Video versus Direct Laryngoscopy for Urgent Intubation of Newborn Infants.

BACKGROUND: Repeated attempts at endotracheal intubation are associated with increased adverse events in neonates. When clinicians view the airway directly with a laryngoscope, fewer than half of first attempts are successful. The use of a video laryngoscope, which has a camera at the tip of the blade that displays a view of the airway on a screen, has been associated with a greater percentage of successful intubations on the first attempt than the use of direct laryngoscopy in adults and children. The effect of video laryngoscopy among neonates is uncertain. METHODS: In this single-center trial, we randomly assigned neonates of any gestational age who were undergoing intubation in the delivery room or neonatal intensive care unit (NICU) to the video-laryngoscopy group or the direct-laryngoscopy group. Randomization was stratified according to gestational age (<32 weeks or ≥32 weeks). The primary outcome was successful intubation on the first attempt, as determined by exhaled carbon dioxide detection. RESULTS: Data were analyzed for 214 of the 226 neonates who were enrolled in the trial, 63 (29%) of whom were intubated in the delivery room and 151 (71%) in the NICU. Successful intubation on the first attempt occurred in 79 of the 107 patients (74%; 95% confidence interval [CI], 66 to 82) in the video-laryngoscopy group and in 48 of the 107 patients (45%; 95% CI, 35 to 54) in the direct-laryngoscopy group (P<0.001). The median number of attempts to achieve successful intubation was 1 (95% CI, 1 to 1) in the video-laryngoscopy group and 2 (95% CI, 1 to 2) in the direct-laryngoscopy group. The median lowest oxygen saturation during intubation was 74% (95% CI, 65 to 78) in the video-laryngoscopy group and 68% (95% CI, 62 to 74) in the direct-laryngoscopy group; the lowest heart rate was 153 beats per minute (95% CI, 148 to 158) and 148 (95% CI, 140 to 156), respectively. CONCLUSIONS: Among neonates undergoing urgent endotracheal intubation, video laryngoscopy resulted in a greater number of successful intubations on the first attempt than direct laryngoscopy. (Funded by the National Maternity Hospital Foundation; VODE ClinicalTrials.gov number, NCT04994652.).

A prospective, pragmatic non-inferiority study of emergency intubation success with the single-use i-view versus standard reusable video laryngoscope.

INTRODUCTION: Video laryngoscope (VL) technology improves first-pass success. The novel i-view VL device is inexpensive and disposable. We sought to determine the first-pass intubation success with the i-view VL device versus the standard reusable VL systems in routine use at each site. METHODS: We performed a prospective, pragmatic study at two major emergency departments (EDs) when VL was used. We rotated i-view versus reusable VL as the preferred device of the month based on an a priori schedule. An investigator-initiated interim analysis was performed. Our primary outcome was a first-pass success with a non-inferiority margin of 10% based on the per-protocol analysis. RESULTS: There were 93 intubations using the reusable VL devices and 81 intubations using the i-view. Our study was stopped early due to futility in reaching our predetermined non-inferiority margin. Operator and patient characteristics were similar between the two groups. The first-pass success rate for the i-view group was 69.1% compared to 84.3% for the reusable VL group. A non-inferiority analysis indicated that the difference (-15.1%) and corresponding 90% confidence limits (-25.3% to -5.0%) did not fall within the predetermined 10% non-inferiority margin. CONCLUSIONS: The i-view device failed to meet our predetermined non-inferiority margin when compared to the reusable VL systems with the study stopping early due to futility. Significant crossover occurred at the discretion of the intubating operator during the i-view month.

Development of an Artificial Intelligence-Based Image Recognition System for Time-Sequence Analysis of Tracheal Intubation.

