Macintosh Blade Research Articles

An approach to difficult airway in infants: Comparison of GlideScope® Spectrum LoPro, GlideScope® Spectrum Miller and conventional Macintosh and Miller blades in a simulated Pierre Robin sequence performed by 90 anesthesiologists.

Airway management can be challenging in neonates and infants. The Pierre Robin sequence (PRS) is a condition characterized by micrognathia, glossoptosis and airway obstruction. The airway management of these patients poses great challenges for anesthesiologists and pediatricians alike. To date, there has been no direct comparison of the hyperangulated GlideScope® Spectrum LoPro (GLP), the straight GlideScope® Spectrum Miller (GSM), a conventional Macintosh (MC) and a conventional Miller blade (ML) in patients with PRS. For this purpose, 90 anesthesiologists (43 with limited experience, 47 with extensive experience) performed orotracheal intubation on an Air-Sim® Pierre Robin X manikin using GLP, GSM, MC and ML in randomized order. 'Time-to-vocal-cords', 'time-to-intubate', 'time-to-ventilate', the severity of oral-soft-tissue-trauma and the subjective evaluation of each device were recorded. A significantly faster and better view of the vocal cords and lower oral-soft-tissue-trauma was achieved using the GLP (p<0.001). Though, there were no significant differences in the 'time-to-intubate' or 'time-to-ventilate'. The highest intubation success rate was found with GSM and the lowest with GLP (GSM 100%, ML 97.8%, MC 96.7%, GLP 93.3%). When using the videolaryngoscopes, there were no undetected esophageal intubations but in six cases prolonged attempts of intubation (>120s) with the GLP. In the sub-group with extensive experience, we found significantly shorter intubation times for the GSM and ML. The GLP was the tool of choice for most participants, while the conventional MC received the lowest rating. Videolaryngoscopy leads to increased safety for the prevention of undetected esophageal intubation in the airway management in a PRS manikin. Hyperangulated blades may ensure a good and fast view of the vocal cords and low oral-soft-tissue-trauma but pose a challenge during the placement of the tube. Specific skills and handling seem to be necessary to ensure a safe tube placement with this sort of blades.

Evaluation of the Hemodynamic Response during Laryngoscopy and Intubation using McCOY and Macintosh Laryngoscope Blades

Basic elements of general anesthesia includeunconsciousness, amnesia, analgesia, muscle relaxation,diminished motor response to noxious stimuli, and reversibility.Muscle relaxation necessitates securing ventilation withendotracheal intubation. Laryngoscopy forms an importantpart of general anaesthesia and endotracheal intubation.Laryngoscopes are used to view the larynx and adjacentstructures for inserting an endotracheal tube into the trachea.Laryngoscopy aims to obtain good visualization of the vocalcords to facilitate smooth endotracheal intubation. The directlaryngoscopic view is best seen in sniffing in the morning airposition, improving the glottis view. Laryngoscopy triggers majorstress responses, one due to sympathetic stimulation releasingcatecholamines that leads to tachycardia and hypertension,which increases the myocardial oxygen demand, and the otherdue to vagal stimulation leading to parasympathetic activationthat manifests as bradycardia and hypotension. Both may becatastrophic in patients with a known history of ischemic heartdisease.Materials and Methods: This hospital-based prospective,observational study was carried out in the Department ofAnaesthesiology, Shri Ram Murti Smarak Institute of MedicalSciences, Bareilly over 112 patients of ASA physical status Iand II, undergoing elective surgery under general anaesthesiaduring a period of 18 months (February 2021 to June 2022).Results: In our study, a total of 112 patients were included,50.0% of cases were managed by Macintosh blade thoseconsisting of group I, and 50.0% of cases were managed byMcCoy blade, those consisting of group II. Pre-op Heart rate(HR) was 80.56 ± 11.48 and 76.79 ± 10.90 in group I and II,respectively and it was reduced pre-intubation in both groupsand it increased significantly during laryngoscopy (p &lt;0.05).Pre-op systolic blood pressure (SBP) was 116.56 ± 11.55 and119.48 ± 11.41 in group I and II, respectively and it was reducedat pre-intubation in both groups and it increased significantlyduring laryngoscopy (p &lt;0.05). Pre-op diastolic blood pressure(DBP) was 73.17 ± 8.54 and 73.61 ± 10.29 in group I and II,respectively and it decreased at pre-intubation and again, it wasincreased during laryngoscopy (p &lt;0.05). Pre-op mean arterialpressure (MAP) was 87.79 ± 8.64 and 89.28 ± 9.0 in group Iand II, respectively and it was decreased at pre-intubationand again, it was increased during laryngoscopy (p&lt;0.05).ECG was found normal in both groups at all time duration withtachycardia, but no change in the ST segment was noticed inany group.Conclusion: Our study concludes that the McCoy bladeproduces significantly lesser marked hemodynamic changes.The vitals like heart rate, systolic blood pressure, diastolicblood pressure and mean arterial pressure all rise in bothgroups following the laryngoscopy and intubation but increaseswith McCoy were less and insignificant than Macintoshlaryngoscopes.

