Macintosh Laryngoscope Blade Research Articles

Comparative study of two different intubating doses of cisatracurium for hemodynamic changes during coronary artery bypass grafting under general anaesthesia

: The aim of the study was to compare hemodynamic response, assessment of intubating condition, time to achieve TOF 0 and any adverse effects associated with two different doses of cisatracurium i.e., 0.15mg/kg (3x ED95) and 0.3mg/kg (6x ED95) for endotracheal intubation during Coronary artery bypass grafting (CABG). : It was a prospective single blinded randomized controlled clinical trial, conducted by two investigators in 296 patients aged between 50-70 years of both sexes of ASA III grades. Patients having ejection fraction >45% and undergoing CABG were included in the study. Patients with neuromuscular diseases, anticipated difficult airway, morbid obesity and any associated valvular heart diseases were excluded from the study. Patients were randomly allocated into 2 groups depending on the doses of cisatracurium. Group R (n=148) → received 0.15 mg/kg, Group D (n=148) → received of 0.3 mg/kg. After 60 seconds of injecting cisatracurium, TOF was recorded every 30 seconds until it reaches 0, then laryngoscopy and endotracheal intubation was carried out using Macintosh laryngoscope blade no. 4 by one of the senior investigators who was blinded. The vital parameters such as heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), Mean arterial pressure (MAP) were monitored for 10 minutes after the administration of cisatracurium. Patients were monitored clinically for any adverse effects of histamine release. : The mean time required to achieve TOF 0 in Group D (0.3mg/kg) was shorter compared to Group R (0.15mg/kg) which was statistically significant. During intubation Group D showed statistically significant stable heart rate variation than Group R. Mean SBP, DBP and MAP did not differ between groups. No incidence of histamine release was observed in any of the group. : Patients who received 0.3mg/kg of cisatracurium showed stable heart rate fluctuation during laryngoscopy and intubation and lesser time to achieve TOF 0 compared to patients who received 0.15mg/kg of cisatracurium.

Comparison of grooved and conventional Macintosh laryngoscope blades for throat pack insertion: A randomized control trial.

Throat pack insertion is required for many otolaryngological surgeries under general anesthesia. To facilitate surgery, an oral Ring, Adair, and Elwyn (RAE) endotracheal tube is used. When the Macintosh blade is used to insert the pack, the tube often moves to the left as per its design. We designed a groove in the Macintosh laryngoscope blade to hold the endotracheal tube in place during pack placement. This study was done to compare the grooved and conventional Macintosh laryngoscope blades for throat pack insertion with respect to the intraoral movement of the tube, ease of packing, time taken, and associated hemodynamic changes in patients who have been intubated with a preformed oral endotracheal tube. This randomized control trial included 80 patients after approval from the institutional ethics committee and CTRI. Informed written consent was taken from all patients. Packing of cases was done with either grooved (group G) or conventional Macintosh laryngoscope blade (group C). Student's t-test, Chi-square test, and Mann-Whitney U test were used to analyze data. The tube remained in the center in 35/40 patients in group G as compared to 10/40 patients in group C (P < 0.0001). Packing the throat was significantly easier (P = 0.005), and time taken to pack the throat was shorter in group G as compared to group C (P = 0.0008). The endotracheal tube remains in the center more often during throat pack insertion using a grooved laryngoscope blade as compared to the conventional Macintosh laryngoscope blade. The grooved blade is easier to use and takes less time to insert the throat pack.