BACKGROUND: Total intubation time (TIT) is an objective indicator of tracheal intubation (TI) difficulties. However, large variations in TIT because of diverse initial and end targets make it difficult to compare studies. A video laryngoscope (VLS) can capture images during the TI process. By using artificial intelligence (AI) to detect airway structures, the start and end points can be freely selected, thus eliminating the inconsistencies. Further deconstructing the process and establishing time-sequence analysis may aid in gaining further understanding of the TI process. METHODS: We developed a time-sequencing system for analyzing TI performed using a #3 Macintosh VLS. This system was established and validated on 30 easy TIs performed by specialists and validated using TI videos performed by a postgraduate-year (PGY) physician. Thirty easy intubation videos were selected from a cohort approved by our institutional review board (B-ER-107-088), and 6 targets were labeled: the lip, epiglottis, laryngopharynx, glottic opening, tube tip, and a black line on the endotracheal tube. We used 887 captured images to develop an AI model trained using You Only Look Once, Version 3 (YOLOv3). Seven cut points were selected for phase division. Seven experts selected the cut points. The expert cut points were used to validate the AI-identified cut points and time-sequence data. After the removal of the tube tip and laryngopharynx images, the durations between 5 identical cut points and sequentially identified the durations of 4 intubation phases, as well as TIT. RESULTS: The average and total losses approached 0 within 150 cycles of model training for target identification. The identification rate for all cut points was 92.4% (194 of 210), which increased to 99.4% (179 of 180) after the removal of the tube tip target. The 4 phase durations and TIT calculated by the AI model and those from the expert exhibited strong Pearson correlation (phase I, r = 0.914; phase II, r = 0.868; phase III, r = 0.964; and phase IV, r = 0.949; TIT, r = 0.99; all P < .001). Similar findings were obtained for the PGY's observations (r > 0.95; P < .01). CONCLUSIONS: YOLOv3 is a powerful tool for analyzing images recorded by VLS. By using AI to detect the airway structures, the start and end points can be freely selected, resolving the heterogeneity resulting from the inconsistencies in the TIT cut points across studies. Time-sequence analysis involving the deconstruction of VLS-recorded TI images into several phases should be conducted in further TI research.

Hyperangulated vs. Macintosh videolaryngoscopy in adults with anticipated difficult airway management: a randomised controlled trial.

BACKGROUND: It is not certain whether the blade geometry of videolaryngoscopes, either a hyperangulated or Macintosh shape, affects glottic view, success rate and/or tracheal intubation time in patients with expected difficult airways. We hypothesised that using a hyperangulated videolaryngoscope blade would visualise a higher percentage of glottic opening compared with a Macintosh videolaryngoscope blade in patients with expected difficult airways. METHODS: We conducted an open-label, patient-blinded, randomised controlled trial in adult patients scheduled to undergo elective ear, nose and throat or oral and maxillofacial surgery, who were anticipated to have a difficult airway. All airway operators were consultant anaesthetists. Patients were allocated randomly to tracheal intubation with either hyperangulated (C-MAC D-BLADE™) or Macintosh videolaryngoscope blades (C-MAC™). The primary outcome was the percentage of glottic opening. First attempt success was designated a key secondary outcome. RESULTS: We assessed 2540 adults scheduled for elective head and neck surgery for eligibility and included 182 patients with expected difficult airways undergoing orotracheal intubation. The percentage of glottic opening visualised, expressed as median (IQR [range]), was 89 (69-99 [0-100])% with hyperangulated videolaryngoscope blades and 54 (9-90 [0-100])% with Macintosh videolaryngoscope blades (p < 0.001). First-line hyperangulated videolaryngoscopy failed in one patient and Macintosh videolaryngoscopy in 12 patients (13%, p = 0.002). First attempt success rate was 97% with hyperangulated videolaryngoscope blades and 67% with Macintosh videolaryngoscope blades (p < 0.001). CONCLUSIONS: Glottic view and first attempt success rate were superior with hyperangulated videolaryngoscope blades compared with Macintosh videolaryngoscope blades when used by experienced anaesthetists in patients with difficult airways.

A comparison of the McGrath videolaryngoscope with direct laryngoscopy for rapid sequence intubation in the operating theatre: a multicentre randomised controlled trial.