Non-channeled Video Laryngoscopy as an Alternative to Conventional Laryngoscopy for Intubating Adult Patients in the Intensive Care Unit.

Background Endotracheal intubation in the intensive care unit (ICU) is often a risky procedure due to the emergency situation, unstable condition of the patient, and technical problems such as inadequate positioning. Several new techniques, such as video laryngoscopy, have been developed recently to improve the success rate of first-pass intubations and reduce complications. We conducted this study to compare a non-channeled reusable video laryngoscope BPL VL-02 (manufactured by BPL Medical Technologies, Bangalore, India) with a conventional laryngoscope for intubation of adult patients in the ICU. Methodology A total of 72 ICU patients were randomly allocated to be intubated with either conventional direct laryngoscopy via Macintosh blade (group A) or video laryngoscopy with BPL VL-02 (group B). All patients were intubated by the primary investigator and the assistant noted the following parameters: the total number of intubation attempts, total duration of intubation, assistance or alternative technique required, Cormack Lehane grading, and any complications. Results There was no significant difference in the Cormack Lehane grading, number of attempts, or complications between the two groups. On comparing the assistance required during intubation in patients, it was observed that four (11.11%) patients in group A and seven (19.44%) patients in group B needed backward, upward, and rightward pressure on the larynx assistance during intubation. In five (13.89%) patients in group B, Stylet was required during intubation. The difference was statisticallysignificant (p = 0.0308). The video laryngoscopy group (group B) had a longer mean duration of intubation (64.36 ± 6.28 seconds) compared to group A (45.72 ± 11.45 seconds), and the difference was statistically significant (p < 0.0001). Conclusions Non-channeled video laryngoscope (BPL VL-02) is not a suitable alternative to conventional direct laryngoscopy with a Macintosh blade in terms of successful first-pass intubation, total duration of intubation, and assistance required.

Single-use versus reusable metallic laryngoscopes for non-emergent intubation: A retrospective review of 72,672 intubations

Study objectiveIncreased regulatory requirements for sterilization in recent years have prompted a widespread transition from reusable to single-use laryngoscopes. The purpose of this study was to determine if the transition from metallic reusable to metallic single-use laryngoscopes impacted the performance of direct laryngoscopy at an academic medical center. DesignSingle-site retrospective cohort study. SettingGeneral anesthetic cases requiring tracheal intubation. PatientsAdult patients undergoing non-emergent procedures. InterventionsData were collected two years before and two years after a transition from metallic reusable to metallic single-use laryngoscopes. MeasurementsThe primary outcome was need for intubation rescue with an alternate device. Secondary outcomes were difficult laryngeal view (modified Cormack-Lehane grade ≥ 2b) and hypoxemia (SpO2 < 90% for >30 s) during direct laryngoscopy intubations. Subgroup analyses for rapid sequence induction, Macintosh blades, Miller blades, and patients with difficult airway risk factors (Obstructive Sleep Apnea, Mallampati ≥3, Body Mass Index >30 kg/m2) were performed. Main resultsIn total, 72,672 patients were included: 35,549 (48.9%) in the reusable laryngoscope cohort and 37,123 (51.1%) in the single-use laryngoscope cohort. Compared with reusable laryngoscopes, single-use laryngoscopes were associated with fewer rescue intubations with an alternate device (covariates-adjusted odds ratio [OR] 0.81 95% CI 0.66–0.99). Single-use laryngoscopes were also associated with lower odds of difficult laryngeal view (OR 0.86; 95% CI 0.80–0.93). Single use laryngoscopes were not associated with hypoxemia during the intubation attempt (OR 1.03; 95% CI 0.88–1.20). Similar results were observed for subgroup analyses including rapid sequence induction, Macintosh blades, Miller blades, and patients with difficult airway risk factors. ConclusionsMetallic single-use laryngoscopes were associated with less need for rescue intubation with alternate devices and lower incidence of poor laryngeal view compared to reusable metallic laryngoscopes.