Comparison of Paraglossal Technique of Miller Blade Insertion with McCoy and Macintosh Adult Laryngoscopes on the Cormack–Lehane Grade in Patients with Simulated Restricted Neck Mobility—A Randomized Control Trial

Abstract Background The paucity in round-the-clock availability of advanced tools like flexible bronchoscopes and video laryngoscopes makes it preferable to have alternative easily available gadgets for securing the airway in patients with cervical spine injuries where head and neck movements must be strictly avoided. This study compared the paraglossal technique of Miller blade insertion with the McCoy and Macintosh laryngoscope blades on the Cormack and Lehane grading (CLG) in patients with simulated restricted neck mobility. Methods We randomized 90 patients undergoing general anesthesia to be intubated either using Miller blade (Group-Mill), McCoy blade (Group-McCoy), or Macintosh blade (Group-Mac) following neck restriction using a soft cervical collar. CLG grade, the number of intubation attempts, use of bougie, intubation time, and hemodynamic parameters were noted. Nonparametric data were compared using the chi-squared test and parametric data using one-way analysis of variance. Results Group-MILL had significantly higher patients with Grade-1 CLG compared to Group-Mac (p = 0.02). The number of attempts, use of bougie, and intubation time were, however, comparable among the three groups. The hemodynamic parameters at intubation were not significantly different among the groups. Conclusion In adult patients with simulated restricted neck, the Miller laryngoscope blade, despite providing a better laryngeal view, showed no benefit in decreasing the intubation time when compared to the McCoy or Macintosh blades.

A Comparison of Miller Straight Blade and Macintosh Blade Laryngoscopes for Intubation in Morbidly Obese Patients

The primary objective of this study was to demonstrate whether the Miller blade laryngoscope could provide better visualization of the vocal cords in morbidly obese patients than the Macintosh blade laryngoscope. The secondary objective was to identify the patient-measured factors associated with better visualization of the vocal cords when using the Miller vs. Macintosh blade, as well as whether the application of external pressure might improve the visibility of the glottis during intubation. A prospective, observational study encompassing 110 patients with a BMI &gt; 40 undergoing elective bariatric surgery and intubation procedure was performed. The evaluation of the vocal cords was performed according to the Cormack–Lehane scale and POGO scale in the same patient during intubation, performed with a Miller and a Macintosh blade laryngoscope, in a random matter. The following parameters were assessed: body weight, height, BMI, neck circumference, thyromental distance, sternomental distance, mouth opening, and Mallampati scale and their impact on visualization of the vocal cords using the Miller blade without the application of external pressure. The Miller blade provides an improved view of the glottis compared to the Macintosh blade measured with both the Cormac–Lehane scale (45 (40.91%) without external pressure application on the larynx, and 18 (16.36%) with external pressure application on the larynx) and the POGO scale (45 (40.91%) without external pressure application on the larynx, and 19 (17.27%) with external pressure application on the larynx). The application of laryngeal pressure improved the view of the glottis. Among the measured features, a significant improvement in the visibility of the glottis could be found in patients with a BMI over 44.244 kg/m2 and a neck circumference over 46 cm. To conclude, the usage of the Miller blade improves the visibility of the glottis compared to the Macintosh blade in morbidly obese patients. The recommendation to use the Miller blade in this group of patients requires further investigation, taking into account the effectiveness of the intubation. Trial Registration: NCT05494463.

The efficacy of apneic oxygenation during intubation using a prototype of an oxygenation laryngoscope - a technical simulation

BackgroundRecently, a non-commercial oxygenation laryngoscope was able to maintain apneic oxygenation during simulated intubation efforts. Since that prototype was 3 mm wider than a standard Macintosh laryngoscope blade, the intubation performance of this device may differ from standard blades. A new prototype of an oxygenation laryngoscope was developed, consisting of a standard-size Macintosh blade and a fixed oxygen supply line to the side. Actually, it is unclear at which point of this blade the oxygen supply line should end to facilitate the best possible oxygen supply for apneic oxygenation.MethodsIn this simulation study using a standardized human airway manikin, the efficacy of apneic oxygenation by oxygen insufflation using standard and modified Macintosh blades was compared: a standard Macintosh blade without oxygen supply line as control, one with an additional oxygen supply line ending proximal near the handle, one with the line ending at the middle of the blade, and one with the line ending near the tip. A preoxygenated test lung was connected to an oximeter with a flow rate of 200ml/min, simulating oxygen consumption of a male adult, and to the trachea of an anatomically correctly shaped airway manikin. Apneic oxygenation was performed and oxygen content was measured over a 20-minutes observation period. Experiments were repeated five times for each laryngoscope blade.ResultsOxygen percentage in the test lung dropped from 100 ± 0% at the start of the experiment to 53 ± 1.5% in the room air control group (p < 0.001 compared to all other groups), and to 74 ± 2.5% in the proximal oxygen line group, whereas oxygen percentage remained at 100% in both the medium and distal oxygen line groups (p = 1 between these groups; p < 0.001 between all other groups).ConclusionsIn this simulation study with a preoxygenated airway manikin, the use of a modified Macintosh laryngoscope blade with oxygen line attached at the tip or at the middle were able to maintain apneic oxygenation without measurable drop of oxygen content over 20 min. Proximal placement of the oxygen supply line still showed an advantage against room air, however it did not completely prevent room air from entering the airway.Trial registrationNot applicable.

