The McGrath®Series 5 videolaryngoscope vs the Macintosh laryngoscope: a randomised, controlled trial in patients with a simulated difficult airway

Systematic Review and Meta-Analysis of Randomized Controlled Trials (RCTs) Revealing the Future of Airway Management: Video Laryngoscopy vs. Macintosh Laryngoscopy for Enhanced Clinical Outcomes

Since the 1940s, Macintosh laryngoscopy (Mac laryngoscopy) has been the gold standard for tracheal intubation, offering visualization of the glottis entrance. However, recent years have witnessed the emergence of various video laryngoscopy (VL) techniques. This systematic review and meta-analysis aims to assess the clinical outcomes of VL versus Mac laryngoscopy in an elective setting. We comprehensively searched five medical databases - PubMed, EMBASE, Medline, Cochrane Library, and Web of Science. All the databases were last searched in January 2023. We only included studies with full texts comparing VL to Mac laryngoscopy clinical outcomes. Studies were excluded if they were non-full text or non-randomized controlled trials (RCTs) and did not compare VL to Mac laryngoscopy. We extracted data comprising author names, publication year, key study outcomes (first-attempt intubation success rate, Cormack and Lehane grade, hypoxia incidence, and glottis view quality), video laryngoscope types, and sample sizes of both VL and Mac laryngoscopy groups. The Cochrane risk of bias tool was used to assess the risk of bias in the included studies. Statistical analysis was performed using Review Manager (RevMan, version 5.4; Cochrane Collaboration, London, UK), presenting results as odds ratio (OR) and risk ratios (RR) at a 95% confidence interval (CI). This facilitated the identification of relevant and appropriate studies of our analysis. The search produced 19 studies that were included in this review. The evaluated sample size ranges from 40 to 802, with 3,238 participants. The rate of success at the first attempt in the use of VL was 1,558/1,890 (82.43%), while the success rate for Mac laryngoscopy was 982/1,348 (72.85%; OR: 1.98 (1.25, 3.12)) at a 95% confidence interval. Pooled analysis indicated no significant difference for hypoxia concerning the type of device used RR (random effects: 1.02; 95% CI: 0.80-1.29). A video laryngoscope had a higher likelihood of visualizing the vocal cords categorized as category 1 in the Cormack-Lehane system of classification (RR: 2.45; 95% CI: 1.43-4.21). Additionally, considerably better glottis views were attained during VL than Mac laryngoscopy (OR: 1.77; 95% CI: 1.19-2.62). In elective tracheal intubation, VL demonstrates superior first-attempt success rates, offers improved glottis visualization, and reduces instances where the glottis cannot be viewed compared to Mac laryngoscopy.

A novel technique of handling the blade for videolaryngoscopy intubation in patients with a semi-rigid neck collar: a prospective randomized controlled trial

BACKGROUND

Semi-rigid neck collars to protect the cervical spine can limit the extent of neck movement and mouth opening; this may further complicate orotracheal intubation. We aimed to compare intubation environments obtained with videolaryngoscopy using the technique of gliding a blade under the epiglottis and that obtained using the conventional Macintosh blade technique of blade tip placement on the vallecula.

METHODS

This prospective randomized study included patients aged ≥ 20 years with American Society of Anesthesiologists physical status I-III scheduled for cervical spine surgery between October 2020 and August 2021. Patients were divided into two groups according to the placement of the blade of the McGrathTM videolaryngoscope: the gliding and conventional groups. The percentage of glottic opening (POGO) score was the primary endpoint. We also recorded the time to obtain the optimal laryngoscopic view, intubation duration, and ease and satisfaction of the researcher performing intubation.

RESULTS

Among 176 patients, the POGO scores were significantly higher in the gliding group than in the conventional group (88.9 ± 14.7 vs. 63.8 ± 27.4, P < 0.001). The time to achieve the optimal glottic view for intubation and duration of intubation were also shorter, and ease and satisfaction in performing intubation were better in the gliding group than in the conventional group.

CONCLUSION

Our findings demonstrated a superior glottic view and more favorable intubation environments when the blade tip was placed under the epiglottis than using the conventional Macintosh technique in patients with immobilized cervical spine.

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.

Comparison of McGrath Videolaryngoscope versus Macintosh Laryngoscope in Tracheal Intubation: An Updated Systematic Review

(1) Background: In the last few years, many randomized controlled trials (RCTs) have compared direct Macintosh laryngoscopy with McGrath videolaryngoscopy in order to assess the potential benefits of the latter; the results were sometimes controversial. (2) Methods: We conducted a comprehensive literature search to identify our articles according to inclusion and exclusion criteria: to be included, each study had to be a prospective randomized trial or comparison between the McGrath videolaryngoscope and the Macintosh laryngoscope in an adult population. We did not include manikin trials or studies involving double-lumen tubes. (3) Results: 10 studies met the inclusion criteria necessary. In total, 655 patients were intubated with the McGrath and 629 with the Macintosh. In total, 1268 of 1284 patients were successfully intubated, showing equivalent results for the two devices: 648 of 655 patients with the McGrath videolaryngoscope and 620 of 629 patients with the Macintosh laryngoscope. No differences were noted in terms of hemodynamic changes or the incidence of adverse events. (4) Conclusions: We can assert that the McGrath videolaryngoscope and Macintosh laryngoscope, even if with equivalent tracheal intubation results, supplement each other.

Ease of Intubation with McGrath Videolaryngoscope and Incidence of Adverse Events During Tracheal Intubation in COVID-19 Patients: A Prospective Observational Study

Background

Tracheal intubation in critically ill patients remains high-risk despite advances in equipment, technique, and clinical guidelines. Many patients with COVID-19 were in respiratory distress and required intubation that is considered an aerosol-generating procedure (AGP). The transition to videolaryngoscopy as a routine first line option throughout anesthetic and ICU practice has been reported. We evaluated the ease of intubation, success rate, use of accessory maneuvers and adverse outcomes during and 24 hours after intubation with the McGrath videolaryngoscope.

Methods

This was a prospective, observational single center study conducted at non-operating room locations that included all adults (>18 years old) with suspected or confirmed COVID-19 infection and were intubated by McGrath videolaryngoscope. The anesthesiologist performed tracheal intubation were requested to fill online data collection form. A co-investigator was responsible to coordinate daily with assigned consultants for COVID intubation and follow up of patients at 24 hours after intubation.

Results

A total of 105 patients were included in our study. Patients were predominantly male (n=78; 74.3%), their COVID status was either confirmed (n=97, 92.4%) or suspected (n=8, 7.6%). Most were intubated in the COVID ward (n=59, 56.2%) or COVID ICU (n=23, 21.9%). The overall success rate of intubation with McGrath in the first attempt was 82.9%. The glottic view was either full (n=85, 80.95%), partial (n=16, 15.24%) or none (n=4, 3.81%). During intubation, hypoxemia occurred in 18.1% and hypotension in 16.2% patients. Within 24 hours of intubation, pneumothorax occurred in 1.9%, cardiac arrest and return of spontaneous circulation in 6.7% and mortality in 13.3% of patients.

Conclusion

These results illustrate the ease and utility of the McGrath videolaryngoscope for tracheal intubation in COVID-19 patients. Its disposable blade is of significant value in protectin during tracheal intubation.

Comparison of the McGRATHTM Video Laryngoscope and Macintosh Laryngoscope for Orotracheal Intubation in a Simulated Difficult Airway Scenario: An Open-Label, Randomized Clinical Trial

Background and Objectives: Difficult intubation, which may be encountered unexpectedly during anesthesia, can increase patients' morbidity and mortality. The McGRATH video laryngoscope is known to provide improved laryngeal visibility in patients with difficult or normal airways. The purpose of this study was to evaluate the efficacy of the McGRATH video laryngoscope for orotracheal intubation compared with that of conventional Macintosh laryngoscopes in simulated difficult airway scenarios. Materials and Methods: In this randomized controlled trial, patients who were scheduled for surgery under general anesthesia requiring orotracheal intubation were assigned to the Macintosh laryngoscope (n = 50) or McGRATH video laryngoscope (n = 45) groups. In this study, to create a simulated difficult airway condition, the subjects performed manual in-line stabilization and applied a soft cervical collar. The primary outcome was the rate of successful intubation within 30 s. The time required for an intubation, glottis grade, intubation difficulty scale (IDS score), the subjective ease of intubation, and optimal external laryngeal manipulation (OLEM) were evaluated. In addition, complications caused by each blade were investigated. Results: The intubation success rate within 30 s was not significantly different between the two groups (44 (88.0%) vs. 36 (80.0%), p = 0.286). The glottic grade was better in the McGRATH group than in the Macintosh group (p = 0.029), but neither the intubation time (26.3 ± 8.2 s vs. 24.2 ± 5.0 s, p = 0.134) nor the rates of oral bleeding (2 (4.0%) vs. 0 (0.0%)) and tooth injury (0 (0.0%) vs. 1 (2.2%)) were significantly different between the two groups. Conclusions: The use of the McGRATH video laryngoscope did not improve the intubation success rate or shorten the intubation time. However, the McGRATH video laryngoscope provided a better glottis view than the conventional Macintosh laryngoscope in patients with a simulated difficult airway.

