Does the Miller blade truly provide a better laryngoscopic view and intubating conditions than the Macintosh blade in small children?

Airway management in neonates and infants: European Society of Anaesthesiology and Intensive Care and British Journal of Anaesthesia joint guidelines

Airway management is required during general anaesthesia and is essential for life-threatening conditions such as cardiopulmonary resuscitation. Evidence from recent trials indicates a high incidence of critical events during airway management, especially in neonates or infants. It is important to define the optimal techniques and strategies for airway management in these groups. In this joint European Society of Anaesthesiology and Intensive Care (ESAIC) and British Journal of Anaesthesia (BJA) guideline on airway management in neonates and infants, we present aggregated and evidence-based recommendations to assist clinicians in providing safe and effective medical care. We identified seven main areas of interest for airway management: i) preoperative assessment and preparation; ii) medications; iii) techniques and algorithms; iv) identification and treatment of difficult airways; v) confirmation of tracheal intubation; vi) tracheal extubation, and vii) human factors. Based on these areas, Population, Intervention, Comparison, Outcomes (PICO) questions were derived that guided a structured literature search. GRADE (Grading of Recommendations, Assessment, Development and Evaluation) methodology was used to formulate the recommendations based on those studies included with consideration of their methodological quality (strong '1' or weak '2' recommendation with high 'A', medium 'B' or low 'C' quality of evidence). In summary, we recommend: 1. Use medical history and physical examination to predict difficult airway management (1C). 2. Ensure adequate level of sedation or general anaesthesia during airway management (1B). 3. Administer neuromuscular blocker before tracheal intubation when spontaneous breathing is not necessary (1C). 4. Use a videolaryngoscope with an age-adapted standard blade as first choice for tracheal intubation (1B). 5. Apply apnoeic oxygenation during tracheal intubation in neonates (1B). 6. Consider a supraglottic airway for rescue oxygenation and ventilation when tracheal intubation fails (1B). 7. Limit the number of tracheal intubation attempts (1C). 8. Use a stylet to reinforce and preshape tracheal tubes when hyperangulated videolaryngoscope blades are used and when the larynx is anatomically anterior (1C). 9. Verify intubation is successful with clinical assessment and end-tidal CO2 waveform (1C). 10. Apply high-flow nasal oxygenation, continuous positive airway pressure or nasal intermittent positive pressure ventilation for postextubation respiratory support, when appropriate (1B).

Airway management in neonates and infants: European Society of Anaesthesiology and Intensive Care and British Journal of Anaesthesia joint guidelines

Airway management is required during general anaesthesia and is essential for life-threatening conditions such as cardiopulmonary resuscitation. Evidence from recent trials indicates a high incidence of critical events during airway management, especially in neonates or infants. It is important to define the optimal techniques and strategies for airway management in these groups. In this joint European Society of Anaesthesiology and Intensive Care (ESAIC) and British Journal of Anaesthesia (BJA) guideline on airway management in neonates and infants, we present aggregated and evidence-based recommendations to assist clinicians in providing safe and effective medical care. We identified seven main areas of interest for airway management: i) preoperative assessment and preparation; ii) medications; iii) techniques and algorithms; iv) identification and treatment of difficult airways; v) confirmation of tracheal intubation; vi) tracheal extubation, and vii) human factors. Based on these areas, Population, Intervention, Comparison, Outcomes (PICO) questions were derived that guided a structured literature search. GRADE (Grading of Recommendations, Assessment, Development and Evaluation) methodology was used to formulate the recommendations based on those studies included with consideration of their methodological quality (strong '1' or weak '2' recommendation with high 'A', medium 'B' or low 'C' quality of evidence). In summary, we recommend: 1. Use medical history and physical examination to predict difficult airway management (1С). 2. Ensure adequate level of sedation or general anaesthesia during airway management (1B). 3. Administer neuromuscular blocker before tracheal intubation when spontaneous breathing is not necessary (1С). 4. Use a videolaryngoscope with an age-adapted standard blade as first choice for tracheal intubation (1B). 5. Apply apnoeic oxygenation during tracheal intubation in neonates (1B). 6. Consider a supraglottic airway for rescue oxygenation and ventilation when tracheal intubation fails (1B). 7. Limit the number of tracheal intubation attempts (1C). 8. Use a stylet to reinforce and preshape tracheal tubes when hyperangulated videolaryngoscope blades are used and when the larynx is anatomically anterior (1C). 9. Verify intubation is successful with clinical assessment and end-tidal CO 2 waveform (1C). 10. Apply high-flow nasal oxygenation, continuous positive airway pressure or nasal intermittent positive pressure ventilation for postextubation respiratory support, when appropriate (1B).