Aspiration of gastric contents is a recognised complication during all phases of anaesthesia. The risk of this event becomes more likely with repeated attempts at tracheal intubation. There is a lack of clinical data on the effectiveness of videolaryngoscopy relative to direct laryngoscopy rapid sequence intubation in the operating theatre. We hypothesised that the use of a videolaryngoscope during rapid sequence intubation would be associated with a higher first pass tracheal intubation success rate than conventional direct laryngoscopy. In this multicentre randomised controlled trial, 1000 adult patients requiring tracheal intubation for elective, urgent or emergency surgery were allocated randomly to airway management using a McGrath™ MAC videolaryngoscope (Medtronic, Minneapolis, MN, USA) or direct laryngoscopy. Both techniques used a Macintosh blade. First-pass tracheal intubation success was higher in patients allocated to the McGrath group (470/500, 94%) compared with those allocated to the direct laryngoscopy group (358/500, 71.6%), odds ratio (95%CI) 1.31 (1.23-1.39); p < 0.001. This advantage was observed in both trainees and consultants. Cormack and Lehane grade ≥ 3 view occurred less frequently in patients allocated to the McGrath group compared with those allocated to the direct laryngoscopy group (5/500, 1% vs. 94/500, 19%, respectively; p < 0.001). Tracheal intubation with a McGrath videolaryngoscope was associated with a lower rate of adverse events compared with direct laryngoscopy (13/500, 2.6% vs. 61/500, 12.2%, respectively; p < 0.001). These findings suggest that the McGrath videolaryngoscope is superior to a conventional direct laryngoscope for rapid sequence intubation in the operating theatre.

Comparison of the success rate of tracheal intubation between stylet and bougie with a hyperangulated videolaryngoscope: a randomised controlled trial.

Hyperangulated videolaryngoscopes are known to increase the success rate of tracheal intubation in the setting of difficult airway management when used with a stylet or bougie. However, there is controversy over which adjunct is more useful. This randomised study aimed to compare first attempt tracheal intubation success rate between a stylet and bougie when using a hyperangulated videolaryngoscope. We recruited patients aged > 20 years who were scheduled for elective surgery under general anaesthesia and required tracheal intubation. We only included patients with factors predicting difficult tracheal intubation based on pre-anaesthesia airway evaluation. Tracheal intubation was attempted using a Glidescope® with either a stylet or bougie as an adjunct according to group assignment. Primary outcome was the success rate of the first tracheal intubation attempt, and secondary outcomes were success of second and third attempts; tracheal intubation time; and occurrence of sore throat, dysphagia or hoarseness. A total of 166 patients were included. The success rate of the first tracheal intubation attempt was significantly higher in patients allocated to the bougie group compared with those allocated to the stylet group (81/83 (98%) vs. 73/83 (88%), respectively; p = 0.032). The number of patients who needed two attempts was significantly lower in those allocated to the bougie group compared with those allocated to the stylet group (1/83 (1%) vs. 9/83 (11%), respectively; p = 0.018). Each group had one patient (1%) where tracheal intubation was achieved after a third attempt. There was no significant difference in the occurrence of sore throat, dysphagia and hoarseness between the two groups. When difficult tracheal intubation is anticipated and a hyperangulated videolaryngoscope is used, the success rate of the first attempt is higher when a bougie is used compared with a stylet.

Efficacy of bougie first approach for endotracheal intubation with video laryngoscopy during continuous chest compression: a randomized crossover manikin trial.

BACKGROUND: Endotracheal intubation is challenging during cardiopulmonary resuscitation, and video laryngoscopy has showed benefits for this procedure. The aim of this study was to compare the effectiveness of various intubation approaches, including the bougie first, preloaded bougie, endotracheal tube (ETT) with stylet, and ETT without stylet, on first-attempt success using video laryngoscopy during chest compression. METHODS: This was a randomized crossover trial conducted in a general tertiary teaching hospital. We included anesthesia residents in postgraduate year one to three who passed the screening test. Each resident performed intubation with video laryngoscopy using the four approaches in a randomized sequence on an adult manikin during continuous chest compression. The primary outcome was the first-attempt success defined as starting ventilation within a one minute. RESULTS: A total of 260 endotracheal intubations conducted by 65 residents were randomized and analyzed with 65 procedures in each group. First-attempt success occurred in 64 (98.5%), 57 (87.7%), 56 (86.2%), and 46 (70.8%) intubations in the bougie-first, preloaded bougie, ETT with stylet, and ETT without stylet approaches, respectively. The bougie-first approach had a significantly higher possibility of first-attempt success than the preloaded bougie approach [risk ratio (RR) 8.00, 95% confidence interval (CI) 1.03 to 62.16, P = 0.047], the ETT with stylet approach (RR 9.00, 95% CI 1.17 to 69.02, P = 0.035), and the ETT without stylet approach (RR 19.00, 95% CI 2.62 to 137.79, P = 0.004) in the generalized estimating equation logistic model accounting for clustering of intubations operated by the same resident. In addition, the bougie first approach did not result in prolonged intubation or increased self-reported difficulty among the study participants. CONCLUSIONS: The bougie first approach with video laryngoscopy had the highest possibility of first-attempt success during chest compression. These results helped inform the intubation approach during CPR. However, further studies in an actual clinical environment are warranted to validate these findings. TRIAL REGISTRATION: Clinicaltrials.gov; identifier: NCT05689125; date: January 18, 2023.