Video Laryngoscopy versus Direct Laryngoscopy for Orotracheal Intubation in the Out-of-Hospital Environment: A Systematic Review and Meta-Analysis

Objective To determine the effect of video and direct laryngoscopy on first-pass success rates for out-of-hospital orotracheal intubation. Methods MEDLINE, Embase, and Cochrane databases were searched from inception to January 2023. Out-of-hospital studies comparing video and direct laryngoscopy on either first-pass or overall intubation success were included. A random effects meta-analysis was performed with a primary outcome of first-pass success stratified by clinician type and laryngoscope blade geometry. The secondary outcomes were overall intubation success stratified by clinician type, and intubation time. All hypotheses and subgroup analyses were determined a priori. Results Twenty-five studies involving 35,489 intubations met inclusion criteria. Substantial heterogeneity (>75%) precluded reporting point estimates for nearly all analyses. For our primary outcome, video laryngoscopy was associated with improved first-pass success in 3/5 physician studies, 4/6 critical care paramedic/registered nurse studies, and 7/10 paramedic studies. Video laryngoscope devices with Macintosh blade geometry were associated with improved first-pass success in 7/10 studies, while devices with hyperangulated geometry were associated with improved first-pass success in 3/7 studies. Overall intubation success was greater with video laryngoscopy in 2/6 studies in the physician subgroup and 9/10 studies in the paramedic subgroup. Video laryngoscopy was not associated with overall intubation success among critical care paramedics/nurses (OR = 1.89, 0.96 to 3.72, I2 = 34%). Lastly, 4/5 studies found video laryngoscopy to be associated with longer intubation times. Conclusions We found substantial heterogeneity among out-of-hospital studies comparing video laryngoscopy to direct laryngoscopy on first-pass success, overall success, or intubation time. This heterogeneity was not explained with stratification by study design, clinician type, video laryngoscope blade geometry, or leave-one-out meta-analysis. A majority of studies showed that video laryngoscopy was associated with improved first pass success in all subgroups, but only for paramedics and not physicians when looking at overall success. This improvement was more common in studies that used Macintosh blades than those that used hyperangulated blades. Future research should explore the heterogeneity identified in our analysis with an emphasis on differences in training, clinical milieu, and specific video laryngoscope devices.

The Importance of Median Glossoepiglottic Fold Engagement on Laryngeal View and Tracheal Intubation Success in Children.

Our study objective was to determine if the location of laryngoscope blade tip placement is associated with clinically important tracheal intubation outcomes in a pediatric emergency department. We conducted a video-based observational study of pediatric emergency department patients undergoing tracheal intubation with standard geometry Macintosh and Miller video laryngoscope blades (Storz C-MAC, Karl Storz). Our main exposures were direct lifting of the epiglottis versus blade tip placement within the vallecula and median glossoepiglottic fold engagement versus not when the blade tip was placed in the vallecula. Our main outcomes were glottic visualization and procedural success. We compared measures of glottic visualization between successful and unsuccessful attempts using generalized linear mixed models. Proceduralists placed the blade tip in the vallecula (indirectly lifting the epiglottis) during 123 (71.9%) of 171 attempts. When compared with indirectly lifting the epiglottis, directly lifting the epiglottis was associated with improved visualization-by percentage of glottic opening (POGO) (adjusted odds ratio [AOR], 11.0; 95% confidence interval [CI], 5.1 to 23.6) and modified Cormack-Lehane (AOR, 21.5; 95% CI, 6.6 to 69.9). When in the vallecula, engagement of the median glossoepiglottic fold was associated with improved POGO (AOR, 3.6; 95% CI, 1.9 to 6.8), modified Cormack-Lehane (AOR, 3.9; 95% CI, 1.1 to 14.1), and success (AOR, 9.9; 95% CI, 2.3 to 43.7). Emergency tracheal intubation can be performed in children at a high level by directly or indirectly lifting the epiglottis. If indirectly lifting the epiglottis, median glossoepiglottic fold engagement is helpful in maximizing glottic visualization and procedural success.