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.

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.

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.

Anti-Toothbreaker: A Novel Low-Budget Device Enabling Contactless Dental Protection and a Forbidden Technique during Direct Laryngoscopy for Endotracheal Intubation

Iatrogenic dental injury is the most common complication of conventional laryngoscopy during orotracheal intubation. The main cause is unintended pressure and leverage forces from the hard metal blade of the laryngoscope. The aim of this pilot study was to introduce and test a novel, reusable low-budget device not only providing contactless dental protection during direct laryngoscopy for endotracheal intubation, but also enabling, in contrast to established tooth protectors, active levering with conventional laryngoscopes for easier visualization of the glottis. A constructed prototype for intrahospital usage was evaluated by seven participants on a simulation manikin for airway management. Endotracheal intubation was performed with and without the device using a conventional Macintosh laryngoscope (blade size 4) and a 7.5 mm endotracheal tube (Teleflex Medical GmbH, Fellbach, Germany). Necessary time and success of first pass were determined. Degree of visualization of the glottis with and without the device was stated by the participants according to the Cormack and Lehane (CL) classification system and the Percentage of Glottic Opening (POGO) scoring system. In addition, subjective physical effort, feeling of safety regarding successful intubation, and risk for dental injury were queried on a numeric scale between 1 and 10. All participants except one stated that the intubation procedure was easier with usage of the device than without it. On average, this was subjectively perceived as being approximately 42% (range, 15-65%) easier. In addition, time to first pass success, as well as degree of glottis visualization, subjective physical effort, and feeling of safety regarding risk for dental injury, were clearly better with usage of the device. Concerning feeling of safety regarding successful intubation, there was only a minor advantage. No difference in first pass success rate and number of total attempts could be observed. The Anti-Toothbreaker is a novel, reusable low-budget device which might not only provide contactless dental protection during direct laryngoscopy for endotracheal intubation, but also enables, in contrast to established tooth protectors, active levering with conventional laryngoscopes for easier visualization of the glottis. Future human cadaveric studies are needed to investigate whether these advantages also prove themselves there.

An Evaluation of the Intubrite Laryngoscope in Simulated In-Hospital and Out-of-Hospital Settings by Individuals with No Clinical Experience: A Randomized, Cross-Over, Manikin Study.

