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.

Comparison of Force Distribution during Laryngoscopy with the C-MAC D-BLADE and Macintosh-Style Blades: A Randomised Controlled Clinical Trial.

Background: The geometry of a laryngoscope's blade determines the forces acting on the pharyngeal structures to a relevant degree. Knowledge about the force distribution along the blade may prospectively allow for the development of less traumatic blades. Therefore, we examined the forces along the blades experienced during laryngoscopy with the C-MAC D-BLADE and blades of the Macintosh style. We hypothesised that lower peak forces are applied to the patient's pharyngeal tissue during videolaryngoscopy with a C-MAC D-BLADE compared to videolaryngoscopy with a C-MAC Macintosh-style blade and direct laryngoscopy with a Macintosh-style blade. Beyond that, we assumed that the distribution of forces along the blade differs depending on the respective blade's geometry. Methods: After ethical approval, videolaryngoscopy with the D-BLADE or the Macintosh blade, or direct laryngoscopy with the Macintosh blade (all KARL STORZ, Tuttlingen, Germany), was performed on 164 randomly assigned patients. Forces were measured at six positions along each blade and compared with regard to mean force, peak force and spatial distribution. Furthermore, the duration of the laryngoscopy was measured. Results: Mean forces (all p < 0.011) and peak forces at each sensor position (all p < 0.019) were the lowest with the D-BLADE, whereas there were no differences between videolaryngoscopy and direct laryngoscopy with the Macintosh blades (all p > 0.128). With the D-BLADE, the forces were highest at the blade's tip. In contrast, the forces were more evenly distributed along the Macintosh blades. Videolaryngoscopy took the longest with the D-BLADE (p = 0.007). Conclusions: Laryngoscopy with the D-BLADE resulted in significantly lower forces acting on pharyngeal and laryngeal tissue compared to Macintosh-style blades. Interestingly, with the Macintosh blades, we found no advantage for videolaryngoscopy in terms of force application.

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.

Using a Disposable Flexible Fiberoptic Scope as a Bougie for Difficult Intubation.

In this case report, we describe two difficult intubations in which an endotracheal tube was threaded over a fiberoptic bronchoscope that was acting as a bougie. Our patients initially presented with limited neck extension, narrow mouth opening, and restricted view of the glottic region. A fiberoptic bronchoscope was guided through while the patient was oxygenated through a laryngeal mask. After the scope provided an unrestricted view of the vocal cords, the digital module was removed by cutting the fiberoptic thread, and an endotracheal tube was passed through. After proper confirmation of the endotracheal tube position, the intubation was deemed successful and thereby, we share our experience with the novel technique. This technique may potentially improve critical patient outcomes whether in trauma or an unexpectedly difficult intubation.

Nasotracheal intubation in pediatrics: a narrative review.

Nasotracheal intubation (NTI) plays an important role in pediatric airway management, offering advantages in specific situations, such as oral and maxillofacial surgery and situations requiring stable tube positioning. However, compared to adults, NTI in children presents unique challenges owing to anatomical differences and limited space. This limited space, in combination with a large tongue and short mandible, along with large tonsils and adenoids, can complicate intubation. Owing to the short tracheal length in pediatric patients, it is crucial to place the tube at the correct depth to prevent it from being displaced due to neck movements, and causing injury to the glottis. The equipment used for NTI includes different tube types, direct laryngoscopy vs. video laryngoscopy, and fiberoptic bronchoscopy. Considering pediatric anatomy, the advantages of video laryngoscopy have been questioned. Studies comparing different techniques have provided insights into their efficacy. Determining the appropriate size and depth of nasotracheal tubes for pediatric patients remains a challenge. Various formulas based on age, weight, and height have been explored, including the recommendation of depth-mark-based NTI. This review provides a comprehensive overview of NTI in pediatric patients, including the relevant anatomy, equipment, clinical judgment, and possible complications.

The utilization of video laryngoscopy in nasotracheal intubation for oral and maxillofacial surgical procedures: a narrative review.

