Performance of custom made videolaryngoscope for endotracheal intubation: A systematic review

Introduction Videolaryngoscope is regarded as the standard of care for airway management in well-resourced setups however the technology is largely inaccessible and costly in middle and low-income countries. An improvised and cost-effective form of customized videolaryngoscope was proposed and studied for patient care in underprivileged areas however there were no distinct conclusions on its performances. Method The study follows PRISMA guidelines for systematic review and the protocol in International Prospective Register for Systematic Reviews. The primary aim was to assess the first attempt success of customized videolaryngoscope for endotracheal intubation. The secondary objective was to evaluate the number of attempts, laryngoscopic view in terms of Cormack Lehane score and Percentage of glottic opening, use of external laryngeal maneuver and stylet and, the airway injuries after the endotracheal intubation. Result Five studies were analyzed for risk of bias using the National Institute of Health Quality Assessment Tool for cross-sectional studies. Most of the studies had a poor to a fair level of evidence with only one study with a good level of evidence. Certainty of evidence was “very low” for all eligible studies when graded using the Grading of Recommendation, Assessment, Development and Evaluation approach for systematic review. Conclusions The certainty of the evidence regarding performance of custom-made videolaryngoscope compared to conventional laryngoscope was very low and the study was performed in small numbers with fair to the poor risk of bias. It was difficult to establish and do further analysis regarding whether the customized form of videolaryngoscope will improve the first attempt success rate for tracheal intubation, reduce the number of attempts, improve the laryngoscopic view, require fewer external aids and reduce the incidences of airway injury with the given low-grade evidence. Some properly conducted randomised clinical trials will be required to further analyze the outcome and make the strong recommendations.

Comparison of RAMP and New Modified RAMP Positioning in Laryngoscopic View During Intubation in Patients with Morbid Obesity: A Randomized Clinical Trial

Background: The prevalence of obesity is increasing worldwide, and anesthesiologists are facing challenges in the airway management of such patients. Excessive adipose tissue influences pharyngeal spaces and affects the laryngoscopic grade. Standard ramp positioning is time-consuming and difficult to prepare, and requires expensive equipment. Objectives: The aim of this study was to compare the standard ramp position with the proposed low-cost and easily accessible modified ramp position in laryngoscopic view during the intubation of patients with morbid obesity. Methods: In this single-blind clinical trial, 84 patients candidate for bariatric surgery at Rasoul Akram Hospital in 2020 were assigned to the rapid airway management positioner (RAMP) (R) and new modified RAMP (MR) groups by the block randomization method. The laryngoscopic view of the glottis based on the Cormack-Lehane scale, ventilation quality, duration of intubation, intubation attempts, oxygen saturation at the end of intubation, and the need for backward, upward, rightward pressure (BURP) maneuver for successful intubation were recorded. Normal distribution tests and Mann-Whitney and Kruskal-Wallis tests were used to analyze the data. Results: The results showed no significant differences between the two groups regarding ventilation score, laryngoscopy grade, number of intubation attempts, duration of intubation, and the need for BURP maneuvers during intubation (P > 0.05). Conclusions: The two methods are not significantly different, and the new modified ramp position can be used with more ease and availability and less cost.

A Comparative Crossover Randomized Study of Miller and Macintosh Blade for Laryngoscopic View and Ease of Intubating Conditions in Adults

Background: Although several types of laryngoscope blades of different sizes and shapes are present, Miller (MIL) blade is the most preferable blade among paediatric population. However, there is dearth in the literature regarding the use of these blades in the adult population. This study aimed to compare the laryngoscopic view and ease of intubation using MIL and Macintosh (MAC) blade among adults. Methods: A total of 172 patients who were >18 years age, with ASA grades I and II, undergoing elective surgeries with general anaesthesia were included. Patients were distributed in two groups (MAC/MIL and MIL/MAC), where laryngoscopy was first done with MAC blade, followed by MIL blade in the MAC/MIL group and vice-versa in the MIL/MAC group. Grading of laryngoscopic views, number of attempts, ease of intubation and use of backward, upward, rightward pressure (BURP) were noted. R v 3.6.0 was used for statistical analysis and P values≤0.05 were considered as statistically significant. Results: MIL blade showed better laryngoscopic view compared to MAC blade (32.6% vs. 15.1%; P< 0.002). BURP application helped improve the laryngoscopic views with MAC blade. Intubation with MIL blade was easier with regards to ease of intubation and number of attempts 19 (P value<0.05). Conclusion: Glottis visualization is better with the MIL blade as compared to the MAC blade. Therefore, the MIL blade might be helpful in securing the airway among adult patients.

Preoperative rigid laryngoscopic examination and modified jaw thrust manoeuver during fibreoptic-assisted tracheal intubation for general anaesthesia

Preoperative laryngoscopic examination of the airway informs general anaesthesia management and planning. However, the same glottic opening view cannot always be obtained during direct laryngoscopy of anaesthetised patients. In this case report, a patient underwent preoperative rigid laryngoscopy due to medical history, and no problems were anticipated in performing tracheal intubation; however, the direct laryngoscopic view was a Grade 4 on the Cormack-Lehane Scale after anaesthesia induction. A jaw thrust manoeuvre to facilitate fibreoptic-assisted nasotracheal intubation was not feasible. In order to compensate, a modified method of jaw thrust was implemented, where both thumbs were placed on the floor of the patient’s mouth, leading to a successful result. Safe airway management should be implemented with proper planning based on a careful preoperative evaluation.

