Comparing McGRATH® MAC, C-MAC®, and Macintosh Laryngoscopes Operated by Medical Students: A Randomized, Crossover, Manikin Study

Novice residents' endotracheal intubation skill retention on a simulated mannequin after rotating at an anaesthesiology department: a randomized controlled study

OBJECTIVE

To compare the endotracheal intubation skill retention of the McGRATH™ MAC video laryngoscope with that of the Macintosh laryngoscope in first-year residents rotating at an anaesthesiology department.

METHODS

This randomized controlled study enrolled first-year residents who completed a 2-month rotation at an anaesthesiology department. Each rotation group was randomly assigned to the Macintosh laryngoscope (ML) or McGRATH™ MAC video laryngoscope (MML) group. Endotracheal intubation skills were evaluated on a mannequin after the rotation and at 3 and 6 months later. The primary endpoint was the time required for intubation. The secondary endpoint was the percentage of glottic opening (POGO) score.

RESULTS

Forty-six residents participated in this study and were assigned to the ML group (n = 23) or the MML group (n = 23). There were no significant differences between the sex, age and the number of endotracheal intubation procedures performed between the two groups. The time required for intubation was significantly shorter in the MML group compared with the ML group. The POGO scores did not show any significant differences between the two groups.

CONCLUSION

Compared with endotracheal intubation training using the Macintosh laryngoscope, the McGRATH™ MAC video laryngoscope shortened the intubation procedure and its effect remained even after 6 months.

TRIAL REGISTRATION

UMIN-CTR Clinical Trials, UMIN000036643, URL: https://www.umin.ac.jp.

Endobronchial Intubation With the King Vision® and McGrath® Laryngoscopes in Simulated Easy and Difficult Airways by Novices (eKingMath)

Objective. The competency of using video laryngoscopes (VL) for double-lumen tube (DLT) endobronchial intubations can be improved with constant training as assessed by measuring the learning curves. We hypothesized that the time to DLT intubation would be reduced over the intubation attempts. Design. A crossover manikin study. Settings. University-affiliated hospital. Participants. Forty-two novice medical students unfamiliar with DLT intubation. Interventions. Participants were randomly allocated to two sequences, including DLT intubation, using King Vision and McGrath VLs. Each participant completed 100 DLT intubation attempts on both simulated easy and difficult airways on two different mannikins using the study devices (25 attempts for each). Measurements and Main Results. The primary outcome was the time to DLT intubation. The secondary outcomes included the best glottic view, optimizing maneuvers, and intubation first-pass success. The use of King Vision VL was associated with a significantly shorter time to DLT intubation (P < 0.044 and P < 0.05, respectively) and a higher percentage of glottic opening (POGO) compared to the McGrath VL (P < 0.011 and P < 0.002, respectively) in the simulated "easy" and "difficult" over most of the intubation attempts. In the simulated "easy" airway, the first-pass success ratio was higher when using the King Vision VL (median [Minimum-Maximum] 100% [100%-100%] and 100% [88%-100%], P = 0.012). Conclusion. Novice medical students developed skills over intubation attempts, meaning achievement of a faster DLT intubation, better laryngeal exposure, and higher success rate on simulated "easy" and "difficult" airways. A median of 9 DLT intubations was required to achieve a 92% or greater DLT intubation success rate.

Clinically Preferred Videolaryngoscopes in Airway Management: An Updated Systematic Review

Videolaryngoscopes (VLs) have emerged as a safety net offering several advantages over direct laryngoscopy (DL). The aim of this study is to expand on our previous study conducted in 2016, to deduce which VL is most preferred by clinicians and to highlight any changes that may have occurred over the past 7 years. An extensive systematic literature review was performed on Medline, Embase, Web of Science, and Cochrane Central Database of Controlled Studies for articles published between September 2016 and January 2023. This review highlighted similar results to our study in 2016, with the CMAC being the most preferred for non-channelled laryngoscopes, closely followed by the GlideScope. For channelled videolaryngoscopes, the Pentax AWS was the most clinically preferred. This review also highlighted that there are minimal studies that compare the most-used VLs, and thus we suggest that future studies directly compare the most-used and -preferred VLs as well as the specific nature of blades to attain more useful results.