Introduction: The aim of the study was to compare the Intubrite laryngoscope and the standard Macintosh blade laryngoscope (MCL) used by persons with no clinical experience in simulated hospital and non-hospital conditions on a manikin model. Materials and methods: The study involved 50 students of Medical Rescue. The hospital conditions (intubation height 110 cm—high position) and those occurring at the scene (intubation of a manikin located at floor level-low position) were simulated. The analysis included: duration of intubation, visibility of the laryngeal opening by the Cormack–Lehane scale, the bioelectrical activity of the intubating muscles, comfort and subjective assessment of physical effort by the Borg scale (Borg’s scale of subjective feeling of effort). The statistical analysis was performed with Microsoft Excel and T-student tests for pairs with unequal variables. The statistical importance was set at p < 0.05. Results: The use of an Intubrite laryngoscope significantly reduces the mean endotracheal intubation time compared to the Macintosh laryngoscope in a low position (17.34 s versus 19.04 s, p < 0.05). A higher rate of repeat intubations was observed in a low position for MCL (from 10% to 14%, p < 0.05). The reverse is true for Intubrite laryngoscope intubation (from 8% to 4%, p < 0.05 Please explain what is compared). The Intubrite laryngoscope improved visualization of glottis in the high and the low positions compared to the Macintosh laryngoscope (54% and 50% to 52% and 38%, respectively, p < 0.05). The risk of tooth damage was the same for the Intubrite and the MCL laryngoscopes in a high position (16% and 14%, respectively, p > 0.05), while in the simulated out-of-hospital setting, it was significantly higher for the MCL (22% versus 8%, p < 0.05). The subjective comfort of intubation in both simulated situations was similar according to the Borg scale (p-value, values). The use of the Intubrite laryngoscope was associated with less effort than the MCL in high versus low positions. For MCL, intubation in a high position was associated with lower mean muscle activity than in a low position (+48.24 µV versus +58.25 µV, p-value). For the Intubrite laryngoscope, these values were at similar levels (+52.03 µV and +52.65 µV, p-value). Conclusions: The use of the Intubrite laryngoscope by people with no clinical experience shortens the time of intubation and improves the laryngeal view compared to the standard Macintosh laryngoscope, but it requires similar muscle work in simulated conditions.

Comparison of the stress response and intubating performance in endotracheal intubation with Macintosh and McCoy laryngoscopes

Introduction: Laryngoscopy and intubation cause stress response and sympathetic stimulation within the body. Attenuation of these changes by pharmacological means and improved technique with modified instruments is of absolute importance, for stable hemodynamics of the patients. Aim: Comparison of stress response to laryngoscopy and intubation, Intubation Difficulty Score (IDS) using Macintosh and McCoy laryngoscopes. Material and methods: After obtaining institutional ethical committee approval and patient consent in this randomized study, sixty patients of ASA grade I and II, posted for elective surgery under general anaesthesia were intubated with Macintosh or McCoy laryngoscopes. Changes in heart rate, mean arterial pressure, systolic and diastolic blood pressure were observed upto 15 minutes after laryngoscopy, along with IDS. Results: McCoy group when compared with Macintosh group had significant reduction in heart rate at T0 (p value &lt;0.0001), systolic blood pressure at T0, T1 and T15 (p value &lt; 0.001), diastolic blood pressure at T0, T10 and T15 (p value &lt;0.05), mean arterial blood pressure at T0, T10 and T15 (p value &lt;0.05) was observed in this study. Conclusion: Hemodynamic stress response with McCoy blade laryngoscope was reduced in magnitude in comparison with Macintosh blade laryngoscope.

Comparison of the Airtraq video laryngoscope versus Macintosh laryngoscope for tracheal intubation in the pediatric patients

Securing a patent airway in patients undergoing general anesthesia is routinely done using gold standard methods of direct laryngoscopy with a Macintosh or Miller laryngoscope blade in children. However, this technique has several limitations. Video laryngoscopes provide the user with a better view of the larynx. We undertook this prospective, randomized, controlled trial to determine the intubation time of Airtraq compared with Macintosh laryngoscope in pediatric patients, number of intubation attempts, quality of visualization, optimization maneuvers, easiness of intubation, and cardiovascular changes during intubation. A total of 80 pediatric patients of either sex, between ages three to twelve years, belonging to American Society of Anesthesiologists (ASA) status I and II, who were divided equally into two groups using the sealed envelope technique. Patients were randomly assigned to be intubated with either Airtraq (Group A) or Macintosh laryngoscope (Group M). The difference between the time required for intubation within the two groups was significant (p &lt; 0.05), optimization maneuvers were more required for Group M than Group A (p &lt; 0.01). Quality of visualization was better in Group A compared with patients in Group M (p &lt; 0.05).