Comparison of Airtraq™ video-laryngoscope and Macintosh laryngoscope for tracheal intubation in adults—a randomised study

BackgroundAirway management by intubation is considered a major responsibility and vital skill for anaesthesiologists. Direct laryngoscopy and endotracheal intubation under vision continues to be the gold standard for airway management. Though conventional laryngoscopy is done with Macintosh blade, it has its own drawbacks. The Airtraq™ is a tube/guide channelled video-laryngoscope and can be used in patients with normal as well as difficult airway. On literature review, studies comparing intubation time with Airtraq™ and Macintosh laryngoscopes have shown heterogeneous results. Therefore, the present study was designed to compare the Airtraq™ video-laryngoscope and Macintosh laryngoscope for tracheal intubation in adults.ResultsThe median time to intubation was significantly longer in group A [45 (27–77) s] than in group M [24 (21–26) s] (p < 0.001). In both groups, 96% patients had POGO score 75–100% and CL grade I. Intubation was noted to be easy in 88% cases in group A and 92% in group M (p > 0.05). Three cases in group A required a second attempt for successful intubation, whereas in group M, all cases were intubated in the first attempt (p > 0.05). Hemodynamic parameters and complications were comparable among the groups (p > 0.05).ConclusionsAirtraq™ video-laryngoscope took longer time for intubation than Macintosh laryngoscope. However, both the devices were similar in terms of glottic view, ease of intubation, number of intubation attempts, incidence of failed intubation, hemodynamic changes, and complications. The overall performance of Airtraq™ video-laryngoscope was similar to Macintosh laryngoscope in patients having normal airways.

The effect of the use of a stylet and/or McGrath videolaryngoscope on intubation time in obese patients: A randomized clinical trial

BackgroundObese people have low oxygen reserves because of low functional capacity. For this reason, the time for airway manipulation before intubation is reduced and airway management may be difficult in obese population. AimThe purpose of the present study was to investigate whether videolaryngoscope or stylet or both, shorten the intubation time in obese patients. MethodsA total of 120 obese patients scheduled for surgery under general anesthesia were included in the study, 30 in each group; Group DL utilizing a standardized Macintosh blade, Group DLS: DL utilizing a standardized Macintosh blade + Stylet, Group VL: McGrath VL (Series 5), Group VLS: McGrath VL (Series 5) + Stylet. Intubation time was investigated as the primary outcome. ResultsIntubation times were found to be significantly different between the study groups (P < 0.001). According to the Post-Hoc Test results, the intubation time of Group DL was significantly lower than the intubation time of Group VL and Group VLS (P < 0.001, P = 0.014, respectively). Group DLS intubation time was significantly lower than those of Group VL and Group VLS (P < 0.001, P < 0.001, respectively). Intubation times were similar between the other groups (P > 0.05). ConclusionsThe intubation times of obese patients were shorter with direct laryngoscopy, with or without a stylet when compared to those with a McGrath videolaryngoscope, with or without a stylet. Among the same type of laryngoscopy groups, the use of stylet did not change the intubation time. The rate of first-pass intubation was lower with the stylet-free McGrath videolaryngoscope when compared to direct laryngoscopy and direct laryngoscopy plus stylet groups.

AN OBSERVATIONAL STUDY OF CARDIOVASCULAR STRESS RESPONSE TO LARYNGOSCOPY WITH MCCOY, MACINTOSH, MILLER LARYNGOSCOPE BLADE FOR INTRAOPERATIVE ANAESTHESIA IN ADULT ELECTIVE SURGERIES