Comparative evaluation of C-MAC and McGrath MAC videolaryngoscopes with Macintosh direct laryngoscope for endotracheal intubation in adult patients undergoing elective surgeries

Background and Aims

Videolaryngoscopes have an undisputed role in difficult airway management, but their role in routine intubation scenarios remains underappreciated. McGrath MAC is a lightweight laryngoscope with a disposable blade. It remains to be proven if it performs as efficiently as the reusable videolaryngoscopes like C-MAC and whether it has an advantage over standard Macintosh laryngoscope in predicted normal airways.

Material and Methods

We recruited 180 adult patients and randomly divided them into three groups for intubation with either Macintosh laryngoscope (Group-A), C-MAC (Group-B), and McGrath (Group-C). The primary objective was to compare the first attempt success rate. Secondary objectives included Cormack-Lehane (CL) grades, laryngoscopy time, intubation time, ease of intubation, need for optimization manoeuver, and the number of passes to place the endotracheal tube.

Results

The two videolaryngoscopes provided a superior first attempt success rate as compared to Macintosh laryngoscope (P = 0.027). The CL grade-I was 100% in group B, 41.7% in group-A and 90% in group-C (B vs C; P = 0.037). Laryngoscopy time was 9.9 ± 2.5 s, 12.6 ± 0.8 s, and 13.1 ± 0.8 s for groups A, B, and C, respectively (B vs C; P = 0.001). Intubation time was 24.4 ± 12 s, 28.3 ± 1.9 s, and 37.3 ± 5.8 s for groups A, B, and C, respectively (P < 0.0001). The number of tube passes was highest in group C.

Conclusion

Videolaryngoscopes provided a superior glottic view and resulted in a superior first attempt success rate as compared to Macintosh laryngoscope. When comparing the two videolaryngoscopes, C-MAC resulted in better intubation characteristics (shorter intubation time, better glottic views, and higher first-attempt success rates) and should be preferred over McGrath for intubation in adult patients with normal airways.

A comparison of endotracheal intubation characteristics between Macintosh, CMAC and Smart Trach laryngoscopes; A randomized prospective clinical trial

BACKGROUND

In this study, we compared the performance characteristics of Macintosh laryngoscope, CMAC videolaryngoscope with a recently developed videolaryngoscope called Smart Trach.

RESEARCH DESIGN AND METHODS

: Three hundred seventy-five patients belonging to mixed population without having anticipated difficult airways undergoing elective surgeries were randomly allocated to be intubated using either of the three laryngoscopes (Macintosh, CMAC or Smart Trach). Time needed for successful intubation, number of attempts, Cormack Lehane's (CL) grading, optimisation maneuverers, intubation difficulty score (IDS), subjective ease of intubation (VAS), subjective lifting force and complications were recorded.

RESULTS

: Demographic and anthropometric measurements (sex, height, weight and body mass index) among the groups were comparable. CL grades, lifting force, IDS, VAS and intubation times (seconds) were significantly different whereas need for maneuver, attempts and complications were similar. (p>0.05 each). Intubation times (seconds) were significantly different between Macintosh [36(29-43) seconds] CMAC [30(24-37)] and Smart Trach [35(30-42] groups. (p<0.001). Subjective ease of intubation based on VAS score was lowest in Smart trach group [1(1-2)] (p<0.001).

CONCLUSION

Shortest intubation times were achieved with CMAC with least use of lifting force. First attempt success rates of were similar. Intubation was easiest subjectively using Smart Trach as manifested by lowest VAS and IDS.

TRIAL REGISTRATION

Clinical Trial registry of India (CTRI/2019/09/021279 dated 17/09/2019).

