Evaluation of ease of intubation with the GlideScope�or Macintosh laryngoscope by anaesthetists in simulated easy and difficult laryngoscopy

The role of video and direct laryngoscopy in medical student intubation training: a comparative study on success rates and learning curves

BACKGROUND

Direct laryngoscopy (DL) is widely recognized as the most commonly used method for tracheal intubation. However, growing evidence highlights the increasingly prominent role of video laryngoscopy (VL) in the management of difficult airways. This study aimed to determine the most effective medical education method to equip medical students with this critical skill. In addition to evaluating the contributions of an intubation training program utilizing direct laryngoscopy and video laryngoscopy to tracheal intubation success among inexperienced medical students, we also aimed to explore the potential benefits of combining these two techniques.

METHODS

This mannequin-based study included 130 medical students. Before the study began, participants attended a 30-minute theoretical training session. Participants were randomly assigned to start with one of two scenarios. In each scenario, participants were given three attempts to perform intubation using each laryngoscope. The maximum allowable time for each intubation was set at 3 min. Students who successfully intubated within 3 min were recorded as successful, while those who failed to do so were recorded as unsuccessful.

RESULTS

The study demonstrated that VL provided higher success rates and shorter intubation times, particularly during the first and second attempts. However, it is noteworthy that no significant difference in success rates was observed between VL and DL during the third attempt.

CONCLUSION

This study highlights the necessity of integrating both VL and DL methods in intubation training programs. The combination of both approaches allows students to achieve quick initial results while progressively developing proficiency for more complex scenarios over time.

CLINICAL TRIAL NUMBER

Not applicable.

Comparison of various video laryngoscopes for nasotracheal intubation in simulated difficult airway scenarios: a randomized self-controlled crossover trial

BACKGROUND

Nasotracheal intubation (NTI) is particularly challenging in patients with rigid neck or micrognathia. Advancements in video laryngoscopy may improve NTI outcomes. We compared performance of direct laryngoscope (DL), King Vision videolaryngoscope (KVL), and C-MAC videolaryngoscope (VL) in normal, rigid neck, and micrognathia airway.

METHODS

A randomized, self-controlled crossover trial was conducted with 20 anesthesiologists who performed NTI on a high-fidelity mannequin under three airway conditions. Device order was randomized using a computer-generated sequence, and outcome assessors were blinded to the sequence of devices used. Primary outcomes were time to glottic view and intubation. Secondary outcomes included ease of intubation and force on incisors.

RESULTS

The median difference (95%CI) in time to intubation suggested that CMAC was better than KVL in normal airway (-9.0[-13.0 to-6.0], p < 0.001), rigid neck (-12.0[-18.0 to -6.5], p < 0.001) and micrognathia (-16.5[-20.0 to -13.5], p < 0.001). When compared to DL, CMAC was better for micrognathia (-8.0[-5.5 to-10.5], p = 0.001) but comparable for normal airway and rigid neck. C-MAC also exerted the least force on incisors, minimizing dental trauma.

CONCLUSION

The C-MAC VL demonstrated superior performance across all airway conditions, offering faster, safer, and easier NTI, making it the preferred device in challenging scenarios.

TRIAL REGISTRATION

Clinical Trial Registry of India: (CTRI/2022/05/042821) www.ctri.nic.in.

Comparative Efficacy of Videolaryngoscopy and Direct Laryngoscopy in Patients Living With Obesity: A Meta-Analysis

Intubation in patients living with obesity poses unique challenges due to altered airway anatomy and reduced physiological reserve, increasing the risk of complications. In synthesizing evidence from multiple trials, our meta-analysis suggests that videolaryngoscopy may provide a higher likelihood of achieving successful intubation on the first attempt compared to direct laryngoscopy while not substantially increasing the procedure time. Videolaryngoscopy was associated with a significant increase in first-pass intubation success compared to direct laryngoscopy, with a pooled risk ratio (RR) of 0.42 (95% CI 0.22 - 0.78, p = 0.0064). There was no significant difference in time to intubation between the two techniques (standardised mean differences (SMD) 0.13, 95% CI -0.26 to 0.52, p = 0.51), a result approached with low certainty due to the high heterogeneity among studies. Although the underlying studies varied in their methods and patient populations, these findings support the consideration of videolaryngoscopy as a potentially more reliable and safer technique for airway management in patients with obesity.

Evaluating the Impact of Direct, Direct Video, and Indirect Video Laryngoscopy Training on the Proficiency of Medical Students in Performing Direct Laryngoscopy: A High-Fidelity Manikin-Based Assessment

Endotracheal intubation (ETI), a potentially lifesaving intervention employed frequently in the emergent setting, is a manual skill that improves with repetitive practice and high-quality feedback. Classically, ETI centered around Direct Laryngoscopy (DL); however, with the advent and recent availability of Indirect Video Laryngoscopy (IVL) and Direct Video Laryngoscopy (DVL), studies have demonstrated varying results on the benefit of Video Laryngoscopy (VL) in training. We hypothesize that a training program centered on DVL, allowing students to visualize the anatomy and simultaneously receive instructor feedback via a real-time video feed, will practically improve student performance in DL. Our study of first-year medical students from the Edward Via College of Osteopathic Medicine (n = 21) randomized participants to one of three cohorts: DL, IVL, and DVL in a manikin-based simulation laboratory evaluated on successful intubation, time to successful intubation, dental injury, Numeric Rating Scale (NRS) to assess the trainee's perception of their performance and confidence level of performing intubation in a real-life scenario. Our results did not demonstrate a statistically significant difference between the three training modalities based on the outcomes assessed. Although IVL and DVL cohorts achieved 100% success following training, compared to 71% in the DL cohort, the results were not statistically significant. This is potentially due to our limited sample size, as our sample did not meet the calculated 162 participants for 80% power. These findings suggest that a larger sample size may be required to determine if there is a significant difference in outcomes for these training modalities.

Videolaryngoscopy versus direct laryngoscopy for tracheal intubation in neonates

BACKGROUND

Establishment of a secure airway is a critical part of neonatal resuscitation in the delivery room and the neonatal intensive care unit. Videolaryngoscopy has the potential to facilitate successful endotracheal intubation, and decrease adverse consequences of a delay in airway stabilization. Videolaryngoscopy may enhance visualization of the glottis and intubation success in neonates. This is an update of a review first published in 2015, and updated in 2018.

OBJECTIVES

To determine the effectiveness and safety of videolaryngoscopy compared to direct laryngoscopy in decreasing the time and attempts required for endotracheal intubation and increasing the success rate on first intubation attempt in neonates (0 to 28 days of age).