Background: The most commonly used equipment to aid endotracheal intubation is a laryngoscope, and the procedure performed is known as laryngoscopy, which leads to profound cardiovascular effects. The process of laryngoscopy causes the release of catecholamines, thereby leading to marked pressor responses and tachycardia. The process of laryngoscopy can be made easier by the use of various types of laryngoscopic blades. This study was conducted to observe cardiovascular stress response to the laryngoscopy with McCoy, Macintosh, Miller laryngoscope blades for anaesthesia in adult elective surgeries. Material: This study was conducted in 51 patients in age group 18-60 years of both sexes, posted for elective surgeries under general anaesthesia in surgery and gynaecology operation theatre. In this study, 51 patients were randomly allocated into three groups each of 17 patients Grope 1 (McCoy Laryngoscope), Group 2 (Macintosh Laryngoscope), Group 3 (Miller Laryngoscope). There Results: was no signicant difference in age and gender distribution between three groups. There was no signicant difference in sex distribution between three groups. There was a signicant difference in mean heart rate between different groups from 2 to 5 mins. There was a signicant difference in mean SBP and DBP comparison between different groups from 1 to 5 mins. It is least with McCoy, most with Miller and in between with Macintosh. There was a signicant difference in Glottic view Distribution between three groups. Glottic visualisation is best with Miller blade. There was a signicant difference in Ease of Intubation Distribution between different groups. So tracheal intubation is easier with McCoy blade as compared with Macintosh and Miller blade. There was no signicant difference in Side Effects Distribution between different groups. Conclusion: It is concluded that the cardiovascular stress response (increased heart rate, blood pressure and mean arterial pressure) to laryngoscopy is least with McCoy laryngoscope and most with Miller laryngoscope and in-between with Macintosh laryngoscope.

A Prospective Comparative Study of Laryngeal Glottic View Using the Vie Scope® versus Standard Macintosh Laryngoscope in Morbidly Obese Patients.

The visualization of the glottis may be inadequate in morbidly obese patients when a standard Macintosh blade laryngoscope (MCL) is used. The Vie Scope® (VS) is a novel type laryngoscope consisting of a straight, enclosed, illuminated tube that offers intubation via a bougie using the paraglossal technique. In this prospective, nonrandomized comparative study, we tested the research hypothesis that the VS may improve visualization of the glottic larynx in comparison to the MCL. After obtaining institutional ethics committee approval, 60 morbidly obese patients (BMI >40 kg/m2) undergoing elective non-head and neck surgery were included in the study. After induction of general anesthesia (GA), the glottic visualization was performed using the two laryngoscopes in succession, first MCL size 3 or 4 followed by the VS and was assessed using the modified Cormack-Lehane scale. Tracheal intubation was performed using the VS The first pass intubation success and the total success rate was recorded only for the VS Intubation time was not measured because of the paired study design. Mean demographic data included: age 41.9±8.2 years, height 171.2±10.2 cm, weight 129.9±21.6 kg, BMI 44.95±3.85 kg/m2. Using MCL, Cormack-Lehane grade 1 was observed in 36 (60%) cases; grade 2 in 7/60 (11.6%); grade 3 in 13/60 (21.7%); and grade 4 in 4/60 (6.7%). Poor laryngeal views represented by grades 3 and 4 were observed in 28.4% of patients with the MCL. Grades obtained with the VS were all grade 1 (100%). The first attempt intubation success was in 58/60 (96.7%) with the VS. No complications were observed. The Vie Scope® laryngoscope, using the paraglossal technique of tracheal intubation, significantly improves visualization of the vocal cords in morbidly obese patients compared to the standard Macintosh laryngoscope.

Conventional versus video-assisted laryngoscopy for perioperative endotracheal intubation (COVALENT) - a randomized, controlled multicenter trial

BackgroundData on the routine use of video-assisted laryngoscopy in peri-operative intubations are rather inconsistent and ambiguous, in part due to small populations and non-uniform outcome measures in past trials. Failed or prolonged intubation procedures are a reason for relevant morbidity and mortality. This study aims to determine whether video-assisted laryngoscopy (with both Macintosh-shaped and hyperangulated blades) is at least equal to the standard method of direct laryngoscopy with respect to the first-pass success rate. Furthermore, validated tools from the field of human factors will be applied to examine within-team communication and task load during this critical medical procedure.MethodsIn this randomized, controlled, three-armed parallel group design, multi-centre trial, a total of more than 2500 adult patients scheduled for perioperative endotracheal intubation will be randomized. In equally large arms, video-assisted laryngoscopy with a Macintosh-shaped or a hyperangulated blade will be compared to the standard of care (direct laryngoscopy with Macintosh blade). In a pre-defined hierarchical analysis, we will test the primary outcome for non-inferiority first. If this goal should be met, the design and projected statistical power also allow for subsequent testing for superiority of one of the interventions.Various secondary outcomes will account for patient safety considerations as well as human factors interactions within the provider team and will allow for further exploratory data analysis and hypothesis generation.DiscussionThis randomized controlled trial will provide a solid base of data in a field where reliable evidence is of major clinical importance. With thousands of endotracheal intubations performed every day in operating rooms around the world, every bit of performance improvement translates into increased patient safety and comfort and may eventually prevent significant burden of disease. Therefore, we feel confident that a large trial has the potential to considerably benefit patients and anaesthetists alike.Trial registrationClincalTrials.gov NCT05228288.Protocol version1.1, November 15, 2021.

