Videolaryngoscopy vs. direct Macintosh laryngoscopy in tracheal intubation in adults: a ranking systematic review and network meta-analysis.

Videolaryngoscopes are thought to improve glottic view and facilitate tracheal intubation compared with the Macintosh direct laryngoscope. However, we currently do not know which one would be the best choice in most patients undergoing anaesthesia. We designed this systematic review with network meta-analyses to rank the different videolaryngoscopes and the Macintosh direct laryngoscope. We conducted searches in PubMed and a further five databases on 11 January 2021. We included randomised clinical trials with patients aged ≥16 years, comparing different videolaryngoscopes, or videolaryngoscopes with the Macintosh direct laryngoscope for the outcomes: failed intubation; failed first intubation attempt; failed intubation within two attempts; difficult intubation; percentage of glottic opening seen; difficult laryngoscopy; and time needed for intubation. We assessed the quality of evidence according to GRADE recommendations and included 179 studies in the meta-analyses. The C-MAC and C-MAC D-Blade were top ranked for avoiding failed intubation, but we did not find statistically significant differences between any two distinct videolaryngoscopes for this outcome. Further, the C-MAC D-Blade performed significantly better than the C-MAC Macintosh blade for difficult laryngoscopy. We found statistically significant differences between the laryngoscopes for time to intubation, but these differences were not considered clinically relevant. The evidence was judged as of low or very low quality overall. In conclusion, different videolaryngoscopes have differential intubation performance and some may be currently preferred among the available devices. Furthermore, videolaryngoscopes and the Macintosh direct laryngoscope may be considered clinically equivalent for the time taken for tracheal intubation. However, despite the rankings from our analyses, the current available evidence is not sufficient to ensure significant superiority of one device or a small set of them over the others for our intubation-related outcomes.

Clinical analysis of the "small plateau" sign on the flow-volume curve followed by deep learning automated recognition.

BACKGROUND: Small plateau (SP) on the flow-volume curve was found in parts of patients with suspected asthma or upper airway abnormalities, but it lacks clear scientific proof. Therefore, we aimed to characterize its clinical features. METHODS: We involved patients by reviewing the bronchoprovocation test (BPT) and bronchodilator test (BDT) completed between October 2017 and October 2020 to assess the characteristics of the sign. Patients who underwent laryngoscopy were assigned to perform spirometry to analyze the relationship of the sign and upper airway abnormalities. SP-Network was developed to recognition of the sign using flow-volume curves. RESULTS: Of 13,661 BPTs and 8,168 BDTs completed, we labeled 2,123 (15.5%) and 219 (2.7%) patients with the sign, respectively. Among them, there were 1,782 (83.9%) with the negative-BPT and 194 (88.6%) with the negative-BDT. Patients with SP sign had higher median FVC and FEV1% predicted (both P < .0001). Of 48 patients (16 with and 32 without the sign) who performed laryngoscopy and spirometry, the rate of laryngoscopy-diagnosis upper airway abnormalities in patients with the sign (63%) was higher than those without the sign (31%) (P = 0.038). SP-Network achieved an accuracy of 95.2% in the task of automatic recognition of the sign. CONCLUSIONS: SP sign is featured on the flow-volume curve and recognized by the SP-Network model. Patients with the sign are less likely to have airway hyperresponsiveness, automatic visualizing of this sign is helpful for primary care centers where BPT cannot available.

Comparison of direct laryngoscopy and video-assisted laryngoscopy in pediatric intensive care unit.

Our objective was to compare video-assisted laryngoscopy (VAL) with direct laryngoscopy (DL) for glottic visualization in a pediatric intensive care unit in terms of the success rate in first attempts. Our study included patients aged from 1 month to 18 years who were admitted to the pediatric intensive care unit. We excluded patients with limited neck extension (C-spine immobilization, congenital abnormality), congenital anomalies (e.g., Pierre Robin syndrome, micrognathia, macroglossia), and recent airway surgery. Patients were premedicated before intubation. The time to intubation was defined as the time between the start of anesthesia and completion of intubation. The start of anesthetic induction was defined as the time the sedative was first administered. Completion of intubation was defined as the time that the end-tidal carbon dioxide tension was detected. We evaluated 120 of 135 intubations that met our inclusion criteria; 15 were excluded because in eight cases (53%) non-pediatric intensive care physicians made the initial attempts, and in seven cases (47%) the recorded intubation times were erroneous. We detected significantly higher POGO scores in the VAL group (p<0.001). VAL provided a fuller view of the glottis (Cormack and Lehane grade 1) than DL (p<0.001). Although the intubation attempts in the DL group were significantly higher (two or more attempts), no intubation failures occurred in either group.

