A comparative study between Truview(PCD) laryngoscope and Macintosh laryngoscope in viewing glottic opening and ease of intubation: A crossover study

Evaluation of the Effect of Intubation Box use on Tracheal Intubation Difficulty with King Vision® and Truview Videolaryngoscope in Manikin in a Tertiary Care Hospital

Background

The procedures of introducing an airway by intubation are associated with increased risk of aerosolisation of SARS-CoV-2 virus, posing a high risk to the personnel involved. Newer and novel methods such as the intubation box have been developed to increase the safety of healthcare workers during intubation.

Methods design

In this study, 33 anaesthesiologist and critical care specialists intubated the trachea of the airway manikin (US Laerdal Medical AS™) 4 times using a King Vision^® videolaryngoscope and TRUVIEW PCD™ videolaryngoscope (with and without an intubation box as described by Lai). Intubation time was primary outcome. Secondary outcomes were first-pass intubation success rate, percentage of glottic opening (POGO) score and peak force to maxillary incisors.

Results

Intubation time and the number of times a click was heard during tracheal intubation were considerably higher in both groups when an intubation box was used (Table 1). When comparing the two laryngoscopes, the King Vision^® videolaryngoscope enabled much less time to intubate than did the TRUVIEW laryngoscope, both with and without the intubation box. (P<0.001) In both laryngoscope groups, first-pass successful intubation was higher without the intubation box, although the difference was statistically insignificant. POGO score was not affected by intubation box but a higher score was observed with King Vision^® laryngoscope (Tables 1,2).

Conclusion

This study indicates that use of an intubation box makes intubation difficult and increases the time needed to perform it. King Vision^® videolaryngoscope results in lesser intubation time and better glottic view as compared to TRUVIEW laryngoscope.

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.

A Comparative Study between Truview PCD Video Laryngoscope and Macintosh Laryngoscope with Respect to Intubation Quality and Hemodynamic Changes

Background and Aims

Video laryngoscopes resemble traditional laryngoscopes, but they have a video chip embedded in the tip of laryngoscope blade. This enables the operator to "look around the corners" which is not possible with conventional direct laryngoscopes. The present study was undertaken to compare Truview video laryngoscope and Macintosh laryngoscope for glottis visualization, ease of tracheal intubation, and associated hemodynamic response.

Setting

The study was conducted in operation theater in a medical college.

Study Design

It was a randomized prospective observational study.

Materials and Methods

Sixty patients of American Society of Anesthesiologists Grade 1 and 2 of either sex aged 18-60 years who were scheduled to undergo elective surgery requiring general anesthesia with orotracheal intubation were selected. In patients of Group T (n = 30), intubation was done using Truview video laryngoscope, while in Group M (n = 30), intubation was done using Macintosh laryngoscope. Various airway and hemodynamic parameters were assessed and compared.

Statistical Analysis

Statistical analysis was done using Chi-square test, paired and unpaired Student's t-test, and ANOVA test. P < 0.05 is considered statistically significant.

Results

Distribution of modified Mallampati Class (MMPC), ease of laryngoscopic blade insertion, and size of cuffed endotracheal tube used were statistically comparable in both the groups. The time to intubation was more in Group T (37.16 ± 8.23 s) as compared to Group M (29.80 ± 6.75 s). There was a statistically significant better modified Cormack and Lehane (CL) grading view obtained in Group T as compared to Group M (P = 0.025). CL Grades 2 and 3 were not seen in any of either of the group. The mean intubation difficulty score (IDS) was significantly lower in Group T (0.3 ± 0.60) as compared to Group M (0.73 ± 0.86). In both the Groups T and M, the mean heart rate, systolic blood pressure (BP), and diastolic BP were significantly increased from baseline for up to 3 min after laryngoscopy, but they were comparable between the two groups all the time.

Conclusion

Truview propaganda cum distribution laryngoscope provides a better glottis view than the Macintosh laryngoscope. Although it requires a longer time to intubate using Truview, the overall IDS score was lower as compared to Macintosh laryngoscope. Hemodynamic changes remained similar in both the groups.

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

Background:

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

Aim and Objectives:

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

Materials and Methods:

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

Statistical Analysis:

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

Results:

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

Conclusion:

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

Suitability of Nasotracheal Intubation using King Vision and TruviewPCD Video Laryngoscopes: A Randomized Clinical Trial

BACKGROUND

Several video laryngoscopes had demonstrated their superiority over conventional oral and nasal intubation techniques. King Vision video laryngoscope has fewer studies supporting its suitability for oral intubations. However, its suitability as a nasal intubating device has not been yet evaluated. We evaluated the suitability of King Vision video laryngoscope for nasotracheal intubation comparing with TruviewPCD.

METHODS

Eighty American Society of Anesthesiologists Grade I and II elective surgical patients were studied. After meeting the inclusion criteria, 80 study subjects were randomized into two groups. Group T were intubated using TruviewPCD and Group K were intubated with the nonchanneled King Vision video laryngoscope. Our primary outcome was single successful nasotracheal intubation without use of any additional maneuvers. The time taken for intubation, use of additional maneuverers, Cormack-Lehane grading, and hemodynamics were also analyzed.

