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 > 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.

Comparison of UESCOPE VL 400, I-View, Non-Channeled Airtraq Videolaryngoscopes and Macintosh Laryngoscope for Tracheal Intubation in Simulated Out-of-Hospital Conditions: A Randomized Crossover Manikin Study.

The aim of the study was to test the hypothesis that the results obtained with three different types of video laryngoscopes (UESCOPE VL-400, I-View, Non-Channeled Aitraq) with and without an endotracheal stylet should be better than the results obtained with a Macintosh laryngoscope in a simulated out-of-hospital scenario by a person without clinical experience. Primary outcome measures were the time taken to successfully achieve tracheal intubation (TI). Secondary outcomes included the grade of glottic view (Cormack and Lehane grades 1-4), the incidence of successful TI, the number of audible dental clicks indicating potential dental damage, the level of effort required to perform TI, and the operator's comfort during the procedure. The time required to achieve tracheal intubation successfully was significantly longer with the Macintosh laryngoscope and Airtraq than with the other video laryngoscopes. The use of the stylet significantly reduced the time required for tracheal intubation with the Macintosh laryngoscope (21.8 sec. vs. 24.0 sec., p = 0.026), UESCOPE VL 400 (18.1 sec. vs. 23.4 sec., p = 0.013), and Airtraq (22.7 sec. vs. 34.5 sec., p < 0.001). There were no significant differences in intubation time when using the I-View with or without stylets. No differences were observed in the Cormack-Lehane grading. The success rate of intubation was 100% for the Macintosh and I-View laryngoscopes used with or without stylets and for the UESCOPE VL 400 and Airtraq laryngoscopes used with stylets. Without stylets, the success rate of intubation was 96.6% for the UESCOPE VL 400 and 86.6% for the Airtraq. There were no significant differences in the risk of dental damage between the Macintosh, UESCOPE VL 400, I-View, and Airtraq laryngoscopes, regardless of the use of stylets (without and with stylets). The use of stylets significantly reduced dental damage only for the Airtraq laryngoscope: 8 (26.6%) vs. 2 (6.6%). Statistically significant differences in perceived exertion were observed between the mentioned laryngoscopes, both with and without stylets. However, there were no differences in the comfort of use between the laryngoscopes, regardless of the use of stylets (without and with stylets. The use of stylets led to better comfort in the case of the Macintosh (2.5 vs. 3, p = 0.043) and UESCOPE VL 400 (2 vs. 3, p = 0.008) laryngoscopes. In our study, the I-View and UESCOPE VL-400 video laryngoscopes provided better intubation results than the Macintosh laryngoscope in terms of time needed to intubate, glottis visibility, and reduction in dental damage. The use of the stylet did not significantly improve the intubation results compared to the results obtained in direct laryngoscopy. Due to the small study group and the manikin model, additional studies should be performed on a larger study group.

A comparison of tracheal intubation using intubrite laryngoscope and conventional MAC laryngoscope: An open, prospective, crossover manikin study.

BACKGROUND: New devices are more available in the pre-hospital environment operational theaters and emergency departments. One is an intubrite laryngoscope (INT) with Dual LED lighting that combines ultraviolet and white LED. The study aimed to compare the efficacy of endotracheal intubation using INT and conventional laryngoscope performed by inexperienced paramedics (paramedics students) and paramedics with experience in advanced airways management in full and limited accessibility settings. METHODS: It was an open, prospective, crossover manikin study. Sixty paramedics and paramedic students were recruited. Participants were divided into 2 equal groups depending on their experience (n = 30). Experienced participants were further randomly divided into 2 groups (n = 15). Inexperienced participants were also randomly divided into 2 groups (n = 15). The criterion of inexperience was 5 or fewer intubation by any laryngoscope. Inexperience participants were asked to perform tracheal intubation in standard pre-hospital settings (without limited access to manikin) (scenario A) and difficult pre-hospital settings (limited access to manikin - narrow space between benches) (scenario B). Experience participants were asked to intubate manikin in difficult pre-hospital settings. RESULTS: In the normal pre-hospital environment, the success rate after the first attempt was 56,7% for conventional laryngoscope and 66,7% for intubrite. However, the overall effectiveness of tracheal intubation using both laryngoscopes in 3 attempts was 90% for both devices. The successful rate of first attempt intubation in a difficult environment by inexperienced was 73,3% for INT and 50% for conventional laryngoscope. Overall effectiveness was 83,3% and 86,7% respectively. The successful rate of first attempt intubation in the experienced group was 86,7% with INT compared to 60% with a conventional laryngoscope in difficult settings. Overall effectiveness was 96,7% for both devices. CONCLUSION: Intubrite provided better working conditions and make up for deficiencies in successful tracheal intubation by inexperienced participants in a normal and difficult environment. Tracheal intubation with intubrite was more effective in the experienced group. Tracheal intubation effectiveness with intubrite was also higher in the experienced group.