Comparison of double lumen tube insertion using the McGrath MAC versus direct laryngoscopy in adult patients with a limited glottis view: A prospective interventional study

Background and Aims

Passage of double-lumen tubes (DLT) can be challenging in patients with limited glottis view. This study aims to determine the usefulness of McGrath® MAC videolaryngoscope (VL) in cases with limited glottis view on direct laryngoscopy with Macintosh blade.

Material and Methods

After study approval and registration of trial, consent was sought from all adult patients planned for elective DLT insertion for lung isolation during the course of general anesthesia. Patients not consenting, less than 18 years, with anticipated difficult mask ventilation or need for rapid sequence induction were excluded. Following routine anesthetic induction, laryngoscopy was attempted by an experienced anesthesiologist using Macintosh scope. If the view obtained was Cormack and Lehane (CL) view IIB and above or the attempt at intubation using DLT failed despite a CL I/IIA view, the patient was included in the trial. The laryngoscope was removed and after ensuring adequate oxygenation and depth of anesthesia, intubation was attempted using McGrath® MAC VL. The percentage of glottis opening (POGO) score was noted for both the scopes.

Results

DLT insertion was attempted in 76 patients in the study period. Eight patients were included in the trial on account of limited glottis view/failure with Macintosh scope. Insertion of DLT with McGrath MAC was tried only in six patients, in two patients, the VL was not available for use. The mean (standard deviation) POGO score with Macintosh scope was 9 (±20), which significantly improved with the use of VL to 71 (±24), P = 0.01.

Conclusion

McGrath MAC is helpful in inserting DLT in patients with limited glottis view with Macintosh scope.

Videolaryngoscopy versus direct laryngoscopy for adults undergoing tracheal intubation

BACKGROUND

Tracheal intubation is a common procedure performed to secure the airway in adults undergoing surgery or those who are critically ill. Intubation is sometimes associated with difficulties and complications that may result in patient harm. While it is traditionally achieved by performing direct laryngoscopy, the past three decades have seen the advent of rigid indirect videolaryngoscopes (VLs). A mounting body of evidence comparing the two approaches to tracheal intubation has been acquired over this period of time. This is an update of a Cochrane Review first published in 2016.

OBJECTIVES

To assess whether use of different designs of VLs in adults requiring tracheal intubation reduces the failure rate compared with direct laryngoscopy, and assess the benefits and risks of these devices in selected population groups, users and settings.

SEARCH METHODS

We searched MEDLINE, Embase, CENTRAL and Web of Science on 27 February 2021. We also searched clinical trials databases, conference proceedings and conducted forward and backward citation searches.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-RCTs with adults undergoing laryngoscopy performed with either a VL or a Macintosh direct laryngoscope (DL) in any clinical setting. We included parallel and cross-over study designs.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We collected data for the following outcomes: failed intubation, hypoxaemia, successful first attempt at tracheal intubation, oesophageal intubation, dental trauma, Cormack-Lehane grade, and time for tracheal intubation.

MAIN RESULTS

We included 222 studies (219 RCTs, three quasi-RCTs) with 26,149 participants undergoing tracheal intubation. Most studies recruited adults undergoing elective surgery requiring tracheal intubation. Twenty-one studies recruited participants with a known or predicted difficult airway, and an additional 25 studies simulated a difficult airway. Twenty-one studies were conducted outside the operating theatre environment; of these, six were in the prehospital setting, seven in the emergency department and eight in the intensive care unit.  We report here the findings of the three main comparisons according to videolaryngoscopy device type. We downgraded the certainty of the outcomes for imprecision, study limitations (e.g. high or unclear risks of bias), inconsistency when we noted substantial levels of statistical heterogeneity and publication bias. Macintosh-style videolaryngoscopy versus direct laryngoscopy (61 studies, 9883 participants) We found moderate-certainty evidence that a Macintosh-style VL probably reduces rates of failed intubation (risk ratio (RR) 0.41, 95% confidence interval (CI) 0.26 to 0.65; 41 studies, 4615 participants) and hypoxaemia (RR 0.72, 95% CI 0.52 to 0.99; 16 studies, 2127 participants). These devices may also increase rates of success on the first intubation attempt (RR 1.05, 95% CI 1.02 to 1.09; 42 studies, 7311 participants; low-certainty evidence) and probably improve glottic view when assessed as Cormack-Lehane grade 3 and 4 (RR 0.38, 95% CI 0.29 to 0.48; 38 studies, 4368 participants; moderate-certainty evidence). We found little or no clear difference in rates of oesophageal intubation (RR 0.51, 95% CI 0.22 to 1.21; 14 studies, 2404 participants) but this finding was supported by low-certainty evidence. We were unsure of the findings for dental trauma because the certainty of this evidence was very low (RR 0.68, 95% CI 0.16 to 2.89; 18 studies, 2297 participants). We were not able to pool data for time required for tracheal intubation owing to considerable heterogeneity (I2 = 96%). Hyperangulated videolaryngoscopy versus direct laryngoscopy (96 studies, 11,438 participants) We found moderate-certainty evidence that hyperangulated VLs probably reduce rates of failed intubation (RR 0.51, 95% CI 0.34 to 0.76; 63 studies, 7146 participants) and oesophageal intubation (RR 0.39, 95% CI 0.18 to 0.81; 14 studies, 1968 participants). In subgroup analysis, we noted that hyperangulated VLs were more likely to reduce failed intubation when used on known or predicted difficult airways (RR 0.29, 95% CI 0.17 to 0.48; P = 0.03 for subgroup differences; 15 studies, 1520 participants). We also found that these devices may increase rates of success on the first intubation attempt (RR 1.03, 95% CI 1.00 to 1.05; 66 studies, 8086 participants; low-certainty evidence) and the glottic view is probably also improved (RR 0.15, 95% CI 0.10 to 0.24; 54 studies, 6058 participants; data for Cormack-Lehane grade 3/4 views; moderate-certainty evidence). However, we found low-certainty evidence of little or no clear difference in rates of hypoxaemia (RR 0.49, 95% CI 0.22 to 1.11; 15 studies, 1691 participants), and the findings for dental trauma were unclear because the certainty of this evidence was very low (RR 0.51, 95% CI 0.16 to 1.59; 30 studies, 3497 participants). We were not able to pool data for time required for tracheal intubation owing to considerable heterogeneity (I2 = 99%). Channelled videolaryngoscopy versus direct laryngoscopy (73 studies, 7165 participants) We found moderate-certainty evidence that channelled VLs probably reduce rates of failed intubation (RR 0.43, 95% CI 0.30 to 0.61; 53 studies, 5367 participants) and hypoxaemia (RR 0.25, 95% CI 0.12 to 0.50; 15 studies, 1966 participants). They may also increase rates of success on the first intubation attempt (RR 1.10, 95% CI 1.05 to 1.15; 47 studies, 5210 participants; very low-certainty evidence) and probably improve glottic view (RR 0.14, 95% CI 0.09 to 0.21; 40 studies, 3955 participants; data for Cormack-Lehane grade 3/4 views; moderate-certainty evidence). We found little or no clear difference in rates of oesophageal intubation (RR 0.54, 95% CI 0.17 to 1.75; 16 studies, 1756 participants) but this was supported by low-certainty evidence. We were unsure of the findings for dental trauma because the certainty of the evidence was very low (RR 0.52, 95% CI 0.13 to 2.12; 29 studies, 2375 participants). We were not able to pool data for time required for tracheal intubation owing to considerable heterogeneity (I2 = 98%).

AUTHORS' CONCLUSIONS

VLs of all designs likely reduce rates of failed intubation and result in higher rates of successful intubation on the first attempt with improved glottic views. Macintosh-style and channelled VLs likely reduce rates of hypoxaemic events, while hyperangulated VLs probably reduce rates of oesophageal intubation. We conclude that videolaryngoscopy likely provides a safer risk profile compared to direct laryngoscopy for all adults undergoing tracheal intubation.

Comparisons of Videolaryngoscopes for Intubation Undergoing General Anesthesia: Systematic Review and Network Meta-Analysis of Randomized Controlled Trials

Background: The efficacy and safety of videolaryngoscopes (VLs) for tracheal intubation is still conflicting and changeable according to airway circumstances. This study aimed to compare the efficacy and safety of several VLs in patients undergoing general anesthesia. Methods: Medline, EMBASE, and the Cochrane Library were searched until 13 January 2020. The following VLs were evaluated compared to the Macintosh laryngoscope (MCL) by network meta-analysis for randomized controlled trials (RCTs): Airtraq, Airwayscope, C-MAC, C-MAC D-blade (CMD), GlideScope, King Vision, and McGrath. Outcome measures were the success and time (speed) of intubation, glottic view, and sore throat (safety). Results: A total of 9315 patients in 96 RCTs were included. The highest-ranked VLs for first-pass intubation success were CMD (90.6 % in all airway; 92.7% in difficult airway) and King Vision (92% in normal airway). In the rank analysis for secondary outcomes, the following VLs showed the highest efficacy or safety: Airtraq (safety), Airwayscope (speed and view), C-MAC (speed), CMD (safety), and McGrath (view). These VLs, except McGrath, were more effective or safer than MCL in moderate evidence level, whereas there was low certainty of evidence in the intercomparisons of VLs. Conclusions: CMD and King Vision could be relatively successful than MCL and other VLs for tracheal intubation under general anesthesia. The comparisons of intubation success between VLs and MCL showed moderate certainty of evidence level, whereas the intercomparisons of VLs showed low certainty evidence.