[Airway Management in Paediatric Anaesthesia]

Due to their low reserves, hypoxia and cardiac arrest occur rapidly in children. The continuous securing of the airway as well as maintenance of oxygenation and ventilation are of prior importance in paediatric anaesthesia. For this purpose, bag-mask ventilation and the opening of the upper airway must be trained and mastered in particular. As the most important supraglottic device, the laryngeal mask has been evaluated for patients of all ages.

Comparative efficacy of C-MAC® Miller videolaryngoscope versus McGrath® MAC size "1" videolaryngoscope in neonates and infants undergoing surgical procedures under general anesthesia: A prospective randomized controlled trial

BACKGROUND

Various anatomical and physiological factors make intubation in infants challenging. C-MAC videolaryngoscope shows better results as compared to the conventional direct laryngoscopy for intubation in infants. McGrath MAC size-1 with a disposable Macintosh type blade has recently been introduced for use in infants and has not been formally evaluated in this population.

AIMS

This study aims to evaluate the intubation characteristics of C-MAC Miller and McGrath MAC in neonates and infants with the primary objective to compare the time with the two devices.

METHODS

After informed consent from the parents, 140 neonates and infants scheduled for surgical procedures were randomized to undergo intubation with either C-MAC Miller or McGrath MAC after standard general anesthesia. The two devices were compared in terms of total intubation time, Percent of Glottic Opening score, Cormack Lehane grades, time to glottis view, intubation difficulty score, overall success rate, first attempt success rate, and complications.

RESULTS

The median glottic view time (6 s [4-9] vs. 6 s [4-9]; p = .40) and intubation time (27 s [25.5-28] vs. 27 s [24.5-29.5]; p = .87) were similar. The mean difference (95% CI) in time to tracheal intubation and time to glottic view was 0.49 s [-3.1 to 2.1] and -1.7 s [-3.8 to 0.47], respectively. However, the Percent of Glottic Opening score, Cormack Lehane grades, and subjective intubation difficulty were significantly better with C-MAC. The first attempt success rates, overall success rates (100% vs. 97.5%), and intubation difficulty scores were comparable. There were two failed intubations with McGrath which were successfully intubated with C-MAC.

CONCLUSION

The C-MAC Miller blade showed similar intubation timings, success rates, and intubation difficulty score as compared to McGrath MAC in neonates and infants, though the former provided superior glottic views. Both the videolaryngoscopes may be safely used in infants and neonates for routine intubation scenarios.

Frequency distribution of modified Cormack-Lehane views-A retrospective audit of tracheal intubation in children with normal airways

BACKGROUND

Paediatric patients with an unanticipated poor grade of laryngoscopic view during tracheal intubation represent a challenging situation potentially associated with increased morbidity and mortality. The aim of this study was to investigate the frequency of modified Cormack-Lehane (MCL) views and to elucidate variables for poor views in a large collective of children without anticipated airway difficulties.

METHODS

The departmental anaesthesia patient database was searched for patients who had undergone general anaesthesia with tracheal intubation between January 2007 and March 2017. Inclusion criteria were age from birth to 17.99 years, general anaesthesia with tracheal intubation using direct laryngoscopy, no history, symptoms or signs of a difficult airway and the best obtained MCL view documented in the database. Patient- and anaesthesia-related variables associated with a poor view (MCL IIb, III and IV) were elucidated using a logistic regression model.

RESULTS

In all, 22 965 patients were included; of these, 17 593 were observed only once. The prevalence of the first observed MCL views I, IIa, IIb, III and IV was 90.6%, 8.5%, 0.86%, 0.05% and 0%, respectively. The logistic regression model indicates that age and gender are the most important variables associated with MCL views IIb and III in the model. The probability for MCL views IIb/III decreases across the first 5-7 years before increasing again.

CONCLUSIONS

The incidence of a poor grade of laryngoscopic view was found to be very low in children with a normal airway. They mainly occurred in infants and adolescent patients and were more common in male patients.

