Comparison of the Glidescope and Pentax AWS laryngoscopes to the Macintosh laryngoscope for use by advanced paramedics in easy and simulated difficult intubation

Implementation of video laryngoscopes and the development in airway management strategy and prevalence of difficult tracheal intubation: A national cohort study

BACKGROUND

We aimed to determine the development in the use of video laryngoscopy over a 9-year period, and its possible impact on airway planning and management.

METHODS

We retrieved 822,259 records of tracheal intubations recorded from 2008 to 2016 in the Danish Anaesthesia Database. The circumstances regarding pre-operative airway assessment, the scheduled airway management plan and the actual airway management concerning video laryngoscopy were reported for each year of observation. Further, the association between year of observation and various airway management related outcomes was evaluated by multivariate logistic regression.

RESULTS

There was a significant increase in airway management with 'advanced technique successfully used within two attempts' from 2.7% in 2008 to 15.5% in 2016 (p < .0001). This predominantly reflects use of video laryngoscopy. The prevalence of tracheal intubations 'scheduled for video laryngoscopy' increased from 3.5% in 2008 to 10.6% in 2016 (p < .0001). We found a significant increase in the prevalence of anticipated difficulties with intubations by direct laryngoscopy from 1.8% in 2008 to 5.2% in 2016 (p < .0001). The prevalence of failed tracheal intubations decreased from 0.14% in 2008 to 0.05% in 2016 (p < .0001).

CONCLUSION

From 2008 to 2016, a period of massive implementation of video laryngoscopes, a significant change in airway management behaviour was recorded. Increasingly, video laryngoscopy is becoming a first-choice device for both acute and routine airway management. Most importantly, the data showed a noticeable reduction in failed intubation over the time of observation.

A Comparative Study in Airway Novices Using King Vision Videolaryngoscope and Conventional Macintosh Direct Laryngoscope for Endotracheal Intubation

Background and Objectives

Tracheal intubation using laryngoscopy is a fundamental skill, for an anesthesiologist. However, teaching this skill is difficult since Macintosh direct laryngoscope (DL) allows only one individual to view the larynx during the procedure. Hence, this study aimed to determine whether King Vision® videolaryngoscope (KVL) provides any advantage over direct laryngoscopy in teaching this skill to airway novices.

Materials and Methods

In this prospective randomized crossover study, Ethical Committee clearance was obtained from the institutional review board (MSRMC/EC/2017) and the study was registered with Clinical Trial Registry. After informed consent, 53 medical students were allotted to perform laryngoscopy and endotracheal intubation on a manikin by using either KVL or Macintosh DL. The participants first performed laryngoscopy with either KVL or Macintosh DL following a brief instruction and then crossed over to the second arm of the study to perform laryngoscopy using the other scope. The primary outcome measure was the time for successful endotracheal intubation. The secondary outcome measures were incidence of esophageal intubation (EI), excess application of pressure on maxillary teeth excess maxillary pressure, and success rate.

Results

Mean time for endotracheal intubation was significantly faster using KVL than in DL (44.64 vs. 87.72 s; P < 0.001). No significant difference was found in the incidence of esophageal intubation 15.1% in KVL group versus 24.5% in DL group (P = 0.223). In the KVL group, 81.1% did not apply pressure on maxillary teeth versus 26.4% in the DL group (P < 0.001). The success rate of intubation was 100% in the KVL group versus 86.8% in the DL group (P = 0.006).

Conclusion

The KVL is a more effective tool to teach endotracheal intubation in comparison to Macintosh laryngoscope in airway novice medical students. Clinical trial registry India registration number: CTRI/2017/11/010491.

Impact of personal protective equipment on prehospital endotracheal intubation performance in simulated manikin

Background

Tracheal intubation in COVID-19 patients is a potentially high-risk procedure for healthcare professionals. Personal protective equipment (PPE) is recommended to minimize contact with critical patients with COVID-19 infection. This study aimed to primarily examine the effect of PPE use on intubation time and success rate among prehospital healthcare professionals; additionally, we compared intubation times among prehospital health care professionals using PPE with direct laryngoscopy and video laryngoscopy assistance.

Methods

In this prospective simulation study, we compared the intubation times and success rates among prehospital healthcare professionals who were or were not using PPE. Furthermore, demographic data, previous intubation experience, and previous intubation experience with PPE were recorded.

Results

Overall time to intubation with PPE use was 51.28 ± 3.89 s, which was significantly higher than that without PPE use (33.03 ± 2.65 s; p < 0.001). In addition, the overall success rate with PPE use was 74.4%, which was significantly lower than that without PPE use (93%;p < 0.001). PPE use increased the average intubation time by 19.73 ± 2.59 s with direct laryngoscopy and by 16.81 ± 2.86 s with video laryngoscopy (p < 0.001).

Conclusions

PPE use is associated with increased intubation time and decreased success rate. Video laryngoscopy assistance in cases where PPE use is required facilitates faster endotracheal intubation than does direct laryngoscopy assistance.

Comparing Four Video Laryngoscopes and One Optical Laryngoscope with a Standard Macintosh Blade in a Simulated Trapped Car Accident Victim

Background

Tracheal intubation still represents the “gold standard” in securing the airway of unconscious patients in the prehospital setting. Especially in cases of restricted access to the patient, video laryngoscopy became more and more relevant.

Objectives

The aim of the study was to evaluate the performance and intubation success of four different video laryngoscopes, one optical laryngoscope, and a Macintosh blade while intubating from two different positions in a mannequin trial with difficult access to the patient.

Methods

A mannequin with a cervical collar was placed on the driver's seat. Intubation was performed with six different laryngoscopes either through the driver's window or from the backseat. Success, C/L score, time to best view (TTBV), time to intubation (TTI), and number of attempts were measured. All participants were asked to rate their favored device.

Results

Forty-two physicians participated. 100% of all intubations performed from the backseat were successful. Intubation success through the driver's window was less successful. Only with the Airtraq® optical laryngoscope, 100% success was achieved. Best visualization (window C/L 2a; backseat C/L 2a) and shortest TTBV (window 4.7 s; backseat 4.1 s) were obtained when using the D-Blade video laryngoscope, but this was not associated with a higher success through the driver's window. Fastest TTI was achieved through the window (14.2 s) when using the C-MAC video laryngoscope and from the backseat (7.3 s) when using a Macintosh blade.

Conclusions

Video laryngoscopy revealed better results in visualization but was not associated with a higher success. Success depended on the approach and familiarity with the device. We believe that video laryngoscopy is suitable for securing airways in trapped accident victims. The decision for an optimal device is complicated and should be based upon experience and regular training with the device.

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

Background

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

Method

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

Results

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

Airway Management in Disaster Response: A Manikin Study Comparing Direct and Video Laryngoscopy for Endotracheal Intubation by Prehospital Providers in Level C Personal Protective Equipment

Introduction Airway management is one of many challenges that medical providers face in disaster response operations. The use of personal protective equipment (PPE), in particular, was found to be associated with higher failure rates and a prolonged time to achieve airway control. Hypothesis/Problem The objective of this study was to determine whether video laryngoscopy could facilitate the performance of endotracheal intubation by disaster responders wearing Level C PPE.