SEARCH METHODS

In November 2022, we updated the search for trials evaluating videolaryngoscopy for neonatal endotracheal intubation in CENTRAL, MEDLINE, Embase, CINAHL, and BIOSIS. We also searched abstracts of the Pediatric Academic Societies, clinical trials registries (www.

CLINICALTRIALS

gov; www.controlled-trials.com), and reference lists of relevant studies.

SELECTION CRITERIA

Randomized controlled trials (RCTs), quasi-RCTs, cluster-RCTs, or cross-over trials, in neonates (0 to 28 days of age), evaluating videolaryngoscopy with any device used for endotracheal intubation compared with direct laryngoscopy.

DATA COLLECTION AND ANALYSIS

Three review authors performed data collection and analysis, as recommended by Cochrane Neonatal. Two review authors independently assessed studies identified by the search strategy for inclusion. We used the GRADE approach to assess the certainty of the evidence.

MAIN RESULTS

The updated search yielded 7786 references, from which we identified five additional RCTs for inclusion, seven ongoing trials, and five studies awaiting classification. Three studies were included in the previous version of the review. For this update, we included eight studies, which provided data on 759 intubation attempts in neonates. We included neonates of either sex, who were undergoing endotracheal intubation in international hospitals. Different videolaryngoscopy devices (including C-MAC, Airtraq, and Glidescope) were used in the studies. For the primary outcomes; videolaryngoscopy may not reduce the time required for successful intubation when compared with direct laryngoscopy (mean difference [MD] 0.74, 95% confidence interval [CI] -0.19 to 1.67; 5 studies; 505 intubations; low-certainty evidence). Videolaryngoscopy may result in fewer intubation attempts (MD -0.08, 95% CI -0.15 to 0.00; 6 studies; 659 intubations; low-certainty evidence). Videolaryngoscopy may increase the success of intubation at the first attempt (risk ratio [RR] 1.24, 95% CI 1.13 to 1.37; risk difference [RD] 0.14, 95% CI 0.08 to 0.20; number needed to treat for an additional beneficial outcome [NNTB] 7, 95% CI 5 to 13; 8 studies; 759 intubation attempts; low-certainty evidence).  For the secondary outcomes; the evidence is very uncertain about the effect of videolaryngoscopy on desaturation or bradycardia episodes, or both, during intubation (RR 0.94, 95% CI 0.38 to 2.30; 3 studies; 343 intubations; very-low certainty evidence). Videolaryngoscopy may result in little to no difference in the lowest oxygen saturations during intubation compared with direct laryngoscopy (MD -0.76, 95% CI -5.74 to 4.23; 2 studies; 359 intubations; low-certainty evidence). Videolaryngoscopy likely results in a slight reduction in the incidence of airway trauma during intubation attempts compared with direct laryngoscopy (RR 0.21, 95% CI 0.05 to 0.79; RD -0.04, 95% CI -0.07 to -0.01; NNTB 25, 95% CI 14 to 100; 5 studies; 467 intubations; moderate-certainty evidence). There were no data available on other adverse effects of videolaryngoscopy. We found a high risk of bias in areas of allocation concealment and performance bias in the included studies.

AUTHORS' CONCLUSIONS

Videolaryngoscopy may increase the success of intubation on the first attempt and may result in fewer intubation attempts, but may not reduce the time required for successful intubation (low-certainty evidence). Videolaryngoscopy likely results in a reduced incidence of airway-related adverse effects (moderate-certainty evidence). These results suggest that videolaryngoscopy may be more effective and potentially reduce harm when compared to direct laryngoscopy for endotracheal intubation in neonates. Well-designed, adequately powered RCTS are necessary to confirm the efficacy and safety of videolaryngoscopy in neonatal intubation.

Effect of table inclination angle on videolaryngoscopy and direct laryngoscopy: Operator's muscle activation and laryngeal exposure analysis

BACKGROUND

Optimal vocal cord visualization depends on the patient's anatomical factors, characteristics of the laryngoscope, and the operator's muscle action. This study evaluated the effect of table inclination and three different laryngoscopic methods on procedural variables. The primary aim of this study is to compare differences in laryngoscopic view among clinicians based on the instrument used and table orientation. The secondary aim is to determine differences in upper extremity muscle activity based on laryngoscope use and table inclination.

METHODS

Fifty-five anesthesia providers with different experience levels performed intubations on a manikin using three angles of table inclination and three laryngoscopy methods. Time to intubation, use of optimization maneuvers, glottic view, operator's comfort level, and upper extremity muscle activation measured by surface electromyography were evaluated.

RESULTS

Table inclination of 15° and 30° significantly reduced intubation time and the need for optimization maneuvers. Fifteen degrees inclination gave the highest comfort level. Anterior deltoid muscle intensity was decreased when table inclination at 15° and 30° was compared to a flat position.

CONCLUSION

Table inclination of 15° reduces intubation time and the need to use optimization maneuvers and is associated with higher operator's comfort levels than 0° and 30° inclination in a simulated scenario using a manikin. Different upper extremity muscle groups are activated during laryngoscopy, with the anterior deltoid muscle exhibiting significantly higher activation levels with direct laryngoscopy at zero-degree table inclination.

A comparative study of the efficacy of Glidescope versus Macintosh direct laryngoscopy for intubation in pediatric patients undergoing cardiac surgery

Background:

The Glidescope is a novel, portable, reusable video laryngoscope that has provided superior laryngeal visualization to facilitate tracheal intubation, especially in the management of difficult airways. In this study, we aimed to compare the efficacy of the Glidescope (video-laryngoscope) against the Macintosh direct laryngoscope.

Methods:

Fifty patients were randomly selected via simple randomization using computer-generated random numbers, and sorted into two groups of 25 patients: the Glidescope group and the Macintosh group. We included pediatric patients undergoing cardiac surgery for the repair of congenital heart disease. Those with suspected difficult intubation, preterm babies with low body weight, and patients at risk of aspiration were all excluded.

Results:

Patients’ baseline demographic and clinical characteristics were found to be comparable in the two groups. The mean intubation time was 24.1 ± 13.6 s in the Glidescope group, as compared to 18.1 ± 5.9 s in the Macintosh group. Blade insertion was easy in 92% and 96% of the patients in the Glidescope and Macintosh groups, respectively. Tracheal intubation was considered easy in 84% of the Glidescope group, compared to 92% of the Macintosh group. There was a statistically significant correlation between the ease of tracheal intubation and the used intubation method (rho = –0.35; P = 0.014).

