to thank Dr. W. Bosseau Murray for his insightful comments.

Video Laryngoscopy with the Macintosh Video Laryngoscope in Simulated Prehospital Scenarios by Paramedic Students

Objective. To investigate the effectiveness of the Karl Storz BERCI DCI Macintosh video laryngoscope (MVL) via the TELE PACK system for facilitating intubation by novice paramedic students in a simulation environment. We assessed the laryngeal view, measured by percentage of glottic opening (POGO), when intubating the SimMan manikin airway in different settings. The primary endpoint was the best POGO achieved by the student. Secondary endpoints included intubation times andsuccess rate. Method. We enrolled 25 novice paramedic students to intubate SimMan manikins. Students were randomized to use either a conventional Macintosh 3 (Mac3) blade alone or the MVL with a Mac3 blade. Students attempted their first intubation with the manikin on a stretcher in a normal neck position andreattempted intubation with the manikin's neck stiffened. The groups then crossed over using the alternate device to repeat the attempts in the manikin with a normal neck andwith a stiffened neck. The students then attempted the same sequence of four intubations with the manikin on the floor. Results. The MVL significantly improved POGO in all scenarios (p < 0.05). The MVL improved mean POGO 16% ± 6% in the manikin with a normal neck position on a stretcher and33% ± 7% in the manikin with a stiff neck on the floor. The improvement was significantly greater in simulated difficult scenarios. The intubation success rate (94%) was equal in the two groups, andthe POGO was significantly worse in the failures. In some subgroups, intubation times were longer with the MVL. Conclusion. The MVL improves the laryngeal view for novice laryngoscopists in a simulated setting, andthis improvement is greatest in simulated difficult scenarios

Evaluation of the Basic Airway Model, a novel mask ventilation training manikin*

The Basic Airway Model is an airway manikin designed for training in mask ventilation. We investigated the ability of the Basic Airway Model to provide varying levels of difficulty for mask ventilation. Volunteers with three levels of experience (novice, intermediate and expert) attempted to ventilate the manikin at three levels of difficulty: easy, intermediate and difficult. The distribution of frequencies of successful ventilation by different groups at the three levels of difficulty were statistically significant (p < 0.0001). The median (IQR (range)) degree of difficulty was 3 (2-5 (1-7)), 4 (3-5.3 (2-7)) and 6 (5-7 (3-9)) for easy, intermediate and difficult settings, respectively. We conclude that the Basic Airway Model can provide different levels of difficulty for mask ventilation training.