Is older still good, or even better? Evaluation of possibility of using Miller laryngoscope for intubation in adults and comparison with the most widely used Macintosh laryngoscope. Protocol of a crossover randomized control trial.

Background: Macintosh laryngoscope is the most widely used laryngoscope for intubation. In some patients, e.g. with flaccid, drooping, aplastic epiglottis, usage of this laryngoscope, or even videolaryngoscopes, may not provide visualization of a glottis. Elevation of the laryngopharynx, like in intubation with Miller laryngoscope, may significantly improve intubating conditions. Methods: An anaesthesiologist with over 20 years of experience will perform direct laryngoscopy with randomly chosen Miller or Macintosh blade, evaluating the visibility of rima glottidis with Cormack-Lehane classification and POGO score with and without external laryngeal pressure. Then the second evaluation of glottis with other blade type will be obtained and the patient will be intubated. Comparison of the rima glottidis visibility when using both blades will be the primary endpoint of the study. The secondary endpoints consist of: demonstrating whether there is a group of adult patients in whom the use of the Miller blade associated with better vocal cord visibility may be predicted based on an anesthesiological examination, and whether external laryngeal pressure improves vocal cord visualization more when using the Miller blade compared with the Macintosh blade. Sample size: We performed minimal sample size calculations based on the data derived from the first 60 patients. We assessed the minimal sample size to obtain the alpha of 5 % and power of 90 %. We decide to enroll at least 286 patients. Discussion: this will be the first trial assessing Miller and Macintosh blades in the same population of adult patients. It will determine group of patients in whom Miller laryngoscope will provide better visualization of rima glottidis than Macintosh blade and associated technique, diminishing rate of prolonging intubations and reducing possible aftermaths of hypoxia.

New Devices, Innovative Technologies, and Non-Standard Techniques for Airway Management: A Narrative Review.

A wide range of airway devices and techniques have been created to enhance the safety of airway management. However, airway management remains a challenge. All techniques are susceptible to failure. Therefore, it is necessary to have and know the greatest number of alternatives to treat even the most challenging airway successfully. The aim of this narrative review is to describe some new devices, such as video laryngeal masks, articulated stylets, and non-standard techniques, for laryngeal mask insertion and endotracheal intubation that are not applied in daily practice, but that could be highly effective in overcoming a difficulty related to airway management. Artificial intelligence and 3D technology for airway management are also discussed.

Supraglottic Airway Devices with Vision Guided Systems: Third Generation of Supraglottic Airway Devices.

Supraglottic airway devices are currently widely used for airway management both for anaesthesia and emergency medicine. First-generation SADs only had a ventilation channel and did not provide protection from possible aspiration of gastric content if regurgitation occurred. Second-generation SADs are equipped with a gastric channel to allow the insertion of a gastric catheter and suctioning of gastric content. Additionally, the seal was improved by a change in the shape of the cuff. Some second-generation SADs were also designed to allow for intubation through the lumen using fiberscopes. Although the safety and efficacy of use of SADs are very high, there are still some issues in terms of providing an adequate seal and protection from possible complications related to misplacement of SAD. New SADs which allow users to choose the insertion scope and control the position of SAD can overcome those problems. Additionally, the Video Laryngeal Mask Airway may serve as an endotracheal intubation device, offering a good alternative to fibre-optic intubation through second-generation SADs. In this narrative review, we provide knowledge of the use of video laryngeal mask airways and the possible advantages of introducing them into daily clinical practice.

A pilot, prospective trial of IntuBrite® versus Macintosh direct laryngoscopy for paramedic endotracheal intubation in out of hospital cardiac arrest.

BACKGROUND: Intubation in the case of out-of-hospital cardiac arrest (OHCA) is one of the most difficult procedures for Emergency Medical Services (EMS). The use of a laryngoscope with a dual light source is an interesting alternative to classic laryngoscopes. However, there are as yet no prospective data concerning the use of double light direct laryngoscopy (DL) by paramedics in traditional ground ambulance agencies in OHCA. METHODS: We performed a non-blinded trial in a single EMS in Poland within ambulances crews, comparing time and first pass success (FPS) for endotracheal intubation (ETI) in DL using the IntuBrite® (INT) and Macintosh laryngoscope (MCL) during cardiopulmonary resuscitation (CPR). We collected both patient and provider demographic information along with intubation details. The time and success rates were compared using an intention-to-treat analysis. RESULTS: Over a period of 40 months, a total of 86 intubations were performed using 42 INT and 44 MCL based on an intention-to-treat analysis. The FPS time of the ETI attempt (13.49 vs. 15.55 s) using an INT which was shorter than MCL was used (p < 0.05). First attempt success (34/42, 80.9% vs. 29/44, 64.4%) was comparable for INT and MCL with no statistical significance. CONCLUSIONS: We found a statistically significant difference in intubation attempt time when the INT laryngoscope was used. Intubation first attempt success rates with INT and MCL were comparable with no statistical significance during CPR performed by paramedics. TRIAL REGISTRATION: Trial was registered in Clinical Trials: NCT05607836 (10/28/2022).