The video laryngoscope is a novel instrument for intubation that enables indirect visualization of the upper airway. It is recognized for its ability to enhance Cormack-Lehane grades in the management of difficult airways. Notably, video laryngoscopy is associated with equal or higher rates of intubation success within a shorter time frame than direct laryngoscopy. Video laryngoscopy facilitates faster and easier visualization of the glottis and reduces the need for Magill forceps, thereby shortening the intubation time. Despite the advanced glottic visualization afforded by video laryngoscopy, nasotracheal tube insertion and advancement occasionally fail. This is particularly evident during nasotracheal intubation, where oropharyngeal blood or secretions may obstruct the visual field on the monitor, thereby complicating video laryngoscopy. Moreover, the use of Magill forceps is markedly challenging or nearly unfeasible in this context, especially in pediatric cases. Furthermore, the substantial blade size of video laryngoscopes may restrict their applicability in individuals with limited oral apertures. This study aimed to review the literature on video laryngoscopy, discuss its clinical role in nasotracheal intubation, and address the challenges that anesthesiologists may encounter during the intubation process.

The influence of clinical experience on reliable evaluation of pharyngeal and laryngeal lesions: comparison of high-definition laryngoscopy using narrow band imaging with fibre-optic laryngoscopy.

BACKGROUND: Fibre-optic laryngoscopy is still widely used in daily clinical practice; however, high-definition laryngoscopy using narrow band imaging could be more reliable in characterising pharyngeal and laryngeal lesions. METHODS: Endoscopic videos were assessed in a tertiary referral hospital by 12 observers with different levels of clinical experience. Thirty pairs of high-definition laryngoscopy with narrow band imaging and fibre-optic laryngoscopy videos were judged twice, with an interval of two to four weeks, in a random order. Inter- and intra-observer reliability, sensitivity and specificity were calculated in terms of detecting a malignant lesion and a specific histological entity, for beginners, trained observers and experts. RESULTS: Using high-definition laryngoscopy with narrow band imaging, inter-observer reliability for detecting malignant lesions increased from moderate to substantial in trained observers and experts (high-definition laryngoscopy with narrow band imaging κ = 0.66 and κ = 0.77 vs fibre-optic laryngoscopy κ = 0.51 and κ = 0.56, for trained observers and experts respectively) and sensitivity increased by 16 per cent. CONCLUSION: Inter-observer reliability increased with the level of clinical experience, especially when using high-definition laryngoscopy with narrow band imaging.

Is ultraviolet light disinfection fit to be the future standard for the disinfection of flexible endoscopes without a working channel?

OBJECTIVE: To investigate colony-forming unit (CFU) reduction on contaminated flexible endoscopes (FEs) without a working channel after UV-C light disinfection, compared to the current disinfection method with the endoscope washer disinfector (EWD). DESIGN, SETTING AND PARTICIPANTS: After pharyngolaryngoscopy, a manual pre-cleaning with tap water was performed. A culture was then collected by rolling the distal 8-10 cm of the FE over an Agar plate. The FE was disinfected using the D60 (60-s disinfection process with UV-C light) or the EWD (gold standard reprocessing process with water and chemicals). Another culture was then taken. After incubation, a CFU count was performed. RESULTS: A total of 200 FEs without a working channel were divided equally between the two disinfection groups. After clinical use and manual pre-cleaning, 84 of the 100 (84.0%) (UV-C light group) and 79 of the 100 (79.0%) (EWD) FEs were contaminated with at least 1 CFU. FEs that showed no contamination after use were excluded from further analysis. After disinfection with UV-C light, 72 (85.7%) FEs showed no contamination (i.e., 0 CFUs) versus 66 (83.5%) FEs after reprocessing with the EWD. CONCLUSION: There is no difference in CFUs reduction on contaminated FEs without a working channel between UV-C light disinfection and the current gold standard, the EWD.

Hyperangulated blades or direct epiglottis lifting to optimize glottis visualization in difficult Macintosh videolaryngoscopy: a non-inferiority analysis of a prospective observational study.