Comparison of the intubation success rate between the intubating catheter and videolaryngoscope in difficult airways: a prospective randomized trial

BACKGROUND

Several devices and algorithms have already been examined and compared for difficult airway management. However, there is no existing study comparing the success of the Intubating Catheter (IC) and the Videolaryngoscope (VL) in patients who are difficult to intubate. We aimed to compare Frova IC and McGrath VL in terms of intubation success rates in patients with difficult intubation.

METHODS

This prospective, randomized study was performed in an university hospital. Patients who underwent an operation under general anesthesia and whom airway management process was deemed difficult were included in this study. Patients were randomly divided into two groups by envelopes containing a number: the intubating catheter group (Group IC), intubated using the Frova IC, and the videolaryngoscope group (Group VL), intubated using the McGrath VL. Study data were collected by a technician who was blind to the study groups and the type of device used in the intubation procedure.

RESULTS

A total of 49 patients with difficult airway were included in the study, including 25 patients in the Frova IC Group and 24 patients in the McGrath VL Group. The rate of successful intubation was determined to be 88% in Group IC and 66% in Group VL (p = 0.074). The mean duration of intubation attempt in Group VL was 44.62 seconds, whereas in Group IC, it was 51.12 seconds (p = 0.593). Group VL was found to have a significantly lower Cormack-Lehane grade compared to Group IC (p < 0.001).

CONCLUSION

Frova IC is a candidate to be an indispensable instrument in terms of cost-effectiveness in clinics such as anesthesia and emergency medicine, where difficult intubation cases are frequently encountered. However, the combination of Frova IC and McGrath VL seems to be more successful in difficult intubation situations, so future studies should focus on using these two devices together.

Comparison of the effects of the McGRATH MAC, C-MAC, and Macintosh laryngoscopes on the intraocular pressures of non-ophthalmic patients: A prospective, randomised, clinical trial

INTRODUCTION

In this prospective, randomised study, we compared the effects of the Macintosh, McGRATH MAC, and C-MAC laryngoscopes on intraocular pressure (IOP) and haemodynamics of non-ophthalmic patients during endotracheal intubation.

METHODS

One hundred and twenty adult patients undergoing non-ophthalmic surgeries performed in the supine position under general anaesthesia requiring orotracheal intubation were included in this study. The patients were separated randomly and prospectively into 3 groups: Macintosh group (n = 40), McGRATH MAC group (n = 40), and C-MAC group (n = 40). Mean arterial pressure (MAP), heart rate (HR) and IOP of left and right eye were measured at specified times.

RESULTS

There were no significant differences with regard to patients characteristics. After intubation, the HR increased significantly in the Macintosh group when compared to the other groups (p = 0.001) and the MAP increased significantly in the Macintosh group when compared to the McGRATH MAC group (p = 0.001) and the C-MAC group (p < 0.001). The IOP values increased in the Macintosh group when compared to the McGRATH MAC group (p < 0.001) and the C-MAC group (p < 0.001) after intubation. Additionally, there was a significant difference between the McGRATH MAC group and C-MAC group in the IOP values of the eyes after intubation (p < 0.001). According to the evaluation within the groups, there were significant differences in all of the groups at all times when compared with the baseline values (p < 0.001).

CONCLUSIONS

In this study, we concluded that the C-MAC VL may be preferable when compared to the Macintosh and McGRATH MAC laryngoscopes for use in ophthalmic patients in whom a rise in the IOP is undesirable.

Comparison of direct laryngoscopy and video-assisted laryngoscopy in pediatric intensive care unit

Our objective was to compare video-assisted laryngoscopy (VAL) with direct laryngoscopy (DL) for glottic visualization in a pediatric intensive care unit in terms of the success rate in first attempts. Our study included patients aged from 1 month to 18 years who were admitted to the pediatric intensive care unit. We excluded patients with limited neck extension (C-spine immobilization, congenital abnormality), congenital anomalies (e.g., Pierre Robin syndrome, micrognathia, macroglossia), and recent airway surgery. Patients were premedicated before intubation. The time to intubation was defined as the time between the start of anesthesia and completion of intubation. The start of anesthetic induction was defined as the time the sedative was first administered. Completion of intubation was defined as the time that the end-tidal carbon dioxide tension was detected. We evaluated 120 of 135 intubations that met our inclusion criteria; 15 were excluded because in eight cases (53%) non-pediatric intensive care physicians made the initial attempts, and in seven cases (47%) the recorded intubation times were erroneous. We detected significantly higher POGO scores in the VAL group (p<0.001). VAL provided a fuller view of the glottis (Cormack and Lehane grade 1) than DL (p<0.001). Although the intubation attempts in the DL group were significantly higher (two or more attempts), no intubation failures occurred in either group.

Anaesthesia protocol evaluation of the videolaryngoscopy with the McGrath MAC and direct laryngoscopy for tracheal intubation in 1000 patients undergoing rapid sequence induction: the randomised multicentre LARA trial study protocol

INTRODUCTION

Rapid sequence induction of anaesthesia is indicated in patients with an increased risk of pulmonary aspiration. The main objective of the technique is to reduce the critical time period between loss of airway protective reflexes and rapid inflation of the cuff of the endotracheal tube to minimise the chance of aspiration of gastric contents. The COVID-19 pandemic has reinforced the importance of first-pass intubation success to ensure patient and healthcare worker safety. The aim of this study is to compare the first-pass intubation success rate (FPS) using the videolaryngoscopy compared with conventional direct laryngoscopy in surgical patients with a high risk of pulmonary aspiration.

METHODS AND ANALYSIS

The LARA trial is a multicentre, patient-blinded, randomised controlled trial. Consecutive patients requiring tracheal intubation are randomly allocated to either the McGrath MAC videolaryngoscope or direct laryngoscopy using the Macintosh laryngoscope. The expected rate of FPS is 92% in the McGrath group and 82% in the Macintosh group. Each group must include a total of 500 patients to achieve 90% power for detecting a difference at the 5% significance level. Successful intubation with the FPS is the primary endpoint. The secondary endpoints are the time to intubation, the number of intubation attempts, the necessity of airway management alternatives, the visualisation of the glottis using the Cormack and Lehane Score and the Percentage Of Glottic Opening Score and definite adverse events.

ETHICS AND DISSEMINATION

The project is approved by the local ethics committee of the Medical Association of the Rhineland Palatine state (registration number: 2020-15502) and medical ethics committee of the University of Freiburg (registration number: 21-1303). The results of this study will be made available in form of manuscripts for publication and presentations at national and international meetings.

TRIAL REGISTRATION

NCT04794764.

Comparing the first-attempt tracheal intubation success of the hyperangulated McGrath® X-blade vs the Macintosh-type CMAC videolaryngoscope in patients with cervical immobilization: a two-centre randomized controlled trial

We compared the hyperangulated McGrath X-blade with the Macintosh-type CMAC videolaryngoscope through the use of manual in-line stabilization on patients. The primary hypothesis was that the McGrath X-blade has a similar first-attempt success rate as the CMAC videolaryngoscope. 210 patients of ASA physical status I to III, aged 21 to 80 years old, undergoing general anesthesia requiring tracheal intubation were prospectively recruited into this two-centre randomized controlled trial, from June 2016 to April 2019. Patients with history of or predicted difficult airway, pre-existing dental risks, BMI > 35 kg/m², cervical spondylosis or myelopathy, aspiration risks, patients who declined to participate or lacked the mental capacity to give consent were excluded. Participants were intubated using either hyperangulated McGrath X-blade (MGX) or Macintosh-type CMAC (CM) videolaryngoscopy, with manual in-line stabilization. Primary outcome measured was first-attempt tracheal intubation success. Secondary outcomes included overall successful intubation within 2 attempts or 120 s, time to intubation, glottic view obtained and intubation-related complications. First-attempt success rates were 71.4% in the MGX group vs. 79.0% in the CM group (p = 0.26), with an absolute difference of -7.6% (95%CI -20%, 5.0%, p value = 0.26), but this trial was underpowered to detect a difference. Overall success was 91.4% (MGX) vs. 92.4% (CM) (p > 0.99). The Cormack & Lehane laryngeal grade was superior in the MGX group compared to CM group (Grade I: MGX 44%, CM 23%; Grade II: MGX 53%, CM 45%; Grade III: MGX 3%, CM 32%; p < 0.001). The median time to intubation using the MGX was longer than the CM [MGX 55.5 s (42.1-78.3), CM 43.8 s (38-55.3); p < 0.001]. Our study did not demonstrate a significant difference in efficacy between the McGrath X-blade and the CMAC videolaryngoscope. In patients with manual in-line stabilization, no anticipated airway difficulty and in the hands of experienced operators, the McGrath X-blade provided superior glottic views but conferred no advantage over the C-MAC, with a longer median time to intubation compared to the CMAC videolaryngoscope.Trial registration: Australian New Zealand Clinical Trial Registry (ACTRN12616000668404).