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

Background: 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. Materials and Methods: 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. Results and Discussion: 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. Conclusion: 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.

Disinfection of Reusable Laryngoscopes: A Survey about the Clinical Practice in Spain.

Airway device-associated infections resulting from the cross-contamination of reusable laryngoscopes are one of the main causes of healthcare-associated infections. Laryngoscope blades are highly contaminated with various pathogens, including Gram-negative bacilli, which can cause prolonged hospitalization, high morbidity and mortality risks, the development of antibiotic-resistant microorganisms, and significant costs. Despite the Centers for Disease Control and Prevention and the American Society of Anesthesiologists' recommendations, this national survey of 248 Spanish anesthesiologists showed that there is great variability in the processing of reusable laryngoscopes in Spain. Nearly a third of the respondents did not have an institutional disinfection protocol, and 45% of them did not know the disinfection procedure used. Good practices for the prevention and control of cross-contamination can be ensured through compliance with evidence-based guidelines, education of healthcare providers, and audits of clinical practices.

Assessment of the Possibility of Using the Laryngoscopes Macintosh, McCoy, Miller, Intubrite, VieScope and I-View for Intubation in Simulated Out-of-Hospital Conditions by People without Clinical Experience: A Randomized Crossover Manikin Study.

The aim of the study was to evaluate the laryngoscopes Macintosh, Miller, McCoy, Intubrite, VieScope and I-View in simulated out-of-hospital conditions when used by people without clinical experience, and to choose the one that, in the case of failure of the first intubation (FI), gives the highest probability of successful second (SI) or third (TI). For FI, the highest success rate (HSR) was observed for I-View and the lowest (LSR) for Macintosh (90% vs. 60%; p < 0.001); for SI, HSR was observed for I-View and LSR for Miller (95% vs. 66,7%; p < 0001); and for TI, HSR was observed for I-View and LSR for Miller, McCoy and VieScope (98.33% vs. 70%; p < 0.001). A significant shortening of intubation time between FI and TI was observed for Macintosh (38.95 (IQR: 30.1-47.025) vs. 32.4 (IQR: 29-39.175), p = 0.0132), McCoy (39.3 (IQR: 31.1-48.15) vs. 28.75 (IQR: 26.475-35.7), p < 0.001), Intubrite (26.4 (IQR: 21.4-32.3) vs. 20.7 (IQR: 18.3-24.45), p < 0.001), and I-View (21 (IQR: 17.375-25.1) vs. 18 (IQR: 15.95-20.5), p < 0.001). According to the respondents, the easiest laryngo- scopes to use were I-View and Intubrite, while the most difficult was Miller. The study shows that I-View and Intubrite are the most useful devices, combining high efficiency with a statistically significant reduction in time between successive attempts.

Selected Predictors of COVID-19 Mortality in the Hospitalised Patient Population in a Single-Centre Study in Poland.

Background: The correct analysis of COVID-19 predictors could substantially improve the clinical decision-making process and enable emergency department patients at higher mortality risk to be identified. Methods: We retrospectively explored the relationship between some demographic and clinical factors, such as age and sex, as well as the levels of ten selected factors, namely, CRP, D-dimer, ferritin, LDH, RDW-CV, RDW-SD, procalcitonin, blood oxygen saturation, lymphocytes, and leukocytes, and COVID-19 mortality risk in 150 adult patients diagnosed with COVID-19 at Provincial Specialist Hospital in Zgierz, Poland (this hospital was transformed, in March 2020, into a hospital admitting COVID-19 cases only). All blood samples for testing were collected in the emergency room before admission. The length of stay in the intensive care unit and length of hospitalisation were also analysed. Results: The only factor that was not significantly related to mortality was the length of stay in the intensive care unit. The odds of dying were significantly lower in males, patients with a longer hospital stay, patients with higher lymphocyte levels, and patients with higher blood oxygen saturation, while the chances of dying were significantly higher in older patients; patients with higher RDW-CV and RDW-SD levels; and patients with higher levels of leukocytes, CRP, ferritin, procalcitonin, LDH, and D-dimers. Conclusions: Six potential predictors of mortality were included in the final model: age, RDW-CV, procalcitonin, and D-dimers level; blood oxygen saturation; and length of hospitalisation. The results obtained from this study suggest that a final predictive model with high accuracy in mortality prediction (over 90%) was successfully built. The suggested model could be used for therapy prioritization.