Purpose: It is unknown if direct epiglottis lifting or conversion to hyperangulated videolaryngoscopes, or even direct epiglottis lifting with hyperangulated videolaryngoscopes, may optimize glottis visualization in situations where Macintosh videolaryngoscopy turns out to be more difficult than expected. This study aims to determine if the percentage of glottic opening (POGO) improvement achieved by direct epiglottis lifting is non-inferior to the one accomplished by a conversion to hyperangulated videolaryngoscopy in these situations. Methods: One or more optimization techniques were applied in 129 difficult Macintosh videolaryngoscopy cases in this secondary analysis of a prospective observational study. Stored videos were reviewed by at least three independent observers who assessed the POGO and six glottis view grades. A linear mixed regression and a linear regression model were fitted. Estimated marginal means were used to analyze differences between optimization maneuvers. Results: In this study, 163 optimization maneuvers (77 direct epiglottis lifting, 57 hyperangulated videolaryngoscopy and 29 direct epiglottis lifting with a hyperangulated videolaryngoscope) were applied exclusively or sequentially. Vocal cords were not visible in 91.5% of the cases with Macintosh videolaryngoscopy, 24.7% with direct epiglottis lifting, 36.8% with hyperangulated videolaryngoscopy and 0% with direct lifting with a hyperangulated videolaryngoscope. Conversion to direct epiglottis lifting improved POGO (mean + 49.7%; 95% confidence interval [CI] 41.4 to 58.0; p < 0.001) and glottis view (mean + 2.2 grades; 95% CI 1.9 to 2.5; p < 0.001). Conversion to hyperangulated videolaryngoscopy improved POGO (mean + 43.7%; 95% CI 34.1 to 53.3; p < 0.001) and glottis view (mean + 1.9 grades; 95% CI 1.6 to 2.2; p < 0.001). The difference in POGO improvement between conversion to direct epiglottis lifting and conversion to hyperangulated videolaryngoscopy is: mean 6.0%; 95% CI -6.5-18.5%; hence non-inferiority was confirmed. Conclusion: When Macintosh videolaryngoscopy turned out to be difficult, glottis exposure with direct epiglottis lifting was non-inferior to the one gathered by conversion to hyperangulated videolaryngoscopy. A combination of both maneuvers yields the best result. Clinical trial registration: ClinicalTrials.gov, NCT03950934.

Advancements in additive manufacturing for video laryngoscopes: a comprehensive scoping and technological review.

The global healthcare crisis with the COVID-19 pandemic has placed a significant overwhelming demand for intubation procedures and the need for reliable and accessible video laryngoscopes. The purpose of this scoping and technological review is to provide a comprehensive overview of the current state of the art, covering the period from 2007 to 2022, pertaining to the manufacturing process, characteristics, and validation of video laryngoscopes produced using additive manufacturing techniques. Following the guidelines outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR), an exhaustive search was conducted across nine prominent databases (PubMed, Web of Science, Scopus, Cochrane, Prospero, Scielo, Embase, Lilacs, Virtual Health Libraries-VHL) and four patent databases (EPO/ESPACENET, WIPO/PATENTSCOPE, National Institute of Industrial Property (INPI), Google Patents). The main materials utilized for the impression, as well as the physical characteristics of the device are introduced at first. Crucial aspects to facilitate proper visualization of the anatomical structures during endotracheal intubation as the optimal angulation of the blade, the mechanical resistance of the device, traction force on the jaw, intubation time, and the experimental methods employed to validate its performance were reviewed in terms of their recent advances.

Comparative evaluation of C-MAC and McGrath MAC videolaryngoscopes with Macintosh direct laryngoscope for endotracheal intubation in adult patients undergoing elective surgeries.

Background and Aims: Videolaryngoscopes have an undisputed role in difficult airway management, but their role in routine intubation scenarios remains underappreciated. McGrath MAC is a lightweight laryngoscope with a disposable blade. It remains to be proven if it performs as efficiently as the reusable videolaryngoscopes like C-MAC and whether it has an advantage over standard Macintosh laryngoscope in predicted normal airways. Material and Methods: We recruited 180 adult patients and randomly divided them into three groups for intubation with either Macintosh laryngoscope (Group-A), C-MAC (Group-B), and McGrath (Group-C). The primary objective was to compare the first attempt success rate. Secondary objectives included Cormack-Lehane (CL) grades, laryngoscopy time, intubation time, ease of intubation, need for optimization manoeuver, and the number of passes to place the endotracheal tube. Results: The two videolaryngoscopes provided a superior first attempt success rate as compared to Macintosh laryngoscope (P = 0.027). The CL grade-I was 100% in group B, 41.7% in group-A and 90% in group-C (B vs C; P = 0.037). Laryngoscopy time was 9.9 ± 2.5 s, 12.6 ± 0.8 s, and 13.1 ± 0.8 s for groups A, B, and C, respectively (B vs C; P = 0.001). Intubation time was 24.4 ± 12 s, 28.3 ± 1.9 s, and 37.3 ± 5.8 s for groups A, B, and C, respectively (P < 0.0001). The number of tube passes was highest in group C. Conclusion: Videolaryngoscopes provided a superior glottic view and resulted in a superior first attempt success rate as compared to Macintosh laryngoscope. When comparing the two videolaryngoscopes, C-MAC resulted in better intubation characteristics (shorter intubation time, better glottic views, and higher first-attempt success rates) and should be preferred over McGrath for intubation in adult patients with normal airways.