METHODS

In this prospective, randomized, crossover study, a convenience sample of practicing prehospital providers were recruited. Following standardized training in PPE use and specific training in the use of airway devices, subjects in Level C PPE were observed while performing endotracheal intubation on a stock airway in a Laerdal Resusci-Anne manikin system (Laerdal Medical; Stavanger, Norway) using one of three laryngoscopic devices in randomized order: a Macintosh direct laryngoscope (Welch Allyn Inc.; New York USA), a GlideScope Ranger video laryngoscope (Verathon Medical; Bothell, Washington USA), and a King Vision video laryngoscope (King Systems; Noblesville, Indiana USA). The primary outcome was time to intubation (TTI), and the secondary outcome was participant perception of the ease of use for each device.

RESULTS

A total of 20 prehospital providers participated in the study: 18 (90%) paramedics and two (10%) Emergency Medical Technicians-Cardiac. Participants took significantly longer when using the GlideScope Ranger [35.82 seconds (95% CI, 32.24-39.80)] to achieve successful intubation than with the Macintosh laryngoscope [25.69 seconds (95% CI, 22.42-29.42); adj. P<.0001] or the King Vision [29.87 seconds (95% CI, 26.08-34.21); adj. P=.033], which did not significantly differ from each other (adj. P=.1017). Self-reported measures of satisfaction evaluated on a 0% to 100% visual analog scale (VAS) identified marginally greater subject satisfaction with the King Vision [86.7% (SD=76.4-92.9%)] over the GlideScope Ranger [73.0% (SD=61.9-81.8%); P=.04] and the Macintosh laryngoscope [69.9% (SD=57.9-79.7%); P=.05] prior to adjustment for multiplicity. The GlideScope Ranger and the Macintosh laryngoscope did not differ themselves (P=.65), and the differences were not statistically significant after adjustment for multiplicity (adj. P=.12 for both comparisons).

CONCLUSION

Use of video laryngoscopes by prehospital providers in Level C PPE did not result in faster endotracheal intubation than use of a Macintosh laryngoscope. The King Vision video laryngoscope, in particular, performed at least as well as the Macintosh laryngoscope and was reported to be easier to use. Yousif S , Machan JT , Alaska Y , Suner S . Airway management in disaster response: a manikin study comparing direct and video laryngoscopy for endotracheal intubation by prehospital providers in Level C personal protective equipment. Prehosp Disaster Med. 2017;32(4):352-356.

Videolaryngoscopes differ substantially in illumination of the oral cavity: A manikin study

Background and Aims:

Insufficient illumination of the oral cavity during endotracheal intubation may result in suboptimal conditions. Consequently, suboptimal illumination and laryngoscopy may lead to potential unwanted trauma to soft tissues of the pharyngeal mucosa. We investigated illumination of the oral cavity by different videolaryngoscopes (VLS) in a manikin model.

Methods:

We measured light intensity from the mouth opening of a Laerdal intubation trainer comparing different direct and indirect VLS at three occasions, resembling optimal to less-than-optimal intubation conditions; at the photographer's dark room, in an operating theatre and outdoors in bright sunlight.

Results:

Substantial differences in luminance were detected between VLS. The use of LED light significantly improved light production. All VLS produced substantial higher luminance values in a well-luminated environment compared to the dark photographer's room. The experiments outside-in bright sunlight-were interfered with by direct sunlight penetration through the synthetic material of the manikin, making correct measurement of luminance in the oropharynx invalid.

Conclusion:

Illumination of the oral cavity differs widely among direct and indirect VLS. The clinician should be aware of the possibility of suboptimal illumination of the oral cavity and the potential risk this poses for the patient.

Comparison of GlideScope video laryngoscope with Macintosh laryngoscope in adult patients undergoing elective surgical procedures

Background:

GlideScope (GS) is a video laryngoscope that allows a real-time view of the glottis and endotracheal intubation. It provides a better view of the larynx without the need for alignment of the airway axes.

Aim:

This prospective randomized comparative study is designed to compare the intubation time, hemodynamic response, and complications associated with intubation using a GS or Macintosh laryngoscope (ML) in adult subjects undergoing elective surgical procedures.

Materials and Methods:

Sixty American Society of Anesthesiologists physical status 1–2 patients were included in this prospective randomized comparative study. Patients were randomized to be intubated using either a GS or an ML. The primary outcome measure was the intubation time. The secondary outcome measures were the hemodynamic response to intubation and the incidence of mucosal injury.

Statistical Analysis:

Mean and standard deviation were calculated for different parameters under the study. The observed results were analyzed using Student's t-test for quantitative data and Z-test of proportions. P<0.05 was considered statistically significant.

Results:

Intubation time was longer in GS group (45.7033 ± 11.649 s) as compared to ML (27.773 ± 5.122 s) P< 0.0001 with 95% confidence interval (95% CI) −13.2794 to −22.5806. GS provided better Cormack and Lehane laryngoscopic view (P = 0.0016 for grade 1 view) with 95% CI −0.1389 to −0.5951. GS group exhibited more laryngoscopic response than ML group with more increase in blood pressure and heart rate, but the difference was not statistically significant. More cases of mucosal trauma were documented in GS group.

Conclusion:

Use of GS to facilitate intubation led to better glottic view but took a longer time to achieve endotracheal intubation. GS was associated with more hemodynamic response to intubation and mucosal injury in comparison with an ML.

Efficacy of the Airway Scope (Pentax-AWS) for training in pediatric intubation

BACKGROUND

The aim of this study was to evaluate the efficacy of the Airway Scope (AWS) in the training of residents in pediatric intubation using high-performance simulators.

METHODS

A total of 51 residents were recruited. Baby SIM is a high-performance simulator with a built-in physiological program that reduces SpO2 if it stops breathing and increases SpO2 if assisted ventilation is provided using a bag mask. Therefore, real-life situations can be simulated with this program. Trial 1: after respiration of Baby SIM was stopped, intubation was initiated. If the intubation time was too long, a built-in physiological program led to desaturation. The intubation time and frequency of SpO2 <90% were compared between the Miller laryngoscope and the AWS. Trial 2: an ALS Baby, which is more difficult to intubate than Baby SIM, was used in comparison of intubation time and frequency of failure to intubate within 60 s between the two laryngoscopes. Mann-Whitney and chi-squared tests were used for statistical analysis.

RESULTS

Intubation time was significantly shorter using the AWS than the Miller laryngoscope in both trials. Furthermore, desaturation occurred significantly less frequently with the AWS than the Miller laryngoscope in trial 1. The frequency of intubation failure within 60 s was also significantly lower for the AWS than the Miller laryngoscope in trial 2.

CONCLUSION

The inclusion of both direct laryngoscopy and the AWS in pediatric resident programs might give pediatricians the option of using a safer and more reliable intubation method for children.

A Comparison of the Effects of Different Types of Laryngoscope on the Cervical Motions: Randomized Clinical Trial

BACKGROUND

The rate of cervical injury among all trauma patients is 3.1%. The most important point during intubation of those patients is not to increase the cervical injury.

AIMS

In this study, we hypothesize that there will be a minimal cervical extension during a laryngoscopy with the use of optical view laryngoscopes.

STUDY DESIGN

Prospective, randomized clinical trial.

