Comparison of the C-MAC D-Blade, Conventional C-MAC, and Macintosh Laryngoscopes in Simulated Easy and Difficult Airways

Assessment of stress response due to C-Mac D-blade guided videolaryngoscopic endotracheal intubation and docking of da Vinci surgical robot using perfusion index in patients undergoing transoral robotic oncosurgery

Clinical utility of perfusion index (PI) has entered a new realm as a non-invasive, quantitative index of stress response to endotracheal intubation. Transoral robotic surgery (TORS) involves F-K retractor aided docking of the surgical robot producing haemodynamic and stress responses akin to laryngoscopy. We compared the stress response to videolaryngoscopy with that due to docking of da Vinci surgical robot using PI, heart rate and mean arterial pressure evaluated at specific time points post-laryngoscopy and post-docking. Twenty-six adult patients, scheduled for TORS under general endotracheal anaesthesia were included in this prospective, observational, single-centric cohort study. Statistical analysis included paired samples t-test, dotted box-whisker plots, trendlines and correlograms for comparative analysis of two stressors, laryngoscopy and docking. Baseline PI was 4.14. PI values increased post-midazolam (4.23), 1 min (5.69) and 3 min (6.25) post anaesthetic-induction, plummeted at laryngoscopy (3.24), remained low at 1 min (3.68), 3 min (4.69) thereafter, and were highest at 10 min (6.17) post-laryngoscopy and predocking (6.84). Docking witnessed a fall in PI (4.1), which remained low at 1 min (4.02), 3 min (4.31) and 10 min (4.79) post-docking. PI was significantly higher at laryngoscopy compared with PI at docking (p = 0.0044). At 1 min and 3 min post-laryngoscopy and post-docking, respectively, the differences in PI were statistically insignificant. PI at 10 min post-laryngoscopy was significantly lower than PI at 10 min post-docking (p < 0.0001). As non-invasively quantified by PI, videolaryngoscopic stress response is more intense but shorter-lived versus that due to docking. PI displays a negative correlation with haemodynamic variables. PI at laryngoscopy is a good predictor of PI at docking, enabling pre-emptive measures (fentanyl bolus; deepening of volatile anaesthesia from MAC-maintenance to MAC-intubation) anticipating the docking-induced stress response.Trial registration http://ctri.nic.in ; Identifier: CTRI/2019/11/022091.

Partial vs full glottic view with CMACTM D blade intubation of airway with simulated cervical spine injury: a randomized controlled trial

PURPOSE

A previous study reported a shorter time to tracheal intubation by reducing percentage of glottic opening (POGO) view to <50% when intubating a normal adult airway using the Glidescope^TM blade. We evaluate the efficacy of reducing POGO to <50% when intubating patients with rigid cervical immobilization using CMAC^TM D blade.

METHODS

One hundred and four adult patients were randomized to group POGO 100% or POGO <50% . Laryngoscopy was performed by advancing tip of the D blade at vallecula. POGO 100% was achieved by exerting upward force to displace epiglottis until glottic opening from the anterior commissure to inter arytenoid notch. POGO < 50% was acquired by withdrawing the D blade tip dorsally from vallecula. The primary outcome was time to intubation.

RESULTS

The median time (IQR) to successful intubation was 29 (25-35) seconds for group POGO < 50% and 34 (28-40) seconds for group with POGO 100% (difference in medians, 5 seconds; 95% confidence interval, 2 to 8, p = 0.003). Complications were minor.

CONCLUSION

Using the CMAC^TM D blade with a reduced POGO in patients with cervical spine immobilization resulted in faster tracheal intubation.

TRIAL REGISTRATION

The trial is registered at ClinicalTrial.gov (CT.gov identifier: NCT04833166).