Conclusion:

Our findings indicate that the Glidescope can be used as an efficient modality for obtaining successful intubations with no complications. Ease of tracheal intubation was the only outcome that was found to be affected by the used modality. Further investigations with proper sample sizes are needed.

Comparison of Macintosh Laryngoscope and GlideScope® for Orotracheal Intubation in Children Older Than One Year

Objectives:

We aim to investigate intubation conditions, intubation times, and hemodynamic response with the GlideScope video laryngoscope or the Macintosh direct laryngoscope for orotracheal intubation in children older than one year.

Methods:

Eighty patients aged 1–12 years, scheduled to undergo elective surgery under general anesthesia with endotracheal intubation were included in a prospective, single-blinded, randomized trial. Exclusion criteria were risk of pulmonary aspiration, craniofacial malformation, difficult intubation, emergency surgery, cardiovascular disease, respiratory disease, and hemodynamic instability. After standard anesthesia induction, patients were randomized into two groups. The group G patients (n=40) were intubated with the GlideScope and the group M patients (n=40) were intubated with the Macintosh laryngoscope. Intubation time, number of attempts, Cormack–Lehane score, airway maneuvers, and visual analog score were recorded. Hemodynamic variables were recorded before and after anesthesia induction, at intubation, and 1., 3., and 5. minutes after intubation. Student’s t-test, Mann–Whitney U test, and the χ² test were used for statistical analysis, with p<0.05 considered significant.

Results:

The demographic data, operation time and hemodynamic parameters were similar between the two groups. The intubation time was longer in Group G than Group M. The incidence of Cormack–Lehane score 1 was higher in Group G than Group M while Cormack–Lehane score 2 was higher in Group M.

Conclusion:

We concluded that the GlideScope video laryngoscope provided better glottis visualization, but prolonged intubation time. There was no superiorty on hemodynamic effect with the video laryngoscope.

The influence of different patient positions during rapid induction with severe regurgitation on the volume of aspirate and time to intubation: a prospective randomised manikin simulation study

BACKGROUND

Aspiration is a main contributor to morbidity and mortality in anaesthesia. The ideal patient positioning for rapid sequence induction remains controversial. A head-down tilt and full cervical spine extension (Sellick) might prevent aspiration but at the same time compromise airway management. We aimed to determine the influence of three different positions during induction of general anaesthesia on the volume of aspirate and on participants' airway management.

METHODS

Eighty-four anaesthetic trainees and consultants participated in a prospective randomised simulation study. Anaesthesia was induced in reverse Trendelenburg position (+ 15°) in a manikin capable of dynamic fluid regurgitation. Participants were randomised to change to Trendelenburg position (- 15°) a) as soon as regurgitation was noticed, b) as soon as 'patient' had been anaesthetised, and c) as soon as 'patient' had been anaesthetised and with full cervical spine extension (Sellick). Primary endpoints were the aspirated volume and the time to intubation. Secondary endpoints were ratings of the laryngoscopic view and the intubation situation (0-100 mm).

RESULTS

Combining head-down tilt with Sellick position significantly reduced aspiration (p < 0.005). Median time to intubate was longer in Sellick position (15 s [8-30]) as compared with the head in sniffing position (10 s [8-12.5]; p < 0.05). Participants found laryngoscopy more difficult in Sellick position (39.3 ± 27.9 mm) as compared with the sniffing position (23.1 ± 22.1 mm; p < 0.05). Both head-down tilt intubation situations were considered equally difficult: 34.8 ± 24.6 mm (Sniffing) vs. 44.2 ± 23.1 mm (Sellick; p = n.s).

CONCLUSIONS

In a simulated setting, using a manikin-based simulator capable of fluid regurgitation, a - 15° head-down tilt with Sellick position reduced the amount of aspirated fluid but increased the difficulty in visualising the vocal cords and prolonged the time taken to intubate. Assessing the airway management in the identical position in healthy patients without risk of aspiration might be a promising next step to take.

Videolaryngoscopy versus direct laryngoscopy for tracheal intubation in neonates

BACKGROUND

Establishment of a secure airway is a critical part of neonatal resuscitation in the delivery room and the neonatal unit. Videolaryngoscopy has the potential to facilitate successful endotracheal intubation and decrease adverse consequences of delay in airway stabilization. Videolaryngoscopy may enhance visualization of the glottis and intubation success in neonates.

OBJECTIVES

To determine the efficacy and safety of videolaryngoscopy compared to direct laryngoscopy in decreasing the time and attempts required for endotracheal intubation and increasing the success rate at first intubation in neonates.

SEARCH METHODS

We used the search strategy of Cochrane Neonatal. In May 2017, we searched for randomized controlled trials (RCT) evaluating videolaryngoscopy for neonatal endotracheal intubation in Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, CINAHL, abstracts of the Pediatric Academic Societies, websites for registered trials at www.clinicaltrials.gov and www.controlled-trials.com, and reference lists of relevant studies.

SELECTION CRITERIA

RCTs or quasi-RCTs in neonates evaluating videolaryngoscopy for endotracheal intubation compared with direct laryngoscopy.

DATA COLLECTION AND ANALYSIS

Review authors performed data collection and analysis as recommended by Cochrane Neonatal. Two review authors independently assessed studies identified by the search strategy for inclusion.We used the GRADE approach to assess the quality of evidence.

MAIN RESULTS

The search yielded 7057 references of which we identified three RCTs for inclusion, four ongoing trials and one study awaiting classification. All three included RCTs compared videolaryngoscopy with direct laryngoscopy during intubation attempts by trainees.Time to intubation was similar between videolaryngoscopy and direct laryngoscopy (mean difference (MD) -0.62, 95% confidence interval (CI) -6.50 to 5.26; 2 studies; 311 intubations) (very low quality evidence). Videolaryngoscopy did not decrease the number of intubation attempts (MD -0.05, 95% CI -0.18 to 0.07; 2 studies; 427 intubations) (very low quality evidence). Moderate quality evidence suggested that videolaryngoscopy increased the success of intubation at first attempt (typical risk ratio (RR) 1.44, 95% CI 1.20 to 1.73; typical risk difference (RD) 0.19, 95% CI 0.10 to 0.28; number needed to treat for an additional beneficial outcome (NNTB) 5, 95% CI 4 to 10; 3 studies; 467 intubation attempts).Desaturation episodes during intubation attempts were similar between videolaryngoscopy and direct laryngoscopy (MD -0.76, 95% CI -5.74 to 4.23; 2 studies; 359 intubations) (low quality evidence). There was no difference in the incidence of airway trauma due to intubation attempts (RR 0.10, 95% CI 0.01 to 1.80; RD -0.04, 95% CI -0.09 to -0.00; 1 study; 213 intubations) (low quality evidence).There were no data available on other adverse effects of videolaryngoscopy.