METHODS

One hundred and fifty adult patients with ASA physical status I to III were enrolled in our study. After routine anesthesia induction, we randomly assigned the patients into three groups according to the type of laryngoscope. Macintosh type, Truview EVO2(®) type and Airtraq® type laryngoscopes were used in Group DL (n=50), Group TW (n=50) and Group ATQ (n=50), respectively. After applying general anesthesia induction and mask ventilation, all of the patients were positioned in the neutral position. An inclinometer was placed on the forehead of the patients. Then, the extension angle during intubation and the Cormack-Lehane Score were measured and the time to intubation was recorded.

RESULTS

One of the 50 patients in the DL Group, 2 of the 50 patients in the TW Group, and 4 of the 50 patients in the ATQ Group were excluded from the study because of the failure of intubation at defined times. The angle of cervical extension during laryngoscopy was found to be 27.24±6.71, 18.08±7.53, and 14.54±4.09 degrees in the Groups DL, TV and ATQ, respectively; these differences also had statistical significance (p=0.000). The duration of intubation was found to be 13.59±5.49, 23.60±15.23, and 29.80±13.82 seconds in Groups DL, TV and ATQ, respectively (p=0.000).

CONCLUSION

A minimal cervical motion was obtained during tracheal intubation with the use of Truview EVO2® and Airtraq® types of laryngoscope compared with the Macintosh laryngoscope. (ClinicalTrials.gov Identifier: NCT02191904).

Performance of intubation with 4 different airway devices by unskilled rescuers: manikin study

INTRODUCTION

This study was designed to compare the performances of 4 airway devices in achieving successful ventilation.

METHODS

A randomized crossover trial was conducted to evaluate 4 airway devices: laryngeal mask airway (LMA), i-gel (iGEL), PENTAX Airway Scope (AWS), and Macintosh laryngoscope (MCL). Thirty-eight unskilled rescuers performed intubation on a manikin during chest compressions in normal and difficult airway scenarios. The time to ventilation, intubation success rate, and difficulty of intubation were measured.

RESULTS

The time to ventilation of the airway devices in the normal scenario had a median value of 8.8 seconds (interquartile range, 7.3-10.5 seconds) for iGEL, 16.1 seconds (13.9-19.3 seconds) for LMA, 30.6 seconds (24.6-37.6 seconds) for AWS, and 35.0 seconds (29.5-45.9 seconds) for MCL. In the difficult airway scenario, the respective time to ventilation was 8.6 seconds (7.8-10.0 seconds), 15.3 seconds (14.3-20.2 seconds), 29.4 seconds (25.7-36.3 seconds) and 59.0 seconds (46.1-103.3 seconds). The success rates were 100% and 100% for LMA, 100% and 100% for iGEL, 97.4% and 94.7% for AWS, and 78.9% and 47.4% for MCL in the normal and difficult airway scenarios. The difficulties of intubation expressed as numerical rating scale were 2.0 and 2.0 (median values) for LMA, 1.0 and 2.0 for iGEL, 3.0 and 3.0 for AWS, and 4.0 and 5.0 for MCL in the normal and difficult airway scenarios, respectively.

CONCLUSION

With novice intubators who were unfamiliar with the airway devices, the LMA, iGEL, and AWS were superior to the MCL for establishing an airway without interruption of chest compressions in a manikin study. Intubation with the iGEL was faster and easier than with the other airway devices.

Influence of clinical experience of the Macintosh laryngoscope on performance with the Pentax-AWS Airway Scope(®), a rigid video-laryngoscope, by paramedics in Japan

PURPOSE

We sought to establish the clinical utility of the Pentax-AWS Airway Scope(®) (AWS) when used by paramedics to intubate the trachea, and to evaluate whether their performance was influenced by previous clinical experience with the Macintosh laryngoscope (ML).

METHODS

Twenty paramedics attempted tracheal intubation using the AWS in five patients each in the operating room. We recorded the success rate, the number of intubation attempts, and the time for intubation and adverse events, and compared these based on the paramedics' previous clinical experience with the ML. Ten paramedics had no prior clinical experience of the ML (group A) and 10 had used it on more than 30 occasions (group B).

RESULTS

The intubation success rate was 99 % (99/100). Notably, 96 % (47/49) of intubations were achieved on the first attempt by the inexperienced paramedics in group A, compared with 64 % (32/50) by the experienced paramedics in group B (p = 0.0001). The time to intubation (mean ± SD) was significantly shorter in group A than in group B (37 ± 24 vs. 48 ± 21 s, p = 0.002). There were marked variations in the times taken to intubate, but no apparent improvement as the intubators gained experience between their first and fifth cases. No complications were encountered in either group.

CONCLUSION

We found that paramedics could achieve a high tracheal intubation success rate using the AWS independent of previous airway management experience. Better intubation performance with the AWS was observed in paramedics without clinical experience with the ML.

Defining and developing expertise in tracheal intubation using a GlideScope(®) for anaesthetists with expertise in Macintosh direct laryngoscopy: an in-vivo longitudinal study

Although videolaryngoscopy can provide excellent views of the laryngeal structures as both the primary method of tracheal intubation and as a rescue technique for difficult direct laryngoscopy, the existing literature is inadequate to define expertise or even competence. We observed the performance of nine trainees during 890 intubations, with an additional 72 intubations performed by expert anaesthetists used as a control group. Univariate and multivariate mixed-effects logistic regression models were applied to detect potential predictors of successful intubation and define the number of intubations necessary for a trainee to achieve expertise (> 90% probability of optimal performance). Optimal performance was predicted by single laryngoscope insertion (p < 0.001) and a Cormack and Lehane grade-1 view (p < 0.001), and not by normal lifting force applied to the device (p = 0.15), with expertise reached after 76 attempts. These results indicate that expertise in videolaryngoscopy requires prolonged training and practice.

Tracheal intubation of pediatric manikins during ongoing chest compressions. Does Glidescope® videolaryngoscope improve pediatric residents' performance?

Our objective was to test the ability of pediatric residents to intubate the trachea of infant and child manikins during continuous chest compressions (CC) by means of indirect videolaryngoscopy with Glidescope® versus standard direct laryngoscopy. A randomized crossover simulation trial was designed. Twenty-three residents trained to intubate child and infant manikins were eligible for the study. They were asked to perform tracheal intubation in manikins assisted by both standard laryngoscopy and Glidescope® while a colleague delivered uninterrupted chest compressions. In the infant cardiac arrest scenario, the median (IQR) total time for intubation was significantly shorter with the Miller laryngoscope [28.2 s (20.4-34.4)] than with Glidescope® [38.0 s (25.3-50.5)] (p = 0.021). The number of participants who needed more than 30 s to intubate the manikin was also significantly higher with Glidescope® (n = 13) than with the Miller laryngoscope (n = 7, p = 0.01). In the child scenario, the total time for intubation and number of intubation failures were similar with Macintosh and Glidescope® laryngoscopes. The participants' subjective difficulty of the procedure was similar for direct and videolaryngoscopy.

CONCLUSION

In simulated infant and child cardiac arrest scenarios, pediatric residents are able to intubate the trachea during CC. The videolaryngoscope Glidescope® does not improve performance in this setting.