Impact of Universal Use of the McGrath Videolaryngoscope as a Device for All Intubations in the Cardiac Operating Room. A Prospective Before-After VIDEOLAR-CAR Study.

OBJECTIVE: Tracheal intubation in cardiac surgery patients has a higher incidence of difficult laryngoscopic views compared with patients undergoing other types of surgery. The authors hypothesized that using the McGrath Mac videolaryngoscope as the first intubation option for cardiac surgery patients improves the percentage of patients with "easy intubation" compared with using a direct Macintosh laryngoscope. DESIGN: A prospective, observational, before-after study. SETTING: At a tertiary-care hospital. PARTICIPANTS: One thousand one hundred nine patients undergoing cardiac surgery. INTERVENTION: Consecutive patients undergoing cardiac surgery were intubated using, as the first option, a Macintosh laryngoscope (preinterventional phase) or a McGrath Mac videolaryngoscope (interventional phase). MEASUREMENTS AND MAIN RESULTS: The main objective was to assess whether the use of the McGrath videolaryngoscope, as the first intubation option, improves the percentage of patients with "easy intubation," defined as successful intubation on the first attempt, modified Cormack-Lehane grades of I or IIa, and the absence of the need for adjuvant airway devices. A total of 1,109 patients were included, 801 in the noninterventional phase and 308 in the interventional phase. The incidence of "easy intubation" was 93% in the interventional phase versus 78% in the noninterventional phase (p < 0.001). First-success-rate intubation was higher in the interventional phase (304/308; 98.7%) compared with the noninterventional phase (754/801, 94.1%; p = 0.005). Intubation in the interventional phase showed decreases in the incidence of difficult laryngoscopy (12/308 [3.9%] v 157/801 [19.6%]; p < 0.001), as well as moderate or difficult intubation (5/308 [1.6%] v 57/801 [7.1%]; p < 0.001). CONCLUSIONS: The use of the McGrath videolaryngoscope as the first intubation option for tracheal intubation in cardiac surgery improves the percentage of patients with "easy" intubation," increasing glottic view and first-success-rate intubation and decreasing the incidence of moderate or difficult intubation.

A prospective randomized comparative trial of pediatric C-MAC D-blade video laryngoscope with McCoy direct laryngoscope for intubation in children posted for elective surgical procedures under general anesthesia.

BACKGROUND: Pediatric airway management requires careful clinical evaluation and experienced execution due to anatomical, physiological, and developmental considerations. Video laryngoscopy in pediatric airways is a developing area of research, with recent data suggesting that video laryngoscopes are better than standard Macintosh blades. Specifically, there is a paucity of literature on the advantages of the C-MAC D-blade compared to the McCoy direct laryngoscope. METHODS: After Ethics Committee approval, 70 American Society of Anesthesiologists physical status 1 and 2 children aged 4-12 years scheduled for elective surgery under general anesthesia were recruited. Patients were randomly allocated to intubation using a C-MAC video laryngoscope size 2 D-blade (Group 1) and a McCoy laryngoscope size 2 blade (Group 2). The Intubation Difficulty Scale (IDS) for ease of intubation was the primary outcome, while Cormack-Lehane grades, duration of laryngoscopy and intubation, hemodynamic responses, and incidence of any airway complications were secondary outcomes. RESULTS: Both groups were comparable in terms of patient characteristics. The median (IQR) Intubation Difficulty Scale (IDS) score was better but was statistically nonsignificant with C-MAC (0 [0-0] vs. 0 [0-2], p = .055). The glottic views were superior (CL grade I in 32/35 vs. 23/35, p = .002), and the time to best glottic view (6 s [5-7] vs. 8.0 s [6-10], p = .006) was lesser in the C-MAC D-blade group while the total duration of intubation was comparable (20 s [16-22] vs. 18 s [15-22], p = .374). All the patients could be successfully intubated on the first attempt. None of the patients had any complications. CONCLUSION: The C-MAC video laryngoscope size 2 D-blade provided faster and better glottic visualization but similar intubation difficulty compared to McCoy size 2 laryngoscope in children. The shorter time to achieve glottic view demonstrated with the C-MAC failed to translate into a shorter total duration of intubation when compared to the McCoy laryngoscope attributable to a pronounced curvature of the D-blade.

