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

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.

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.

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.

Risk Factors for Postoperative Sore Throat After Nasotracheal Intubation

OBJECTIVE

Postoperative sore throat is relatively frequent complication after orotracheal intubation. However, there are few reports about postoperative sore throat in nasotracheal intubation. In this retrospective study, we investigated the risk factors of postoperative sore throat in nasotracheal intubation.

METHODS

Anesthesia records of patients 16 to 80 years of age who underwent nasotracheal intubation were included. Patients underwent oral and maxillofacial surgery from February 2015 until September 2018. Airway device (Macintosh laryngoscope, Pentax-AWS, or McGRATH video laryngoscope, or fiberoptic scope), sex, age, height, weight, American Society of Anesthesiologists classification, intubation attempts, duration of intubation, intubation time, tube size, and fentanyl and remifentanil dose were investigated. Fisher exact test, Wilcoxon rank sum test, Welch t test, and Steel-Dwass multiple test were used, and a multivariable analysis was performed using stepwise logistic regression to determine the risk factors of postoperative sore throat.

RESULTS

A total of 169 cases were analyzed, and 126 patients (74.6%) had a postoperative sore throat. Based on the univariate analysis of the data, 12 factors were determined to be potentially related to the occurrence of a postoperative sore throat. However, after evaluation using stepwise logistic regression analysis, the 2 remaining variables that correlated with postoperative sore throat were airway device (P < .05) and intubation attempts (P = .04). In the model using logistic regression analysis, the fiberoptic scope had the strongest influence on the incidence of sore throat with reference to Pentax-AWS (odds ratio = 5.25; 95% CI = 1.54-17.92; P < .05).

CONCLUSION

Use of a fiberoptic scope was identified as an independent risk factor for postoperative throat discomfort. Compared with direct laryngoscopy and other video laryngoscopes, the use of a fiberoptic scope had a significantly higher incidence of sore throat.

Comparison of self-assembled video laryngoscope versus McGrath MAC®: A randomised controlled trial

Background and Aims:

Video laryngoscopy highly improves the success rate for endotracheal intubation. However, commercially available video laryngoscopes such as McGrath MAC^® can be costly. An economical video laryngoscope was assembled by attaching a fibreoptic videoscope into a Macintosh laryngoscope. This randomised study aimed to compare the intubation time of this self-assembled modified Macintosh video laryngoscope (SAM-VL) and McGrath MAC^® (McGrath).

Methods:

This study enroled 62 adults scheduled for elective surgery under general anaesthesia with endotracheal intubation. The primary outcome was total intubation time. Secondary outcomes were the time for glottic visualisation (time A), time for tube insertion after glottic visualisation (time B), first-attempt intubation success rate, degree of glottic visualisation, and need for backward, upward, rightward pressure (BURP) assistance, complications, and user satisfaction. The tests used were: Kolmogorov-Smirnov and the Mann-Whitney test to analyse the data’s distribution and the primary outcome, respectively.

Results:

The median total intubation time in the SAM-VL group versus the McGrath was 63 s (27–114s) versus 74 s (40–133s), respectively (P = 0.032). Intubation time B was significantly faster, while the score of glottic visualisation and BURP assistance was significantly higher in the SAM-VL group. The differences in the rate of successful first attempts and complications were not statistically significant. SAM-VL users rated the ease of blade insertion and manoeuvrability, degree of glottic visualisation, and overall rating as very high.

Conclusion:

Endotracheal intubation using self-assembled modified video laryngoscope is faster and allows better glottis visualisation than McGrath MAC^®.

Comparison of four channelled videolaryngoscopes to Macintosh laryngoscope for simulated intubation of critically ill patients: the randomized MACMAN2 trial

Background

Videolaryngoscopes with an operating channel may improve the intubation success rate in critically ill patients. We aimed to compare four channelled videolaryngoscopes to the Macintosh laryngoscope used for intubation of a high-fidelity simulation mannikin, in a scenario that simulated critical illness due to acute respiratory failure.

Results

Of the 79 residents who participated, 54 were considered inexperienced with orotracheal intubation. Each participant used all five devices in random order. The first-pass success rate was 97.5% [95% CI 91.1–99.7] for Airtraq™, KingVision™, and Pentax AWS200™, 92.4% [95% CI 84.2–97.2] for VividTrac VT-A100™, and 70.9% [95% CI 59.6–80.6] for direct Macintosh laryngoscopy. The first-pass success rate was significantly lower with direct Macintosh laryngoscopy than with the videolaryngoscopes (p  <  0.0001 for Airtraq™, KingVision™, Pentax AWS200™, and VividTrac VT-A100™).

Conclusion

The Airtraq™, KingVision™, and Pentax AWS200™ channelled videolaryngoscopes produced high first-pass success rates with a lower boundary of the 95% CI above 90%. A multicentre, randomised controlled clinical study comparing channelled videolaryngoscopy to direct laryngoscopy should include one of these three videolaryngoscopes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00916-3.

Development and performance testing of the low-cost, 3D-printed, smartphone-compatible 'Tansen Videolaryngoscope' vs. Pentax-AWS videolaryngoscope vs. direct Macintosh laryngoscope: A manikin study

BACKGROUND

While videolaryngoscopes help in the management of difficult airways, they remain too expensive for those with limited resources. We have developed a robust, re-usable, low-cost videolaryngoscope at United Mission Hospital Tansen, Nepal, by combining a smartphone-compatible endoscope capable of capturing still and video images with a three dimensional-printed, channelled, hyperangulated blade. The computer-aided design file for the videolaryngoscope blade was emailed and printed in London before evaluation of its performance on a difficult airway manikin.