Effectiveness of intubation devices in patients with cervical spine immobilisation: a systematic review and network meta-analysis

BACKGROUND

Cervical spine immobilisation increases the difficulty of tracheal intubation. Many intubation devices have been evaluated in this setting, but their relative performance remains uncertain.

METHODS

MEDLINE, EMBASE, and the Cochrane Library were searched to identify randomised trials comparing two or more intubation devices in adults with cervical spine immobilisation. After critical appraisal, a random-effects network meta-analysis was used to pool and compare device performance. The primary outcome was the probability of first-attempt intubation success (first-pass success). For relative performance, the Macintosh direct laryngoscopy blade was chosen as the reference device.

RESULTS

We included 80 trials (8039 subjects) comparing 26 devices. Compared with the Macintosh, McGrath™ (odds ratio [OR]=11.5; 95% credible interval [CrI] 3.19-46.20), C-MAC D Blade™ (OR=7.44; 95% CrI, 1.06-52.50), Airtraq™ (OR=5.43; 95% CrI, 2.15-14.2), King Vision™ (OR=4.54; 95% CrI, 1.28-16.30), and C-MAC™ (OR=4.20; 95% CrI=1.28-15.10) had a greater probability of first-pass success. This was also true for the GlideScope™ when a tube guide was used (OR=3.54; 95% CrI, 1.05-12.50). Only the Airway Scope™ had a better probability of first-pass success compared with the Macintosh when manual-in-line stabilisation (MILS) was used as the immobilisation technique (OR=7.98; 95% CrI, 1.06-73.00).

CONCLUSIONS

For intubation performed with cervical immobilisation, seven devices had a better probability of first-pass success compared with the Macintosh. However, more studies using MILS (rather than a cervical collar or other alternative) are needed, which more accurately represent clinical practice.

CLINICAL TRIAL REGISTRATION

PROSPERO 2019 CRD42019158067 (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=158067).

A randomized controlled trial comparing McGRATH series 5 videolaryngoscope with the Macintosh laryngoscope for nasotracheal intubation

Background and Aims:

The aim of this study was to compare the efficacy of McGRATH series 5 videolaryngoscope (VL) with Macintosh laryngoscope for nasotracheal intubation (NTI) in patients without anticipated difficult airways undergoing head and neck cancer surgeries.

Material and Methods:

We randomized 60 adult patients for NTI by experienced anesthetists with either Macintosh laryngoscope or McGRATH series 5 VL (VL group). The primary objective was to compare time taken for intubation (TTI). The secondary objectives included success rates, number of attempts, need for optimization maneuvers, Cormack and Lehane (CL) grade, and percentage of difficult intubations.

Results:

The mean TTI in the VL group was 43 (±10.6) versus 75 (±38.0) s in the Macintosh group (99% CI: 12.5; –51.6 s; P < 0.001). The overall intubation success rate was 100% in both groups. All 29 (100%) patients in the VL group were intubated in the first attempt versus 26 (86%) patients in the Macintosh group (99% CI –5; 33%; P = 0.11). In the Macintosh group, 20 (66%) patients needed optimization maneuver versus none in the VL group (99% CI 40; 91%; P < 0.001). In the VL group, 28 (96%) patients had a CL grade 1 view versus 9 (31%) in Macintosh group (99% CI 38; 92%; P < 0.001). There were no difficult intubations in the VL group versus 3 (10%) in the Macintosh group (99% CI: 7; 28%; P = 0.237). There was no trauma to oropharyngeal structures in either group.

Conclusion:

The McGRATH series 5 VL has faster TTI, better glottic visualization, and less need for optimization maneuvers than the Macintosh laryngoscope for NTI in patients with unanticipated difficult airways, when performed by experienced anesthetists.

The VL3 videolaryngoscope for tracheal intubation in adults: A prospective pilot study

Background:

Videolaryngoscopy (VLS) is recommended by international guidelines for the management of difficult airways. We conducted an observational prospective pilot study to assess the efficacy of the new VL3 videolaryngoscope for routine tracheal intubation (TI) in adults; in terms of success rate, the number of attempts, and maneuver duration, including both normal and difficult airways.

Methods:

This prospective observational pilot study comprised a sample of 56 adult patients undergoing elective general anesthesia. For each patient, we performed VLS by VL3 recording the following data: successful TI rate, number of attempts, time of intubation, time to glottis visualization, Cormack-Lehane grade (CL), need for external laryngeal pressure, and presence of post-laryngoscopy side effects.

Results:

TI was successfully carried out in the totality of patients. In only 4 out of 56 cases, the VL3 offered a CL II. The first attempt intubation was achieved in 48 patients (85.7%). In one case, external laryngeal pressure was needed. No CL III or CL IV were observed. We did not find any significant difference between the predicted difficult airways sample and the rest of the population.

Conclusion:

VL3 videolaryngoscope showed to be an effective and safe device for routine TI, even in those patients with predicted difficult airway. More studies are needed to confirm our findings and verify its efficacy even in other settings.

McGrath Video Laryngoscope Versus Macintosh Direct Laryngoscopy for Intubation of Morbidly Obese Patients: A Randomized Trial

BACKGROUND

Two-thirds of the US population is considered obese and about 8% morbidly obese. Obese patients may present a unique challenge to anesthesia clinicians in airway management. Videolaryngoscopes may provide better airway visualization, which theoretically improves intubation success. However, previous work in morbidly obese patients was limited. We therefore tested the primary hypothesis that the use of McGrath video laryngoscope improves visualization of the vocal cords versus Macintosh direct laryngoscopy (Teleflex, Morrisville, NC) in morbidly obese patients.

METHODS

We enrolled 130 surgical patients, aged 18-99 years, with a body mass index ≥40 kg/m and American Society of Anaesthesiologists (ASA) physical status I-III. Patients were randomly allocated 1:1-stratified for patient's body mass index ≥50 kg/m-to McGrath video laryngoscope versus direct laryngoscopy with a Macintosh blade. The study groups were compared on glottis visualization, defined as improved Cormack and Lehane classification, with proportional odds logistic regression model.

RESULTS

McGrath video laryngoscope provided significantly better glottis visualization than Macintosh direct laryngoscopy with an estimated odds ratio of 4.6 (95% confidence interval [CI], 2.2-9.8; P < .01). We did not observe any evidence that number of intubation attempts and failed intubations increased or decreased.

CONCLUSIONS

McGrath video laryngoscope improves glottis visualization versus Macintosh direct laryngoscopy in morbidly obese patients. Large clinical trials are needed to determine whether improved airway visualization with videolaryngoscopy reduces intubation attempts and failures.

Video Assisted Laryngoscope Facilitates Intubation Skill Learning in the Emergency Department

Background

Up-to-date technology has been increasingly useful for learning resuscitation skills in the emergency and resuscitation settings. It improves the learning curve of the learners and helps them to avoid making mistakes on real patients. This study aimed to evaluate the educational efficiency for tracheal intubation by comparing Macintosh (direct) laryngoscope (DL) and video laryngoscope (VL) learning in novices.

Methods

This prospective randomized controlled study was conducted in an emergency department between 2013 and 2014. Fifth- and sixth-year medical students were enrolled and assigned to normal airway and difficult airway groups, respectively. They were then further randomized into using a VL or DL for tracheal intubation learning. Participants had three practices before proceeding to the post-course assessment. Our primary outcome was post-course assessment performance, which included intubation success rate, total intubation time and best glottic view. The secondary outcome was the sum of total intubation learning times during the three practices.

Results

We recruited 177 undergraduate students. Of these, 97 were assigned to the normal airway group (49 VL and 48 DL) and 80 were placed in the difficult airway group (40 each for VL and DL). VL significantly quickened the intubation learning time in both the normal airway and difficult airway groups (140 s vs. 158 s, 141 s vs. 221.5 s; both p < 0.05). The learning curve was much improved with VL when compared using time-to-event analysis (p < 0.001). VL also improved the glottic view performance during post-course assessments.

Conclusions

VL improves the learning curve in acquiring intubation skills compared with traditional DL. It shortens the time undergraduate students take to develop such skills and increased their first attempt success rates.

Comparing the McGrath Mac Video Laryngoscope and Direct Laryngoscopy for Prehospital Emergency Intubation in Air Rescue Patients: A Multicenter, Randomized, Controlled Trial

Supplemental Digital Content is available in the text.

Tracheal intubation in prehospital emergency care is challenging. The McGrath Mac Video Laryngoscope (Medtronic, Minneapolis, MN) has been proven to be a reliable alternative for in-hospital airway management. This trial compared the McGrath Mac Video Laryngoscope and direct laryngoscopy for the prehospital setting.

Comparison of direct laryngoscope and McGrath videolaryngoscope in terms of glottic view and hemodynamics in bariatric surgery

Background/aim

In the recent years, videolaryngoscopes (VL) have emerged as alternative devices to direct laryngoscopes (DL) in difficult intubation situations. Therefore, we aimed to compare the Macintosh DL and McGrath VL in terms of the glottic image quality, intubation success, intubation time, hemodynamic response after intubation, and complications in bariatric surgery patients.