Comparison of Mc Grath-MAC and C-MAC video laryngoscopes for intubation in a COVID simulated mannequin by novice users wearing face protective gear: A randomized crossover trial

Introduction

Intubation in COVID patients is challenging. Various guidelines suggest the use of video-laryngoscope (VL) as the first device to aid intubation in a COVID patient. The best VL to facilitate intubation in such a setting especially by novices is not ascertained. We compared intubation characteristics by two VL's (McGrath-MAC and C-MAC) for intubation in a COVID simulated mannequin by novices.

Methodology

This prospective randomized manikin-based crossover study was done in thirty medical professionals with no previous experience of intubation with VL. All participants were trained on Laerdel airway management trainer and were allowed 5 practice sessions with each scope with an intubation box while wearing face protective personal protective equipment (PPE). Participants were randomized into two groups of 15 each, one group performed the intubation first with McGrath and the other with C-MAC before crossing over.

Results

The mean (S. D.) time to intubation was similar with both McGrath-VL and CMAC VL [31.33 (14.72) s vs 26.47 (8.5) s, P = (p-0.063)]. POGO score [mean (S. D.)] was better with CMAC [81.33 (16.24) vs 60.33 (14.73), p-0.00. The majority of the users preferred C-MAC VL for intubation (93.33%). The incidence of failed intubation and multiple attempts at intubating were similar with the two scopes.

Conclusion

The time to intubation was similar with both VL's but the majority of novices preferred CMAC probably due to a bigger screen that helped them to have a better view of glottis in the COVID simulated mannequin.

Macintosh Videolaryngoscope for Intubation in the Operating Room: A Comparative Quality Improvement Project

BACKGROUND

"Macintosh"-videolaryngoscopes (VLs) are VLs that allow both direct and indirect laryngoscopy for intubation. We describe the decision-making and implementation-processes that our hospital used regarding the choice of device. We compared the performances of 4 Macintosh-VLs both in direct and indirect laryngoscopy.

METHODS

A quality-improvement-project for airway management aiming at implementing Macintosh-VL for all intubation procedures performed in the operating room, involving 4 Macintosh-VLs (McGrath-Mac, C-MAC-S, C-MAC-S-Pocket-Monitor [PM], and APA). Three consecutive steps were described: (1) direct laryngoscopy with Macintosh-VL, (2) indirect laryngoscopy with Macintosh-VL (intubation attempt with Macintosh-style blade in case of Cormack I or II), (3) intubation attempt with hyperangulated blade in case of Cormack III/IV or failure of Macintosh-style blade. The main end point was the need to move to step III and use a hyperangulated blade. A mixed-effects multivariable logistic regression analysis was performed to compare devices on the main end point while considering site as a random effect. Comparison of means was performed using analysis of variance and Tukey's test for multiple comparisons (number of laryngoscopy attempts, numeric rate scale [NRS] difficulty of intubation and NRS user-friendliness). Comparison of percentages was performed using a χ2 test for the need to move to step III and a Kruskal-Wallis test for the quality of image (bad, passable, good, very good, excellent). A P value ≤.008 was considered statistically significant.

RESULTS

From May to September 2017, 589 patients were included. Using the McGrath-Mac (22/180 [12%]) was associated with less use of hyperangulated blade than using the C-MAC-S (39/132 [30%], odds ratio [OR] [99.2% confidence interval {CI}] 0.34 [0.16-0.77], P = .0005), the APA (35/138 [25%], OR [99.2% CI] 0.42 [0.19-0.93]; P = .004), but not the C-MAC-S-PM (29/139 [21%], OR [99.2% CI] 0.53 [0.23-1.2]; P = .04).Overall, the number of intubation attempts was significantly lower using the McGrath Mac than the C-MAC-S or the C-MAC-S-PMVLs. Subjective appreciation of intubation difficulty and user-friendliness of the devices showed respectively lower and higher NRS scores for the McGrath-Mac compared to the other devices, whereas subjective assessment of image quality showed higher quality for the C-MAC-S and C-MAC-S-PM compared to the APA or McGrath-Mac.

CONCLUSIONS

Among 4 single-use Macintosh-VLs, glottic visualization in direct and indirect laryngoscopy with the Macintosh-style blade was significantly improved with the McGrath-Mac compared to other Macintosh-VLs, leading to a less frequent need to resort to the hyperangulated blade and reduced overall number of intubation attempts.