Learner and educator experiences and priorities in paediatric airway education: A qualitative study

Paediatric airway management is a challenging area of anaesthesia practice to learn. Techniques and skills required need modification from adult practice and gaining experience through exposure takes considerable time. Preparation to manage airway emergencies can be particularly difficult as these events are rare in paediatric practice. This study aimed to examine what educational approaches health professionals of varying backgrounds find useful when learning or teaching paediatric airway management. This qualitative study involved the conduct of five interdisciplinary focus groups; each group consisted of four to six health professionals from nursing, anaesthetic, simulation and critical care backgrounds. After transcription, focus group content was analysed using a qualitative method to identify common themes expressed within the interviews. Five themes were most prominent. These included the high value of hands-on learning, the challenges created by variability in exposure, the importance of developing basic airway skills, the potential for simulation to cover rare situations, and the problems of current airway models. These themes were evident in comments from both experienced and novice practitioners, clinicians with different subspecialty backgrounds and both medical and nursing staff. Learners and educators have similar priorities in airway education. This includes a strong recognition of the importance of spending time mastering basic airway techniques, a role for simulation in building non-technical skills and noted deficiencies in current airway models.

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.

Improvement of laryngoscopic view by hand-assisted elevation and caudad traction of the shoulder during tracheal intubation in pediatric patients

Pediatric patients have large heads and relatively small bodies, making it difficult to perform intubation even in the sniffing position. Therefore, this study was planned on the assumption that hand-assisted elevation and caudad traction of the shoulder (HA-ECTS) would compensate for the laryngoscopic view. In this observational study, 45 pediatric patients aged 0–36 months with an ASA physical status of I-III and scheduled for elective surgery under general anesthesia were enrolled. HA-ECTS was defined as hand-assisted personalized traction in the upper and caudad directions with both hands under the lower cervical area. The POGO (percentage of glottis opening) score, MO (mouth opening), and LHS (laryngoscopic handling score) were compared before and after HA-ECTS. The median [range] POGO score was 30[10–50]% and 60[15–80]% before and after HA-ECTS, respectively (median difference, 20; 95% confidence interval [CI] 10 to 25%; P = 0.002). MO was 1.0[0.8–1.9] cm and 1.8[1.3–2.0] cm before and after HA-ECTS, respectively (median difference, 0.45 cm; 95% CI 0.25 to 0.60; P < 0.001). The ease of laryngoscopic handling was improved after HA-ECTS(P < 0.001). The application of HA-ECTS to pediatric patients younger than 3 years improved POGO score, MO, and LHS and could prove to be an assistive technique for tracheal intubation.

Laryngoscopes for difficult airway scenarios: a comparison of the available devices

INTRODUCTION

According to the American Society of Anesthesiologists, the incidence of difficult intubation in the operating room is 1.2-3.8%; however, in emergency conditions, this rate is higher and reaches even 5.3%. Successful emergency airway management is an essential component of the modern practice of medicine.

AREAS COVERED

The aim of the study is to review the literature regarding different devices used to perform endotracheal intubation (Macintosh, Miller, and McCoy laryngoscopes; ETView, GlideScope, TruView, Airtraq, McGrath MAC, Pentax AWS, Trachlight, Shikani, and Bullard) and discuss their clinical and experimental role in difficult airway management.

EXPERT COMMENTARY

Owing to the development of medical technology, there are an increasing number of videolaryngoscopes and other devices facilitating endotracheal intubation in difficult airway scenarios, including cardiopulmonary resuscitation, cervical spine injury, or face-to-face intubation. Each of these devices may bring benefits in the form of increasing the intubation effectiveness, as well as shortening the procedure, provided that the person performing intubation is familiar with the use of the device.

Airtraq Laryngoscope Versus the Conventional Macintosh Laryngoscope During Pediatric Intubation Performed by Nurses: A Randomized Crossover Manikin Study With Three Airway Scenarios

OBJECTIVES

We hypothesized that the Airtraq laryngoscope (Airtraq LLC, Bonita Springs, Fla) is beneficial for intubation of pediatric manikins while performing cardiopulmonary resuscitation (CPR). In the present study, we evaluated the effectiveness of the Macintosh (MAC) laryngoscope (HEINE Optotechnik, Munich, Germany) and Airtraq in 3 simulated CPR scenarios.

METHODS

A randomized crossover simulation trial was designed. Eighty-three nurses intubated the trachea of a PediaSIM CPR training manikin (FCAE HealthCare, Sarasota, Fla) using the MAC and Airtraq in a normal airway scenario, normal airway with chest compression scenario, and difficult airway with chest compression scenario. The participants were directed to perform a maximum of 3 attempts in each scenario. The success rate, time to intubation, Cormack & Lehane grade, dental compression, and the ease of intubation were measured.

RESULTS

All participants performed successful intubation with the Airtraq in all 3 scenarios. In all scenarios, the success rate was significantly higher and the time to intubation was significantly shorter with the Airtraq than with the MAC. Glottic visualization using the Cormack-Lehane scale was also better when using Airtraq in all scenarios.