Material and methods

After obtaining approval by the ethics committee and receiving informed consent, we recorded the demographic and physical data of patients undergoing bariatric surgery. Patients were divided into 2 groups: Group M was intubated with the Macintosh DL, and Group V was intubated with the McGrath VL. After intubation, we noted the Cormack–Lehane score, the duration of intubation, the number of intubation interventions, and the hemodynamic data of patients.

Results

A total of 62 patients (ASA II, body mass index of >35 kg/m2) were included in the study. All patients except 1 patient were intubated on the first attempt. Although there was a decrease in heart rate and blood pressure with induction, similar hemodynamic data were obtained between groups during the operation. In group V, we obtained a better glottic image (P = 0.011), but intubation success was similar between the study groups. We also measured the intubation time in group M as 45.9 ± 19.1 s and group V as 57.1 ± 15.8 s (P = 0.015).

Discussion

Although we measured longer intubation times with the McGrath VL compared with the Macintosh DL, we obtained a better glottic image without causing hemodynamic changes. However, these findings did not make any difference in terms of intubation success.

A randomized controlled comparison of non-channeled king vision, McGrath MAC video laryngoscope and Macintosh direct laryngoscope for nasotracheal intubation in patients with predicted difficult intubations

BACKGROUND

King Vision and McGrath MAC video laryngoscopes (VLs) are increasingly used. The purpose of this study was to evaluate the performance of nasotracheal intubation in patients with predicted difficult intubations using non-channeled King Vision VL, McGrath MAC VL or Macintosh laryngoscope by experienced intubators.

METHODS

Ninety nine ASA I or II adult patients, scheduled for oral maxillofacial surgeries with El-Ganzouri risk index 1-7 were enrolled. Patients were randomly allocated to intubate with one of three laryngoscopes (non-channeled King Vision, McGrath MAC and Macintosh). The intubators were experienced with more than 100 successful nasotracheal intubations using each device. The primary outcome was intubation time. The secondary outcomes included first success rate, time required for viewing the glottis, Cormack-Lehane grade of glottis view, the number of assist maneuvers, hemodynamic responses, the subjective evaluating of sensations of performances and associated complications.

RESULTS

The intubation time of King Vision and McGrath group was comparable (37.6 ± 7.3 s vs. 35.4 ± 8.8 s) and both were shorter than Macintosh group (46.8 ± 10.4 s, p < 0.001). Both King Vision and McGrath groups had a 100% first attempt success rate, significantly higher than Macintosh group (85%, p < 0.05). The laryngoscopy time was comparable between King Vision and McGrath group (16.7 ± 5.5 s vs. 15.6 ± 6.3 s) and was shorter than Macintosh group (22.8 ± 7.2 s, p < 0.05) also. Compared with Macintosh laryngoscope, Glottis view was obviously improved when exposed with either non-channeled King Vision or McGrath MAC VL (p < 0.001), and assist maneuvers required were reduced (p < 0.001). The maximum fluctuations of MAP were significantly attenuated in VL groups (47.7 ± 12.5 mmHg and 45.1 ± 10.3 mmHg vs. 54.9 ± 10.2 mmHg, p < 0.05 and p < 0.01). Most device insertions were graded as excellent in McGrath group, followed by Macintosh and King Vision group (p = 0.0014). The tube advancements were easier in VLs compared with the Macintosh laryngoscope (p < 0.001). Sore throat was found more frequent in Macintosh group compared with King Vision group (p < 0.05).

CONCLUSIONS

Non-channeled King Vision and McGrath MAC VLs were comparable and both devices facilitated nasotracheal intubation in managing predicted difficult intubations compared with Macintosh laryngoscope.

TRIAL REGISTRATION

ClinicalTrials registration number NCT03126344 . Registered on April 24, 2017.

Randomized comparison of McGrath MAC videolaryngoscope, Pentax Airway Scope, and Macintosh direct laryngoscope for nasotracheal intubation in patients with manual in-line stabilization

BACKGROUND

The objective of this study was to determine the clinical usefulness of videolaryngoscopes (VLs) by comparing the time to intubation (TTI) and the ease of intubation of McGrath MAC VL (MVL), Pentax Airway Scope VL (PVL), and Macintosh direct laryngoscope (DL) during nasotracheal intubation using manual in-line stabilization to simulate difficult airways.

METHODS

One hundred and twenty patients were randomly assigned to the MVL group (n = 40), the PVL group (n = 40), and the DL group (n = 40). Nasotracheal intubation was performed using MVL, PVL, or DL, according to group assignments. The primary outcome was TTI and secondary outcomes were glottic view, ease of intubation, and bleeding.

RESULTS

The TTI was significantly shorter in the MVL group than in the DL group (45 sec vs 57 sec; difference in means: - 12; 95% confidence interval [CI], - 21 to - 3; P = 0.01). The percentage of glottic opening and Cormack Lehane grade were significantly superior in the MVL and the PVL groups compared with the DL group (both P < 0.001). The intubation difficulty scale and numeric rating scale regarding ease of intubation were also significantly lower in the MVL and PVL groups than in the DL group (all P < 0.007). The incidence of bleeding was significantly lower in the MVL group than in the DL group (3 vs 15, relative risk 0.2; 95% CI, 0.06 to 0.64; P = 0.001).

CONCLUSION

This study showed that both MVL and PVL provided better visualization of the glottis and easier intubation, with less additional manipulation than DL during nasotracheal intubation in simulated difficult airways. Additionally, use of the MVL significantly shortened the TTI compared with the DL.

TRIAL REGISTRATION

www.clinicaltrials.gov (NCT02647606); registered 6 January, 2016.

Comparison of the McGrath video laryngoscope and macintosh direct laryngoscope in obstetric patients: A randomized controlled trial

Objective:

In obstetric patients’ airway, guidelines have recommended the availability of advanced airway equipment. Our aim was to compare the larynx visualization provided by the Macintosh direct laryngoscope and McGrath video laryngoscope and the intubation time of patients undergoing cesarean section.

Methods:

This study was conducted at a private obstetrics and gynecology hospital during one month between June and July 2018. A hundred patients scheduled for elective cesarean section under general anesthesia were randomized into two different group’s as intubated using either McGrath VL or Macintosh DL. The intubation times, Cormack–Lehane grade, percentage of glottic opening, mean arterial blood pressure, and heart rates before and after intubation were compared among the groups.

Results:

The McGrath VL significantly reduced the intubation time compared to the Macintosh DL. In the McGrath VL group, better glottic view set the time of tracheal intubation as assessed using the Cormack-Lehane classification system and POGO scores were recorded. After intubation, hemodynamic parameters were significantly higher in the Macintosh DL group than in the McGrath VL group.

Conclusion:

The McGrath VL significantly lowered intubation time relative to the Macintosh DL, which may be a critical finding considering the importance of maintaining the mother’s airway for the health of both mother and baby.

Comparison of three video laryngoscopes and direct laryngoscopy for emergency endotracheal intubation: a retrospective cohort study

OBJECTIVE

Video laryngoscopes are used for managing difficult airways. This study compared three video laryngoscopes' (Pentax-Airway Scope [Pentax], King Vision[King] and McGrath MAC [McGrath]) performances with the Macintosh direct laryngoscope (Macintosh) as emergency tracheal intubations (TIs) reference.

DESIGN

Retrospective cohort study.

SETTING

The emergency department (ED) and the intensive care unit (ICU) of two Japanese tertiary-level hospitals.

PARTICIPANTS

All consecutive video-recorded emergency TI cases in EDs and ICUs between December 2013 and June 2015.

PRIMARY OUTCOME MEASURES

The primary study endpoint was first-pass intubation success. A subgroup analysis examined the first-pass intubation success of expert versus non-expert operators. A logistic regression analysis was performed to identify the predictors of first-pass intubation success.

RESULTS

A total of 287 emergency TIs were included. The first-pass intubation success rates were 78%, 58%, 78% and 58% for the Pentax, King, McGrath and Macintosh instruments, respectively (p=0.004, Fisher's exact test). The non-expert operators' success rates were significantly higher (p=0.00004, Fisher's exact test) for the Pentax (87%) and McGrath (78%) instruments than that for the King (50%) and Macintosh (46%) instruments, unlike that of the experts (67%, 67%, 78% and 78% for Pentax, McGrath, King and Macintosh, respectively; p=0.556, Fisher's exact test). After TI indication, difficult airway characteristics, and expert versus non-expert operator parameters adjustments, the Pentax (OR=3.422, 95% CI 1.551 to 7.550; p=0.002) and McGrath (OR= 3.758, CI 1.640 to 8.612; p=0.002) instruments showed significantly higher first-pass intubation success odds when compared with the Macintosh laryngoscope (reference, OR=1). The King instrument, however, (OR=1.056; 95% CI 0.487 to 2.289, p=0.889) failed to show any significant superiority.

CONCLUSION

The Pentax and McGrath laryngoscopes showed significantly higher emergency TI first-pass intubation success rates than the King laryngoscope when compared with the Macintosh laryngoscope, especially for non-expert operators.