Upper Aerodigestive Tract Endoscopy Combining Rigid Laryngoscopy and Flexible Endoscopy.

Upper Aerodigestive Tract Endoscopy (UATE) is recommended for initial examination of head and neck squamous cell carcinomas. Reducing delay of initial examination must be a challenge to manage head and neck cancers. We hereby describe the technic combining UATE and flexible endoscopy in a unique general anesthesia with overview of hypopharyngeal, larygeal, tracheal, esophageal, nasopharyngeal sub sites in a unique procedure with system of magnificense and to perform percutaneous gastrostomy during the same time before initiation of therapy.

Evaluation of a novel, low-cost, 3D printed video laryngoscope with borescope in anesthetized Beagle dogs.

OBJECTIVE: To develop and evaluate a low-cost three-dimensional (3D)-printed video laryngoscope (VLVET) for use with a commercial borescope. STUDY DESIGN: Instrument development and pilot study. ANIMALS: A total of six adult male Beagle dogs. METHODS: The VLVET consisted of a laryngoscope handle and a Miller-type blade, and a detachable camera holder that attached to various locations along the blade. The laryngoscope and camera holder were 3D-printed using black polylactic acid filament. Dogs were premedicated with intravenous (IV) medetomidine (15 µg kg-1) and anesthesia induced with IV alfaxalone (1.5 mg kg-1). The VLVET, combined with a borescope, was used for laryngeal visualization and intubation. Performance was evaluated by comparing direct and video-assisted views in sternal recumbency. The borescope camera was sequentially positioned at 2, 4, 6, 8 and 10 cm from the blade tip (distanceLARYNX-CAM), which was placed on the epiglottis during intubation or laryngoscopy. At the 10 cm distanceLARYNX-CAM, laryngeal visualization was sequentially scored at inter-incisor gaps of 10, 8, 6, 4 and 2 cm. Laryngeal visualization scores (0-3 range, with 0 = obstructed and 3 = unobstructed views) were statistically analyzed using the Friedman's test. RESULTS: Under direct visualization, the 2 cm distanceLARYNX-CAM had a significantly lower score compared with all other distanceLARYNX-CAM (all p = 0.014) because the view was obstructed by the camera holder and borescope camera. With both direct and camera-assisted views, visualization scores were higher at inter-incisor gaps ≥ 4 cm compared with 2 cm (all p < 0.05). CONCLUSIONS AND CLINICAL RELEVANCE: During laryngoscopy and intubation, the VLVET and borescope facilitated both direct and video laryngoscopy at distanceLARYNX-CAM in Beagle dogs when inter-incisor gaps were ≥ 4 cm.

A Comparison of the Effectiveness of the McCoy Laryngoscope and the C-MAC D-Blade Video Laryngoscope in Obese Patients.

Background and Objective: Obesity is associated with difficult or failed intubation attempts, making general anesthesia challenging for anesthesiologists to perform. The purpose of this study was to evaluate and compare the efficacy of a McCoy laryngoscope and a C-MAC D-blade video laryngoscope for intubation in obese patients with a body mass index (BMI) ≥ 35 kg/m2. Methods: In total, 104 patients were randomly assigned to be intubated with a McCoy (McCoy group) or C-MAC D-blade video laryngoscope (C-MAC group). The primary outcome was intubation time. The secondary outcomes were vocal cord exposure time, vocal cord passage time, proportion of successful intubation, mask ventilation scale, intubation difficulty scale (IDS), percentage of glottis opening (POGO) score, and hemodynamic variables. Results: Although the intubation time did not significantly differ, the C-MAC group showed shorter vocal cord exposure times and a higher rate of successful vocal cord exposure within 5 s. The IDS value was significantly lower in the C-MAC group than in the McCoy group. The proportion of patients who required an increase in lifting force during laryngoscopy was higher in the McCoy group than in the C-MAC group, which may explain the difference in MAP between the groups. Conclusions: Both the McCoy laryngoscope and the C-MAC D-blade video laryngoscope were useful during the intubation of obese patients. The C-MAC D-blade video laryngoscope might be more useful for obese patients in terms of hemodynamic stability.