CONCLUSIONS

In this manikin study, we found that the Airtraq can be used successfully for the intubation of pediatric manikins with normal and difficult airways by medical staff without previous experience in pediatric intubation. Moreover, intubation can be achieved without interrupting chest compression. The use of the Airtraq compared with the MAC led to faster time to intubation. Nevertheless, we recommend that the performance of the Airtraq and the MAC during CPR should be further evaluated in a clinical setting.

Implementation of NAP4 emergency airway management recommendations in a quaternary-level pediatric hospital

Emergency airway management, particularly outside of the operating room, is associated with a high incidence of life-threatening adverse events. Based on the recommendations of the 4th National Audit Project, we aimed to develop hospital-wide systems changes to improve the safety of emergency airway management. We describe a framework for governance in the form of a hospital airway special interest group. We describe the development and implementation of the following systems changes: 1. A local intubation algorithm modified from the Difficult Airway Society's plan A-B-C-D approach, including clear pathways for airway escalation, and emphasizing the concepts of resuscitation prior to intubation, planning for failure, and avoidance of fixation error. 2. Simplified and standardized airway equipment located in identical airway carts in all critical care areas. 3. A preintubation checklist and equipment template to standardize preparation for airway management. 4. Availability of continuous waveform endtidal capnography in all critical care areas for confirmation of correct endotracheal tube placement. 5. Multidisciplinary team training to address the technical and nontechnical aspects of nonoperating room intubation. In addition, we describe methodology for ongoing monitoring of performance through a quality assurance framework. In conclusion, changes in the process of emergency airway management at a hospital level are feasible through collaboration. Their impact on patient-based outcomes requires further study.

Comparative evaluation of Airtraq™ optical Laryngoscope and Miller's blade in paediatric patients undergoing elective surgery requiring tracheal intubation: A randomized, controlled trial

BACKGROUND AND AIMS

The Airtraq™ optical laryngoscope is the only marketed videolaryngoscope for paediatric patients besides the fibre-optic bronchoscope. We hypothesized that intubation would be easier with Airtraq™ compared to Miller blade. Hence, we compared Airtraq™ with the Miller laryngoscope as intubation devices in paediatric patients.

METHODS

This prospective, randomized study was conducted in a tertiary care teaching hospital. Sixty children belonging to American Society of Anesthesiologists' Grade I-II, aged 2-10 years, posted for routine surgery requiring tracheal intubation were randomly allocated to undergo intubation using a Miller (n = 30) or Airtraq™ (n = 30) laryngoscope. The primary outcome measure was time of intubation. We also measured ease of intubation, number of attempts, percentage of glottic opening score (POGO), haemodynamic changes and airway trauma. Student t test was used to analyse parametric data.

RESULTS

Intubation time was comparable between Miller's laryngoscope (15.13 ± 1.33s) compared to Airtraq™ (11.53 ± 0.49 s) (P = 0.29) The number of first and second attempts at intubation were 25 and 5 for the Miller laryngoscope and 29 and 1 for the Airtraq™. Median visual analogue score (VAS) for ease of intubation was 5 in Miller group compared to 3 in Airtraq™ group. The median POGO score was 75 in the Miller group and 100 in the Airtraq™ group (P = 0.01). Haemodynamic changes were maximum and most significant immediately and 1 min after intubation. Airway trauma occurred in three patients (9.09%) in Miller group and one patient (3.33%) in Airtraq™ group.

CONCLUSION

The Airtraq™ reduced the difficulty of tracheal intubation and degree of haemodynamic stimulation compared to the Miller laryngoscope in paediatric patients.

Comparison of the Success of Two Techniques for the Endotracheal Intubation with C-MAC Video Laryngoscope Miller Blade in Children: A Prospective Randomized Study

Background. Ease of endotracheal intubation with C-MAC video laryngoscope (VLS) with Miller blades 0 and 1 has not been evaluated in children. Methods. Sixty children weighing 3-15 kg with normal airway were randomly divided into two groups. Intubation was done with C-MAC VLS Miller blade using either nonstyletted endotracheal tube (ETT) (group WS) or styletted ETT (group S). The time for intubation and total procedure, intubation attempts, failed intubation, blade repositioning or external laryngeal maneuver, and complications were recorded. Results. The median (minimum/maximum) time for intubation in group WS and group S was 19.5 (9/48) seconds and 13.0 (18/55) seconds, respectively (p = 0.03). The median (minimum/maximum) time for procedure in group WS was 30.5 (18/72) seconds and in group S was 24.5 (14/67) seconds, respectively (p = 0.02). Intubation in first attempt was done in 28 children in group WS and in 30 children in group S. Repositioning was required in 14 children in group WS and in 7 children in group S (p = 0.06). There were no failure to intubate, desaturation, and bradycardia in both groups. Conclusion. Styletted ETT significantly reduces time for intubation and time for procedure in comparison to nonstyletted ETT.