Prevention of contamination after endotracheal intubation using a dedicated sleeve.

Background: Contamination of work surfaces by used laryngoscopes after endotracheal intubation is a serious infection control concern but no strategies are available to address it. We assessed if contamination of the surfaces after endotracheal intubation would be reduced when providers used a dedicated, self-erected, disposable plastic sleeve (BladePouch) to store the used laryngoscope as compared to using single gloves or double gloves and sheathing the laryngoscope with the outer gloves. Methods: Twenty participants were recruited including attending physicians, trainees and allied health care professionals. They performed endotracheal intubation on a mannequin with oral cavity coated with a dye and stored the used laryngoscope blade using single gloves, double gloves or BladePouch. Each participant used both direct and video laryngoscopes. Following intubation, dye contamination of gloves, gown and work surface was evaluated. Results: There was no difference in the contamination of gloves or gowns between the single gloves, double gloves or BladePouch groups. However, work surface contamination was significantly reduced when using BladePouch compared to single or double gloves (13% vs. 100% vs. 80% respectively, P<0.001). The odds of work surface contamination were significantly lower with BladePouch vs. single or double gloves, even when adjusted for intubation device, role and experience of participants with an adjusted odds ratio of 0.0054 (95% confidence interval: 0.0009-0.0314), P<0.001. Conclusions: In conjunction with standard precautions, the use of a dedicated plastic sleeve to store contaminated laryngoscope blade after endotracheal intubation may reduce the work surface contamination, independent of intubation device, role and experience of providers.

Vie Scope® versus videolaryngoscopy in expected difficult airways: a randomized controlled trial.

PURPOSE: The management of patients with an anticipated difficult airway remains challenging. We evaluated laryngeal visualization with the recently introduced Vie Scope® as a straight blade laryngoscope consisting of an illuminated tube necessitating bougie-facilitated intubation vs Macintosh videolaryngoscopy. METHODS: We conducted a prospective randomized controlled noninferiority trial. Patients undergoing elective ear, nose, and throat or oral and maxillofacial surgery with an anticipated difficult airway were randomized 1:1 to receive tracheal intubation with the Vie Scope or Macintosh videolaryngoscope (C-MAC®). The primary outcome measure was laryngeal visualization by the percentage of glottis opening (POGO) scale. Secondary outcome measures were the time to successful intubation (TTI) and first-attempt and overall success rates. RESULTS: We included two sets of 29 patients in our analysis. For visualization, the Vie Scope was noninferior to videolaryngoscopy (VL) with mean (standard deviation [SD]) POGO scores of 71 (31)% vs 64 (30)% in the VL group [difference in means, 7 (8)%; 95% confidence interval, -9 to 23; P = 0.38]. Mean (SD) TTI was 125 (129) sec in the Vie Scope and 51 (36) sec in the VL group (difference in means, 75 sec; 95% confidence interval, 25 to 124; P = 0.005). The first-attempt and overall success rates were 22/29 (76%) and 27/29 (93%) in both groups. Two patients per group were switched to a different device. Four accidental esophageal intubations occurred in the Vie Scope group, these were presumably due to bougie misplacement. CONCLUSION: Visualization with the Vie Scope was noninferior to VL in patients with an anticipated difficult airway, but TTI was longer in the Vie Scope group. STUDY REGISTRATION: ClinicalTrials.gov (NCT05044416); registered 5 September 2021.