POSTOPERATIVE SORE THROAT AFTER LARYNGOSCOPY WITH MACINTOSH VERSUS VIDEOLARYNGOSCOPE BLADE

Introduction: Direct laryngoscopy guided by a Macintosh curved blade, is the standard traditional method of endotracheal intubation in patients under general anaesthesia. Post Operative Sore Throat [POST] is a common problem faced. With the advent of newer technology, various videolaryngoscopes have come into usage. To know the incidence of sore throat after Aim: intubation with the Macintosh versus videolaryngoscope. To compare the incidence of hoarseness, hemodynamic response and time taken for intubation by two methods. A prospective, randomized study was conducted on 110 patient Method: s with normal airway undergoing general anaesthesia for elective surgeries. Patients were enrolled into two groups randomly by Systemic Randomization Technique. All patients underwent thorough pre-anaesthestic evaluation with general and systemic examination. In the operation theatre, baseline vital parameters were recorded. The standard anaesthetic regimen and surgical procedures was followed. Postoperative sore throat was assessed with 10 point score at 0,6,12,24 hours post extubation. The mean incidence of sore throat at 0,6,12 and 24 hours Result: post extubation was 6.67, 5.44, 4.91 and 3.93 in the Macintosh group whereas 4.18, 3.09, 1.22 and 1.25 in the videolaryngoscope group. The mean time taken for intubation was 19.5 sec in Macintosh group and 36.6 sec in videolaryngoscope group. All patients were haemodynamically stable throughout the procedure. Conclusion: The incidence of postoperative sore throat was more with Macintosh blade whereas the time taken for intubation and the hemodynamic stability was more with the videolaryngoscope blade

A multicentre randomised controlled trial of the McGrath Mac videolaryngoscope versus conventional laryngoscopy.

Before completion of this study, there was insufficient evidence demonstrating the superiority of videolaryngoscopy compared with direct laryngoscopy for elective tracheal intubation. We hypothesised that using videolaryngoscopy for routine tracheal intubation would result in higher first-pass tracheal intubation success compared with direct laryngoscopy. In this multicentre randomised trial, 2092 adult patients without predicted difficult airway requiring tracheal intubation for elective surgery were allocated randomly to either videolaryngoscopy with a Macintosh blade (McGrath) or direct laryngoscopy. First-pass tracheal intubation success was higher with the McGrath (987/1053, 94%), compared with direct laryngoscopy (848/1039, 82%); absolute risk reduction (95%CI) was 12.1% (10.9-13.6%). This resulted in a relative risk (95%CI) of unsuccessful tracheal intubation at first attempt of 0.34 (0.26-0.45; p < 0.001) for McGrath compared with direct laryngoscopy. Cormack and Lehane grade ≥ 3 was observed more frequently with direct laryngoscopy (84/1039, 8%) compared with McGrath (8/1053, 0.7%; p < 0.001) No significant difference in tracheal intubation-associated adverse events was observed between groups. This study demonstrates that using McGrath videolaryngoscopy compared with direct laryngoscopy improves first-pass tracheal intubation success in patients having elective surgery. Practitioners may consider using this device as first choice for tracheal intubation.

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

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. 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. 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. 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.

Effect of Laryngoscope Blade Size on First Pass Success of Tracheal Intubation in Critically Ill Adults.