AUTHORS' CONCLUSIONS

Moderate to very low quality evidence suggests that videolaryngoscopy increases the success of intubation in the first attempt but does not decrease the time to intubation or the number of attempts for intubation. However, these studies were conducted with trainees performing the intubations and these results highlight the potential usefulness of the videolaryngoscopy as a teaching tool. Well-designed, adequately powered RCTs are necessary to confirm efficacy and address safety and cost-effectiveness of videolaryngoscopy for endotracheal intubation in neonates by trainees and those proficient in direct laryngoscopy.

C-MAC videolaryngoscope compared with direct laryngoscopy for rapid sequence intubation in an emergency department: A randomised clinical trial

BACKGROUND

Airway management in the emergency room can be challenging when patients suffer from life-threatening conditions. Mental stress, ignorance of the patient's medical history, potential cervical injury or immobilisation and the presence of vomit and/or blood may also contribute to a difficult airway. Videolaryngoscopes have been introduced into clinical practice to visualise the airway and ultimately increase the success rate of airway management.

OBJECTIVE

The aim of this study was to test the hypothesis that the C-MAC videolaryngoscope improves first-attempt intubation success rate compared with direct laryngoscopy in patients undergoing emergency rapid sequence intubation in the emergency room setting.

DESIGN

A randomised clinical trial.

SETTING

Emergency Department of the University Hospital, Zurich, Switzerland.

PATIENTS

With approval of the local ethics committee, we prospectively enrolled 150 patients between 18 and 99 years of age requiring emergency rapid sequence intubation in the emergency room of the University Hospital Zurich. Patients were randomised (1 : 1) to undergo tracheal intubation using the C-MAC videolaryngoscope or by direct laryngoscopy.

INTERVENTIONS

Owing to ethical considerations, patients who had sustained maxillo-facial trauma, immobilised cervical spine, known difficult airway or ongoing cardiopulmonary resuscitation were excluded from our study. All intubations were performed by one of three very experienced anaesthesia consultants.

MAIN OUTCOME MEASURES

First-attempt success rate served as our primary outcome parameter. Secondary outcome parameters were time to intubation; total number of intubation attempts; Cormack and Lehane score; inadvertent oesophageal intubation; ease of intubation; complications including violations of the teeth, injury/bleeding of the larynx/pharynx and aspiration/regurgitation of gastric contents; necessity of using further alternative airway devices for successful intubation; maximum decrease of oxygen saturation and technical problems with the device.

RESULTS

A total of 150 patients were enrolled, but three patients had to be excluded from the analysis, resulting in 74 patients in the C-MAC videolaryngoscopy group and 73 patients in the direct laryngoscopy group. Tracheal intubation was achieved successfully at the first attempt in 73 of 74 patients in the C-MAC group and all patients in the direct laryngoscopy group (P = 1.0). Time to intubation was similar (32 ± 11 vs. 31 ± 9 s, P = 0.51) in both groups. Visualisation of the vocal cords, represented as the Cormack and Lehane score, was significantly better using the C-MAC videolaryngoscope (P < 0.001).

CONCLUSION

Our study demonstrates that visualisation of the vocal cords was improved by using the C-MAC videolaryngoscope compared with direct laryngoscopy. Better visualisation did not improve first-attempt success rate, which in turn was probably based on the high level of experience of the participating anaesthesia consultants.

TRIAL REGISTRATION

Clinicaltrials.gov identifier NCT02297113.

Comparison of Macintosh, McCoy, and Glidescope video laryngoscope for intubation in morbidly obese patients: Randomized controlled trial

Objectives:

The aim of the study was to compare time to intubation and glottic visualization between Macintosh, McCoy, and Glidescope video laryngoscope (GVL) in morbidly obese patients.

Methodology:

Forty-five American Society of Anesthesiologists I–III morbidly obese patients were randomized into three groups of 15 each and time to intubation, Cormack–Lehane grading, and Intubation Difficulty Score (IDS) were compared.

Results:

GVL took more time to intubate (TTI) compared to Macintosh and McCoy laryngoscope (P = 0.0001). Overall IDS were similar between the groups.

Conclusion:

To conclude, GVL takes longer TTI with no added advantage in IDS and hemodynamic response to intubation in morbidly obese patients. McCoy is only as effective as Macintosh and hence Macintosh laryngoscope should be laryngoscope of choice due to its widespread availability and familiarity.

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)

Faucial Pillar Perforation by Glidescope Intubation with Incorrectly Placed Stylet

Glidescope GVL® is frequently used in intubation of difficult airway. We report a case of right side of faucial pillar perforation during intubation with Glidescope®. A rigid stylet can facilitate placing of endotracheal tube quickly but it may also penetrate the soft tissue to cause injuries.

Comparison of the Karl Storz Video Laryngoscope with the Macintosh Laryngoscope for Intubating Difficult Airway: A Manikin Study

Objective

To compare the Karl Storz video laryngoscope (KSVL) with the conventional Macintosh laryngoscope in simulated difficult airway scenarios, using a Laerdal resuscitation manikin.

Methods

This was a prospective comparative study. The scenarios were normal airway, reduced mouth opening, tongue oedema and cervical spine immobilisation. Thirty-five doctors performed endotracheal intubation with both devices in each of the scenarios. The outcome measures were the successful rate of intubation, time taken for intubation, vocal cord visualisation, and ease of intubation. We also surveyed the doctors' preference for the intubation devices.

Results

The use of the KSVL resulted in significantly better laryngoscopic grading than the Macintosh laryngoscope in all four scenarios. The mean time of intubation in the cervical spine immobilisation scenario was significantly shorter with the KSVL than the Macintosh laryngoscope (12.56 sec and 14.00 sec, respectively; P=0.049). The mean time of intubation in the tongue oedema scenario was shorter with the KSVL than the Macintosh laryngoscope (19.37 sec and 22.04 sec, respectively), although this was not statistically significant (P=0.546). There was no difference in the mean time required for intubation in the normal and reduced mouth opening scenarios. There was no significant difference in the success rate in all four scenarios. The ease of intubation score of the KSVL was significantly better than that of the Macintosh laryngoscope in all three difficult airway scenarios

Conclusions

Our study showed that the KSVL provided a better glottic view in both normal and difficult airways than the conventional Macintosh laryngoscope. It also showed an advantage over the conventional Macintosh laryngoscope in the time required for intubation in patients under cervical immobilisation.