Pentax Airway Scope® vs Macintosh laryngoscope for tracheal intubation in adult patients: a systematic review and meta-analysis

The Pentax Airway Scope(®) is a single-use optical videolaryngoscope designed to assist with difficult tracheal intubation. We systematically reviewed the efficacy of the Pentax Airway Scope with that of a conventional laryngoscope for tracheal intubation in adults with 'normal' and 'difficult' airways. We included 17 randomised controlled trials with a total of 1801 participants. We used the DerSimonian and Laird random-effects model to calculate pooled relative risk or weighted mean differences. The relative risk (95% CI) of a Cormack-Lehane grade-1 laryngeal view was 2.40 (1.76-2.49) with the Pentax Airway Scope compared with the Macintosh laryngoscope, p < 0.00001. We found no other differences between the two laryngoscopes. Despite a superior laryngeal view, the Pentax Airway Scope provides little clinical benefit over the conventional laryngoscope.

Videolaryngoscopy

The approach to airway management has undergone a dramatic transformation since the advent of videolaryngoscopy (VL). Videolaryngoscopes have quickly gained popularity as an intubation device in a variety of clinical scenarios and settings, as well as in the hands of airway experts and non-experts. Their indirect view of upper airway improves glottic visualization, including in suspected or encountered difficult intubation. Yet, more studies are needed to determine whether VL actually improves endotracheal intubation (ETI) success rates, intubation times, and first attempt success rates; and thereby a potential replacement to traditional direct laryngoscopy. Furthermore, advances in technology have heralded a wide array of models each with their own strengths, weaknesses, and optimal applications. Such limitations need to be better understood and alternative strategies should be available. Thus, the role of VL continues to evolve. Though it is clear VL expands the armamentarium not only for anesthesiologists, but all healthcare providers potentially involved in airway management.

First comparison of the Venner(TM) A.P. Advance(TM) versus the Macintosh laryngoscope for intubations by non-anaesthetists: a manikin study

OBJECTIVE

The present study aims to study whether using a videolaryngoscope (A.P. Advance™) facilitates or hinders intubation by non-anaesthetists inexperienced in its use.

METHODS

Thirty doctors from Emergency and Intensive Care Medicine backgrounds performed laryngoscopy and tracheal intubation using the Macintosh laryngoscope (MAC), A.P. Advance™ Normal Blade (AP N) and A.P. Advance™ Difficult Airway Blade (AP DAB) in simulated normal and difficult airway manikins. The primary outcomes measured were time to successful tracheal intubation and failure to intubate within 3 min or three attempts. Secondary outcomes were number of intubation attempts, adjuncts used, glottic view and ease of intubation.

RESULTS

There was a higher rate of failed intubation in the simulated difficult airway in participants using the AP N blade than either the MAC or AP DAB (23% vs 3% and 7%, P = 0.031). This was associated with a longer median time to intubate with the AP N and the AP DAB versus MAC (56.6, 50.2 vs 39.9 s, P = 0.007 and P = 0.041). In the normal airway median time to intubate was longest with the AP N (27.8 s), and this was significantly slower than the MAC (18.1 s, P = 0.003) and the AP DAB (17.3 s, P < 0.001). No one failed to intubate the normal manikin.

CONCLUSIONS

The use of the A.P. Advance™ videolaryngoscope should not be considered, without adequate prior training and experience, in the management of a difficult airway. The level of adequate training has yet to be established.

Mapping the use of simulation in prehospital care - a literature review

Background

High energy trauma is rare and, as a result, training of prehospital care providers often takes place during the real situation, with the patient as the object for the learning process. Such training could instead be carried out in the context of simulation, out of danger for both patients and personnel. The aim of this study was to provide an overview of the development and foci of research on simulation in prehospital care practice.

Methods

An integrative literature review were used. Articles based on quantitative as well as qualitative research methods were included, resulting in a comprehensive overview of existing published research. For published articles to be included in the review, the focus of the article had to be prehospital care providers, in prehospital settings. Furthermore, included articles must target interventions that were carried out in a simulation context.

Results

The volume of published research is distributed between 1984- 2012 and across the regions North America, Europe, Oceania, Asia and Middle East. The simulation methods used were manikins, films, images or paper, live actors, animals and virtual reality. The staff categories focused upon were paramedics, emergency medical technicians (EMTs), medical doctors (MDs), nurse and fire fighters. The main topics of published research on simulation with prehospital care providers included: Intubation, Trauma care, Cardiac Pulmonary Resuscitation (CPR), Ventilation and Triage.

Conclusion

Simulation were described as a positive training and education method for prehospital medical staff. It provides opportunities to train assessment, treatment and implementation of procedures and devices under realistic conditions. It is crucial that the staff are familiar with and trained on the identified topics, i.e., intubation, trauma care, CPR, ventilation and triage, which all, to a very large degree, constitute prehospital care. Simulation plays an integral role in this. The current state of prehospital care, which this review reveals, includes inadequate skills of prehospital staff regarding ventilation and CPR, on both children and adults, the lack of skills in paediatric resuscitation and the lack of knowledge in assessing and managing burns victims. These circumstances suggest critical areas for further training and research, at both local and global levels.

Comparison of success rates between two video laryngoscope systems used in a prehospital clinical trial

OBJECTIVES

The primary aims of this study were to compare paramedic success rates and complications of two different video laryngoscopes in a prehospital clinical study.

METHODS

This study was a multi-agency, prospective, non-randomized, cross over clinical trial involving paramedics from four different EMS agencies. Following completion of training sessions, six Storz CMAC™ video laryngoscopes and six King Vision™ (KV) video laryngoscopes were divided between agencies and placed into service for 6 months. Paramedics were instructed to use the video laryngoscope for all patients estimated to be ≥ 18 years old who required advanced airway management per standard operating procedure. After 6 months, the devices were crossed over for the final 6 months of the study period. Data collection was completed using a telephone data collection system with a member of the research team (available 24/7). First attempt success, overall success, and success by attempt, were compared between treatment groups using exact logistic regression adjusted for call type and user experience.

RESULTS

Over a 12-month period, 107 patients (66 CMAC, 41 KV) were treated with a study device. The CMAC had a significantly higher likelihood of first attempt success (OR = 1.85; 95% CI 0.74, 4.62; p = 0.188), overall success (OR = 7.37; 95% CI 1.73, 11.1; p = 0.002), and success by attempt (OR = 3.38; 95% CI 1.67, 6.8; p = 0.007) compared to KV. Providers reverted to direct laryngoscopy in 80% (27/34) of the video laryngoscope failure cases, with the remaining patients having their airways successfully managed with a supraglottic airway in 3 cases and bag-valve mask in 4 cases. The provider-reported complications were similar and none were statistically different between treatment groups. Complication rates were not statistically different between devices.

CONCLUSION

The CMAC had a higher likelihood of successful intubation compared to the King Vision. Complication rates were not statistically different between groups. Video laryngoscope placement success rates were not higher than our historical direct laryngoscopy success rates.

Continuous professional competence (CPC) for emergency medical technicians in Ireland: educational needs assessment

Background

As in other countries, the Irish Regulator for Pre-Hospital practitioners, the Pre-Hospital Emergency Care Council (PHECC), will introduce a Continuous Professional Competence (CPC) framework for all Emergency Medical Technicians (EMTs), Paramedics and Advanced Paramedics (APs). This framework involves EMTs participating in regular and structured training to maintain professional competence and enable continuous professional developments. To inform the development of this framework, this study aimed to identify what EMTs consider the optimum educational outcomes and activity and their attitude towards CPC.

Methods

All EMTs registered in Ireland (n = 925) were invited via email to complete an anonymous online survey. Survey questions were designed based on Continuous Professional Development (CPD) questionnaires used by other healthcare professions. Quantitative and qualitative analyses were performed.