Factors Influencing the Time of Intubation Using C-MAC D-Blade® Video Laryngoscope: An Observational Cross-Sectional Study

Purpose C-MAC D-Blade® (Karl Storz, Tuttlingen, Germany) video laryngoscope (VL) has proved to be of immense utility in difficult intubation. But unfortunately, in an urgent situation, the predictable correct curvature of the endotracheal tube for effortless intubation is not met. We hypothesized that expertise is the most important variable in intubation and that novice students will be unable to intubate if the angle of curvature is incorrect. Methods An observational cross-sectional study was planned with 30 anesthesia residents, categorized into three groups based on their expertise in laryngoscopy. Students had to intubate an airway mannequin using the C-MAC D-Blade® VL with three different stylet angulations. The curvatures were 80, 100, and 120 degrees, which are commonly encountered in routine day-to-day practice. The time to get a stable glottic view, time to intubate, and ease of intubation were measured. Results The mean time to intubate was the least with 100-degree angulation in group C (19.60 ± 0.97) while the maximum time was in group A with 80-degree angulation (61.49 ± 3.69). A significant difference was noted in time to get a stable glottic view when compared between the groups. There was no difference in time to intubate with different stylet angulations when compared between groups. Conclusions Novices and experts could intubate even if the angle of curvature was incorrect taking more time. The time to laryngoscopy is significantly dependent on experience, but the time to intubate is influenced by the angle of curvature of the stylet.

Comparison of the C-MAC D-blade video laryngoscope and the McCoy laryngoscope for double-lumen endotracheal tube intubation: A prospective randomized controlled study

BACKGROUND

Inserting a double-lumen endotracheal tube (DLT) poses more challenge than inserting a single-lumen tube. The C-MAC D-blade videolaryngoscope is a useful alternative to the direct laryngoscope. However, no study has compared its performance with that of the McCoy laryngoscope, which has a hyperangulated blade tip similar to that of the C-MAC D-blade. We aimed to compare the performance of the C-MAC D-blade videolaryngoscope with that of the McCoy laryngoscope in DLT intubation.

METHODS

In this prospective randomized controlled study, 90 patients requiring DLT intubation were randomly allocated to either the C-MAC D-blade videolaryngoscope group (group C, n = 47) or McCoy laryngoscope group (group M, n = 43). During intubation, the percentage of glottic opening, modified Cormack-Lehane grade, time taken for intubation, malposition of the bronchial lumen, and hemodynamic parameters were recorded. After intubation, we assessed the intubation difficulty scale score and, a postoperative sore throat in the recovery room.

RESULTS

The time taken for intubation was 35.85 ± 10.77 seconds and 33.18 ± 11.97 seconds in groups C and M, respectively (P = .269). The modified Cormack-Lehane grade was significantly lower in group C than in group M (P = .000). Percentage of glottic opening was significantly higher in group C (79.36 ± 13.42%) than in group M (53.49 ± 29.83%) (P = .000). The intubation difficulty scale score was significantly lower in group C than in group M (P = .030). There were no significant differences between the 2 groups in terms of malposition status, hemodynamic parameters, or visual analog scale score for a postoperative sore throat.

CONCLUSION

Although the time taken for intubation was comparable between the 2 intubation devices, the C-MAC D-blade videolaryngoscope facilitated glottis visualization and reduced the intubation difficulty scale better than the McCoy laryngoscope in patients undergoing DLT intubation.

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

BACKGROUND

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

RESEARCH DESIGN AND METHODS

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

RESULTS

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

CONCLUSION

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

TRIAL REGISTRATION

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

Management of a Difficult Airway Scenario in a Case of Hurler’s Syndrome with a D-Blade Video Laryngoscope

Hurler’s syndrome is a rare genetic disease characterized by progressive multiorgan accumulation of glycosaminoglycans. It is associated with progressive craniofacial, skeletal, and cardiac involvement, which increases the risk of anesthesia. Patients with Hurler’s syndrome could present as the worst airway management problem an anesthesiologist could deal with due to abnormal upper airway anatomy and limited neck manipulation, owing to the atlantoaxial instability. We report a case of difficult airway scenario of a child with Hurler’s syndrome, leading to an apparent cannot ventilate cannot intubate scenario, which was managed successfully with the help of a C-MAC video laryngoscope with unique D-blade. In Hurler’s syndrome, C-MAC with D-blade is an excellent tool in establishing an airway in a pediatric difficult airway scenario. Moreover, D-blade C-MAC could be considered as the primary tool for establishing an airway in pediatric patients with Hurler’s syndrome.

Intubation outcomes using the aerosol box during the COVID-19 pandemic: A prospective, observational study

BACKGROUND AND AIMS

The aerosol box (AB), an improvised device used during the coronavirus disease (COVID)-19 pandemic, has attracted both interest and controversy. Several simulated studies have examined its protective efficacy as well as intubation efficiency. The aim of this study was to evaluate the practical conduct of intubation using the AB in patients undergoing elective, oncological surgery during the pandemic.