RéSUMé: OBJECTIF: La prise en charge des patients dont les voies aériennes sont anticipées comme étant difficiles demeure un défi. Nous avons évalué la visualisation laryngée obtenue avec le nouveau Vie Scope®, un laryngoscope à lame droite constitué d'un tube éclairé nécessitant une intubation facilitée par bougie, par rapport à celle obtenue avec un vidéolaryngoscope Macintosh. MéTHODE: Nous avons réalisé une étude randomisée contrôlée prospective de non-infériorité. Les patient·es bénéficiant d'une chirurgie non urgente des oreilles, du nez et de la gorge ou une chirurgie buccale et maxillo-faciale présentant des voies aériennes anticipées comme difficiles ont été randomisé·es à un ratio 1:1 à recevoir une intubation trachéale avec un laryngoscope Vie Scope ou un vidéolaryngoscope Macintosh (C-MAC®). Le critère d'évaluation principal était la visualisation laryngée selon l'échelle de pourcentage d'ouverture de la glotte (POGO). Les critères d'évaluation secondaires étaient le délai avant une intubation réussie et les taux de réussite de la première tentative et globaux. RéSULTATS: Nous avons inclus deux groupes de 29 patient·es dans notre analyse. En matière de visualisation, le Vie Scope n'était pas inférieur à la vidéolaryngoscopie (VL), avec des scores POGO moyens (écart type [ET]) de 71 (31) % vs 64 (30) % dans le groupe VL [différence dans les moyennes, 7 (8) %; intervalle de confiance à 95 %, ­9 à 23; P = 0,38]. Le délai moyen (ET) avant une intubation réussie était de 125 (129) sec avec le Vie Scope et de 51 (36) secondes dans le groupe VL (différence dans les moyennes, 75 sec; intervalle de confiance à 95 %, 25 à 124; P = 0,005). Les taux de réussite de la première tentative et de réussite globale étaient de 22/29 (76 %) et 27/29 (93 %) dans les deux groupes. Un dispositif différent a dû être utilisé chez deux patient·es par groupe. Quatre intubations œsophagiennes accidentelles sont survenues dans le groupe Vie Scope; celles-ci étaient probablement dues à un mauvais placement de la bougie. CONCLUSION: La visualisation obtenue avec le Vie Scope n'était pas inférieure à la vidéolaryngoscopie chez les patient·es dont les voies aériennes étaient anticipées comme difficiles, mais le délai avant une intubation réussie était plus long dans le groupe Vie Scope. ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT05044416); registered 5 September 2021.

Value of the Hyomental Distance Measured With Ultrasound in Forecasting Difficult Laryngoscopy in Newborns.

PURPOSE: Preoperative evaluations of difficult airways are imperative, especially in newborns. The hyomental distance is a reliable index for predicting difficult airways in adults. However, few studies have evaluated the value of the hyomental distance for predicting difficult airways in newborns. It is unclear whether the hyomental distance forecasts a restricted or difficult view when using direct laryngoscopy. We intended to develop an effective system for predicting difficult tracheal intubation in newborns. DESIGN: A prospective observational clinical study. METHODS: Newborns aged 0 to 28 days undergoing oral endotracheal intubation with direct laryngoscopy for elective surgery under general anesthesia were enrolled. The hyomental distance and hyoid level tissue thickness were assessed by ultrasound. Other parameters, such as the mandibular length and sternomental distance, were also evaluated before anesthesia. The glottic structure view under laryngoscopy was graded according to the Cormack-Lehane classification. The patients with Grade 1 and 2 laryngeal views were assigned to Group E. Those with Grade 3 and 4 views were assigned to Group D. FINDINGS: A total of 123 newborns were recruited for our study. The incidence of poor visualization of the larynx during laryngoscopy in our study was 10.6%. The multifactor logistic regression results showed that the hyomental distance was a powerful predictor of difficult laryngoscopy (OR = 0.16, 95% CI 0.03-0.74, P = .019). The curve with the highest sensitivity and specificity and the maximum area under the curve (AUC) was the hyomental distance. The receiver operating characteristic (ROC) curve for the hyomental distance suggested that the best cut-off value was less than equal to 2.74 cm, with an AUC of 0.80 (95% CI 0.64-0.95). CONCLUSIONS: It is noninvasive and feasible to accurately measure the hyomental distance with ultrasound in newborns, and the results are reliable. We believe that the hyomental distance measured with ultrasound could be used as a marker for predicting difficult laryngoscopy in newborns.

Comparison of C-MAC Miller blade video laryngoscope with conventional Miller blade in infants undergoing elective surgery- A prospective randomised trial.