Endoscopic laryngeal findings in patients undergoing thyroid and parathyroid surgery.

OBJECTIVES: This study aimed to report the pre- and post-operative laryngeal endoscopic findings in patients referred by non-otolaryngologists who are undergoing thyroid and/or parathyroid surgery, and to determine the number and nature of referrals before and after the release of the clinical practice guideline for improving voice outcomes after thyroid surgery. METHODS: This retrospective cohort study, conducted at a tertiary care academic hospital, comprised adult patients referred by the endocrine surgery service for laryngoscopy from 2007 to 2018 (n = 166). Data regarding patient demographics, reason for referral and endoscopic findings were recorded. RESULTS: The number of referrals increased significantly after the release of the practice guideline. The most common indication for referral pre- and post-operatively was voice change. The most common finding during laryngoscopy was normal examination findings (pre-operatively) and unilateral vocal fold immobility (post-operatively). CONCLUSION: Peri-operative thyroid and/or parathyroid patients have laryngoscopic findings other than vocal fold immobility. Laryngoscopy to detect structural and functional pathology is warranted.

Impact of videolaryngoscopy introduction into prehospital emergency medicine practice: a quality improvement project.

INTRODUCTION: Advanced airway management is necessary in the prehospital environment and difficult airways occur more commonly in this setting. Failed intubation is closely associated with the most devastating complications of airway management. In an attempt to improve the safety and success of tracheal intubation, we implemented videolaryngoscopy (VL) as our first-line device for tracheal intubation within a UK prehospital emergency medicine (PHEM) setting. METHODS: An East of England physician-paramedic PHEM team adopted VL as first line for undertaking all prehospital advanced airway management. The study period was 2016-2020. Statistical process control charts were used to assess whether use of VL altered first-pass intubation success, frequency of intubation-related hypoxia and laryngeal inlet views. A survey was used to collect the team's views of VL introduction. RESULTS: 919 patients underwent advanced airway management during the study period. The introduction of VL did not improve first-pass intubation success, view of laryngeal inlet or intubation-associated hypoxia. VL improved situational awareness and opportunities for training but performed poorly in some environments. CONCLUSION: Despite the lack of objective improvement in care, subjective improvements meant that overall PHEM clinicians wanted to retain VL within their practice.

Abnormal Laryngeal Electromyography Findings in Asymptomatic Adults Across the Age Spectrum.

OBJECTIVES/HYPOTHESIS: Laryngeal electromyography (LEMG) is a diagnostic tool for patients with suspected neurogenic abnormalities of the larynx. LEMG is often used with the assumption that any abnormality is symptom-/disease-related. We sought to determine the prevalence of abnormal LEMG findings in a group of healthy asymptomatic adults across a large age spectrum. STUDY DESIGN: Open, prospective study, gender-match and age balanced by decade. METHODS: Forty-six healthy participants (age 20-78) underwent LEMG, including 178 muscles. Participants had no history of voice problems, normal VHI-10, and normal flexible laryngoscopy. Qualitative and quantitative LEMG (bilateral) were performed involving the thyroarytenoid-lateral cricoarytenoid muscle complex (TA-LCA) and cricothyroid (CT) muscles. LEMG parameters included evaluation for fibrillation potentials, sharp waves, reduced recruitment, polyphasic potentials, electrical synkinesis, and measurement of turns per second. RESULTS: Of participants, 4% had at least one abnormal qualitative finding (slightly reduced recruitment or two to three discrete polyphasic potentials). There were no findings of fibrillation potentials or sharp waves. There were no abnormal qualitative findings in the CT muscles tested. Of participants, 16% had at least one abnormal synkinesis finding. LEMG qualitative abnormalities and quantitative abnormalities do not appear to correlate with gender or age. CONCLUSION: Abnormal qualitative and quantitative LEMG findings were uncommon and minor in severity in our group of asymptomatic healthy adults. The likelihood of abnormal LEMG results in asymptomatic adults was 2.2% for qualitative findings, 9.3% for synkinesis, and 5.4% for turns/s. LEVEL OF EVIDENCE: 3 Laryngoscope, 131:2065-2069, 2021.

Macintosh Videolaryngoscope for Intubation in the Operating Room: A Comparative Quality Improvement Project.