COMBINED USE OF VIDEOLARYNGOSCOPE AND BONFILS INTUBATION ENDOSCOPE AS RESCUE OPTION FOR DIFFICULT AIRWAY MANAGEMENT: A CASE REPORT.

Difficult airway management poses a great challenge for clinicians, especially if it is unanticipated. Numerous guidelines and a wide array of devices constitute the anesthesiologist's armamentarium for managing the airway. When the use of individual devices fails, the use of combination techniques is advised. We present a case of difficult intubation in a 50-year-old male patient scheduled for aortic valve replacement. He had no prior history of difficult airway management, and no abnormalities were detected on preoperative airway assessment. Body mass index was 29 kg/m2. After the separate use of direct laryngoscopy, videolaryngoscopy and a BONFILS intubation endoscope (BIE) had failed, we resorted to a combination technique, combining videolaryngoscopy and BIE. While the videolaryngoscope provided the space needed for BIE and visual guidance through copious secretions, the BIE served as a stylet for endotracheal tube guidance, leading to successful intubation. Since the technique requires costly equipment, experience in handling it and at least two operators, it is more appropriate as a rescue measure than an elective procedure. Given the potentially disastrous outcomes of failed intubation, mastering advanced airway management techniques remains of vital importance, and the combination technique is one of them.

Airway devices for awake tracheal intubation in adults: a systematic review and network meta-analysis.

BACKGROUND: Awake tracheal intubation is commonly performed with flexible bronchoscopes, but the emerging role of alternative airway devices, such as videolaryngoscopes, direct laryngoscopes, and optical stylets, has been recognised. METHODS: CENTRAL, CINAHL, EMBASE, MEDLINE, and Web of Science were searched for RCTs that compared flexible bronchoscopes, direct laryngoscopes, optical stylets and channelled or unchannelled videolaryngoscopes in adult patients having awake tracheal intubation were included. The co-primary outcomes were first-pass success rate and time to tracheal intubation. Continuous outcomes were extracted as mean and standard deviation, and dichotomous outcomes were converted to overall numbers of incidence. Frequentist network meta-analysis was conducted, and network plots and network league tables were produced. RESULTS: Twelve RCTs were included, none of which evaluated direct laryngoscopes. The first-pass success rate was not different between flexible bronchoscopes, optical stylets, and channelled and unchannelled videolaryngoscopes, with the quality of evidence rated as moderate in view of imprecision. Optical stylets, followed by unchannelled videolaryngoscopes and then felxible bronchoscopes resulted in the shortest time to tracheal intubation, with the quality of evidence rated as high. No differences were shown between the airway devices with respect to the incidence of oesophageal intubation, change of airway technique, oxygen desaturation, airway bleeding, or the rate of hoarseness and sore throat. CONCLUSIONS: Flexible bronchoscopes, optical stylets, and channelled and unchannelled videolaryngoscopes were clinically comparable airway devices in the setting of awake trachela intubation and the time to tracheal intubation was shortest with optical stylets and longest with flexible bronchoscopes.

A comparison of videolaryngoscopy using standard blades or non-standard blades in children in the Paediatric Difficult Intubation Registry.

BACKGROUND: The design of a videolaryngoscope blade may affect its efficacy. We classified videolaryngoscope blades as standard and non-standard shapes to compare their efficacy performing tracheal intubation in children enrolled in the Paediatric Difficult Intubation Registry. METHODS: Cases entered in the Registry from March 2017 to January 2020 were analysed. We compared the success rates of initial and eventual tracheal intubation, complications, and technical difficulties between the two groups and by weight stratification. RESULTS: Videolaryngoscopy was used in 1313 patients. Standard and non-standard blades were used in 529 and 740 patients, respectively. Both types were used in 44 patients. In children weighing <5 kg, standard blades had significantly greater success than non-standard blades at initial (51% vs 26%, P=0.002) and eventual (81% vs 58%, P=0.002) attempts at tracheal intubation. In multivariable logistic regression analysis, standard blades had 3-fold greater odds of success at initial tracheal intubations compared with non-standard blades (adjusted odds ratio 3.0, 95% confidence interval): 1.32-6.86, P=0.0009). Standard blades had 2.6-fold greater odds of success at eventual tracheal intubation compared with non-standard blades in children weighing <5 kg (adjusted odds ratio 2.6, 95% confidence interval: 1.08-6.25, P=0.033). There was no significant difference found in children weighing ≥5 kg. CONCLUSIONS: In infants weighing <5 kg, videolaryngoscopy with standard blades was associated with a significantly greater success rate than videolaryngoscopy with non-standard blades. Videolaryngoscopy with a standard blade is a sensible choice for tracheal intubation in children who weigh <5 kg.