OBJECTIVE

To benchmark the intubation performance of the Tansen Videolaryngoscope (TVL) in a 'difficult airway' manikin (SimMan3G, tongue fully inflated, neck stiff), against a commercially available videolaryngoscope and a conventional Macintosh laryngoscope.

DESIGN

A manikin study.

SETTING AND PARTICIPANTS

Forty-three experienced videolaryngoscope users in two London teaching hospitals.

INTERVENTION AND OUTCOME

Primary outcome: Intubation success rate.

SECONDARY OUTCOMES

grade of laryngeal view, median time to intubation and intubator-rated 'ease of use'.

RESULTS

Our device was equivalent to Pentax-AWS and superior to Macintosh laryngoscope (TVL vs. Pentax-AWS vs. Macintosh) in overall intubation success rate (88 vs. 98 vs. 67%, P < 0.05); grade of view (median Cormack-Lehane grade 1 vs. 1 vs. 3, P < 0.01); median time to intubation (17.5 vs. 15.5 vs. 27 s, P < 0.01). In subjective 'ease of use' scores, Pentax-AWS was superior to the TVL, which was superior to Macintosh laryngoscope (Likert-type 1 to 5 scale: 4 vs. 4 vs. 1, P < 0.00001).

CONCLUSION

In this manikin simulation of a difficult airway, the 'TVL' was superior to the Macintosh laryngoscope, and noninferior to the Pentax-AWS videolaryngoscope in intubation success rate, grade of laryngeal view and time to intubation. Participants found the Pentax device easier to use, and their feedback has given us valuable insights for improving our device. The TVL is well suited to settings in which resources are limited, being inexpensive, simple and re-usable.

Tracheal intubation with the McGrath MAC X-blade videolaryngoscope in morbidly obese and nonobese patients

Background/aim

Increased body mass index (BMI) and neck circumference are the two independent predictors of difficult intubation. McGrath MAC X-Blade is a videolaryngoscope specifically designed for difficult intubations.

Materials and methods

Eighty patients with the American Society of Anesthesiologists (ASA) physical status I–III undergoing elective surgery requiring endotracheal intubation were enrolled in the study. Patients were divided into two groups, nonobese (BMI < 30) and morbidly obese (BMI > 35). All patients were intubated with the McGrath MAC X-Blade in both groups. View optimization and tube insertion maneuvers such as reinsertion of the device, slight removal of the device, cricoid pressure, handling force, 90° anticlockwise rotation of the tube, use of stylet, and head flexion maneuvers were recorded. Cormack–Lehane grades, insertion times, intubation, and total intubation times were recorded. The hemodynamic changes and postoperative minor complications were also recorded.

Results

Body mass index, neck circumference, Mallampati scores, and ASA physical status were statistically higher in the morbidly obese group (P < 0.001 and P < 0.05). Sternomental distances were shorter in the morbidly obese (P < 0.05). Cormack–Lehane grades were comparable among the groups. The morbidly obese patients required more reinsertion attempts and cricoid pressure maneuvers during intubation than the nonobese patients (P = 0.019 versus P = 0.012, respectively). Slight removal of the device, handling force, use of the stylet, 90° anticlockwise rotation of the tube, and head flexion maneuvers were also helpful in both groups. Although device insertion times were similar between the groups, intubation and total intubation times were longer in the morbidly obese group (P = 0.009 and P = 0.034, respectively). The groups were comparable in hemodynamic changes and postoperative minor complications.

Conclusion

The McGrath MAC X-Blade videolaryngoscope could safely be used both in nonobese (BMI < 30) and morbidly obese (BMI > 35) patients with the aid of some key maneuvers and with a statistically significant but clinically negligible prolongation of the intubation time.

Postoperative sore throat and subglottic injury after McGrath® MAC videolaryngoscopic intubation with versus without a stylet in patients with a high Mallampati score: a randomized controlled trial

Background

A tracheal tube stylet can be used to assist successful tracheal intubation, especially during videolaryngoscopic intubation because videolaryngoscopes with a Macintosh-type blade such as McGrath® MAC videolaryngoscope have more acute angle than conventional Macintosh laryngoscope. However, the use of a stylet during tracheal intubation can raise concerns about stylet-induced postoperative airway complications, such as sore throat, subglottic injury, and hoarseness. In this study, we compared the incidence of postoperative airway complications after McGrath® MAC videolaryngoscopic intubation with versus without a stylet in patients with a high Mallampati score.

Methods

In 104 patients with Mallampati score III or IV and who were scheduled for lumbar or thoracic spine surgery, McGrath® MAC videolaryngoscopic intubation was performed either with a stylet (group S, n = 52) or without a stylet (group N, n = 52). The primary outcome measure was the incidences of sore throat evaluated at 1 and 24 h postoperatively. Secondary outcome measures were the incidences of subglottic injury and postoperative hoarseness.

Results

The incidence of CL grade III in group S and N was 3.8 and 5.8%, respectively. No patient showed CL grade IV. The incidences of sore throat at 1 (26.9 vs 19.2%, P = 0.485) and 24 h (17.3 vs 13.5%, P = 0.786, respectively) postoperatively were not significantly different between the group S and N. However, the incidence of subglottic injury was significantly higher in the group S, compared with the group N (65.4 vs 42.3%, P = 0.030). The incidence of postoperative hoarseness did not differ significantly between the two groups.

Conclusions

The use of a stylet during McGrath® MAC videolaryngoscopic intubation did not have a significant impact on the incidence of postoperative sore throat in patients with a high Mallampati score. Avoiding the use of a stylet during intubation with McGrath® MAC videolaryngoscope may reduce the incidence of subglottic injury in such patients.

Trial registration

Clinical Research Information Service (identifier: KCT0002427, date of registration: June 12, 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.