METHODS

This prospective, observational study included adult patients undergoing oncological surgery. Thirteen anaesthesiologists performed 132 intubations using one of three ABs designated as AB 1, AB 2 and AB 3. The primary outcome was the difference in the time to intubation (TTI) between patients with Mallampati score MP I-II (Group 1) and MP III-IV (Group 2). Secondary outcomes included first-pass success rate, fall in peripheral oxygen saturation to < 95%, total number of attempts and failure to intubate using the AB.

RESULTS

The mean TTI was not significantly different in Group 1 and Group 2 (71.02 (61.66) s vs. 101.35 (121.94) s respectively, P = 0.119). Desaturation during intubation was seen in 20 patients (15.1%). First pass success rate was achieved in 109 patients (82.6%). Twenty-one patients (15.9%) needed more than one attempt to intubate and the box had to be removed in 8 patients (6.1%) for facilitating intubation. The Mallampati score did not significantly influence either desaturation or first pass success rate.

CONCLUSION

There was a non-significant increasing TTI trend in patients with a higher MP score with the use of an aerosol box. However, this did not translate to a clinically significant difference in the overall intubation outcomes.

Comparison of Endotracheal Intubation Skills With Video Laryngoscopy and Direct Laryngoscopy in Providing Airway Patency in a Moving Ambulance

BACKGROUND

Early and successful management of the airway in the prehospital and hospital settings is critical in life-threatening situations.

OBJECTIVE

We aimed to perform endotracheal intubation (ETI) by direct laryngoscopy (DL) and video laryngoscopy (VL) on airway manikins on a moving track and to compare the properties of intubation attempts.

METHODS

Overall, 79 participants with no previous VL experience were given 4 h of ETI training with DL and VL using a standard airway manikin. ETI skill was tested inside a moving ambulance. The number of attempts until successful ETI, ETI attempt times, time needed to see the vocal cords, and the degree of convenience of both ETI methods were recorded.

RESULTS

Overall, 22 of 79 individuals were men; mean age was 30.3 ± 4.5 years. No difference was found in the comparison of the two methods (p = 0.708). Time needed to see the vocal cords for those who were successful in their first attempt were between 1 and 8 s in both methods. In the VL method, time needed to see the vocal cords (p = 0.001) and the intubation time (p < 0.001) in the first attempt were shorter than in the DL method. The VL method was easier (p < 0.001). The success rate was 97.5% in DL and 93.7% in VL.

CONCLUSIONS

The VL method is rapid and easier to see the vocal cords and perform successful ETI. Therefore, it might be preferred in out-of-hospital ETI applications.

Adding Flexible Instrumentation to a Curved Videolaryngoscope: A Novel Tool for Laryngeal Surgery

OBJECTIVES

Transoral surgery of the larynx with rigid instruments is not always possible. This may result in insufficient therapy or in an increased need for open surgery. For these patients, alternative surgical systems are needed. Here, we demonstrate a curved prototype for laryngeal surgery equipped with flexible instruments.

STUDY DESIGN

Pre-clinical user study in an ex vivo porcine laryngeal model.

METHODS

The prototype was built from established medical devices, namely a hyperangulated videolaryngoscope and modified flexible instruments as well as three-dimensional printed parts. Feasibility of laryngeal manipulation was evaluated in a user study (n = 19) with a porcine ex vivo laryngeal model. Using three different visualization technologies, the participants performed various fine motor skills tasks and rated the usability of the system on a 5-point Likert scale.

RESULTS

Exposure, accessibility, and manipulation of important laryngeal structures were always possible using the new prototype. The participants needed considerably less time (mean, 96.4 seconds ± 6.4 seconds vs. 111.5 seconds ± 4.5 seconds, P = .18), reported significantly better general impression (mean score 3.0 vs. 3.8, P = .041) and significantly lower user head and neck strain (2.6 vs. 1.7, P = .022) using a 40-inch television screen as compared to a standard videolaryngoscope monitor.

CONCLUSION

The results indicate that our curved prototype and large monitor visualization may provide a cost-effective minimally invasive alternative for difficult laryngeal exposure. Its special advantages include avoiding the need for a straight line of sight and a simple and cost-effective construction. The system could be further improved through advances in camera chip technology and smaller instruments. Laryngoscope, 131:E561-E568, 2021.