RESULTS

Seventy-one patients (88.75%) were successfully intubated in a single attempt, i.e. 35 patients (90%) in Group K and 36 patients (87.5%) in Group T. Intubation time (mean ± standard deviation) was 67.9 ± 24.1 s in Group T and 64.9 ± 20.0 s in Group K where comparison was not statistically significant (P = 0.5). The additional maneuvers (P = 0.2) and hemodynamic changes were not clinically significant. There were no associated serious complications.

CONCLUSION

King Vision video laryngoscope is just as effective as TruviewPCD video laryngoscope for successful nasotracheal intubation.

Comparison of King Vision and Truview Laryngoscope for Postextubation Visualization of Vocal Cord Mobility in Patients Undergoing Thyroid and Major Neck Surgeries: A Randomized Clinical Trial

Background:

Visualization of vocal cords following extubation after thyroid and major neck surgeries is highly desirable for the surgeon as well as the anaesthesiologist to rule out vocal cord palsy or oedema. As the patient is emerging from general anaesthesia, it may be challenging for the anaesthesiologist to optimally visualise and grade vocal cord movement following extubation.

Setting:

Randomized clinical trial at a tertiary care centre.

Methodology:

After obtaining institutional ethics committee approval, 60 patients posted for thyroid and major neck surgeries under American Society of Anesthesiologists (ASA) grade I and II were recruited for the study. Written informed consent was obtained. Pre-operatively indirect laryngoscopy was performed in all the patients to assess baseline vocal cord function. All patients were premedicated and induced and maintained as per standardized anaesthesia protocol. Patients were randomized using a sealed envelope technique to either Group K where intubation was performed using Kings vision laryngoscope or Group T where intubation was performed using True view laryngoscope. Glottis visualization was graded in all patients and intubated. Ten minutes prior to extubation injection. dexmedetomidine 1 μg/kg was administered. Once patients satisfied extubation criteria, laryngoscopy was performed using respective video-laryngoscope in each group, patient extubated under vision and assessed for vocal cord visualization and mobility grade (VMG) and patient reactivity score (PRS). Heart rate, systolic blood pressure, diastolic blood pressure and mean arterial pressure was also noted. Total intraoperative morphine consumption was recorded. Vocal cord function was assessed again before the day of discharge by indirect laryngoscopy.

Results:

Age (P = 0.27), sex (P = 0.08), body mass index (P = 0.70), ASA (P = 0.39), mallampati class (P = 0.72) and morphine used (P = 0.39) were comparable in both groups. There was no statistically significant difference among the two groups with respect to VMG (P = 0.18). There was no statistical difference in the PRS (P = 0.06) in both groups. Increase in heart rate or mean arterial pressure from baseline was not significant statistically in both groups. Time taken for laryngoscopy during extubation was significantly less with group T as compared to group K (P = 0.000).

Conclusion:

Both Kings Vision and Truview Video-laryngoscopes provide comparable laryngoscopic view with similar patient comfort, although clinically Truview may be a better choice due to less time consumed for visualisation and rating vocal cord movement during extubation.

Comparison of success of tracheal intubation using Macintosh laryngoscope-assisted Bonfils fiberscope and Truview video laryngoscope in simulated difficult airway

Background and Aims:

Restriction of head and neck movements prevents the alignment of the oral, pharyngeal, and laryngeal axes and increases the incidence of difficult tracheal intubation in patients with cervical spine fractures. Video laryngoscopes have gained an important role in the management of difficult intubation, especially in situations with limited head and neck movements. This study compares the success of intubation using Macintosh laryngoscope assisted Bonfils^® fiberscope (ML-BF) with Truview^PCD video laryngoscope (TV) in patients with simulated restricted head and neck movements.

Material and Methods:

One hundred and fifty-two patients satisfying the inclusion criteria were randomly allocated to two groups of 76 each. Patients were made to lie supine on the table without a pillow and a soft collar was used to restrict head and neck movements. After a standardized premedication-induction sequence, tracheal intubation was done either with ML-BF or TV. Success of intubation, time taken for successful intubation, hemodynamic changes, airway trauma, and postoperative oropharyngeal morbidity were noted.

Results:

Intubation was successful in all the 76 patients in direct laryngoscopy-Bonfils fiberscope group and 75 out of 76 patients in TV group within the specified time (90 s). The median time taken for successful intubation with TV and ML-BF were 44 (range 26–80) s and 49 (range 28–83) s, respectively. Hemodynamic changes, airway trauma, and postoperative oropharyngeal morbidity were similar in both groups.

Conclusion:

Both TV and ML-BF are equally effective for successful tracheal intubation in patients with simulated restricted head and neck movements. In cases of difficult laryngeal visualization with routine Macintosh laryngoscope, Bonfils can be used as an adjunct to achieve successful intubation in the same laryngoscopy attempt.