How to perform endoscopy in paediatric otorhinolaryngology?

Upper airway endoscopy in children is a high-risk procedure, which should only be performed by a well trained and fully equipped team. The sequence of procedures, at least at the beginning of the procedure, is always the same and must be performed very rigorously. Communication between the various operators, especially the surgeon, the anaesthetist and the operating room nurse, is essential before starting the procedure, as anticipation of sudden difficulties is the key to effective management. The authors report their experience and endoscopy practices.

Video rigid flexing laryngoscope (RIFL) vs Miller laryngoscope for tracheal intubation during pediatric resuscitation by paramedics: a simulation study

OBJECTIVES

Endotracheal intubation (ETI) is an essential resuscitation procedure in children. Video laryngoscopes have been developed to avoid intubation failures in a variety of scenarios, including cardiopulmonary resuscitation. We hypothesized that the video laryngoscope RIFL (AI Medical Devices, Inc, Williamston, MI) offers advantages in the ETI of a pediatric manikin while performing chest compressions (CCs).

METHODS

Randomized nonblinded crossover simulation trial conducted among 132 paramedics with no prior experience with RIFL. Each participant performed intubations with Miller (MIL; Mercury Medical, Clearwater, FL) laryngoscope and RIFL in a PediaSIM CPR training manikin (FCAE HealthCare, Sarasota, FL) in 3 airway scenarios: (a) normal airway at rest (without concomitant CC), (b) normal airway with mechanically controlled CC, and (c) difficult airway with concomitant CC. The primary outcome was the time to intubation, and secondary one was the success of the intubation attempt.

RESULTS

In the manikin at rest with normal airway, nearly all participants performed successful ETI both with MIL and RIFL, with similar intubation times. However, in the other scenarios (normal and difficult airway with uninterrupted CC), the results with RIFL were significantly better than with MIL (P < .05) for all the analyzed variables (success of first attempt, overall success rate, time to intubation, Cormac-Lehane grade, dental compression, and easy of intubation scores).

CONCLUSIONS

In simulated child arrest scenarios with normal/difficult airway conditions and with concomitant mechanical CC, paramedics performed better with the RIFL video laryngoscope than with the standard MIL.

Comparison of the TruView PCD video laryngoscope and macintosh laryngoscope for pediatric tracheal intubation by novice paramedics: a randomized crossover simulation trial

The aim of the present study was to evaluate whether the TruView video laryngoscope (TruView) facilitates pediatric endotracheal intubation (ETI) more quickly and safely than conventional Macintosh laryngoscope (MAC) in three manikin-based airway scenarios. This was a randomized crossover manikin study including 120 novice paramedics. The participants performed tracheal intubations using both TruView and MAC on a pediatric manikin in a control scenario (A), chest compression scenario (B), and chest compression cervical stabilization scenario (C). The sequence of scenarios was randomized. The primary outcome was time to intubation. Secondary outcomes were overall success rates, incidence of dental trauma, and ease of intubation. All intubation attempts were assessed by a trained assistant. The overall success rate was significantly higher with the TruView compared than the MAC in scenario B (100 vs. 81.7 %; p = 0.011) and scenario C (100 vs. 68.3 %; p < 0.001). The intubation time was significantly lower with the TruView than the MAC (18.5 vs. 24.3 s, p = 0.017, for scenario A; 21.6 vs. 25.7 s, p = 0.023, for scenario B; and 28.9 vs. 45.4 s, p < 0.001, for scenario C). Glottic view quality was better with TruView than the MAC in all scenarios, p < 0.001.

CONCLUSIONS

The TruView offers better intubation conditions than the MAC on a pediatric manikin in the control scenario, chest compression scenario, and chest compression scenario with cervical stabilization scenario. The TruView may be used to elevate the epiglottis for orotracheal intubation. Further clinical studies are necessary to confirm these initial positive findings.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT02289872.

WHAT IS KNOWN

•Prehospital pediatric intubation using a standard laryngoscope is varied and ranges from 63.4 to 82 %. What is New: •This is the first study showing efficiency of pediatric endotracheal intubation using the TruView PCD by paramedics in tree simulation scenarios. •TruView PCD offers better pediatric intubation conditions than the Macintosh laryngoscope.