TRIAL REGISTRATION NUMBER

UMIN000027925; Results.

Comparison of hemodynamic responses and QTc intervals to tracheal intubation with the McGRATH MAC videolaryngoscope and the Macintosh direct laryngoscope in elderly patients

Our hypothesis was that intubations with the McGRATH MAC videolaryngoscope in elderly patients would produce less hemodynamic responses and ECG changes than the Macintosh direct laryngoscope. The patients were divided into two groups: patients who were intubated using the McGRATH MAC (Group V, n = 45) and patients who were intubated using the Macintosh direct laryngoscope (Group L, n = 45). Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MAP), heart rate (HR) were recorded before induction with anesthesia (baseline), immediately after induction and at 1 min, 3 min, and 5 min after intubation, with simultaneous ECG. When Group L was compared to Group V, there was an increase in the first, third and fitth minutes after intubation in terms of HR. SBP, MAP increased only at 1 min after intubation and DBP increased in the first and third minutes after intubation in Group L. In Group L, there was a significant difference in the HR values immediately after induction and the first minute after intubation compared with the baseline values. There was a difference in the SBP values immediately after induction and at 3 min and 5 min after intubation compared with the baseline values. There was a difference in DBP and MAP values immediately after induction and at 5 min after intubation. When the McGRATH MAC videolaryngoscope was compared with the Macintosh direct laryngoscope in elderly patients, the McGRATH MAC videolaryngoscope decreased the hemodynamic fluctuations due to tracheal intubation.

Videolaryngoscopy versus direct laryngoscopy for adult patients requiring tracheal intubation: a Cochrane Systematic Review

Difficulties with tracheal intubation commonly arise and impact patient safety. This systematic review evaluates whether videolaryngoscopes reduce intubation failure and complications compared with direct laryngoscopy in adults. We searched CENTRAL, MEDLINE, Embase and clinicaltrials.gov up to February 2015, and conducted forward and backward citation tracking. We included randomized controlled trials that compared adult patients undergoing laryngoscopy with videolaryngoscopy or Macintosh laryngoscopy. We did not primarily intend to compare individual videolaryngoscopes. Sixty-four studies (7044 participants) were included. Moderate quality evidence showed that videolaryngoscopy reduced failed intubations (Odds Ratio (OR) 0.35, 95% Confidence Interval (CI) 0.19-0.65) including in participants with anticipated difficult airways (OR 0.28, 95% CI 0.15-0.55). There was no evidence of reduction in hypoxia or mortality, but few studies reported these outcomes. Videolaryngoscopes reduced laryngeal/airway trauma (OR 0.68, 95% CI 0.48-0.96) and hoarseness (OR 0.57, 95% CI 0.36-0.88). Videolaryngoscopy increased easy laryngeal views (OR 6.77, 95% CI 4.17-10.98) and reduced difficult views (OR 0.18, 95% CI 0.13-0.27) and intubation difficulty, typically using an 'intubation difficulty score' (OR 7.13, 95% CI 3.12-16.31). Failed intubations were reduced with experienced operators (OR 0.32, 95% CI 0.13-0.75) but not with inexperienced users. We identified no difference in number of first attempts and incidence of sore throat. Heterogeneity around time for intubation data prevented meta-analysis. We found evidence of differential performance between different videolaryngoscope designs. Lack of data prevented analysis of impact of obesity or clinical location on failed intubation rates. Videolaryngoscopes may reduce the number of failed intubations, particularly among patients presenting with a difficult airway. They improve the glottic view and may reduce laryngeal/airway trauma. Currently, no evidence indicates that use of a videolaryngoscope reduces the number of intubation attempts or the incidence of hypoxia or respiratory complications, and no evidence indicates that use of a videolaryngoscope affects time required for intubation.

McGrath MAC video laryngoscope versus direct laryngoscopy for the placement of double-lumen tubes: A randomised control trial

Background and Aims

Role of video laryngoscopes (VLs) in the management of difficult airway with single-lumen tubes (SLTs) is established. VLs provide improved glottis view but are associated with longer time to intubate (TTI). We aimed to compare the TTI for double-lumen tube (DLT) insertion using the McGrath^® MAC VL versus direct Macintosh laryngoscope (DL).

Methods

Eleven senior anaesthesiologists experienced in SLT insertion, but not DLT insertion with VL participated. Seventy-four adults belonging to American Society of Anesthesiologists physical status I-II posted for elective surgery needing lung isolation were randomised to both intubator and laryngoscope (VL/DL). Primary endpoint was TTI; secondary endpoints included glottic view assessed by the Cormack and Lehane (CL) grade, need for external laryngeal manipulation, ease of intubation [scored using Numeric Rating Scale (1 - easiest, 10 - most difficult)] and associated complications. TTI was compared using Student's t-test.

Results

No difference was found in TTI with DL and VL [(56.6 ± 14) s vs (64.4 ± 24) s, P = 0.104] as well as ease of use of laryngoscope [median score of 2 (1-3) in both]. Use of VL resulted in more patients with CL I glottic view - 86.0% versus 58.0% (P = 0.007). Fewer patients required external laryngeal manipulations (19% vs 47%, P = 0.013), and complications were fewer in the VL group (5% vs 24%, P = 0.023).

Conclusion

TTI for DLT insertion was similar with VL and DL. However, VL was associated with better glottis visualisation, reduced need of external laryngeal manipulation and fewer complications.

McGrath videolaryngoscope versus Macintosh laryngoscope for tracheal intubation: A systematic review and meta-analysis with trial sequential analysis

STUDY OBJECTIVE

The McGrath laryngoscope is a novel self-contained videolaryngoscope with a single-use blade. There are several anecdotal reports that the McGrath is superior to the Macintosh laryngoscope for tracheal intubation. However this remains controversial.

DESIGN

Meta-analysis and systematic review.

SETTING

Operating room or intensive care unit.

MEASUREMENTS

A comprehensive literature search was conducted to identify clinical trials that met our inclusion criteria. To qualify, studies had to be prospective randomized trials comparing tracheal intubation between the McGrath and the Macintosh in an adult population. We extracted data on success rate, glottic visualization during intubation, and intubation time from the studies identified. In subgroup analysis, we assessed the influence on each of these parameters which included airway condition (normal or difficult) and operator (novice or experienced). We then conducted a trial sequential analysis (TSA).

MAIN RESULTS

Fourteen articles met our inclusion criteria. The McGrath offered better glottic visualization than the Macintosh (risk ratio, 1.34; 95% confidence interval (CI), 1.25-1.45). However, the McGrath required longer intubation time (mean difference, 10.1s; CI, 2.74-17.5) and demonstrated similar success rate of tracheal intubation (risk ratio, 1.00; CI, 0.95-1.05) compared to the Macintosh. TSA showed that total sample size reached the required information size (RIS) in glottic visualization and success rate. However, only 15.1% of the RIS was achieved in intubation time. In the subgroup analysis for airway condition and operator experience level, there were no subgroup differences in both glottic visualization and intubation time.

CONCLUSIONS

Our meta-analysis suggests that the McGrath is superior to the Macintosh in terms of glottic visualization (GRADE: moderate). However, it significantly extends intubation time (GRADE: very low) and its success rate (GRADE: very low) for tracheal intubation is not excellent. TSA suggests that further studies are necessary to confirm the results of intubation time.

Comparison of the McGrath videolaryngoscope and the Macintosh laryngoscope for double lumen endobronchial tube intubation in patients with manual in-line stabilization: A randomized controlled trial

BACKGROUND

Double lumen endobronchial tube (DLT) intubation is commonly used for one-lung ventilation in thoracic surgery. However, because of its large size and shape, it is difficult to perform intubation compared with a single lumen tube. The aim of this randomized controlled trial was to determine whether the McGrath videolaryngoscope has any advantage over the direct Macintosh laryngoscope for DLT intubation in patients with a simulated difficult airway.

METHODS

Forty-four patients (19-60 years of age); scheduled to undergo general anesthesia with one-lung ventilation were assigned to 1 of 2 groups: DLT intubation with the McGrath videolaryngoscope (ML group [n = 22]); or conventional Macintosh laryngoscope (DL group [n = 22]). After manual in-line stabilization was applied as a way of simulating a difficult airway, the time required for intubation and the quality of glottic view were evaluated.

RESULTS

The time to successful intubation was not different between the 2 groups (ML group, 45 s [interquartile range, 38-52 s] versus DL group, 54 s [45-59 s]; P = .089). The McGrath videolaryngoscope, however, provided a significantly better glottic view. Modified Cormack and Lehane grade was better (P < .001), and the percentage of glottis opening score was higher in the ML group (P < .001). Overall intubation difficulty scale score was lower in the ML group (1 [0-2]) versus the DL group (3 [2-4]) (P < .001).

CONCLUSION

The McGrath videolaryngoscope improved glottic view and resulted in lower overall intubation difficulty scale score in patients with in-line stabilization.