Comparison of conventional C-MAC video laryngoscope guided intubation by anesthesia trainees with and without Frova endotracheal introducer: A randomized clinical trial

BACKGROUND AND AIMS

Successful intubation with video laryngoscopes necessitates good hand-eye coordination and the use of intubation adjuncts like bougie and stylet. We proposed this study to find whether using Frova introducer with C-MAC video laryngoscope will reduce the intubation time in trainee anesthesiologists.

MATERIAL AND METHODS

We enrolled 140 adults without any difficult airway predictors. They were randomly assigned to undergo C-MAC video laryngoscope guided intubation by anesthesia residents using tracheal tube preloaded over Frova introducer (n = 70) or without Frova introducer (n = 70). Primary outcome was the intubation time. Secondary outcomes were the number of redirections of tracheal tube or Frova introducer toward glottis, need for external laryngeal maneuvers (ELMs), first attempt intubation success rate, and ease of intubation.

RESULTS

The median actual intubation time (IQR) in Frova and non-Frova group, respectively, were 25.46 (28.11-19.80) and 19.96 (26.59-15.52) s (P = 0.001). The number of redirections of TT or Frova introducer toward glottis, first attempt success rate, and ease of intubation were comparable. The need for ELMs [n (%)] was 15 (21.4) and 26 (37.1) in Frova and non-Frova group, respectively (P = 0.04).

CONCLUSION

Frova introducer guided endotracheal intubation with C-MAC videolaryngoscope in patients with normal airways had a marginally prolonged intubation time with a significant reduction in the need of external laryngeal manoeuvres but with a comparable number of redirections and attempts. Further research is needed to generalize these findings to patients with difficult airways.

Comparative Evaluation of McGrath MAC, Truview Video Laryngoscopes and Macintosh Laryngoscope for Endotracheal Intubation in Patients Undergoing Surgery under General Anaesthesia

Background:

Videolaryngoscopy is a newly developed technique to improve tracheal intubation success. It was made to bypass the need of directly visualising the glottic inlet. These devices are advantageous as there is no need of aligning the laryngeal, pharyngeal and oral axes for a clear view, thus making intubation easier and faster.

Aim and Objectives:

Primary objective of the study was to determine the duration of laryngoscopy and intubation and Cormack - Lehane grading when intubating with McGrath MAC, Truview video laryngoscope and Macintosh laryngoscope. Secondary objectives of the study were to determine the number of attempts and optimization manouveres required to intubate.

Materials and Methods:

This study was conducted on total of 120 patients in age 20-70 years, either sex, with American Society of Anaesthesiologists physical status classes I or II scheduled for elective surgery under general anaesthesia. They were randomly assigned equally to group 1, 2 and 3 (n = 40) to be intubated by Mcgrath MAC video laryngoscope, Truview video laryngoscope and Macintosh laryngoscope respectively. Parameters recorded were duration of laryngoscopy and intubation, Cormack Lahane grading, ease of intubation, number of attempts and optimisation manouveres required for intubation.

Statistical Analysis:

Comparison of mean value among the three groups was done using student t test and percentage comparison was done using chi square test. To compare more than two variables ANOVA test was used. The P values of less than 0.05 was considered statistically significant.

Results:

Duration of laryngoscopy was significantly less in McGrath MAC group when compared to Truview group (P = 0.02) and to Macintosh group (P < 0.001) and the duration of intubation was comparable among all three study groups (P > 0.05). The difference in Cormack - Lehane grading was not significant between McGgrath MAC and Trueview (P = 0.71) but was significant between McGrath MAC and Macintosh (P = 0.002) and Trueview and Macintosh (P = 0.002). Ease of intubation was better in McGrath MAC and Truview groups compared to Macintosh group (P < 0.05). Intubation was successful in the first attempt in 39 (97.50%) patients in McGrath MAC group, 40 (100%) patients in Truview group and 35 (87.50%) patients in Macintosh group. McGrath MAC and Truview groups performed better with respect to optimization manoeuvres compared to Macintosh group (P < 0.05). Trauma was observed in 2 (5%) patients in Truview group and 5 (12.50%) patients in Macintosh group. In McGrath MAC group, no patient underwent any trauma.