Comparison of the C-MAC video laryngoscope size 2 Macintosh blade with size 2 C-MAC D-Blade for laryngoscopy and endotracheal intubation in children with simulated cervical spine injury: A prospective randomized crossover study

Background and Aims:

CMAC video laryngoscope size 2 D-Blade has been recently introduced for management of pediatric difficult airway. Our primary outcome was to compare glottic view, intubation time, and ease of intubation with the size 2 Macintosh versus D-Blade of C-MAC video laryngoscope in simulated cervical injury in children.

Material and Methods:

This randomized crossover study was conducted in a tertiary care hospital of Northern India. Forty children of 4–14 years of age were enrolled in this study. After induction of anesthesia, video laryngoscopy was performed either with size 2 CMAC Macintosh (group M) or D-Blade (group D) with manual in-line stabilization. After removal of the first blade, second video laryngoscopy was performed with the alternative blade. Endotracheal intubation was done with the second laryngoscopy. Best glottic view, time for best glottic view, and difficulty in blade insertion were recorded during both the video laryngoscopies. During second video laryngoscopy, difficulty of tube insertion and time for intubation were noted.

Results:

The glottic view grade was significantly better in group D compared with the group M (P = 0.0002). Insertion of D-Blade was more difficult than Macintosh blade (P = 0.0007). There was no statistical difference in terms of time for best glottic view in group M and group D (13.40 ± 4.90 vs 13.62 ± 5.60 s) and endotracheal tube insertion time (24.80 ± 7.90 vs 27.90 ± 10.90 s), respectively. Number of intubation attempts was similar in both the groups.

Conclusions:

Size 2 D-Blade of C-MAC video laryngoscope provided a better glottic view in children with simulated cervical spine injury as compared with CMAC Macintosh blade. Success of intubation, intubation time, and ease of intubation were comparable with both the blades.

GlideScope versus D-blade for tracheal intubation in cervical spine patients: A randomised controlled trial

Background and Aims

Airway management in patients with cervical spine pathology is challenging. The aim of the study was to evaluate GlideScope (GVL) and D blade of C-MAC (CMAC-D) using manual inline axial stabilisation (MIAS) for tracheal intubation in patients with cervical spine injury/pathology.

Methods

This is a randomised, single-blind, hospital-based study. After obtaining informed consent, 54 patients with cervical spine pathology/injury were grouped into GVL group or CMAC-D group, (n = 27 each) based on computer-generated random number table. Preoperative airway difficulty score (ADS) was calculated. The primary outcome of the study was intubation difficulty score (IDS) and the secondary outcomes included total time taken to secure airway, failure to intubate, haemodynamic parameters and adverse events. Data was represented in the form of number (%) or mean and standard deviation and median and interquartile range as appropriate. Chi square test was used for analysing IDS.

Results

The mean ± SD of IDS of the CMAC-D and GVL groups were 0.04 ± 0.2 (0.04-0.11) and 0.19 ± 0.40 (0.03-0.34), respectively, (P value = 0.096). The number (%) of patients with IDS > 0 was 1 (3.7) in CMAC-D and 5 (18.5) in GVL group, (P value = 0.192). Demographic data, ADS, Cormack-Lehane grading, success rate, time of tracheal intubation, type of surgeries, haemodynamic parameters and post-operative complications were similar in both the groups.

Conclusion

Both GVL and CMAC-D with MIAS are equally efficacious in tracheal intubation in cervical spine injury/pathology patients without other difficult airway management criteria.

A randomized controlled trial comparing C Mac D Blade and Macintosh laryngoscope for nasotracheal intubation in patients undergoing surgeries for head and neck cancer

Purpose

Several devices are available to take care of difficult airway, but C-MAC D-Blade has scant evidence of its use in nasotracheal intubation in a difficult airway scenario.

Aims and Objectives

We compared the C-MAC D-Blade videolaryngoscope^™, and the standard Macintosh laryngoscope for nasal intubation in patients with difficult airways selected by El-Ganzouri risk index using parameters of time and attempts required for intubation, glottic view in terms of Cormack-Lehane grade, ease of intubation, success rate, use of accessory maneuvers, incidence of complications, and hemodynamic changes.