A comparison between McGrath MAC videolaryngoscopy and Macintosh laryngoscopy in children

BACKGROUND

This prospective, randomised, controlled study was performed to evaluate the usefulness of the McGrath VL compared with Macintosh laryngoscopy in children with expected normal airway during endotracheal intubation, by comparing the time to intubation and difficulty of intubation.

METHODS

Eighty-four patients aged 1-10 years who underwent endotracheal intubation for elective surgery were randomly assigned to the McGrath group (n = 42) or the Macintosh group (n = 42). Anaesthesia was induced with 2.5-3.0 mg/kg of propofol and sevoflurane 5-8 vol%. Orotracheal intubation was performed 2 min after injection of rocuronium 0.6 mg/kg with McGrath VL or Macintosh laryngoscope; the primary outcome was the time to intubation. The Cormack and Lehane glottic grade, intubation difficulty score (IDS), and success rate on intubation were assessed. Haemodynamic changes were also recorded.

RESULTS

As the primary outcome, median time to intubation [interquartile range] did not differ between the McGrath group and the Macintosh group (25.0 [22.8-28.3] s vs. 26.0 [24.0-29.0] s, P = 0.301). The incidence of grade I glottic view was significantly higher in the McGrath group than in the Macintosh group (95% vs. 74%, P = 0.013). Median IDS was lower in the McGrath group than in the Macintosh group (0 [0-0] vs. 0 [0-1], P = 0.018). There were no significant differences in success rate on intubation or haemodynamics between the two groups.

CONCLUSIONS

McGrath VL provides better laryngeal views and lower IDS but similar intubation times and success rates compared with the Macintosh laryngoscope in children with normal airway.

A Manikin Study Comparing McGrath Mac® and Airtraq® with Macintosh Laryngoscope in Tracheal Intubation by Intensive Care Unit Doctors

Objective

To compare the performance of the McGrath Mac® and the Airtraq® with the Macintosh laryngoscope for tracheal intubation.

Design

A manikin study with different simulated difficult airway scenarios.

Methods

Thirty intensive care unit (ICU) doctors (10 specialists and 20 non-specialists) performed intubation by using the 3 airway devices in the manikin with (i) normal airway, (ii) cervical rigidity, and (iii) tongue oedema. The intubation time, success rate, oesophageal intubation and number of episodes of dental injury were measured and compared.

Results

The mean intubation time was significantly less by using the Airtraq® comparing to the McGrath Mac® in the manikin with normal airway (12.77 sec vs. 24.23 sec; p<0.001). Similarly, the mean intubation time was less by using Airtraq® when comparing to the McGrath Mac® in the manikin with cervical rigidity (12.73 sec vs. 17.5 sec; p=0.013). In the scenario of simulated tongue oedema, the mean intubation time of Airtraq® was shorter than Macintosh laryngoscope (24.83 sec vs. 34.20 sec; p=0.011) while there was no difference between Airtraq® and the McGrath Mac®. Less dental injury was noted when using the Airtraq® compared to the Macintosh laryngoscope in simulated cervical rigidity (p=0.005) and tongue oedema (p<0.001). Less dental injury was also noted when using the McGrath Mac® compared to the Macintosh laryngoscope in simulated tongue oedema (p<0.001).

Conclusion

Even with prior limited experience in using the McGrath Mac®, the performance of tracheal intubation by using this new device is comparable with the Airtraq®. The McGrath Mac® can be a good alternative for tracheal intubation in difficult airway situations. (Hong Kong j.emerg.med. 2015;22:337-344)

Comparison of the Pentax AirwayScope and McGrath MAC videolaryngoscope for endotracheal intubation in patients with a normal airway

Various videolaryngoscopes (VLs) have been developed to provide a better laryngeal view and facilitate difficult intubations. The goal of this study was to compare 2 VLs, the Pentax AWS and the McGrath VL, with respect to intubation time and ease of intubation.One hundred forty patients aged 19 to 65 years (American Society of Anesthesiologists classification I or II), who required tracheal intubation for elective surgery, were randomly assigned to 1 of the 2 groups: the Pentax AWS (n = 70) or the McGrath VL (n = 70). The primary outcome was time to intubation (TTI) measured by a blind observer. The intubation difficulty scale (IDS), percentage of glottic opening (POGO) scale, glottic grade, use of optimal external laryngeal manipulation (OELM), and ease of intubation were also recorded.The Pentax AWS provided a better laryngeal view than the McGrath VL with respect to the Cormack-Lehane (CL) glottic grade (1/2a/2b) (63/7/0 vs 43/24/3, P < .001) and the POGO scale (median [interquartile range, IQR]) (100 [100-100] vs 100 [80-100], P < .001). The IDS was significantly lower in the Pentax AWS group compared with the McGrath VL group (median [IQR]) (0 [0-0] vs 0 [0-1], P < .001). However, the TTI was similar in both the Pentax AWS and McGrath VL groups (median [IQR]) (30 [27-34] vs 32 [27-35] seconds, P = .440). OELM and ease of intubation were also similar between the 2 groups.The Pentax AWS offered a superior laryngeal view compared with the McGrath VL. There was no significant difference in either the intubation time or ease of intubation using these 2 devices in patients with normal airways.

Stylet angulation for routine endotracheal intubation with McGrath videolaryngoscope

BACKGROUND

The McGrath videolaryngoscope (VL) provides excellent laryngoscopic views, but directing an endotracheal tube can be difficult, and thus the routine use of a stylet is recommended. The goal of this study is to determine the appropriate angle (60° vs 90°) of the stylet when using the McGrath VL by comparing the time to intubation (TTI).

METHODS

One hundred and forty patients aged 19 to 70 years (American Society of Anesthesiologists classification I or II) who required tracheal intubation for elective surgery were randomly allocated to 1 of 2 groups, at the 60° angle (n = 70) or the 90° angle (n = 70). Anesthesia was induced with propofol, fentanyl, and rocuronium. The primary outcome was TTI assessed by a blind observer. Glottic grade, use of optimal external laryngeal manipulation, failed intubation at first attempt, ease of intubation, and severity of oropharyngeal bleeding were also recorded.

RESULTS

The mean TTI was significantly shorter in the 60° group than in the 90° group (29.3 ± 6.4 vs 32.5 ± 9.4 s, P = 0.022). The glottic grade and degree of intubation difficulty were not significantly different between the 2 groups.

CONCLUSIONS

When intubating the patients with the McGrath videolaryngoscope, the 60° angled stylet allowed for faster orotracheal intubation than did the 90° angled stylet.

Video Laryngoscopy Improves Odds of First-Attempt Success at Intubation in the Intensive Care Unit. A Propensity-matched Analysis

RATIONALE

Urgent tracheal intubation is performed frequently in intensive care units and incurs higher risk than when intubation is performed under more controlled circumstances. Video laryngoscopy may improve the chances of successful tracheal intubation on the first attempt; however, existing comparative data on outcomes are limited.

OBJECTIVES

To compare first-attempt success and complication rates during intubation when using video laryngoscopy compared with traditional direct laryngoscopy in a tertiary academic medical intensive care unit.

METHODS

We prospectively collected and analyzed data from a continuous quality improvement database of all intubations in one medical intensive care unit between January 1, 2012, and December 31, 2014. Propensity matching and multivariable logistic regression were used to reduce the risk of bias and control for confounding.

MEASUREMENTS AND MAIN RESULTS

A total of 809 intubations took place over the study period. Of these, 673 (83.2%) were performed using video laryngoscopy and 136 (16.8%) using direct laryngoscopy. First-attempt success with video laryngoscopy was 80.4% (95% confidence interval [CI], 77.2-83.3%) compared with 65.4% (95% CI, 56.8-73.4%) for intubations performed with direct laryngoscopy (P < 0.001). In a propensity-matched analysis, the odds ratio for first-attempt success with video laryngoscopy versus direct laryngoscopy was 2.81 (95% CI, 2.27-3.59). The rate of arterial oxygen desaturation events during the first intubation attempt was significantly lower for video laryngoscopy than for direct laryngoscopy (18.3% vs. 25.9%; P = 0.04). The rate of esophageal intubation during any attempt was also significantly lower for video laryngoscopy (2.1% vs. 6.6%; P = 0.008).

CONCLUSIONS

Video laryngoscopy was associated with significantly improved odds of first-attempt success at tracheal intubation by nonanesthesiologists in a medical intensive care unit. Esophageal intubation and oxygen desaturation occurred less frequently with the use of video laryngoscopy. Randomized clinical trials are needed to confirm these findings.

Evaluation of the McGrath® MAC videolaryngoscope in a tertiary teaching hospital

Background:

Videolaryngoscopes have become increasingly popular in recent years for use in both normal and difficult airways. Despite this trend, their benefit remains controversial. The McGrath® MAC videolaryngoscope (Aircraft Medical Ltd, Edinburgh, UK) is used for first line or rescue intubation, and for training in videolaryngoscopy intubation. We conducted a prospective observational study to assess the performance of the McGrath® MAC.

Methods:

We evaluated the use of the McGrath® MAC videolaryngoscope from January 2016 to April 2016. We recruited 500 adult patients undergoing elective surgery requiring endotracheal intubation. Data was collected via an online survey. The primary outcome was the success of intubation with the McGrath® MAC. Secondary outcomes included the ease of the McGrath® MAC insertion, best glottic view, ease of tracheal tube insertion, number of intubation attempts, evidence of airway trauma, quality of view, adjunct used, airway manoeuvres used, quality of image on monitor screen and overall impression of the device.