Results

Response rate was 43% (n = 399). 84% of participants had been registered in Ireland for less than 24 months, while 59% had been registered EMTs for more than one year. Outcomes were: evidence of CPC should be a condition for EMT registration in Ireland (95%), 78% believed that EMTs who do not maintain CPC should be denied the option to re-register. Although not required to do so at the time of survey, 69% maintained a professional portfolio and 24% had completed up to 20 hours of CPC activities in the prior 12 months. From a list of 22 proposed CPC activities, 97% stated that practical scenario-based exercises were most relevant to their role. E-learning curricula without practical components were considered irrelevant (32%), but the majority of participants (91%) welcomed access to e-learning when supplemented by related practical modules.

Conclusion

EMTs are supportive of CPC as a key part of their professional development and registration. Blended learning, which involves clinical and practical skills and e-learning, is the optimum approach.

Comparison of GlideScope Videolaryngoscopy to Direct Laryngoscopy for Intubation of a Pediatric Simulator by Novice Physicians

Objective. To compare novice clinicians' performance using GlideScope videolaryngoscopy (GVL) to direct laryngoscopy (DL). Methods. This was a prospective, randomized crossover study. Incoming pediatric interns intubated pediatric simulators in four normal and difficult airway scenarios with GVL and DL. Primary outcomes included time to intubation and rate of successful intubation. Interns rated their satisfaction of the devices and chose the preferred device. Results. Twenty-five interns were included. In the normal airway scenario, there were no differences in mean time for intubation with GVL or DL (61.4 versus 67.4 seconds, P = NS) or number of successful intubations (19 versus 18, P = NS). In the difficult airway scenario, interns took longer to intubate with GVL than DL (87.7 versus 61.3 seconds, P = 0.018), but there were no differences in successful intubations (14 versus 15, P = NS). There was a trend towards higher satisfaction for GVL than DL (7.3 versus 6.4, P = NS), and GVL was chosen as the preferred device by a majority of interns (17/25, 68%). Conclusions. For novice clinicians, GVL does not improve time to intubation or intubation success rates in a pediatric simulator model of normal and difficult airway scenarios. Still, these novice clinicians overall preferred GVL.

Comparative analysis of airway scope and Macintosh laryngoscope for intubation primarily for cardiac arrest in prehospital setting

STUDY OBJECTIVE

This study sought to determine and compare the utility of the Airway scope (AWS; Pentax Corporation, Tokyo, Japan) and the conventional Macintosh laryngoscope (MLS) for intubation in the prehospital setting.

METHODS

In this randomized controlled trial in the prehospital setting, the primary outcome was time required for intubation, and the secondary outcomes were ultimate success, first attempt success, and difficulty of intubation. The intent-to-treat principle was used to analyze time to intubation. Ultimate success was defined as intubation completed within 600 s regardless of the device ultimately used.

RESULTS

A total of 109 patients, primarily with cardiac arrest, were randomly assigned to the AWS or MLS arms. Median time (interquartile range) to intubation was 155 (71-216) s with the AWS versus 120 (60-170) s with the MLS (P = .095). Ultimate success rate was slightly lower with the AWS (96.4%) than with the MLS (100%) (P = .496), while the first attempt success rate was significantly lower (46% and 75%, respectively; P = .002). There was no significant difference in difficulty of intubation (P = .066). Multivariate logistic regression analysis revealed that cervical immobilization and oral contamination, such as vomit, was associated with first attempt success (odds ratio [95% confidence interval]: 0.11 [0.01-0.87] and 0.43 [0.18-0.99], respectively).

CONCLUSION

Despite its many advantages seen in other settings, the AWS did not show superior efficacy to the MLS in relation to time required for intubation, ultimate or first attempt success rate, or difficulty level of intubation in the prehospital setting.

Comparison of intubation performance between the King Vision and Macintosh laryngoscopes in novice personnel: a randomized, crossover manikin study

PURPOSE

The King Vision laryngoscope is a newly developed video laryngoscope. We conducted a simulation study to evaluate the efficacy of the King Vision in novice personnel.

METHODS

Thirty-one registered nurses with no previous experience with tracheal intubation were enrolled. Participants made 6 consecutive attempts at intubation of the manikin's trachea with a Macintosh laryngoscope (MAC) and the King Vision with channeled blade (KVC) and non-channeled blade (KVNC) in a randomized cross-over fashion. The Grading Scale of Intubation Difficulty (GSID) was rated on a 5-point scale.

RESULTS

Overall median (range) intubation times (sec) were 16.9 (8.0-60.0) with the MAC, 20.5 (7.2-60.0) with the KVC, and 60.0 (11.0-60.0) with the KVNC. The KVNC required significantly longer intubation time compared with the MAC or the KVC (p < 0.001). Success rate with the KVNC was 47.3 %, which was significantly inferior to that with the MAC (91.4 %) or KVC (86.6 %). Median GSID was 2 (range 1-5) with the KVC and 3 (1-4) with the MAC, which were both significantly lower than the 4 (2-5) with the KVNC (p < 0.001). Esophageal intubation with the MAC occurred in 18 of 186 attempts, whereas no incidents of esophageal intubation occurred with the KVC or KVNC.

CONCLUSION

The KVC facilitated intubation by novice personnel without incidence of esophageal intubation. However, intubation times, success rates, and GSID scores were similar to the values obtained with the MAC. These findings suggest that the KVC, but not the KVNC, could be used as an alternative device for intubation by novice personnel.

[Video laryngoscopy olé! Time to say good bye to direct and flexible intubation?]

A number of video laryngoscopy systems have been introduced into anesthetic practice in recent years. Due to the technical concepts of these systems exposure of the laryngeal structures is usually better than with direct laryngoscopy, both in normal airways as well as in those that are difficult to manage. With the increasing use of video laryngoscopy it seems as if direct laryngoscopy and flexible fibrescopic intubation are at risk of becoming redundant. This article describes current developments and discusses why expertise in direct laryngoscopy and flexible fibrescopic intubation should be maintained, particularly by experts in airway management.

Evaluation of the Storz CMAC®, Glidescope® GVL, AirTraq®, King LTS-D™, and direct laryngoscopy in a simulated difficult airway

OBJECTIVE

The aim of this study was to compare first-attempt and overall success rates and success rates in relation to placement time among 5 different airway management devices: Storz CMAC, Glidescope GVL, AirTraq, King LTS-D, and direct laryngoscopy (DL).

METHODS

Emergency medical technician basic (EMT-B), EMT-paramedics (EMT-P), and emergency medicine residents and staff physicians placed each of the 5 devices in a random order into an AirSim (TruCorp, Belfast, UK) part-task training manikin. The difficult airway scenario was created by fixing the manikin head to a stationary object and introducing simulated emesis into the hypopharynx. First-attempt and overall success and success in relation to placement time were compared. Provider feedback about device performance was also evaluated.