BACKGROUND: "Macintosh"-videolaryngoscopes (VLs) are VLs that allow both direct and indirect laryngoscopy for intubation. We describe the decision-making and implementation-processes that our hospital used regarding the choice of device. We compared the performances of 4 Macintosh-VLs both in direct and indirect laryngoscopy. METHODS: A quality-improvement-project for airway management aiming at implementing Macintosh-VL for all intubation procedures performed in the operating room, involving 4 Macintosh-VLs (McGrath-Mac, C-MAC-S, C-MAC-S-Pocket-Monitor [PM], and APA). Three consecutive steps were described: (1) direct laryngoscopy with Macintosh-VL, (2) indirect laryngoscopy with Macintosh-VL (intubation attempt with Macintosh-style blade in case of Cormack I or II), (3) intubation attempt with hyperangulated blade in case of Cormack III/IV or failure of Macintosh-style blade. The main end point was the need to move to step III and use a hyperangulated blade. A mixed-effects multivariable logistic regression analysis was performed to compare devices on the main end point while considering site as a random effect. Comparison of means was performed using analysis of variance and Tukey's test for multiple comparisons (number of laryngoscopy attempts, numeric rate scale [NRS] difficulty of intubation and NRS user-friendliness). Comparison of percentages was performed using a χ2 test for the need to move to step III and a Kruskal-Wallis test for the quality of image (bad, passable, good, very good, excellent). A P value ≤.008 was considered statistically significant. RESULTS: From May to September 2017, 589 patients were included. Using the McGrath-Mac (22/180 [12%]) was associated with less use of hyperangulated blade than using the C-MAC-S (39/132 [30%], odds ratio [OR] [99.2% confidence interval {CI}] 0.34 [0.16-0.77], P = .0005), the APA (35/138 [25%], OR [99.2% CI] 0.42 [0.19-0.93]; P = .004), but not the C-MAC-S-PM (29/139 [21%], OR [99.2% CI] 0.53 [0.23-1.2]; P = .04).Overall, the number of intubation attempts was significantly lower using the McGrath Mac than the C-MAC-S or the C-MAC-S-PMVLs. Subjective appreciation of intubation difficulty and user-friendliness of the devices showed respectively lower and higher NRS scores for the McGrath-Mac compared to the other devices, whereas subjective assessment of image quality showed higher quality for the C-MAC-S and C-MAC-S-PM compared to the APA or McGrath-Mac. CONCLUSIONS: Among 4 single-use Macintosh-VLs, glottic visualization in direct and indirect laryngoscopy with the Macintosh-style blade was significantly improved with the McGrath-Mac compared to other Macintosh-VLs, leading to a less frequent need to resort to the hyperangulated blade and reduced overall number of intubation attempts.

Reducing potential aerosol generation in flexible nasolaryngoscopy: a novel method.

BACKGROUND: Fibre-optic nasoendoscopy and fibre-optic laryngoscopy are high-risk procedures in the coronavirus disease 2019 era, as they are potential aerosol-generating procedures. Barrier protection remains key to preventing transmission. METHODS: A device was developed that patients can wear to reduce potential aerosol contamination of the surroundings. CONCLUSION: This device is simple, reproducible, easy to use, economical and well-tolerated. Full personal protection equipment should additionally be worn by the operator.

BET 2: Video laryngoscopy for patients requiring endotracheal intubation in the emergency department.

A short-cut review of the literature was carried out to examine whether video laryngoscopy (VL) could improve first-pass success and reduce complication rates in ED patients requiring endotracheal intubation, when compared with direct laryngoscopy. Four papers were identified as suitable for inclusion using the reported search strategy. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of the best papers are tabulated. It is concluded that current evidence suggests VL is likely to improve first-pass success and reduce oesophageal intubation rates, but there is no evidence at present that it improves clinically relevant outcomes. In addition, no difference was found between first-pass success rates in senior/experienced operators, who should use techniques with which they are familiar.

Application of a Modified Endoscopy Face Mask for Flexible Laryngoscopy During the COVID-19 Pandemic.

Diagnostic flexible laryngoscopy (DFL) is a critical tool in the armamentarium of an otolaryngologist. However, in the midst of the COVID-19 pandemic, DFL represents a high-risk procedure for patients and otolaryngologists due to the risk of aerosolization. In cases where DFL is required, in patients with COVID-19 positivity or unknown COVID-19 status, we describe the use of a modified endoscopy face mask as an adjunct to personal protection equipment to reduce occupational transmission of COVID-19 while performing DFL. Our modified endoscopy mask provides an additional barrier against the transmission of airborne pathogens. The modified endoscopy face mask may also serve as a useful tool for otolaryngologists as they return to performing more aerosol-generating procedures in the outpatient setting.