Comparison of Three Video Laryngoscopes and Direct Laryngoscopy for Emergency Endotracheal Intubation While Wearing PPE-AGP: A Randomized, Crossover, Simulation Trial.

BACKGROUND: The COVID-19 pandemic has necessitated changes in the safety protocols of endotracheal intubation at every level of care. This study aimed to compare the first-pass success rates (FPS) and intubation times (IT) of three video laryngoscopes (VL) and direct laryngoscopy (DL) for simulated COVID-19 patient emergency intubation (EI). METHODS: The study was a prospective, randomized, crossover trial. Fifty-three active paramedics performed endotracheal intubation with the I-viewTM VL, UESCOPE® VL, ProVu® VL and Macintosh direct laryngoscope (MAC) wearing personal protective equipment for aerosol-generating procedures (PPE-AGP) on a manikin with normal airway conditions. RESULTS: The longest IT was noted when the UESCOPE® (29.4 s) and ProVu® (27.7 s) VL were used. The median IT for I-view was 17.4 s and for MAC DL 17.9 s. The FPS rates were 88.6%, 81.1%, 83.0% and 84.9%, respectively, for I-view, ProVu®, UESCOPE® and MAC DL. The difficulty of EI attempts showed a statistically significant difference between UESCOPE® and ProVu®. CONCLUSIONS: The intubation times performed by paramedics in PPE-AGP using UESCOPE® and ProVu® were significantly longer than those with the I-view and Macintosh laryngoscopes. The use of VL by prehospital providers in PPE did not result in more effective EI than the use of a Macintosh laryngoscope.

A comparison of face-to-face endotracheal intubation and standard intubation using Airtraq video laryngoscope in morbidly obese patients: A randomized controlled trial.

BACKGROUND: Routine endotracheal intubation requires a patient in supine position with an operator standing behind the patient's head. In case of a morbidly obese patient positioned in the recommended semi-recumbent position, an alternative method can be considered. Face-to-face intubation can be used both in patients in sitting as well as in prone position and when there is difficult access to the head. Evaluation of effectiveness and safety of face-to-face intubation in morbidly obese adult patients with body mass index over 40 kg m-2. METHODS: The study was approved by the Local Ethics Committee and written informed consent from patients was obtained. We conducted a parallel randomized controlled trial with patients scheduled for elective sleeve gastrectomy. The trial was registered in ClinicalTrials with a number NCT04959149. Randomization and allocation to trial groups were carried out using the envelope method. The primary outcomes were the time of intubation and the first pass success of endotracheal intubation. RESULTS: 76 patients (routine intubation n = 36, face-to-face intubation n = 40) were included in the study with no dropouts. The intubation success rates were 82.5% versus 100%, mean intubation time was 17.1 ±â€…18 seconds versus 29 ±â€…11 seconds and the need for additional maneuvers (backward, upward, rightward pressure or flexing the neck) was 15% versus 19.5%, in face-to-face and routine intubation, respectively. No injuries to teeth or mucosa have been reported. There were no incidents of desaturation below 92% or other complications associated with intubation. CONCLUSION: Face-to-face intubation is shorter than the routine intubation in obese patients. This method may be an alternative to standard intubation in case of airway management in morbidly obese patients in semi-erect position; however, it requires both training and practice.

Video laryngeal masks in airway management.

INTRODUCTION: Video laryngeal masks have become alternatives to classical supraglottic airway devices in recent years. This review provides information on the background of these new medical devices, the most popular and widely used video laryngeal masks, their advantages, disadvantages and their main applications in airway management. AREAS COVERED: In this review, the physical differences between video laryngeal masks and second-generation laryngeal mask airways, and their properties in specific clinical settings are discussed. EXPERT COMMENTARY: To limit airway-related morbidity, an optimal position of supraglottic airway devices must be the primary goal. Extensive research has shown that blindly inserted laryngeal mask can be malpositioned in 50% to 80% of the cases. Therefore, blind insertion should be the exception rather than the rule unlike current practice. Video laryngeal mask airways have clear advantages in routine use and in difficult airway management since they allow a vision-guided technique. Henceforth, the properties perceived in clinical practice must be endorsed with quality clinical evidence.

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 cm­high 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.

Pre-oxygenation and apneic oxygenation in patients living with obesity - A review of novel techniques.

Morbidly obese patients are in the group of patients, who can desaturate fast because of changes in lung volumes and reduction in Functional Residual Capasity due to obesity. There are novel methods to improve preoxygenation and to maintain oxygneation during intubation efforts. In this paper we present methods of apneic oxygenation for morbidly obese patients.