RESULTS

Ninety-four providers (16 EMT-basics, 54 EMT-paramedics, and 24 emergency department doctors of medicine) consented to participation. First-attempt and overall success rates for DL, King LTS-D, GVL, and CMAC were not statistically different. Compared with DL, the AirTraq was 96% less likely to be placed successfully (odds ratio, 0.04; 95% confidence interval [CI], 0.01-0.14). When time was factored into the model, the odds of successful placement of the King LTS-D were higher compared with DL (hazard ratio [HR], 1.80; 95% CI, 1.34-2.42) and lower for GVL (HR, 0.59; 95% CI, 0.44-0.80) and AirTraq (HR, 0.228; 95% CI, 0.16-0.325). Providers ranked the CMAC first in terms of performance and preference for use in their practice setting.

CONCLUSION

Overall success rates for DL, King-LTS-D, and both video laryngoscope systems were not different. When time was factored into the model, the King LTS-D was more likely to be placed successfully.

Videolaryngoscopy with glidescope reduces cervical spine movement in patients with unsecured cervical spine

BACKGROUND

Unconscious patients with severe trauma often require urgent endotracheal intubation. In trauma victims with possible cervical spine injury, any movement of the head and neck should be avoided.

STUDY OBJECTIVES

We investigated the effect of GlideScope videolaryngoscopy on cervical spine movement compared with conventional laryngoscopy in anesthetized patients with unsecured cervical spines.

METHODS

Sixty patients scheduled for elective surgery with general anesthesia and without anticipated airway problems were enrolled in the study after ethics committee approval and written informed consent. Intubation was performed with videolaryngoscopy (GlideScope(®), Verathon Inc., Bothell, WA) or conventional laryngoscopy (MacIntosh). Using video motion analysis with a lateral view, the maximum extension angle α was measured with reference to anatomical points (baseline and line drawn from processus mastoideus to os frontale [glabella]). Values were analyzed using Mann Whitney U-tests.

RESULTS

The deviation of α was a median 11.8° in the videolaryngoscope group and 14.3° in the conventional group (p = 0.045), with a maximum of 19.2° (videolaryngoscopy) vs. 29.3° (conventional). Intubation by physicians with some experience in videolaryngoscopy was associated with a reduced angle deviation (α = 10.3°) compared to inexperienced physicians (12.8°, p = 0.019). Intubation time was a median 24 s (min/max 12/75 s) in the MacIntosh group and 53 s (min/max 28/210 s) in the GlideScope group. In 3 patients randomized to the conventional group in whom conventional intubation failed, intubation could be successfully performed using videolaryngoscopy.

CONCLUSION

GlideScope videolaryngoscopy reduces movements of the cervical spine in patients with unsecured cervical spines and therefore might reduce the risk of secondary damage during emergency intubation of patients with cervical spine trauma.

Telebation: next-generation telemedicine in remote airway management using current wireless technologies

INTRODUCTION

Since the first remote intubation with telemedicine guidance, wireless technology has advanced to enable more portable methods of telemedicine involvement in remote airway management.

MATERIALS AND METHODS

Three voice over Internet protocol (VoIP) services were evaluated for quality of image transmitted, data lag, and audio quality with remotely observed and assisted intubations in an academic emergency department. The VoIP clients evaluated were Apple (Cupertino, CA) FaceTime(®), Skype™ (a division of Microsoft, Luxembourg City, Luxembourg), and Tango(®) (TangoMe, Palo Alto, CA). Each client was tested over a Wi-Fi network as well as cellular third generation (3G) (Skype and Tango).

RESULTS

All three VoIP clients provided acceptable image and audio quality. There is a significant data lag in image transmission and quality when VoIP clients are used over cellular broadband (3G) compared with Wi-Fi.

CONCLUSIONS

Portable remote telemedicine guidance is possible with newer technology devices such as a smartphone or tablet, as well as VoIP clients used over Wi-Fi or cellular broadband.

Success rates and endotracheal tube insertion times of experienced emergency physicians using five video laryngoscopes: a randomised trial in a simulated trapped car accident victim

CONTEXT

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.

OBJECTIVE

The aim of the present study was to evaluate whether five video laryngoscopes facilitate tracheal intubation more quickly or more securely than conventional laryngoscopy.

DESIGN

Prospective, controlled, randomised crossover trial.

SETTING

An airway manikin was placed on the driver's seat of a compact car. Access was possible only through the opened driver's door.

PARTICIPANTS

Twenty-five experienced anaesthetists.

INTERVENTION

Tracheal intubation in a simulated trapped patient using video laryngoscopes in a typical out-of-hospital setting.

MAIN OUTCOME MEASURES

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.

RESULTS

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).

CONCLUSION

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.

A comparison of the C-MAC video laryngoscope to the Macintosh direct laryngoscope for intubation in the emergency department

STUDY OBJECTIVE

We determine the proportion of successful intubations with the C-MAC video laryngoscope (C-MAC) compared with the direct laryngoscope in emergency department (ED) intubations.

METHODS

This was a retrospective analysis of prospectively collected data entered into a continuous quality improvement database during a 28-month period in an academic ED. After each intubation, the operator completed a standardized data form evaluating multiple aspects of the intubation, including patient demographics, indication for intubation, device(s) used, reason for device selection, difficult airway characteristics, number of attempts, and outcome of each attempt. Intubation was considered ultimately successful if the endotracheal tube was correctly inserted into the trachea with the initial device. An attempt was defined as insertion of the device into the mouth regardless of whether there was an attempt to pass the tube. The primary outcome measure was ultimate success. Secondary outcome measures were first-attempt success, Cormack-Lehane view, and esophageal intubation. Multivariate logistic regression analyses, with the inclusion of a propensity score, were performed for the outcome variables ultimate success and first-attempt success.

RESULTS

During the 28-month study period, 750 intubations were performed with either the C-MAC with a size 3 or 4 blade or a direct laryngoscope with a Macintosh size 3 or 4 blade. Of these, 255 were performed with the C-MAC as the initial device and 495 with a Macintosh direct laryngoscope as the initial device. The C-MAC resulted in successful intubation in 248 of 255 cases (97.3%; 95% confidence interval [CI] 94.4% to 98.9%). A direct laryngoscope resulted in successful intubation in 418 of 495 cases (84.4%; 95% CI 81.0% to 87.5%). In the multivariate regression model, with a propensity score included, the C-MAC was positively predictive of ultimate success (odds ratio 12.7; 95% CI 4.1 to 38.8) and first-attempt success (odds ratio 2.2; 95% CI 1.2 to 3.8). When the C-MAC was used as a video laryngoscope, a Cormack-Lehane grade I or II view (video) was obtained in 117 of 125 cases (93.6%; 95% CI 87.8% to 97.2%), whereas when a direct laryngoscope was used, a grade I or II view was obtained in 410 of 495 cases (82.8%; 95% CI 79.2% to 86.1%). The C-MAC was associated with immediately recognized esophageal intubation in 4 of 255 cases (1.6%; 95% CI 0.4% to 4.0%), whereas a direct laryngoscope was associated with immediately recognized esophageal intubation in 24 of 495 cases (4.8%; 95% CI 3.1% to 7.1%).

CONCLUSION

When used for emergency intubations in the ED, the C-MAC was associated with a greater proportion of successful intubations and a greater proportion of Cormack-Lehane grade I or II views compared with a direct laryngoscope.

First robotic tracheal intubations in humans using the Kepler intubation system

BACKGROUND

Intubation is one of the most important anaesthetic skills. We developed a robotic intubation system (Kepler intubation system, KIS) for oral tracheal intubation.