Comparison of McGrath(®) Series 5 video laryngoscope with Macintosh laryngoscope: A prospective, randomised trial in patients with normal airways

Objective:

The McGrath Video laryngoscope is a newly developed video laryngoscope that significantly improves laryngeal view and facilitates endotracheal intubation in difficult airways. However in patients with normal airway that is not mentioned before. The aim of this study was to compare the McGrath video laryngoscope with the Macintosh laryngoscope in patients with normal airways.

Methods:

A total of 100 patients requiring orotracheal intubation, were randomized to either having intubation with the McGrath video laryngoscope or the Macintosh laryngoscope. The primary outcome was the laryngoscopy view using percentage of glottic opening (POGO) score. Secondary outcomes included Cormack and Lehane grading system, time to intubation, number of failed intubations, number of attempts before successful intubation and hemodynamic parameters during intubation.

Results:

POGO scores were significantly higher in the McGrath group compared with the Macintosh group (p<0.001) despite time to successful intubation was similar in both groups. The McGrath video laryngoscope provided more Grade-I laryngoscopic views than the Macintosh laryngoscope (p<0.001). Number of more than one attempts in order to achieve success was significantly higher in the Macintosh group (p=0.001). The number of minor complications were significantly higher in the Macintosh group (p=0.004). There were no significant changes in hemodynamic responses between the two groups (p>0.05).

Conclusion:

McGrath video laryngoscope allows patients with normal airways to achieve higher POGO scores and significantly more Grade-I laryngoscopic views when compared with the Macintosh laryngoscope.

Intubation Performance of Advanced Airway Devices in a Helicopter Emergency Medical Service Setting

OBJECTIVE

This study attempts to determine if newer indirect laryngoscopes or intubating devices are superior to a standard laryngoscope for intubation success among helicopter emergency medical service (HEMS) personnel.

METHODS

Flight nurses and paramedics intubated standardized mannequins with a normal airway, a trauma airway, and a difficult airway using a standard laryngoscope, a gum elastic bougie, the Airtraq laryngoscope (King System Corp, Noblesville, IN), the Glidescope Ranger laryngoscope (Verathon Inc, Bothell, WA), and the S.A.L.T. device (Microtek Medical, Inc, Lehmberg, IN) in grounded helicopters wearing helmets and flight gear. Participant demographics, time to glottic view, the modified Cormack-Lehane score, total intubation time, number of attempts, and overall successful intubation were recorded for each type of airway.

RESULTS

Two-hundred thirty-six subjects were initially enrolled across 107 bases in 15 states, and 177 completed the study. First-attempt success rates did not vary by device for the normal airway (P = .203), but the Airtraq laryngoscope and the S.A.L.T. device were highest in the difficult airway (82.0% and 85.0%, respectively; P < .0001). The time to first-attempt success in the difficult airway was lowest for the S.A.L.T. device and the Airtraq laryngoscope (mean = 9.72 seconds and 19.70 seconds, respectively; P < .0001).

CONCLUSION

Using HEMS providers, the Airtraq laryngoscope and the S.A.L.T. device showed the fastest and highest intubation success on the first attempt in difficult simulated HEMS airway scenarios.

Intubation of a Paediatric Manikin in Tongue Oedema and Face-to-Face Simulations by Novice Personnel: a Comparison of Glidescope, Airtraq and Direct Laryngoscopy

OBJECTIVE

Glidescope and Airtraq were designed for facilitating intubation and for teaching regarding the airway anatomy. We aimed to evaluate their efficacy in normal airway, tongue oedema and face-to-face orotracheal intubation models when used by novice personnel.

METHODS

After the local human research ethics committee approval, 36 medical students who were in the beginning of their third year were enrolled in this study. After watching a video regarding intubation using one of these devices, the students intubated a paediatric manikin with a Glidescope or Airtraq via the normal airway, tongue oedema and face-to-face approach.

RESULTS

Although the insertion and intubation times were similar among the groups, the intubation success rate of the Glidescope was higher in the normal airway (100% vs 67%) and tongue oedema (89% vs. 50%) compared with the Airtraq (p=0.008 and p=0.009). The success rates with the paediatric manikin by the face-to-face approach were similar among the groups (50%) (p=0.7). The need for manoeuvres in the Glidescope was lower in the normal and tongue oedema models (p=0.02 and p=0.002). In addition, oesophageal intubation was low in the control and tongue oedema models with the Glidescope (p=0.03 and p<0.001).

CONCLUSION

Novice personnel could more easily intubate the trachea with the Glidescope than with the Airtraq. Intubation with the Glidescope was superior to that with the Airtraq in the normal and tongue oedema models. The face-to-face intubation success rates were both low with both the Glidescope and Airtraq groups.

Virtual reality in anesthesia "simulation"

Simulation in anesthesia is a field that has revolutionized the teaching outlook. The uncommon grave situations are no more unseen. The ability of these devices to test and give a taste of nerves to an anesthetist is actually preparing him for a safe future management when the need be. The role of simulation in testing a new device for its likely success in clinical world can be foreseen. Mastering a difficult skill no longer subjects a patient to danger. These advanced methods not only see how anesthetist responds to environment, but also how the OT environment reacts to him. The review highlights how technology will help us become technically sound clinicians for tomorrow.

Videolaryngoscopy versus direct laryngoscopy for tracheal intubation in neonates

BACKGROUND

Establishment of secure airway is a critical part of neonatal resuscitation both in the delivery room and in the neonatal unit. Videolaryngoscopy is a new technique that has the potential to facilitate successful endotracheal intubation and decrease adverse consequences of delay in airway stabilization. Videolaryngoscopy may enhance visualization of the glottis and intubation success in neonates.

OBJECTIVES

To determine the efficacy and safety of videolaryngoscopy compared to direct laryngoscopy in decreasing the time and attempts required and increasing the success rate for endotracheal intubation in neonates.

SEARCH METHODS

We used the search strategy of the Cochrane Neonatal Review Group. We searched for randomized controlled trials evaluating videolaryngoscopy for neonatal endotracheal intubation in May 2013 in the electronic databases; the Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE; EMBASE; CINAHL; abstracts of the Pediatric Academic Societies; websites for registered trials at www.clinicaltrials.gov and www.controlled-trials.com; and in the reference lists of relevant studies.

SELECTION CRITERIA

Randomized or quasi-randomized trials in neonates evaluating videolaryngoscopy for endotracheal intubation compared with direct laryngoscopy.