[Noninvasive evaluation of airways prior to sedation or anesthesia : An update within the framework of the revision of the German S1 guidelines on airway management 2015 of the German Society for Anesthesiology and Intensive Care Medicine]. / Nichtinvasive Evaluation der Atemwege vor Sedierungen oder Narkosen : Update im Rahmen der Überarbeitung der S1-Leitlinie "Atemwegsmanagement" 2015 der DGAI.

As a single and reliable parameter for prediction of the difficult airway is missing, the specialist societies for anesthesiology recommend the use of scores that combine the individual parameters. Contemporary scores include head-neck mobility, mouth opening and anatomical distances. Their training and correct performance are essential. For a broad acceptance the performance has to be easy and fast. In addition, before anesthesia a check must be made for pathological alterations (e.g. tumors) in the head and neck region and the patient history must be thoroughly determined. If the patient reports difficulties with securing the airway in the past, these are likely to occur again if they have not been surgically resolved. This includes an accurate documentation of the airway and knowledge of the in-house standard operating procedure on unexpected difficult airways as well as local equipment. Preparation causes work but may save lives.

Assessment of Airway Parameters for Predicting Difficult Laryngoscopy and Intubation in a Tertiary Center in Western Nepal.

BACKGROUND: The screening tests used for pre-operative evaluation of airway to predict difficult laryngoscopy and intubation have variable diagnostic accuracy. The unanticipated poor laryngeal view is gold standard for defining difficult intubation. We aimed to find out the prevalence of difficult laryngoscopy and intubation, which airway parameter better predicts difficult intubation and whether difficult laryngoscopy is associated with difficult intubation or not. METHODS: This analytic cross sectional study was conducted in 665 ASA I/II adult patients, aged 18-65, without obvious airway pathology undergoing elective surgery under general anesthesia. The pre-operative screening tests included mouth opening, modified mallampatti, ratio of height to thyromental distance, sternomentaldistance and upper lip bite test. Cormack-Lehane grade III/ IV was defined as difficult laryngoscopy and potentially difficult intubation. Sensitivity, specificity, positive predictive value, negative predictive value, accuracy and area under curve at 95% confidence interval was calculated for all five screening tests. RESULTS: The prevalence of difficult laryngoscopy and intubation was 6.6% (44 cases). The upper lip bite test because of its highest specificity, positive predictive value, negative predictive value, accuracy and area under curve (99.7%; 93.9%; 99.7%; 95.2%; 85.1% respectively) with moderate level of sensitivity (70.5%) was better predictor of difficult intubation than other tests. The difficult laryngoscopy was associated with difficult intubation (p=0.00). CONCLUSIONS: The prevalence of difficult laryngoscopy and intubation was 6.6%.The upper lip bite test was a better predictor of difficult intubation and there was a significant association of difficult laryngoscopy with difficult intubation.

The Case for Bougie Use on Every Intubation.

Despite its value in emergency airway management, the endotracheal tube introducer, commonly known as the bougie, has traditionally been a point of disagreement between providers. It is typically viewed as a "rescue" device and not a primary airway tool. However, its value as a primary device during plan A has recently been recognized. Two studies have shown increased first-pass success using a bougie on the initial attempt. Additionally, bougie use on every intubation increases provider comfort with the device so that, on a truly difficult intubation, the skills and mechanics are instilled. In the out-of-hospital and critical care transport settings, intubation is often inherently more difficult because of varying environments. For these reasons, the bougie should be integrated into the first intubation attempt in emergent intubation.

Comparison of Macintosh Laryngoscopy in Bed-up-Head-Elevated Position With GlideScope Laryngoscopy: A Randomized, Controlled, Noninferiority Trial.