METHODS

In this pilot study, 12 patients were enrolled after approval of the local Ethics board and written informed consent. The KIS consists of four main components: a ThrustMaster T.Flight Hotas X joystick (Guillemot Inc., New York, NY, USA), a JACO robotic arm (Kinova Rehab, Montreal, QC, Canada), a Pentax AWS video laryngoscope (Ambu A/S, Ballerup, Denmark), and a software control system. The joystick allows simulation of the wrist or arm movements of a human operator. The success rate of intubation and intubation times were measured.

RESULTS

Eleven men and one woman aged 66 yr were included in this study. Intubation was successful in all but one patient using KIS at a total time of [median (inter-quartile range; range)] 93 (87, 109; 76, 153) s; in one patient, fogging of the video laryngoscope prevented intubation using KIS.

CONCLUSIONS

We present the first human testing of a robotic intubation system for oral tracheal intubation. The success rate was high at 91%. Future studies are needed to assess the performance and safety of such a system.

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

BACKGROUND

The 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.

METHODS

After 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.

RESULTS

Twenty-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±23.9 s, p=0.002; Pentax AirwayScope 32.4±14.9 s, p=0.001; Storz C-MAC 34.1±23.9 s, p<0.001; McGrath Series5 101.7±108.3 s, p<0.001; Glidescope Ranger 46.3±59.1 s, 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).

CONCLUSION

When 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.

Force and pressure distribution using Macintosh and GlideScope laryngoscopes in normal and difficult airways: a manikin study

BACKGROUND

The forces applied to the soft tissues of the upper airway may have a deleterious effect. This study was designed to evaluate the performance of the GlideScope compared with the Macintosh laryngoscope.

METHODS

Twenty anaesthetists and 20 trainees attempted tracheal intubation of a Laerdal SimMan manikin. Forces and pressure distribution applied by both laryngoscope blades onto the soft upper airway tissues were measured using film pressure transducers. The minimal force needed to achieve a successful intubation, in the same simulated scenario, was measured; additionally, we considered the visualization score achieved by using the Cormack-Lehane grades.

RESULTS

All participants applied, on average, lower force with the GlideScope than with the Macintosh in each simulated scenario. Forces [mean (sd)] applied in the normal airway scenario [anaesthetists: Macintosh 39 (22) N and GlideScope 27 (15) N; trainees: Macintosh 45 (24) N and GlideScope 21 (15) N] were lower than forces applied in the difficult airway scenario [anaesthetists: Macintosh 95 (22) N and GlideScope 66 (20) N; trainees: Macintosh 100 (38) N and GlideScope 48 (16) N]. All the intubations using the GlideScope were successful, regardless of the scenario and previous intubation experience. The average pressure on the blades was 0.13 MPa for the Macintosh and 0.07 MPa for the GlideScope, showing a higher uniformity for the latter.

CONCLUSIONS

The GlideScope allowed the participants to obtain a successful intubation applying a lower force. A flatter and more uniform pressure distribution, a higher successful rate, and a better glottic view were observed with the GlideScope.

Validation of a model of graded difficulty in Laerdal SimMan: functional comparisons between Macintosh, Truview EVO2, Glidescope Video Laryngoscope and Airtraq

BACKGROUND AND OBJECTIVE

A randomised, cross-over study was designed to validate a new model of graded difficulty (based on mandibular space reduction) in the Laerdal 'SimMan' mannnequin and to suggest functional comparisons between Macintosh. Glidescope Video Laryngoscope, Truview EVO2 and Airtraq.

METHODS

Twenty anaesthetists attempted intubation with all four laryngoscopes in three settings: easy, intermediate (based on a custom-made removable prosthetic insert) and difficult ('tongue oedema', a mannnequin feature). Laryngoscopic view and time to intubate were the primary outcome measures. Other measures were successful intubation, ease of laryngoscopy [visual analogue scale (VAS)] and intubation (VAS), tongue compression score and number of attempts.

RESULTS

Between settings comparisons demonstrated that Macintosh, Glidescope and Airtraq had worsening scores from easy to intermediate with lesser changes for Truview. However, with the intermediate to difficult comparison, Airtraq was the only blade with no worsening of scores. Within-blade comparisons showed that Macintosh was superior over all in both the easy and intermediate settings, whereas Airtraq was the most successful blade in the difficult setting.

CONCLUSION

Our study suggests that Glidescope and, to some extent Truview, are functionally similar to Macintosh and suffer from similar limitations in the difficult setting. On the contrary, Airtraq was functionally unique in providing good laryngeal exposure in the difficult setting and without excessive tongue compression.

A randomized comparison of the GlideScope videolaryngoscope to the standard laryngoscopy for intubation by pediatric residents in simulated easy and difficult infant airway scenarios

BACKGROUND

Videolaryngoscopy has been developed mainly to assist difficult airway intubation. However, there is a lack of studies demonstrating the real efficacy of its use in children. In this study, we tested the hypothesis that GlideScope (Verathon Inc, Bothell, Wash) videolaryngoscope improves tracheal intubation when used by pediatric residents in an advanced patient simulation model.

METHODS

Pediatric residents who passed a pediatric advanced life support course were eligible for the study. An advanced infant simulator was used, and 4 scenarios were proposed: normal airway (NA), tongue edema (TE), tongue edema and oropharyngeal edema, and cervical collar. No participant had prior experience with any videolaryngoscope. After a brief instruction in GlideScope technique, each participant performed the 4 scenarios using both the standard Miller and GlideScope laryngoscopes, in a random sequence.

RESULTS

Sixteen residents were included. The number of failed intubations was higher with GlideScope in NA and TE scenarios (3 vs 0, in both cases). Mean (SD) time to successful intubation was significantly longer with GlideScope in the NA scenario (GlideScope, 38 [SD, 13] vs Miller, 26 [SD, 16] seconds; P = 0.043). The number of maneuvers was significantly higher with GlideScope in the tongue edema and oropharyngeal edema scenario (2.3 [SD, 1.5] vs 1.5 [SD, 1]; P = 0.04). Upper jaw injury index was significantly lower with GlideScope in NA (2.0 [SD, 1] vs 2.6 [SD, 0.8]; P = 0.008) and cervical collar (2.1 [SD, 1.0] vs 2.8 [SD, 0.5]; P = 0.011) scenarios. Participants considered GlideScope technique more difficult than standard Miller in NA (5 [SD, 2.0] vs 3 [SD, 1.3]; P = 0.04) and TE (5.9 [SD, 2.5] vs 3.9 [SD, 1.7]; P = 0.02) scenarios.

CONCLUSIONS

In simulated scenarios of infant NA and difficult airway, when used by pediatric residents, GlideScope did not improve intubation performance when compared with the standard laryngoscope. Nevertheless, GlideScope may be safer for upper jaw injury and could have advantages in the management of complicated airway. Further studies are needed to assess if specific training will improve GlideScope intubation performance and whether the "in simulator" results translate into clinical practice.

Advances in prehospital trauma care

Prehospital trauma care developed over the last decades parallel in many countries. Most of the prehospital emergency medical systems relied on input or experiences from military medicine and were often modeled after the existing military procedures. Some systems were initially developed with the trauma patient in mind, while other systems were tailored for medical, especially cardiovascular, emergencies. The key components to successful prehospital trauma care are the well-known ABCs of trauma care: Airway, Breathing, Circulation. Establishing and securing the airway, ventilation, fluid resuscitation, and in addition, the quick transport to the best-suited trauma center represent the pillars of trauma care in the field. While ABC in trauma care has neither been challenged nor changed, new techniques, tools and procedures have been developed to make it easier for the prehospital provider to achieve these goals in the prehospital setting and thus improve the outcome of trauma patients.