Background and Aims: Endotracheal intubation (ET) in infants is considered a challenging task over the decades. Infants have short safe apnoea time, and this difficulty has been vanquished to some extent by using the videolaryngoscopes (VLs), but there exists a dearth of research particularly in this vulnerable subset. Therefore, this trial was conducted to evaluate intubation times obtained with C-MAC VL and conventional Miller laryngoscopes in infants. Methods: A total of 80 infants aged between 1 month and 1 year with American Society of Anesthesiologists physical status I-II requiring ET were randomised in two groups; the C-MAC VL or Miller laryngoscope ML. Anaesthesia was induced with sevoflurane 1-8% and atracurium 0.5 mg/kg IV. The primary outcome was evaluated as the total time taken to intubate. Secondary outcomes were time to achieve best glottic view (TBGV), tube insertion time (TIT), percentage of glottic opening (POGO) score, number of attempts and intubation difficulty score (IDS). Results: The median (interquartile range) of time taken for ET was less in VL; 22.5 (20.75-26) compared to ML; 26 (21.75-31). TBGV was achieved early in VL group than the ML group (6.03 ± 1.33s/7.88 ± 2.44) respectively (P-value < 0.001). POGO was better in VL (99.12 ± 4.795s) compared to ML (85.50 ± 31.13s). IDS was less in the VL group (0.07 ± 0.27) than in ML (0.70 ± 1.14). Other parameters, such as the number of attempts, bougie usage, adverse effects and TIT, were comparable across the two groups. Conclusion: When compared to the ML group, the C-MAC VL group exhibited a decreased intubation time, early TBGV, better POGO score, reduced IDS and subjective intubation difficulty. As a result, we consider VL to be a more efficacious device for intubating the trachea in infants.

Nasendoscopy to Predict Difficult Videolaryngoscopy: A Multivariable Model Development Study.

BACKGROUND: Transnasal videoendoscopy (TVE) is the standard of care when staging pharyngolaryngeal lesions. This prospective study determined if preoperative TVE improves the prediction of difficult videolaryngoscopic intubation in adults with expected difficult airway management in addition to the Simplified Airway Risk Index (SARI). METHODS: 374 anesthetics were included (252 with preoperative TVE). The primary outcome was a difficult airway alert issued by the anesthetist after Macintosh videolaryngoscopy. SARI, clinical factors (dysphagia, dysphonia, cough, stridor, sex, age and height) and TVE findings were used to fit three multivariable mixed logistic regression models; least absolute shrinkage and selection operator (LASSO) regression was used to select co-variables. RESULTS: SARI predicted the primary outcome (odds ratio [OR] 1.33; 95% confidence interval [CI] 1.13-1.58). The Akaike information criterion for SARI (327.1) improved when TVE parameters were added (311.0). The Likelihood ratio test for SARI plus TVE parameters was better than for SARI plus clinical factors (p < 0.001). Vestibular fold lesions (OR 1.82; 95% CI 0.40-8.29), epiglottic lesions (OR 3.37; 0.73-15.54), pharyngeal secretion retention (OR 3.01; 1.05-8.63), restricted view on rima glottidis <50% (OR 2.13; 0.51-8.89) and ≥50% (OR 2.52; 0.44-14.56) were concerning. CONCLUSION: TVE improved prediction of difficult videolaryngoscopy in addition to traditional bedside airway examinations.

A novel technique of handling the blade for videolaryngoscopy intubation in patients with a semi-rigid neck collar: a prospective randomized controlled trial.

BACKGROUND: Semi-rigid neck collars to protect the cervical spine can limit the extent of neck movement and mouth opening; this may further complicate orotracheal intubation. We aimed to compare intubation environments obtained with videolaryngoscopy using the technique of gliding a blade under the epiglottis and that obtained using the conventional Macintosh blade technique of blade tip placement on the vallecula. METHODS: This prospective randomized study included patients aged ≥ 20 years with American Society of Anesthesiologists physical status I-III scheduled for cervical spine surgery between October 2020 and August 2021. Patients were divided into two groups according to the placement of the blade of the McGrathTM videolaryngoscope: the gliding and conventional groups. The percentage of glottic opening (POGO) score was the primary endpoint. We also recorded the time to obtain the optimal laryngoscopic view, intubation duration, and ease and satisfaction of the researcher performing intubation. RESULTS: Among 176 patients, the POGO scores were significantly higher in the gliding group than in the conventional group (88.9 ± 14.7 vs. 63.8 ± 27.4, P < 0.001). The time to achieve the optimal glottic view for intubation and duration of intubation were also shorter, and ease and satisfaction in performing intubation were better in the gliding group than in the conventional group. CONCLUSION: Our findings demonstrated a superior glottic view and more favorable intubation environments when the blade tip was placed under the epiglottis than using the conventional Macintosh technique in patients with immobilized cervical spine.

Successful Tracheal Intubation With Airway Scope After Failure With McGrath.