BACKGROUND: Approximately half of all difficult tracheal intubations (DTIs) are unanticipated; hence, proper positioning during intubation is critical to increase the likelihood of success. The bed-up-head-elevated (BUHE) intubation position has been shown to improve laryngeal view, reduce airway complications, and prolong safe apneic time during intubation. In this study, we sought to determine whether the BUHE intubation position is noninferior to Glidescope (GLSC)-assisted intubation with regard to laryngeal exposure. METHODS: A total of 138 American Society of Anesthesiologists (ASA) I to III patients were randomly assigned into 2 groups and underwent baseline laryngoscopy in the sniffing position. Group BUHE patients (n = 69) were then intubated in the BUHE position, while group GLSC patients (n = 69) were intubated using GLSC laryngoscopy. Laryngeal exposure was measured using Percentage of Glottic Opening (POGO) score and Cormack-Lehane (CL) grading, and noninferiority will be declared if the difference in mean POGO scores between both groups do not exceed -15% at the lower limit of a 98% confidence interval (CI). Secondary outcomes measured included time required for intubation (TRI), number of intubation attempts, use of airway adjuncts, effort during laryngoscopy, and complications during intubation. RESULTS: Mean POGO score in group BUHE was 80.14% ± 22.03%, while in group GLSC it was 86.45% ± 18.83%, with a mean difference of -6.3% (98% CI, -13.2% to 0.6%). In both groups, there was a significant improvement in mean POGO scores when compared to baseline laryngoscopy in the sniffing position (group BUHE, 25.8% ± 4.7%; group GLSC, 30.7% ± 6.8%) (P < .0001). The mean TRI was 36.23 ± 14.41 seconds in group BUHE, while group GLSC had a mean TRI of 44.33 ± 11.53 seconds (P < .0001). In patients with baseline CL 3 grading, there was no significant difference between mean POGO scores in both groups (group BUHE, 49.2% ± 19.6% versus group GLSC, 70.5% ± 29.7%; P = .054). CONCLUSIONS: In the general population, BUHE intubation position provides a noninferior laryngeal view to GLSC intubation. The laryngeal views obtained in both approaches were superior to the laryngeal view obtained in the sniffing position. In view of the many advantages of the BUHE position for intubation, the lack of proven adverse effects, the simplicity, and the cost-effectiveness, we propose that clinicians should consider the BUHE position as the standard intubation position for the general population.

A checklist for intrahospital transport of critically ill patients improves compliance with transportation safety guidelines.

OBJECTIVES: Critically ill patients are often transferred from the intensive care unit (ICU) to other locations around the hospital during which adverse events, some life threatening, are common. An intercollegiate guideline covering the transport of critically ill patients exists in Australasia; however, compliance with this guideline has previously been shown to be poor, and its role in improving safety in transportation of patients in the ICU is unknown. We performed a pre-post interventional study in a tertiary metropolitan ICU, assessing the impact of the introduction of a transport checklist on guideline compliance. METHODS: We performed a prospective, pre-post interventional study, including a total of 76 transfers of critically ill patients between August 2016 and April 2017. RESULTS: After introduction of the checklist, aggregate median (interquartile range) guideline compliance improved from 86.7% (80.0-92.9) to 90% (86.7-100) (p = 0.01). Significant improvements were found in notification of the transport destination (83.7% vs 100%, p = 0.010) and transporting doctors' knowledge of the Cormack-Lehane grade of laryngoscopy (60.5% vs. 84.2%, p = 0.021). There was, however, a reduction in the proportion of full oxygen cylinders taken on transports (100% vs. 76.3%, p = 0.002). CONCLUSIONS: We conclude that a checklist is useful in improving safety in the transport of a critically ill patient population.

From Voice Clinic to Operating Room: Are We Out of Tune?

INTRODUCTION: To determine the consistency and accuracy of preoperative diagnosis in the voice clinic with intraoperative diagnosis and to suggest a standardized laryngeal examination protocol in the UK that is supported by evidence-based findings. METHOD: From January 2011-September 2014, 164 patients were referred to the Multidisciplinary Team voice clinic and diagnosed with laryngeal pathology that required phonosurgery. The visualization (videostrobolaryngoscopy) in clinic was performed using either rigid laryngoscope or a video-naso-laryngoscope. Intraoperatively, laryngeal visualization and surgical procedure was conducted using Storz Aida HD system, 10-mm rigid laryngoscope 0° or 5-mm rigid laryngoscope 0°/30° and a Zeiss S7 microscope. RESULTS: Of the 164 patients seen in the multidisciplinary voice clinic, 86 clinic diagnoses were confirmed intraoperatively (52.4%), 15 patients had the diagnosis confirmed intraoperatively with additional lesion found (9.1%). The clinic diagnosis changed intraoperatively in 63 cases (38.4%). 61 (37.2%) patients seen in the voice clinic were diagnosed with cyst, in 39.3% the diagnosis was confirmed intraoperatively with 5 cases (8.2%) having an additional diagnosis. Twenty (12.2%) patients were diagnosed with polyps, with 80% confirmation intraoperatively; 3 patients (10%) had an additional diagnosis. CONCLUSION: Videolaryngostroboscopy imaging of the larynx provides an outpatient tool for accurately diagnosing more than 50% of laryngeal pathologies when interpreted by multidisciplinary voice clinicians. However direct laryngeal examination under general anesthesia remains the gold standard when obtaining accurate diagnoses of laryngeal pathology. Patients diagnosed with nonorganic voice disorders should be considered for direct laryngoscopy under general anesthetic should they fail to respond to conservative management.