Retrospective analysis using a propensity score and inverse probability weighting of data from six prior multicenter randomized trials. Adult patients who underwent nonelective TI at participating emergency departments and ICUs. We compared the first-pass success of TI with DL in subjects intubated with a size 4 Macintosh blade on the first TI attempt to subjects with a size 3 Macintosh blade on the first TI attempt. Among 979 subjects, 592 (60.5%) had TI using DL with a Macintosh blade, of whom 362 (37%) were intubated with a size 4 blade and 222 (22.7%) with a size 3 blade. We used inverse probability weighting with a propensity score for analyzing data. We found that patients intubated with a size 4 blade had a worse (higher) Cormack-Lehane grade of glottic view than patients intubated with a size 3 blade (adjusted odds ratio [aOR], 1.458; 95% CI, 1.064-2.003; p = 0.02). Patients intubated with a size 4 blade had a lower first pass success than those with a size 3 blade (71.1% vs 81.2%; aOR, 0.566; 95% CI, 0.372-0.850; p = 0.01). In critically ill adults undergoing TI using DL with a Macintosh blade, patients intubated using a size 4 blade on first attempt had a worse glottic view and a lower first pass success than patients intubated with a size 3 Macintosh blade. Further prospective studies are needed to examine the optimal approach to selecting laryngoscope blade size during TI of critically ill adults.

Accuracy of Preoperative Ultrasonographic Airway Assessment in Predicting Difficult Laryngoscopies in Adult Patients.

Background and objectives Presently, neck ultrasonography is used as a tool to predict a difficult airway. There are no standardized ultrasonographic criteria that help to predict a difficult airway. This study aims to ultrasonographically assess the anterior neck soft tissue thickness preoperatively based on two parameters-the minimal distance from the hyoid bone to skin (DSHB) and the distance from the skin to the epiglottis midway between the hyoid bone and thyroid cartilage (DSEM)-and find out whether these parameters can predict a difficult airway in adults by correlating with the Cormack-Lehane (CL) grading. Background and objectives After obtaining ethical committee clearance and patient consent, we conducted this study on 96 patients aged between 18 and 60 years, belonging to American Society of Anesthesiologists (ASA) classes one and two, who were admitted for elective surgery under general anesthesia with endotracheal intubation to RL Jalappa Hospital and Research Centre, Tamaka, Kolar, from January 2020 to May 2021. The exclusion criteria were patients with anticipated difficult airway cases, such as obesity, pregnancy, head and neck anatomical pathologies, maxillofacial anomalies, and edentulous patients. The sonography of the airway was first performed preoperatively by an anesthesiologist along with standard clinical tests such as Mallampati (MP) grading. The sonography included two parameters: DSHB and DSEM. The patients were later classified as having easy or difficult laryngoscopy based on USG criteria from the available literature. A DSHB value of greater than 0.66 cm was predicted to be a difficult airway, and less than 0.66 cm was predicted to be easy. A DSEM value greater than 2.03 cm was predicted to be a difficult airway, and less than 2.03 cm was predicted to be easy. After induction of anesthesia, another experienced anesthesiologist performed direct laryngoscopy in the sniffing position with an appropriate-sized Macintosh blade and CL grades. CL grades I and II were considered to be easy laryngoscopies. The quantitative data were presented by mean SD and confidence interval (CI). The qualitative data were presented in percentages, and p-values less than 0.05 were considered statistically significant. To determine the discriminative power of individual tests, the receiver operating characteristic curve and the area under the curve with a 95% confidence interval was noted. Results The two USG parameters DSHB and DSEM may be used to predict difficult laryngoscopy in adult patients, as both have very strong statistical significance. Of the two parameters, DSHB seems to have a better diagnostic value for predicting a difficult airway in our study, as supported by thearea under the curve (AUC) of 97.4% compared to DSEM with an AUC of 88.8%. DSHB has better sensitivity (100%), and DSEM has better specificity (89.77%). Conclusion Our study showed that DSHB and DSEM may aid in predicting difficult laryngoscopies, as a strong statistical significance was present between sonographic measurements and CL grading. DSHB also appeared to have a better diagnostic value for predicting a difficult airway.