DATA COLLECTION AND ANALYSIS

Review authors performed data collection and analysis as recommended by the Cochrane Neonatal Review Group. Two review authors (KL and MP) independently assessed studies identified by the search strategy for inclusion.

MAIN RESULTS

Our search strategy performed in May 2013 yielded 7057 references. Two review authors (MP and KL) independently assessed all references for inclusion. We did not find any completed studies for inclusion but identified three ongoing trials and one study awaiting classification.

AUTHORS' CONCLUSIONS

There was insufficient evidence to recommend or refute the use of videolaryngoscopy for endotracheal intubation in neonates. Well-designed, adequately powered randomized controlled studies are necessary to address efficacy and safety of videolaryngoscopy for endotracheal intubation in neonates.

Efficacy of video-guided laryngoscope in airway management skills of medical students

Background & Aims:

Video-guided laryngoscopy, though unproven in achieving better success rates of laryngoscopy outcome and intubation, seems to provide better glottic visualization compared with direct laryngoscopy. The objective of this study was to compare the efficacy of video-guided laryngoscope (VGL) in the airway management skills of medical students.

Materials and Methods:

Medical students throughout their anesthesiology rotations were enrolled in this study. All students received standard training in the airway management during their course and were randomly allocated into two 20 person groups. In Group D, airway management was performed by direct laryngoscopy via Macintosh blade and in Group G intubation was performed via VGL. Time to intubation, number of laryngoscopy attempts and success rate were noted. Successful intubation was considered as the primary outcome.

Statistical Analysis:

All data were analyzed using SPSS 16 software. Chi-square and Fisher's exact test were used for analysis of categorical variables. For analyzing continuous variables independent t-test was used. P < 0.05 was considered as statistically significant.

Results:

Number of laryngoscopy attempts was less in Group G in comparison to Group D; this, however, was statistically insignificant (P: 0.18). Time to intubation was significantly less in Group G as compared to Group D (P: 0.02). Successful intubation in Group G was less frequently when compared to Group D (P: 0.66). Need for attending intervention, esophageal intubation and hypoxemic events during laryngoscopy were less in Group G; this, however, was statistically insignificant.

Conclusions:

The use of video-guided laryngoscopy improved the first attempt success rate, time to intubation, laryngoscopy attempts and airway management ability of medical students compared to direct laryngoscopy.

Combined use of a McGrath® MAC video laryngoscope and Frova Intubating Introducer in a patient with Pierre Robin syndrome: a case report

Patients with Pierre Robin syndrome are characterized by micrognathia, retrognathia, glossoptosis, and respiratory obstruction and are prone to have a difficult-to-intubate airway. The McGrath® MAC video laryngoscope provides a better view of the glottis than a Macintosh laryngoscope, but it is not easy to insert an endotracheal tube through the vocal cords because a video laryngoscope has a much greater curvature than that of a conventional direct laryngoscope and an endotracheal tube has a different curvature. The Frova Intubating Introducer is used as a railroad for an endotracheal tube in cases of a difficult airway. We thought that a combination of these two devices would make it easy to insert an endotracheal tube through the vocal cords, as a McGrath® MAC video laryngoscope provides a better glottic view and the Frova Intubating Introducer is a useful device for placing an endotracheal tube through the glottis. We report a successful endotracheal intubation with use of the McGrath® MAC video laryngoscope and Frova Intubating Introducer in a patient with Pierre Robin syndrome.

Comparing GlideScope Video Laryngoscope and Macintosh Laryngoscope Regarding Hemodynamic Responses During Orotracheal Intubation: A Randomized Controlled Trial

BACKGROUND

To determine if the GlideScope® videolaryngoscope (GVL) could attenuate the hemodynamic responses to orotracheal intubation compared with conventional Macintosh laryngoscope.

OBJECTIVES

The aim of this relatively large randomized trial was to compare the hemodynamic stress responses during laryngoscopy and tracheal intubation using GVL versus MCL amongst healthy adult individuals receiving general anesthesia for elective surgeries.

PATIENTS AND METHODS

Ninety five healthy adult patients with American Society of Anesthesiologists physical status class I or II that were scheduled for elective surgery under general anesthesia were randomly allocated to either Macintosh or GlideScope arms. All patients received a standardized protocol of general anesthesia. Hemodynamic changes associated with intubation were recorded before and at 1, 3 and 5 minutes after the intubation. The time taken to perform endotracheal intubation was also noted in both groups.

RESULTS

Immediately before laryngoscopy (pre-laryngoscopy), the values of all hemodynamic variables did not differ significantly between the two groups (All P values > 0.05). Blood pressures and HR values changed significantly over time within the groups. Time to intubation was significantly longer in the GlideScope (15.9 ± 6.7 seconds) than in the Macintosh group (7.8 ± 3.7 sec) (P< 0.001). However, there were no significant differences between the two groups in hemodynamic responses at all time points.

CONCLUSIONS

The longer intubation time using GVL suggests that the benefit of GVL could become apparent if the time taken for orotracheal intubation could be decreased in GlideScope group.

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.

Comparing the novel GlideScope Groove videolaryngoscope with conventional videolaryngoscopy: a randomized mannequin study of novice providers

STUDY OBJECTIVE

To compare the GlideScope Groove (GG) with conventional GlideScope videolaryngoscopy (GVL) and direct laryngoscopy (DL) on intubation times, intubation attempts, and glottic visualization of an airway mannequin by medical students.

DESIGN

Randomized crossover trial.

SETTING

Intensive care unit of an academic tertiary-care hospital.

PARTICIPANTS

34 medical students with no airway management experience.

MEASUREMENTS

Each participant received standardized video instruction on all three laryngoscopes and was given 10 minutes to practice with each device. The participants had two attempts using DL, and then had two attempts each with either the GG or GVL in random order.

MEASUREMENTS

Time-to-intubate the mannequin in seconds was recorded. Secondary outcomes were Cormack-Lehane grade and number of intubation attempts, also recorded.

MAIN RESULTS

The median number of seconds required to successfully intubate the mannequin with DL, GVL, and GG were 17.4 seconds [interquartile range (IQR) 13.2 - 22.1)], 17.7 seconds (IQR 14.9 - 21.0), and 21.7 seconds (IQR 15.4 - 37.0), respectively. No differences in time-to-intubate was noted among the three devices (P = 0.45). A Cormack-Lehane grade 1 view was obtained for 25 of 34 participants (74%) with DL, 32 of 34 participants (94%) with GVL, and 34 of 34 participants (100%) with GG. First-attempt intubation success was 30 of 34 participants (88%) with DL, 34 of 34 participants (100%) with GVL, and 11 of 34 participants (32%) with GG. Using the GG, 6 of 24 participants (18%) required three attempts. More attempts were required for the GG than for DL (P < 0.001) or GVL (P < 0.001).