A Comparative Study of Glottic Visualization and Ease of Intubation with McCoy and Macintosh Laryngoscopes

Introduction: The anaesthetist should protect the airways during induction, recovery and maintenance during anaesthesia. The Macintosh blade is the utmost prevalent blades with a slightly back curved that extends all the way to the tip. The McCoy blade is grounded on a normal Macintosh blade with a hinged tip and is functioned by a lever mechanism located at the handle back. Objective: This study attempts to compare McCoy and Macintosh blades to facilitate intubation for glottis imaging. Place and Duration: In the Department of Anesthesia, Divisional Headquarter teaching Hospital Mirpur Azad Kashmir for six months duration from June 2021 to November 2021. Method: The study included 70 Grade I and II ASA adults of both sexes (20 to 60 years) who endured planned surgery under GA necessitating intubation by endotracheal tube. Using a computer-generated randomization table, individuals were assigned randomly to any of the 2 groups contingent on the type of laryngoscope blades used while doing intubation. After anaesthesia induction, ‘laryngoscopy’ was done and the intubation of trachea was done. McCoy Laryngoscope Blade was used in In Group A while Macintosh Laryngoscope Blade in Group B. The number of trials, Cormack Lehane classification, the necessity for external laryngeal manipulation and degree of intubation difficulty were evaluated. Results: Both groups were comparable for sex, weight, age, height, MPC grading, ASA status and among the two groups; no statistically significant alteration was noted (p-value&gt; 0.05). In Group A and B Cormack Lehane classification in Grade-I scored 82.9% and 60%, correspondingly, while Grade-II scoring in Group A and B were 17% and 25.8%, correspondingly. The Grade-I Intubation Difficulty score (IDS) in Groups A and Group B were 88.6% and 80%, respectively, while Grade-II IDS in Groups A and B were 11.4% and 14.2%. 8.5% of patients in group A and 5.7% of patients in group B required two intubation attempts. Conclusion: There are no significant fluctuations to the glottis visualization with Macintosh and McCoy laryngoscopes, but in terms of external manipulation of larynx, the McCoy laryngoscope is superior to the Macintosh laryngoscope in terms of comfort of intubation. Keyword: endotracheal tube, Macintosh blades, Macintosh and McCoy laryngoscopes.

A randomized control led study comparing CMAC video laryngoscope and Macintosh laryngoscope for insertion of double lumen tube in patients undergoing elective thoracotomy.

Background and Aims:Double lumen tube (DLT) insertion for isolation of lung during thoracic surgery is challenging and is associated with considerable airway trauma. The advent of video laryngoscopy has revolutionized the management of difficult airway. Use of video laryngoscopy may reduce the time to intubate for DLTs even in patients with normal airway.Material and Methods:A total of 87 ASA 1–3 adults, scheduled to undergo elective thoracotomy, requiring a DLT were randomly allocated to videolaryngoscope (CMAC) arm or Macintosh laryngoscope arm. It was on open label study, and only the patient was blinded. The primary objective of this study was to compare the mean time taken for DLT intubation with CMAC (Mac 3) and Macintosh laryngoscope blade and the secondary objectives included the hemodynamic response to intubation, the level of difficulty using the intubation difficulty scale (IDS), and complications associated with intubation. Data was analysed using the statistical software SPSS (version 18.0).Results:The time taken for intubation was not significantly different (42.8 ± 14.8 s for CMAC and 42.5 ± 11.5 s for Macintosh laryngoscope P -0.908). The CMAC video laryngoscope was associated with an improved laryngoscopy grade (Grade I in 81.8% with CMAC and in 46.5% with Macintosh), less pressure applied on the tongue, and less external laryngeal pressure required. Hemodynamic responses to intubation were similar in both groups.Conclusion:Macintosh blade is as good as CMAC (mac 3) blade to facilitate DLT intubation in adult patients with no anticipated airway difficulty, however CMAC was superior as it offers better laryngoscopic view, needed less force, and fewer external laryngeal manipulations.