The use of video laryngoscopy is growing in patients with anatomical factors suggestive of a difficult airway. This case report describes the successful tracheal intubation of a 54-year-old female patient with limited mouth opening scheduled for third molar extraction under general anesthesia. The Airway scope (AWS) along with a gum-elastic bougie was used to secure the airway after failed direct laryngoscopy and video laryngoscopy using the McGrath MAC with an X-blade. The AWS has a J-shaped structure in which the blade approximates the curvature of the pharynx and larynx. This blade shape makes it easy to match the laryngeal axis with the visual field direction, enabling successful tracheal intubation even for patients with limited mouth opening. A major key to successful video laryngoscopy is to select a video laryngoscope based on the anatomical characteristics of patients with a difficult airway.

Comparison of the McGRATHTM Video Laryngoscope and Macintosh Laryngoscope for Orotracheal Intubation in a Simulated Difficult Airway Scenario: An Open-Label, Randomized Clinical Trial.

Background and Objectives: Difficult intubation, which may be encountered unexpectedly during anesthesia, can increase patients' morbidity and mortality. The McGRATH video laryngoscope is known to provide improved laryngeal visibility in patients with difficult or normal airways. The purpose of this study was to evaluate the efficacy of the McGRATH video laryngoscope for orotracheal intubation compared with that of conventional Macintosh laryngoscopes in simulated difficult airway scenarios. Materials and Methods: In this randomized controlled trial, patients who were scheduled for surgery under general anesthesia requiring orotracheal intubation were assigned to the Macintosh laryngoscope (n = 50) or McGRATH video laryngoscope (n = 45) groups. In this study, to create a simulated difficult airway condition, the subjects performed manual in-line stabilization and applied a soft cervical collar. The primary outcome was the rate of successful intubation within 30 s. The time required for an intubation, glottis grade, intubation difficulty scale (IDS score), the subjective ease of intubation, and optimal external laryngeal manipulation (OLEM) were evaluated. In addition, complications caused by each blade were investigated. Results: The intubation success rate within 30 s was not significantly different between the two groups (44 (88.0%) vs. 36 (80.0%), p = 0.286). The glottic grade was better in the McGRATH group than in the Macintosh group (p = 0.029), but neither the intubation time (26.3 ± 8.2 s vs. 24.2 ± 5.0 s, p = 0.134) nor the rates of oral bleeding (2 (4.0%) vs. 0 (0.0%)) and tooth injury (0 (0.0%) vs. 1 (2.2%)) were significantly different between the two groups. Conclusions: The use of the McGRATH video laryngoscope did not improve the intubation success rate or shorten the intubation time. However, the McGRATH video laryngoscope provided a better glottis view than the conventional Macintosh laryngoscope in patients with a simulated difficult airway.

Usefulness of C-curved stylet for intubation with the C-MAC® Miller videolaryngoscope in neonates and infants: a prospective randomized controlled trial.

BACKGROUND: Optimizing endotracheal tube (ETT) shape is important for successful videolaryngoscope-aided intubation. This prospective randomized controlled study aimed to compare the tube-handling time between a C-curved and hockey stick-shaped stylet in infants and neonates using the C-MAC® videolaryngoscope Miller blade. METHODS: A total of 110 infants (age < 1 year) were randomly assigned to either the hockey stick-curved stylet group (group H, n = 53) or the C-curved stylet group (group C, n = 57). The primary outcome was tube handling time after glottis visualization and the secondary outcomes were the total intubation time, incidence of successful intubation, initial tube tip location at the laryngeal inlet, and numerical rating scale for ease of intubation. RESULTS: Tube insertion time and total intubation duration (both in seconds) were significantly shorter in group C than in group H (13.3 ± 8.9 vs. 25.1 ± 27.0, P = 0.002; 19.9 ± 9.4 vs. 32.8 ± 27.1, P = 0.001, respectively). Group C displayed a higher rate of intubation success within 30 s than group H (87.7% vs. 69.8%, P = 0.029). The initial tube tip was located at the center in 34 children in group C (59.6%) and 12 children in group H (26.1%, P < 0.001). Laryngoscope operators rated intubation as easier when provided with a C-curved stylet. CONCLUSIONS: In neonates and infants, modification of the ETT shape into a C-curve may reduce tube handling time compared to the conventional hockey stick-shaped tube during intubation using a C-MAC® video laryngoscope Miller blade.