To evaluate the stress response to tracheal intubation by macintosh laryngoscope and intubating laryngeal mask airway

Aim: To evaluate the hemodynamic changes and side effects during endotracheal intubation with Macintosh laryngoscope and intubating laryngeal mask airway. Materials and methods: A prospective, simple randomized, comparative study on 100 patients 18 years - 60 years of age, divided into two groups: Group A comprising intubation with Macintosh laryngoscope and Group B intubation through ILMA. Results: Total intubation time (in seconds) of group A was 24.38 + 3.26 seconds and of the group, B was 42.94 + 1.24 seconds. At 2,4 and 6, a higher rise in mean heart rate was noted in group A (p &lt; 0.05). At 2,4,6 and 8 minutes difference in mean SBP and mean DBP of the two groups was statistically significant with a p - value of &lt; 0.05 with a significant increase of mean SBP and mean DBP in patients of group A. The difference for all complications was not significant between the two groups. Conclusion: Intubation via intubating laryngeal mask airway can be done as an alternative to direct laryngoscopy using a Macintosh blade as intubation via intubating laryngeal mask airway has shown to have lesser hemodynamic changes.

MT14 How Should Clinical Outcomes Factor Into Purchasing Decisions About Macintosh-Style Laryngoscopes?

Intubation with a Macintosh blade is a routine procedure in perioperative care and evidence demonstrates that video laryngoscopy (VL) improves intubation success versus direct laryngoscopy (DL). We wish to understand the type of health-economic analysis required to inform purchasing decisions between the two common VL devices, C-MAC and McGrath MAC.

CASE REPORT OF ANAESTHETIC MANAGEMENT OF BRONCHOGENIC CYST IN 11-MONTH OLD CHILD

Introduction: Bronchogenic cysts are foregut-derived cystic malformations of the respiratory tract, are the most common cystic mediastinal lesion in children.Case: We report a case of 11-month old child who presented with repeated lower respiratory tract infections for last 3-4 months. She underwent CT chest which revealed a cystic lesion measuring 2.2 x 1.8 x 2.5cm in the posterior mediastinum. Patient was posted for Right postero-lateral thoracotomy with excision of cyst. Thorough Pre-anaesthetic evaluation was done and antibiotics and bronchodilators were continued. General anaesthesia with one lung ventilation was planned. Patient was intubated with Inj.propofol 10mg, Inj.succinylcholine 10mg and uncuffed no.4 endotracheal tube using no.0 Macintosh blade and Inj.vecuronium 0.4 mg given. Patient was maintained on sevourane+O2+ air. Patient was placed in left lateral position. Right T4 intercostal space postero-lateral incision was taken, right lung collapsed and cyst was tried to excised – suddenly we noticed fall in ETco2, followed by severe bradycardia and hypoxia (Spo2 not recordable) Accidental rent in trachea was noticed. Cardiac massage/Inj.Adrenaline/ventilation with 100% oxygen started. Tracheal rent was sutured. Patient was revived successfully. Surgery later was completed uneventfully. Patient was extubated on table and shifted to Paediatric ICU. CONCLUSION: Airway management in paediatric age group is very challenging to anaesthetist. In our scenario resuscitation from asystole and airway management becomes a vital role.

Comparison of the ‘D blade’ with the conventional blade of C-MAC® for endotracheal intubation in patients with simulated limitation of cervical movements

Background: The C-MAC® videolaryngoscope enables better visualisation of glottis for rapid and successful endotracheal intubation. Aim: The present study is aimed at comparing the conventional C-MAC® blade with new ‘D’ blade in patients with simulated cervical spine immobilisation. Methods: This was a prospective, randomised and crossover study. Eighty patients were randomised to one of two groups: Group CD or Group DC (CD - Conventional blade first, DC-D blade first). Patients in each group had laryngoscopy performed with both the blades in random order following which the patient’s trachea was intubated using the blade used for second laryngoscopy. Results: The mean (± SD) age was 39.4 (± 12.4) years. There were 33 male and 47 female patients. The average weight was 57.2 kg. No patient had a grade 3 or 4 view at initial laryngoscopy (without cervical spine immobilisation) with Macintosh blade and hence not excluded. 75 patients had a grade 1 view and 5 patients with grade 2 view with D blade whereas 63 patients had a grade 1 view and 17 patients had a grade 2 view with the conventional blade. The difference was clinically and statistically very significant. The time taken for laryngoscopy and intubation, and the overall satisfaction score did not differ between the groups. Conclusions: The D blade of C-MAC® videolaryngoscope enables better visualisation of glottis as compared to the conventional blade, for endotracheal intubation in patients with simulated limitation of cervical movements. The time taken for laryngoscopy, endotracheal intubation and the overall satisfaction score did not differ between the two blades. Keywords: C-MAC®, D blade, videolaryngoscope, cervical immobilisation