Comparison of the GlideScope Videolaryngoscope to the standard Macintosh for intubation by pediatric residents in simulated child airway scenarios

OBJECTIVES

Videolaryngoscopy may facilitate tracheal intubation in difficult airway scenarios. Our objective was to compare the ability of residents to intubate a child manikin using the standard Macintosh laryngoscope and the novel GlideScope.

METHODS

Pediatric residents who passed an advanced pediatric life support course were eligible. Four scenarios were proposed: Macintosh (M) and GlideScope (G) "easy" intubation and M and G "difficult"; intubation (cervical immobilization with rigid collar). No participant had previous experience with videolaryngoscope. Each participant performed the 4 scenarios in a random sequence. Time from initiation of intubation procedure to inflation of manikin's chest was recorded, as well as the number of intubation attempts, number of additional maneuvers, dental injury index, and participant's subjective impression.

RESULTS

Eighteen subjects were included. Median (range) time for easy airway intubation was 18 seconds (8-120 seconds) with M versus 37 seconds (18-96 seconds) with G (P = 0.029). Time for intubation with cervical immobilization was 19 seconds (9-120 seconds) with M versus 49 seconds (22-120 seconds) with G (P = 0.006). The G intubation in case of cervical immobilization needed significantly more maneuvers than with the M intubation (P = 0.014). There were no significant differences when number of attempts, dental injury index, and participant's subjective difficulty rate were compared.

CONCLUSIONS

Without specific training, videolaryngoscope-guided intubation did not improve intubation performance by pediatric residents in this manikin model of normal and simulated difficult intubation caused by a cervical collar in place. To achieve skills with videolaryngoscope intubation in children, a specific training program is needed.

Video-laryngoscopes in the adult airway management: a topical review of the literature

The aim of the present paper is to review the literature regarding video-laryngoscopes (Storz V-Mac and C-Mac, Glidescope, McGrath, Pentax-Airway Scope, Airtraq and Bullard) and discuss their clinical role in airway management. Video-laryngoscopes are new intubation devices, which provide an indirect view of the upper airway. In difficult airway management, they improve Cormack-Lehane grade and achieve the same or a higher intubation success rate in less time, compared with direct laryngoscopes. Despite the very good visualization of the glottis, the insertion and advancement of the endotracheal tube with video-laryngoscopes may occasionally fail. Each particular device's features may offer advantages or disadvantages, depending on the situation the anaesthesiologist has to deal with. So far, there is inconclusive evidence indicating that video-laryngoscopy should replace direct laryngoscopy in patients with normal or difficult airways.

Advances in laryngoscopy: rigid indirect laryngoscopy

There is a growing body of evidence to support the use of rigid indirect laryngoscopy or 'video' laryngoscopy for tracheal intubation. We summarise some of the key issues, comparing rigid indirect laryngoscopy with direct conventional laryngoscopy.

Tracheal intubation using Macintosh and 2 video laryngoscopes with and without chest compressions

PURPOSE

The aim of the study was to compare the time taken for intubation (TTI) using the Macintosh and 2 video laryngoscopes (VLs) (GlideScope [GVL]; Saturn Biomedical System, Burnaby, British Columbia, Canada, and Airway Scope [AWS]; Pentax, Tokyo, Japan) with and without chest compressions by experienced intubators in a mannequin model.

METHODS

This was a randomized crossover study. Twenty-two experienced physicians who have limited experience in the VLs participated in the study. The TTI using 3 laryngoscopes with and without compressions were compared.

RESULTS

Median TTI difference between 2 conditions was only significant in the AWS (1.64 seconds; P = .01). There were no significant differences in the TTI between the Macintosh and the GVL or the AWS during compressions.

CONCLUSION

In a mannequin model, the Macintosh or the GVL was not affected by chest compressions. The TTI using the AWS was delayed by compressions but not clinically significant. Considering the lack of experience, 2 VLs may be useful adjuncts for intubation by experienced intubators during chest compressions.

Tracheal intubation of a difficult airway using Airway Scope, Airtraq, and Macintosh laryngoscope: a comparative manikin study of inexperienced personnel

BACKGROUND

The Airway Scope (AWS) (Pentax-AWS, Hoya Corp., Tokyo, Japan) and the Airtraq (ATQ) (Prodol, Vizcaya, Spain) have similarities in the novel structures of their blades. In this study, we evaluated the ease of use of the AWS and ATQ compared with the Macintosh laryngoscope (ML) by inexperienced personnel in a simulated manikin difficult airway.

METHODS

Twenty-four fifth-year medical students with no previous experience in tracheal intubation participated in this study. We used an advanced patient simulator (SimMan(R), Laerdal Medical, Stavanger, Norway) to simulate difficult airway scenarios including cervical spine rigidity, limited mouth opening, and pharyngeal obstruction. The sequences in selecting devices and scenarios were randomized. Success rates for tracheal intubation, and the time required for visualization of the glottis, tracheal intubation, and inflation of the lungs, and the number of optimization maneuvers and dental click sounds were analyzed. The 3 different intubation devices were tested in 4 different scenarios by 24 students.

RESULTS

Both the AWS and ATQ had very high success rates of tracheal intubation compared with the ML (AWS 100%*; ATQ 98%*; and ML 89%; *P < 0.05 AWS, ATQ versus ML). The time to intubation with the AWS was significantly shorter than with the ATQ and ML (AWS 11 +/- 6 seconds; ATQ 16 +/- 12 seconds; and ML 16 +/- 11 seconds; *P < 0.05 AWS versus ATQ, ML). The number of optimization maneuvers with the AWS was significantly lower than with the ATQ and ML. There were significantly more audible dental click sounds with the ML than with the AWS and ATQ.

CONCLUSION

Both the AWS and ATQ may be suitable devices for difficult intubation by inexperienced personnel in this manikin simulated scenario. Further studies in a clinical setting are necessary to confirm these findings.

Comparison of the C-MAC videolaryngoscope with the Macintosh, Glidescope, and Airtraq laryngoscopes in easy and difficult laryngoscopy scenarios in manikins

The C-MAC comprises a Macintosh blade connected to a video unit. The familiarity of the Macintosh blade, and the ability to use the C-MAC as a direct or indirect laryngoscope, may be advantageous. We wished to compare the C-MAC with Macintosh, Glidescope and Airtraq laryngoscopes in easy and simulated difficult laryngoscopy. Thirty-one experienced anaesthetists performed tracheal intubation in an easy and difficult laryngoscopy scenario. The duration of intubation attempts, success rates, number of intubation attempts and of optimisation manoeuvres, the severity of dental compression, and difficulty of device use were recorded. In easy laryngoscopy, the duration of tracheal intubation attempts were similar with the C-MAC, Macintosh and Airtraq laryngoscopes; the Glidescope performed less well. The C-MAC and Airtraq provided the best glottic views, but the C-MAC was rated as the easiest device to use. In difficult laryngo-scopy the C-MAC demonstrated the shortest tracheal intubation times. The Airtraq provided the best glottic view, with the Macintosh providing the worst view. The C-MAC was the easiest device to use.