Conclusion:

Although duration of laryngoscopy was significantly shorter in McGrath as compared to Truview video laryngoscope and Macintosh laryngoscope but the duration of intubation was comparable between the three groups. Both these video laryngoscopes performed significantly better than Macintosh laryngoscope with respect to laryngoscopic view, requirement of optimization manoeuvre and need for second attempt for intubation.

Comparison of McGrath, Pentax, and Macintosh laryngoscope in normal and cervical immobilized manikin by novices: a randomized crossover trial

BACKGROUND

The aim of this study was to compare tracheal intubation performance regarding the time to intubation, glottic view, difficulty, and dental click, by novices using McGrath videolaryngoscope (VL), Pentax Airway Scope (AWS) and Macintosh laryngoscope in normal and cervical immobilized manikin models.

METHODS

Thirty-five anesthesia nurses without previous intubation experience were recruited. Participants performed endotracheal intubation in a manikin model at two simulated neck positions (normal and fixed neck via cervical immobilization), using three different devices three times each. Performance parameters included intubation time, success rate of intubation, Cormack Lehane laryngoscope grading, dental click, and subjective difficulty score.

RESULTS

Intubation time and success rate during first attempt were not significantly different between the 3 groups in normal airway manikin. In the cervical immobilized manikin, the intubation time was shorter (p = 0.012), and the success rate with the first attempt was significantly higher (p < 0.001) when using McGrath VL and Pentax AWS compared with Macintosh laryngoscope. Both VLs showed less difficulty score (p < 0.001) and more Cormack Lehane grade I (p < 0.001) in both scenarios. The incidence of dental clicks was higher with Macintosh laryngoscope compared with McGrath VL in cervical immobilized airway (p < 0.001).

CONCLUSIONS

McGrath VL and Pentax AWS did not show clinically significant decrease in intubation time, however, they achieved higher first attempt success rate, easier intubation and better glottis view compared with Macintosh laryngoscope by novices in a cervical immobilized manikin model. McGrath VL may reduce the risk of dental injury compared with Macintosh laryngoscope in cervical immobilized scenario.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT03161730), May 22, 2017 https://clinicaltrials.gov/ct2/hom.

Haemodynamic Response to Four Different Laryngoscopes

Objective

In this prospective randomized study, we aimed to evaluate the effect of tracheal intubation with four different laryngoscopes [Macintosh direct laryngoscope-classic laryngoscope (CL), McCoy (MC), C-Mac video-laryngoscope (CM) and McGrath video-laryngoscope (MG)] on haemodynamic responses in patients with a normal airway.

Methods

One hundred and sixty patients were included. Succeeding haemodynamic measurements were performed immediately after intubation (T2) and for 5 min with 1-min intervals (T3-T4-T5-T6-T7). The primary outcome was the heart rate (HR) and systolic blood pressure (SBP) change triggered by the four different laryngoscopes. The intubation time, the number of intubation attempts, need for stylet or additional manipulation, glottic view and traumatic complications caused by intubation procedure were recorded as secondary outcomes.

Results

HR values significantly increased with the completion of laryngoscopy and intubation at T2 for the CL, MC and CM groups. Lesser fluctuation in HR and SBP was observed in the MG group. Intubation time was significantly shorter in the MG group (p<0.001). There was no statistically significant difference between the groups regarding the number of intubation attempts, need for stylette and glottic view. Fewer patients in the MG and CM groups experienced a moderate and severe sore throat than in the other two groups. Shorter intubation time and lesser sore throat incidence were observed in the MG group.

Conclusion

MG offers less haemodynamic stimulation than CL, MC, and CM. Our findings showed that tracheal intubation with MG is advantageous in preventing cardiovascular stress responses with short intubation time and less sore throat incidence.