A comparative study of laryngeal view and pressor response by using three different blades- Macintosh, miller and Mccoy laryngoscopes

Maintenance of airway during anaesthesia is very important to anaesthesiologist. A prospective, randomized study was conducted in 90 patients (ASA-I & II) posted for various surgeries under general anaesthesia with endotracheal intubation to evaluate differences in glottic view, attempts and duration of laryngoscopy and intubation attempts along with hemodynamic variability associated with the three blades- Macintosh, McCoy and Miller laryngoscope blade. Patients were randomly allocated in three groups. In first group laryngoscopy was done with Macintosh blade, in second group with Miller blade, in third group with McCoy blade. In this study it was found that McCoy laryngoscope is distinctly superior to the Macintosh and Miller with less hemodynamic changes and better glottic visualization. Degree of difficulty in intubation was more with Miller blade in comparison to Macintosh and McCoy blade which is statistically significant (p value < 0> Keywords: Cormack lehane grade, Macintosh blade, McCoy blade, Miller blade, Degree of difficulty in intubation.

A Comparison of a Standard Macintosh Blade Laryngoscope, Pentax-AWS Videolaryngoscope and Intubrite Videolaryngoscope for Tracheal Intubation in Manikins in Sitting and Prone Positions: A Randomized Cross-Over Study.

Background: Intubation of a patient in different positions may be done not only in emergency settings, but also in routine anesthesia (e.g., prone position for lumbar spine surgery). Methods: The aim of the study was to compare the classic Macintosh blade laryngoscope with two videolaryngoscopes: the Pentax-AWS and the Intubrite in a simulated scenario of a manikin placed in a sitting and prone position. Additionally, intubation with the use of all three devices was performed in a standard supine position as the control group. The time of intubation and the pressure exerted on the tongue was assessed. The ANOVA Friedman (analysis of variance) and Wilcoxon with Bonferroni correction tests were used for statistical analysis. Results: The time of intubation in a prone position was significantly shorter for the Pentax-AWS videolaryngoscope compared to the Macintosh and the Intubrite. There were no significant differences in the obtained results of the evaluated devices in sitting and standard positions. The lowest pressure exerted on the tongue was with the Pentax-AWS, followed by the Intubrite and the Macintosh laryngoscopes. Conclusions: The use of the Pentax-AWS was associated with faster tracheal intubation, creating lower pressure on tongue when compared with standard Macintosh and Intubrite laryngoscopes in both prone and sitting positions.

Comparision of the hemodynamic response to laryngoscopy and intubation using McCoy and Macintosh laryngoscopic blade

Background: The Macintosh blade is one of the most popular blades with a gently curved tongue which extends to the tip. The McCoy blade laryngoscope has a hinge on the tip to avoid the lifting force in the vallecula reducing the amount of force exerted in the vallecula causing less hemodynamic changes. Aim: An attempt had been made to compare hemodynamic changes during laryngoscopy with Macintosh and McCoy laryngoscopes in adult patients undergoing elective surgeries. Materials and Methods: Institutional Ethics Committee approval was taken before the commencement of the study. An informed and written consent was taken from every patient selected for the study. Sixty adults (18–60 years) of both sexes, American Society of Anesthesiologists Grade I and II, undergoing elective surgery under general anesthesia requiring endotracheal intubation were enrolled in this study. Patients were randomly divided into two groups. Group A – where McCoy laryngoscope blade was used for laryngoscopy and Group B – where Macintosh laryngoscope blade was used for laryngoscopy. After induction of anesthesia, laryngoscopy was performed, and trachea was intubated. The change in systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and heart rate (HR) was observed for 10 min post intubation. Statistical Analysis Used: All the data were compiled and using independent t test they were compared. Results: McCoy group showed statistically significant lower values of mean HR, SBP, DBP, and MAP till 5 min after intubation when compared to Macintosh group (P < 0.05). Conclusions: HR, SBP, DBP, and MAP all did rise in both the group following laryngoscopy and intubation but changes with McCoy laryngoscope were less and statistically significant when compared to Macintosh laryngoscopes.