Methods

One hundred American Society of Anesthesiologists (ASA) I-III patients aged 20-70 years with EGRI score 1-≤7 scheduled for head and neck surgery requiring nasal intubation. ASA IV patients, patients with mouth opening <2.5 cm, patients difficult to mask ventilate, and patients with hyperkalemia and history of malignant hyperthermia were excluded from the study. Primary outcome was time taken to intubation, and secondary outcomes were a number of attempts, glottic view in terms of C/L grade, use of accessory maneuvers, success rate, incidence of trauma, ease of intubation, and hemodynamic changes before and after intubation.

Results

Time required for intubation was less (39.56 ± 15.65 s) in Group C than in Group M (50.34 ± 15.65 s). Cormack-Lehane Grade I and II view were more in C-MAC D-Blade group (P < 0.05). Success rate and ease of intubation were found to be more in C-MAC D-Blade group than in Macintosh group (P < 0.05). A number of attempts and incidence of complications such as trauma, bleeding, and failed intubation were greater in Macintosh group than in C-MAC D-Blade group. Hemodynamic changes were observed to be comparable in both the groups.

Conclusion

C-MAC D-Blade videolaryngoscope^™ is a better tool in anesthetic management of difficult airway for nasal intubation compared to conventional Macintosh laryngoscope.

Comparison of intubation success and glottic visualization using King Vision and C-MAC videolaryngoscopes in patients with cervical spine injuries with cervical immobilization: A randomized clinical trial

Background:

Glottic visualization can be difficult with cervical immobilization in patients with cervical spine injury. Indirect laryngoscopes may provide better glottic visualization in these groups of patients. Hence, we compared King Vision videolaryngoscope, C-MAC videolaryngoscope for endotracheal intubation in patients with proven/suspected cervical spine injury.

Methods:

After standard induction of anesthesia, 135 patients were randomized into three groups: group C (conventional C-MAC videolaryngoscope), group K (King Vision videolaryngoscope), and group D (D blade C-MAC videolaryngoscope). Cervical immobilization was maintained with Manual in line stabilization with anterior part of cervical collar removed. First pass intubation success, time for intubation, and glottic visualization (Cormack – Lehane grade and percentage of glottic opening) were noted. Intubation difficulty score (IDS) was used for grading difficulty of intubation. Five-point Likert scale was used for ease of insertion of laryngoscope.

Results:

First attempt success rate were 100% (45/45), 93.3% (42/45), and 95.6% (43/45) in patients using conventional C-MAC, King Vision, and D blade C-MAC videolaryngoscopes, respectively. Time for intubation in seconds was significantly faster with conventional C-MAC videolaryngoscope (23.3 ± 4.7) compared to D blade C-MAC videolaryngoscope (26.7 ± 7.1), whereas conventional C-MAC and King Vision were comparable (24.9 ± 7.2). Good grade glottic visualization was obtained with all the three videolaryngoscopes.

Conclusion:

All the videolaryngoscopes provided good glottic visualization and first attempt success rate. Conventional C-MAC insertion was significantly easier. We conclude that all the three videolaryngoscopes can be used effectively in patients with cervical spine injury.

Comparison of Macintosh, McCoy and C-MAC D-Blade video laryngoscope intubation by prehospital emergency health workers: a simulation study

The aim of the this study is to evaluate the intubation success rates of emergency medical technicians using a Macintosh laryngoscope (ML), McCoy laryngoscope (MCL), and C MAC D-Blade (CMDB) video laryngoscope on manikin models with immobilized cervical spines. This randomized crossover study included 40 EMTs with at least 2 years' active service in ambulances. All participating technicians completed intubations in three scenarios-a normal airway model, a rigid cervical collar model, and a manual in-line cervical stabilization model-with three different laryngoscopes. The scenario and laryngoscope model were determined randomly. We recorded the scenario, laryngoscope method, intubation time in seconds, tooth pressure, and intubation on a previously prepared study form. We performed Friedman tests to determine whether there is a significant change in the intubation success rate, duration of tracheal intubation, tooth pressure, and visual analog scale scores due to violations of parametric test assumptions. We performed the Wilcoxon test to determine the significance of pairwise differences for multiple comparisons. An overall 5 % type I error level was used to infer statistical significance. We considered a p value of less than 0.05 statistically significant. The CMDB and MCL success rates were significantly higher than the ML rates in all scenario models (p < 0.05). The CMDB intubation duration was significantly shorter when compared with ML and MCL in all models. CMDB and MCL may provide an easier, faster intubation by prehospital emergency health care workers in patients with immobilized cervical spines.