CONCLUSIONS

GG was not superior to DL or GVL in time-to-intubate an airway mannequin.

Feasibility of the video-laryngoscope (GlideScope®) for endotracheal intubation during uninterrupted chest compressions in actual advanced life support: a clinical observational study in an urban emergency department

AIM

This is the first clinical trial to evaluate whether successful endotracheal intubation (ETI) using a video-laryngoscope (VL) (GlideScope(®)) can be performed easily without chest compression interruptions during actual cardiopulmonary resuscitation (CPR) after brief VL training, regardless of the physicians' levels of experience with successful ETI in the past.

METHODS

We performed a prospective, clinical observation study. After completing a brief 1-h VL training, 14 emergency physicians intubated arrest victims using a VL during CPR in the emergency department for a period of 1 year. All CPRs were recorded by video and were reviewed retrospectively. Outcomes were based on the success rate of the first ETI attempt, the time until the first successful ETI attempt (TUS) and chest compression interruptions during ETI. The outcomes were compared based on the physicians' varying experience with successful ETI in the past.

RESULTS

Of 71 CPRs, all cases were successful and 66 cases (93%) were successful at the first ETI attempt with no significant chest compression interruptions. The median TUS was 41.5 (33.8, 61.2) s. There were no differences between less and more experienced physicians in the success rate of the first ETI attempts (97.3% vs. 88.2%; p=0.187), or the median TUS (41.5 (33.5, 58.0) vs. 42.0 (33.8, 64.3) s; p=0.842).

CONCLUSIONS

In a clinical setting, the use of a VL had a high success rate for the first ETI attempt with notably few chest compression interruptions, regardless of the physicians' varying experience with successful ETI in the past.

Post-intubation sore throat and menstruation cycles

BACKGROUND

Postoperative sore throat is one of the most common complications of general anesthesia and intubation with prevalence of 18%-65% in different studies. Several risk factors including female gender, postoperative nausea and vomiting and so on have been mentioned.

OBJECTIVES

The aim of this study was to evaluate the incidence of postoperative sore throat in females and its association with menstrual cycles.

PATIENTS AND METHODS

One hundred females between 18-45 years old with ASA class I or II without predicted difficult airway that were candidate for operation in supine position were enrolled in study. Patients who had pulmonary disease, smoking, common cold within two weeks prior to the operation, previous traumatic intubation history, removable dentures, any congenital or acquired deformity in face, neck, mouth and airway, any known pathology in mouth like aphthous and mouth ulcer,pregnant women, and patients with irregular cycles, and those taking oral contraceptive pills were excluded. By the same protocol general anesthesia was provided and the patients were asked to fill out a three-point scale questionnaire (Low, High, None) 1,6 and 24 hours following intubation to study and record the incidence and severity of sore throat, dysphagia and hoarseness. The date of last menstrual period had been recorded as well.

RESULTS

Of 100 patients, in the first six hours, 51 patients had sore throat and 49 had no pain. During the first 6 hours, 33 patients (33%) had dysphagia and 13 patients had hoarseness at 6th postoperative hour. Age, weight, LMP, intubation time, operation and extubation time and coughing were compared to sore throat, dysphagia and hoarseness. The association between the incidence of coughing and bucking and sore throat was significant (P = 0.03). None of the parameters had a statistically meaningful association with dysphagia.

CONCLUSIONS

According to our results, by omitting probable risk factors of incidence of sore throat and evaluation of role of hormonal changes in women represented in menstrual cycles, there was no significant association between menstrual cycle and sore throat incidence.

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

STUDY OBJECTIVE

There is growing use of video laryngoscopy in US emergency departments (EDs). This study seeks to compare intubation success between the GlideScope video laryngoscope and the C-MAC video laryngoscope (C-MAC) in ED intubations.

METHODS

This was an analysis of quality improvement data collected during a 3-year period in an academic ED. After each intubation, the operator completed a standardized data form reporting patient demographics, indication for intubation, device(s) used, reason for device selection, difficult airway characteristics, number of attempts, and outcome of each attempt. An attempt was defined as insertion of the device into the mouth regardless of attempt at tube placement. The primary outcomes were first pass and overall intubation success. The study compared success rates between the GlideScope video laryngoscope and the C-MAC groups, using multivariable logistic regression and adjusting for potential confounders.

RESULTS

During the 3-year study period, there were 463 intubations, including 230 with the GlideScope video laryngoscope as the initial device and 233 with the C-MAC as the initial device. The GlideScope video laryngoscope resulted in first-pass success in 189 of 230 intubations (82.2%; 95% confidence interval [CI] 76.6% to 86.9%) and overall success in 221 of 230 intubations (96.1%; 95% CI 92.7% to 98.2%). The C-MAC resulted in first-pass success in 196 of 233 intubations (84.1%; 95% CI 78.8% to 88.6%) and overall success in 225 of 233 intubations (96.6%; 95% CI 93.4% to 98.5%). In a multivariate logistic regression analysis, the type of video laryngoscopic device was not associated with first-pass (odds ratio 1.1; 95% CI 0.6 to 2.1) or overall success (odds ratio 1.2; 95% CI 0.5 to 3.1).

CONCLUSION

In this study of video laryngoscopy in the ED, the GlideScope video laryngoscope and the C-MAC were associated with similar rates of intubation success.

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.

Video Laryngoscopy in the Prehospital Setting

In the prehospital setting, the emergency care provider must anticipate that some patients will manifest with difficult airways. The use of video laryngoscopy to secure an airway in the prehospital setting has not been explored widely, but has the potential to be a useful tool. This article briefly reviews some of the major video laryngoscopes on the market and their usefulness in the prehospital setting. Studies and case reports indicate that the video laryngoscope is a promising device for emergency intubation, and it has been predicted that, in the future, video laryngoscopy will dominate the field of emergency airway management.

Direct laryngoscopy always should be retained as a primary skill; however, the video laryngoscope has the potential to be a good primary choice for the patient with potential cervical spine injuries or limited jaw or spine mobility, and in the difficult-to-access patient.The role of video laryngoscopes in securing an airway in head and neck trauma victims in the prehospital setting has yet to be determined, but offers interesting possibilities. Further clinical studies are necessary to evaluate its role in airway management by prehospital emergency medical services.

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.