Evaluation and comparison of haemodynamic response and ease of intubation between Truview PCD TM, McCOY and Macintosh laryngoscope blades

Evaluation and comparison of haemodynamic response and ease of intubation between Truview PCD TM, McCOY and Macintosh laryngoscope blades - IJCA- Print ISSN No: - 2394-4781 Online ISSN No:- 2394-4994 Article DOI No:- 10.18231/j.ijca.2019.039, Indian Journal of Clinical Anaesthesia-Indian J Clin Anaesth

Comparison between Macintosh, Miller and McCoy laryngoscope blade size 2 in paediatric patients - A randomised controlled trial.

Background and Aims:Paediatric airway needs special consideration as it is not a miniature replica of adult airway, rather it has different anatomy with different proportion and angulations. This study was conducted with the aim to find a laryngoscope blade that provides best laryngoscopic and intubation conditions in paediatric patients of age 2–6 years.Methods:This trial was conducted in a total of 75 children age 2–6 years, either gender, with American Society of Anesthesiologists grade I or II scheduled for elective surgery under general anaesthesia. They were randomly allocated to groups A, B and C to be intubated with Macintosh, Miller and McCoy blades, respectively. Intubation Difficulty Score (IDS) was considered as primary outcome, and Cormack–Lehane grade and Percentage of Glottic Opening (POGO) score were taken as secondary outcome. Data were compared by ANOVA or Kruskal-Wallis or chi square test using Statistica, SPSS and GraphPad Prism softwares. P < 0.05 was considered statistically significant.Results:IDS score was significantly lower (P = 0.002) in group B (0.6 ± 0.7) as compared to group A (1.4 ± 0.9) and group C (1.3 ± 1.1); majority of patients in group B (48%) had Cormack–Lehane grade Ι (P = 0.002) unlike group A (0%) and group C (20%) and POGO score (P < 0.001) was higher in group B (86 ± 23.4) when compared with groups A (68.2 ± 20.5) and C (59.8 ± 28.9). Haemodynamic changes and other intubation parameters were comparable among the groups.Conclusion:Miller blade may be considered superior to Macintosh and McCoy blades in terms of glottic visualisation and ease of intubation in paediatric patients.

COMPARATIVE ASSESSMENT OF DIFFERENT TYPES OF LARYNGOSCOPES BLADES - MACINTOSH, MILLER AND MCCOY FOR LARYNGEAL VIEW AND PRESSOR RESPONSE

The laryngoscopy is known to have profound cardiovascular effects. This includes pressor response and tachycardia along with an increase in catecholamine concentration, mainly norepinephrine. The major cause of the sympathoadrenal response is believed to arise from stimulation of supraglottic region by laryngoscopic blade with tracheal tube placement and cuff inflation contributing little additional stimulation. Complications of pressor respo laryngoscopy include myocardial ischemia, cardiac failure, intracranial haemorrhage and increase in intracranial pressure. Hence the present study planned to evaluate the laryngeal view and pressor response by using three different blades – Macintosh, McCoy and Miller laryngoscopes.&#x0D; The study was planned in the Department of Anaesthesia in Andaman and Nicobar Islands Institute of Medical Science (ANIIMS), Port Blair India, From Jun 2016 to Jun 2017 . The 30 patient undergoing the Laryngoscopy were enrolled in the present study. For the 10 patients using the Macintosh Blade were divided in Group I. The next 10 patients using the Miller blade were considered in the Group II. The remaining 10 patients were studied by use of McCoy blade.&#x0D; The results in our study show that the MacCoy laryngoscope blade improves the visualization of the larynx and significantly attenuates haemodynamic parameters during laryngoscopy and intubation as compared to that with Macintosh laryngoscope blade.&#x0D; Keywords: Laryngoscopy, Intubation, pressor response, Macintosh, miller and Mccoy laryngoscopes, etc