The influence of a Perspex intubation box on time to intubation: a simulation-based randomised crossover study

Background: Standard personal protective equipment guidelines are insufficient to prevent contamination of healthcare workers with droplet spread during the COVID-19 crisis. The added challenge of adequate aerosol protection has led to the development of an initial prototype intubation box. The primary objective was to determine the impact of an intubation box on the mean time to completion of intubation in a simulated airway. Secondary objectives included the best laryngoscopic view, the effect of intubator seniority and mode of laryngoscopy on intubation. Methods: This was a randomised crossover study of the influence of an intubation box on mean time to completion of intubation of an airway management part-task trainer. Senior anaesthesiology staff were assigned to two groups and recordings of their attempts at intubation were analysed by two independent observers. Results: The intubation box led to a significantly longer mean time to completion of intubation of 7.6 seconds (95% CI 3.1; 12.2; p = 0.001) with direct laryngoscopy and 9.2 seconds (95% CI 3.8; 14.7; p = 0.001) with videolaryngoscopy. It did not influence best glottic view. Conclusion: We found that the use of an intubation box significantly prolonged the time to completion of intubation, but the clinical significance of the effect size is uncertain.

C-MAC D-Blade vs Airtraq for Intubation with Manual Inline Axial Stabilisation- A Randomised Clinical Trial

Introduction: One of the most important skills in anaesthesia is securing the airway with an endotracheal tube. Difficult tracheal intubation however is considered one of the major contributors of anaesthesia related morbidity and mortality. Video laryngoscopy offers several advantages during endotracheal intubation. The view of the glottis provided by Videolaryngoscopes is better compared to the Macintosh laryngoscope in difficult airways which makes it more attractive for routine difficult airway intubations. Aim: To compare the time taken for intubation between two Videolaryngoscopes, namely C-MAC D-blade and Airtraq and to assess the quality of laryngoscopy view between the two groups. Materials and Methods: This was a randomised clinical trial conducted in 116 American Society of Anesthesiologists 1 (ASA1) and ASA2 patients undergoing elective surgeries in Pondicherry Institute of Medical Sciences. Patients are randomised into two groups, Group C-MAC D-blade and Group Airtraq by computer randomisation. Statistical analysis was performed using t-test, Repeated measures of ANOVA was used to find the significance from preinduction to 10 mins period for each group and Bonferoni’s correction for intergroup comparison. Results: The time taken for intubation was comparable in two study groups (Group C-MAC D-blade 41.88 secs) and (Group Airtraq -40.78 sec) with p-value of 0.734. Laryngoscopic view was not statistically significant with p-value of 0.083. Optimisation maneuvers were required in 63.8% in Group Airtraq on comparison with 44.8% in Group C-MAC D-blade. In both Group C-MAC D-blade and Group Airtraq, there was a significant rise in the heart rate and BP at 0 minute compared to preinduction. But after 5 minutes, the heart rate and BP were back to preinduction values. Conclusion: Both the Videolaryngoscopes, C-MAC D-blade and Airtraq performed equally, with respect to time taken for intubation and laryngoscopic view. However, External Laryngeal Manipulation (ELM) was required more in Group Airtraq and was statistically significant.

The “BURP” maneuver improves the glottic view during laryngoscopy but remains a difficult procedure

Objective We investigated the “BURP” maneuver’s effect on the association between difficult laryngoscopy and difficult intubation, and predictors of a difficult airway. Methods Adult patients who underwent general anesthesia and tracheal intubation from September 2016 to May 2018 were included. The “BURP” maneuver was performed when glottic exposure was classified as Cormack–Lehane grade 3 or 4, suggesting difficult laryngoscopy. The thyromental distance, modified Mallampati score, and interincisor distance were assessed before anesthesia. Results Among this study’s 2028 patients, the “BURP” maneuver decreased difficult laryngoscopies from 428 (21.1%) to 124 (6.1%) cases and increased the difficult intubation to difficult laryngoscopy ratio from 53/428 (12.4%) to 52/124 (41.9%). For laryngoscopies classified as difficult without the “BURP” maneuver, the area under the curve (AUC) of the thyromental distance, modified Mallampati score, and interincisor distance was 0.60, 0.57, and 0.66, respectively. In difficult laryngoscopies using the “BURP” maneuver, the AUC of the thyromental distance, modified Mallampati score, and interincisor distance was 0.71, 0.67, and 0.76, respectively. Conclusions The “BURP” maneuver improves the laryngoscopic view and assists in difficult laryngoscopies. Compared with difficult laryngoscopies without the “BURP” maneuver, those with the “BURP” maneuver are more closely associated with difficult intubations and are more predictable. Trial registration: www.chictr.org.cn identifier: ChiCTR-ROC- 16009050.