Bayesian predictive probabilities: a good way to monitor clinical trials.

BACKGROUND: Bayesian methods, with the predictive probability (PredP), allow multiple interim analyses with interim posterior probability (PostP) computation, without the need to correct for multiple looks at the data. The objective of this paper was to illustrate the use of PredP by simulating a sequential analysis of a clinical trial. METHODS: We used data from the Laryngobloc trial that planned to include 480 patients to demonstrate the equivalence of success between a laryngoscopy performed with the Laryngobloc® device and a control device. A crossover Bayesian design was used. The success rates of the two laryngoscopy devices were compared. Interim analyses, computed from random numbers of subjects, were simulated. RESULTS: The PostP of equivalence rapidly reached the predefined bound of 0.95. The PredP computed with an equivalence margin of 10% reached the efficacy bound between 352 and 409 of the 480 included patients. If a frequentist analysis had been made on the basis of 217 out of 480 subjects, the study would have been prematurely stopped for equivalence. The PredP indicated that this result was nonetheless unstable and that the equivalence was, thus far, not guaranteed. CONCLUSIONS: Based on these interim analyses, we can conclude with a sufficiently high probability that the equivalence would have been met on the primary outcome before the predetermined end of this particular trial. If a Bayesian approach using PredP had been used, it would have allowed an early termination of the trial by reducing the calculated sample size by 15-20%.

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).

Macintosh Videolaryngoscope for Intubation in the Operating Room: A Comparative Quality Improvement Project.

BACKGROUND: "Macintosh"-videolaryngoscopes (VLs) are VLs that allow both direct and indirect laryngoscopy for intubation. We describe the decision-making and implementation-processes that our hospital used regarding the choice of device. We compared the performances of 4 Macintosh-VLs both in direct and indirect laryngoscopy. METHODS: A quality-improvement-project for airway management aiming at implementing Macintosh-VL for all intubation procedures performed in the operating room, involving 4 Macintosh-VLs (McGrath-Mac, C-MAC-S, C-MAC-S-Pocket-Monitor [PM], and APA). Three consecutive steps were described: (1) direct laryngoscopy with Macintosh-VL, (2) indirect laryngoscopy with Macintosh-VL (intubation attempt with Macintosh-style blade in case of Cormack I or II), (3) intubation attempt with hyperangulated blade in case of Cormack III/IV or failure of Macintosh-style blade. The main end point was the need to move to step III and use a hyperangulated blade. A mixed-effects multivariable logistic regression analysis was performed to compare devices on the main end point while considering site as a random effect. Comparison of means was performed using analysis of variance and Tukey's test for multiple comparisons (number of laryngoscopy attempts, numeric rate scale [NRS] difficulty of intubation and NRS user-friendliness). Comparison of percentages was performed using a χ2 test for the need to move to step III and a Kruskal-Wallis test for the quality of image (bad, passable, good, very good, excellent). A P value ≤.008 was considered statistically significant. RESULTS: From May to September 2017, 589 patients were included. Using the McGrath-Mac (22/180 [12%]) was associated with less use of hyperangulated blade than using the C-MAC-S (39/132 [30%], odds ratio [OR] [99.2% confidence interval {CI}] 0.34 [0.16-0.77], P = .0005), the APA (35/138 [25%], OR [99.2% CI] 0.42 [0.19-0.93]; P = .004), but not the C-MAC-S-PM (29/139 [21%], OR [99.2% CI] 0.53 [0.23-1.2]; P = .04).Overall, the number of intubation attempts was significantly lower using the McGrath Mac than the C-MAC-S or the C-MAC-S-PMVLs. Subjective appreciation of intubation difficulty and user-friendliness of the devices showed respectively lower and higher NRS scores for the McGrath-Mac compared to the other devices, whereas subjective assessment of image quality showed higher quality for the C-MAC-S and C-MAC-S-PM compared to the APA or McGrath-Mac. CONCLUSIONS: Among 4 single-use Macintosh-VLs, glottic visualization in direct and indirect laryngoscopy with the Macintosh-style blade was significantly improved with the McGrath-Mac compared to other Macintosh-VLs, leading to a less frequent need to resort to the hyperangulated blade and reduced overall number of intubation attempts.