A randomised trial comparing the CEL-100 videolaryngoscope(TM) with the Macintosh laryngoscope blade for insertion of double-lumen tubes

We performed a randomised trial comparing the CEL-100 videolaryngoscope(TM) with the Macintosh laryngoscope blade in 170 patients undergoing double-lumen tube placement for thoracic surgery. Compared with the Macintosh laryngoscope blade, use of the CEL-100 resulted in significantly more patients with a Cormack and Lehane Grade-1 laryngeal view (90.4% vs 61.0%, p < 0.001), a higher rate of successful intubation on the first attempt (92.8% vs 79.3%, p = 0.012), a lower median (IQR [range]) intubation difficulty score (0 (0-0 [0-60]) vs 15 (0-30 [0-80]), p < 0.001), a higher incidence of correct positioning of the tube (90.3% vs 79.2%, p = 0.041) and significantly fewer patients requiring external laryngeal pressure (19.3% vs 32.9%, p = 0.046). Median (IQR [range]) time to successful intubation was 45 (38-55 [22-132]) s with the CEL-100 compared with 51 (40-61 [30-160] s using the Macintosh laryngoscope blade. We conclude that the CEL-100 videolaryngoscope is superior to the Macintosh laryngoscope blade for double-lumen tube insertion.

Standard clinical risk factors for difficult laryngoscopy are not independent predictors of intubation success with the GlideScope

STUDY OBJECTIVES

To determine whether the first-attempt tracheal intubation incidence using the GlideScope videolaryngoscope is higher in patients with predicted increased risk of difficult laryngoscopy, and to assess the ability of other a priori defined standard risk factors to predict first-attempt intubation success, in aggregate and by forming scores.

DESIGN

Prospective study.

SETTING

Operating room in a tertiary-care academic center.

PATIENTS

357 patients intubated with the GlideScope for nonemergent general anesthesia.

INTERVENTIONS AND MEASUREMENTS

Mallampati airway class was used to create two groups of patients, one with higher and the other, lower, potential difficult laryngoscopy (Mallampati classes 3-4 and 1-2, respectively). Intubation success on the first attempt with the GlideScope videolaryngoscope in patients with a Mallampati class 3 or 4 airway versus those with Mallampati class 1 or 2 airway was tested. We also evaluated the predictive ability of the Mallampati airway class (1 and 2 vs 3 and 4) along with 9 other possible predictors of difficult intubation on first-attempt intubation success: gender, age, body mass index, level of training within our anesthesia residency program (Clinical Anesthesia Resident years 1, 2, and 3), ASA physical status, mouth opening, thyromental distance, neck flexion, and neck extension.

MAIN RESULTS

None of the standard predictors of difficult intubation was significantly associated with outcome after adjusting for other predictors. A multivariable model containing the aggregate set of variables predicted outcome significantly better than a risk score formed as the sum of 10 predictors ("Risk 10"; P = 0.0176).

CONCLUSIONS

With GlideScope-assisted tracheal intubation, Mallampati airway class is not an independent risk factor for difficult intubation. Other standard clinical risk factors of difficulty with direct laryngoscopy also do not appear to be individually predictive of first-attempt success of tracheal intubation.

The use of the GlideScope® for tracheal intubation in patients with halo vest

OBJECTIVE

GlideScope® provides better laryngoscopic view and is advantageous in tracheal intubation in ankylosing spondylitis patients with difficult airway.

METHODS

This study was performed to investigate the use of the GlideScope® for tracheal intubation in 15 patients wearing halo vests scheduled for elective surgery under general anesthesia. Preoperative airway assessments were evaluated to predict the difficulty of tracheal intubation. Before intubation, all patients were given a modified Cormack and Lehane (MCLS) grade and percentage of glottic opening (POGO) score by the intubating anesthesiologist having resorted to direct laryngoscopy (DL) with a Macintosh Size 3 blade depiction. Then intubation with the GlideScope® was performed, during which the larynx was inspected and given another MCLS grade and POGO score.

RESULTS

Fourteen of the 15 patients had MCLS Grade III or IV by direct Macintosh laryngoscopy and were considered to have a difficult laryngoscopy. Nasal tracheal intubation by the GlideScope® was successful on all occasions. The GlideScope® improved the MCLS grade and POGO score in all patients who had put on a halo vest as compared with those on DL (p<0.01). The GlideScope® also provided a better laryngoscopic view than that by a DL. All of the patients who wore halo vests and presented with suspected difficult airways could be intubated successfully with the GlideScope®.

CONCLUSION

The use of the GlideScope® for tracheal intubation could be an alternative option in patients with a difficult airway, whose surgery was circumscribed under general anesthesia with tracheal intubation.

GlideScope versus flexible fiber optic for awake upright laryngoscopy

STUDY OBJECTIVES

We compare laryngoscopic quality and time to highest-grade view between a face-to-face approach with the GlideScope and traditional flexible fiber-optic laryngoscopy in awake, upright volunteers.

METHODS

This was a prospective, randomized, crossover study in which we performed awake laryngoscopy under local anesthesia on 23 healthy volunteers, using both a GlideScope video laryngoscopy face-to-face technique with the blade held upside down and flexible fiber-optic laryngoscopy. Operator reports of Cormack-Lehane laryngoscopic views and video-reviewed time to highest-grade view, as well as number of attempts, were recorded.

RESULTS

Ten women and 13 men participated. A grade II or better view was obtained with GlideScope video laryngoscopy in 22 of 23 (95.6%) participants and in 23 of 23 (100%) participants with flexible fiber-optic laryngoscopy (relative risk GlideScope video laryngoscopy versus flexible fiber-optic laryngoscopy 0.96; 95% confidence interval 0.88 to 1.04). Median time to highest-grade view for GlideScope video laryngoscopy was 16 seconds (interquartile range 9 to 34) versus 51 seconds (interquartile range 35 to 96) for flexible fiber-optic laryngoscopy. A distribution of interindividual differences demonstrated that GlideScope video laryngoscopy was, on average, 39 seconds faster than flexible fiber-optic laryngoscopy (95% confidence interval 0.2 to 76.9 seconds).

CONCLUSION

GlideScope video laryngoscopy can be used to obtain a Cormack-Lehane grade II or better view in the majority of awake, healthy volunteers when an upright face-to-face approach is used and was slightly faster than traditional flexible fiber-optic laryngoscopy. However, flexible fiber-optic laryngoscopy may be more reliable at obtaining high-grade views of the larynx. Awake, face-to-face GlideScope use may offer an alternative approach to the difficulty airway, particularly among providers uncomfortable with flexible fiber-optic laryngoscopy.

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.