Results:

A total of 428 responses were analysed. The overall success rate was 97.9% (95% confidence interval 96.0–99.0%). The success rate for those with predictors of difficult airway was 95.5% (95% confidence interval 87.6–99.5%). Easy scope insertion was reported by 97.2% of anaesthetists and 89.7% reported easy tube insertion. Some of our cases (1.9%) were complicated by airway trauma involving superficial oropharyngeal or lip injury.

Conclusion:

The McGrath® MAC videolaryngoscope is a good choice for a videolaryngoscope, conferring advantages of a high intubation success rate, ease of laryngoscope insertion and ease of intubation. It is suitable for use in predicted difficult airways.

Videolaryngoscopy versus direct laryngoscopy for adult patients requiring tracheal intubation

BACKGROUND

Successful tracheal intubation during general anaesthesia traditionally requires a line of sight to the larynx attained by positioning the head and neck and using a laryngoscope to retract the tongue and soft tissues of the floor of the mouth. Difficulties with intubation commonly arise, and alternative laryngoscopes that use digital and/or fibreoptic technology have been designed to improve visibility when airway difficulty is predicted or encountered. Among these devices, a rigid videolaryngoscope (VLS) uses a blade to retract the soft tissues and transmits a lighted video image to a screen.

OBJECTIVES

Our primary objective was to assess whether use of videolaryngoscopy for tracheal intubation in adults requiring general anaesthesia reduces risks of complications and failure compared with direct laryngoscopy. Our secondary aim was to assess the benefits and risks of these devices in selected population groups, such as adults with obesity and those with a known or predicted difficult airway.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and Embase on 10 February 2015. Our search terms were relevant to the review question and were not limited by outcomes. We carried out clinical trials register searches and forward and backward citation tracking. We reran the search on 12 January 2016; we added potential new studies of interest from the 2016 search to a list of 'Studies awaiting classification', and we will incorporate these studies into the formal review during the review update.

SELECTION CRITERIA

We considered all randomized controlled trials and quasi-randomized studies with adult patients undergoing laryngoscopy performed with a VLS or a Macintosh laryngoscope in a clinical, emergency or out-of-hospital setting. We included parallel and cross-over study designs.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data, consulting a third review author to resolve disagreements. We used standard Cochrane methodological procedures, including assessment of risk of bias.

MAIN RESULTS

We included 64 studies identified during the 2015 search that enrolled 7044 adult participants and compared a VLS of one or more designs with a Macintosh laryngoscope. We identified 38 studies awaiting classification and seven ongoing studies. Of the 64 included studies, 61 included elective surgical patients, and three were conducted in an emergency setting. Among 48 studies that included participants without a predicted difficult airway, 15 used techniques to simulate a difficult airway. Seven recruited participants with a known or predicted difficult airway, and the remaining studies did not specify or included both predicted and not predicted difficult airways. Only two studies specifically recruited obese participants. It was not possible to blind the intubator to the device, and we noted a high level of inevitable heterogeneity, given the large number of studies.Statistically significantly fewer failed intubations were reported when a VLS was used (Mantel-Haenszel (M-H) odds ratio (OR), random-effects 0.35, 95% confidence Interval (CI) 0.19 to 0.65; 38 studies; 4127 participants), and fewer failed intubations occurred when a VLS was used in participants with an anticipated difficult airway (M-H OR, random-effects 0.28, 95% CI 0.15 to 0.55; six studies; 830 participants). We graded the quality of this evidence as moderate on the basis of the GRADE system. Failed intubations were fewer when a VLS was used in participants with a simulated difficult airway (M-H OR, random-effects 0.18, 95% CI 0.04 to 0.77; nine studies; 810 participants), but groups with no predicted difficult airway provided no significant results (M-H OR, random-effects 0.61, 95% CI 0.22 to 1.67; 19 studies; 1743 participants).Eight studies reported on hypoxia, and only three of these described any events; results showed no differences between devices for this outcome (M-H OR, random-effects 0.39, 95% CI 0.10 to 1.44; 1319 participants). Similarly, few studies reported on mortality, noting no differences between devices (M-H OR, fixed-effect 1.09, 95% CI 0.65 to 1.82; two studies; 663 participants), and only one study reporting on the occurrence of respiratory complications (78 participants); we graded these three outcomes as very low quality owing to lack of data. We found no statistically significant differences between devices in the proportion of successful first attempts (M-H OR, random-effects 1.27, 95% CI 0.77 to 2.09; 36 studies; 4731 participants) nor in those needing more than one attempt. We graded the quality of this evidence as moderate. Studies reported no statistically significant differences in the incidence of sore throat in the postanaesthesia care unit (PACU) (M-H OR, random-effects 1.00 (95% CI 0.73 to 1.38); 10 studies; 1548 participants) nor at 24 hours postoperatively (M-H OR random-effects 0.54, 95% CI 0.27 to 1.07; eight studies; 844 participants); we graded the quality of this evidence as moderate. Data combined to include studies of cross-over design revealed statistically significantly fewer laryngeal or airway traumas (M-H OR, random-effects 0.68, 95% CI 0.48 to 0.96; 29 studies; 3110 participants) and fewer incidences of postoperative hoarseness (M-H OR, fixed-effect 0.57, 95% CI 0.36 to 0.88; six studies; 527 participants) when a VLS was used. A greater number of laryngoscopies performed with a VLS achieved a view of most of the glottis (M-H OR, random-effects 6.77, 95% CI 4.17 to 10.98; 22 studies; 2240 participants), fewer laryngoscopies performed with a VLS achieved no view of the glottis (M-H OR, random-effects 0.18, 95% CI 0.13 to 0.27; 22 studies; 2240 participants) and the VLS was easier to use (M-H OR, random-effects 7.13, 95% CI 3.12 to 16.31; seven studies; 568 participants).Although a large number of studies reported time required for tracheal intubation (55 studies; 6249 participants), we did not present an effects estimate for this outcome owing to the extremely high level of statistical heterogeneity (I2 = 96%).

AUTHORS' CONCLUSIONS

Videolaryngoscopes may reduce the number of failed intubations, particularly among patients presenting with a difficult airway. They improve the glottic view and may reduce laryngeal/airway trauma. Currently, no evidence indicates that use of a VLS reduces the number of intubation attempts or the incidence of hypoxia or respiratory complications, and no evidence indicates that use of a VLS affects time required for intubation.

Intubation without use of stylet for McGrath videolaryngoscopy in patients with expected normal airway: A randomized noninferiority trial

BACKGROUND

During McGrath videolaryngoscope (VL) intubation, a styletted endotracheal tube maintaining an upward distal tip angle is recommended by some manufacturers. However, a styletted endotracheal tube can elicit rare but potentially serious complications. The purpose of this study was to demonstrate that a nonstyletted tube with exaggerated curvature would be noninferior to a styletted tube for orotracheal intubation using McGrath VL in patients with expected normal airway, by comparing the time to intubation and ease of intubation.

METHODS

One hundred forty patients, ages 19 to 70 years (American Society of Anesthesiologists physical status I-II), undergoing tracheal intubation for elective surgery were randomly allocated to the nonstylet group (n = 70) or the stylet group (n = 70). Anesthesia induction consisted of propofol, remifentanil, and rocuronium. The primary outcome was time to intubation assessed by a blind observer. Cormack and Lehane glottic grade, easy of intubation, and intubation difficulty score (IDS) were also assessed.

RESULTS

Median time to intubation [interquartile range] was not different between the nonstylet group and the stylet group (26 [24-32.5] s vs 27 [25-31] s, P = 0.937). There was no significant in median IDS between the nonstylet group and the stylet group (P = 0.695).

CONCLUSION

This study shows that a nonstyletted endotracheal tube with exaggerated curvature has a similar performance to a styletted tube with a hockey-stick curvature during intubation using McGrath VL regarding time taken to successful intubation and easiness of intubation.

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.

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

We hypothesized that the McGRATH MAC would decrease the time of intubation compared to C-MAC for novices. Thirty-nine medical students who had used the Macintosh blade to intubate a manikin fewer than 3 times were recruited. The participants performed sequential intubations on the manikin in two simulated settings that included a normal airway and a difficult airway (tongue edema). The intubation time, success rate of intubation, Cormack-Lehane grade at laryngoscopy, and difficulty using the device were recorded. Each participant was asked to identify the device that was most useful. The intubation time decreased significantly and by a similar amount to the McGRATH MAC and C-MAC compared to the Macintosh blade (P < 0.001 and P = 0.017, resp.). In the difficult airway, the intubation times were similar among the three devices. The McGRATH MAC and C-MAC significantly increased the success rate of intubation, improved the Cormack-Lehane grade, and decreased the difficulty score compared to the Macintosh blade in both airway settings. The majority of participants selected the McGRATH MAC as the most useful device. The McGRATH MAC and C-MAC may offer similar benefits for intubation compared to the Macintosh blade in normal and difficult airway situations.