Effect of Paratracheal Pressure on the Glottic View During Direct Laryngoscopy: A Randomized Double-Blind, Noninferiority Trial.

BACKGROUND: Cricoid pressure has been used as a component of the rapid sequence induction and intubation technique. However, concerns have been raised regarding the effectiveness and safety of cricoid pressure. Paratracheal pressure, a potential alternative to cricoid pressure to prevent regurgitation of gastric contents or aspiration, has been studied to be more effective to cricoid pressure in preventing gastric insufflation during positive pressure ventilation. However, to adopt paratracheal compression into our practice, adverse effects including its effect on the glottic view during direct laryngoscopy should be studied. We conducted a randomized, double-blind, noninferiority trial comparing paratracheal and cricoid pressures for any adverse effects on the view during direct laryngoscopy, together with other secondary outcome measures. METHODS: In total, 140 adult patients undergoing general anesthesia randomly received paratracheal pressure (paratracheal group) or cricoid pressure (cricoid group) during anesthesia induction. The primary end point was the incidence of deteriorated laryngoscopic view, evaluated by modified Cormack-Lehane grade with a predefined noninferiority margin of 15%. Secondary end points included percentage of glottic opening score, ease of mask ventilation, change in ventilation volume and peak inspiratory pressure during mechanical mask ventilation, ease of tracheal intubation, and resistance encountered while advancing the tube into the glottis. The position of the esophagus was assessed by ultrasound in both groups to determine whether pressure applied to the respective area would be likely to result in esophageal compression. All secondary outcomes were tested for superiority, except percentage of glottic opening score, which was tested for noninferiority. RESULTS: Paratracheal pressure was noninferior to cricoid pressure regarding the incidence of deterioration of modified Cormack-Lehane grade (0% vs 2.9%; absolute risk difference, -2.9%; 95% confidence interval, -9.9 to 2.6, P <.0001). Mask ventilation, measured on an ordinal scale, was found to be easier (ie, more likely to have a lower score) with paratracheal pressure than with cricoid pressure (OR, 0.41; 95% confidence interval, 0.21-0.79; P = .008). The increase in peak inspiratory pressure was significantly less in the paratracheal group than in the cricoid group during mechanical mask ventilation (median [min, max], 0 [-1, 1] vs 0 [-1, 23]; P = .001). The differences in other secondary outcomes were nonsignificant between the groups. The anatomical position of the esophagus was more suitable for compression in the paratracheal region, compared to the cricoid cartilage region. CONCLUSIONS: Paratracheal pressure was noninferior to cricoid pressure with respect to the effect on glottic view during direct laryngoscopy.

McGRATH MAC video laryngoscope assistance during transesophageal echocardiography may reduce the risk of complications: a manikin study.

BACKGROUND: Although transesophageal echocardiography (TEE) is considered a relatively safe diagnostic monitoring method, blind probe insertion is associated with pharyngeal trauma. Through visual observation of the esophageal inlet with the McGRATH video laryngoscope, it may be possible to insert the TEE probe at an appropriate angle and prevent pharyngeal trauma. We conducted a manikin study to investigate whether the use of the McGRATH video laryngoscope for TEE probe insertion reduced the pressure on the posterior pharyngeal wall. METHODS: Twenty-seven junior (inexperienced group) and 10 senior (experienced group) anesthesiologists participated in this study. The TEE probe was inserted into an airway manikin in a blind fashion (blind group) or under visualization with the McGRATH (McGRATH group) video laryngoscope (three times each). A sealed bag filled with normal saline was placed on the back of the posterior pharyngeal wall of the manikin and connected to a patient monitoring system via a pressure transducer. We measured the internal bag pressure and approximated this value to the pressure on the posterior pharyngeal wall. RESULTS: The pressure on the posterior pharyngeal wall was significantly lower in the McGRATH group than in the blind group (p < 0.001) and was significantly reduced when the McGRATH was employed in both the inexperienced (p < 0.001) and experienced (p < 0.001) groups. CONCLUSIONS: These findings suggest that TEE probe insertion under the assistance of the McGRATH video laryngoscope can reduce the pressure on the posterior pharyngeal wall, regardless of the clinician's experience, and may inform clinical practice with the potential to reduce probe insertion-associated complication rates.