In-office Laryngeal Procedures: a Modern Perspective for Vocal Fold Interventions

Introduction: The purpose of this article is to discuss in-office laryngeal procedures as an alternative to surgical intervention under general anesthesia. In-office procedures have become more common due to technological advancements. As a result, these approaches are less invasive and more patient-friendly, with increased pain tolerance and reduced procedure time and cost. Methods: We conducted a thematic analysis of published reports regarding the best known and performed in-office laryngeal interventions. Three questions guided our analysis: What laryngological procedures can be performed in the office setting? What are the advantages of in-office laryngology procedures compared to operating room surgical procedures? Why aren't more in-office procedures performed in some Latin American countries? Discussion: Despite being performed more frequently, there is still controversy whether in-office procedures should be performed as often due to the risk of complications. Furthermore, procedures that are done in the office setting are more popular in some countries than in others, even though their benefit has been well demonstrated. This article describes various in-office procedures, including biopsy, vocal fold injections, and laser surgery. We also discuss what factors might contribute to having office-procedures being performed more frequently in some countries than others. Conclusion: Awake interventions offer numerous benefits, including shorter procedure time, reduced costs, and lower patient morbidity. These advantages have significantly transformed the treatment of laryngeal diseases in modern laryngology practice in a global manner.

Introducción: El propósito de este artículo es discutir los procedimientos laríngeos en el consultorio como una alternativa a la intervención quirúrgica bajo anestesia general. Los procedimientos en consultorio se han vuelto más comunes debido a los avances tecnológicos. Como resultado, estos enfoques son menos invasivos y más amigables para el paciente, con mayor tolerancia al dolor y reducción del tiempo y costo del procedimiento. Métodos: Realizamos un análisis temático de los informes publicados sobre las intervenciones laríngeas más conocidas y realizadas. Tres preguntas guiaron nuestro análisis: ¿Qué procedimientos laringológicos se pueden realizar en el consultorio y cuales sin los más frecuentes?, ¿cuáles son las ventajas de los procedimientos laringológicos fuera del quirófano frente a los que se realizan bajo anestesia general?, ¿por qué no se realizan más procedimientos laringológicos en el consultorio en la mayoría de los países en Latinoamérica? Discusión: A pesar de que se realizan con mayor frecuencia, aún existe controversia sobre si los procedimientos en consultorio deben realizarse con tanta frecuencia debido al riesgo de complicaciones. Además, los procedimientos que se realizan en el consultorio son más populares en algunos países que en otros, aunque sus beneficios han sido bien demostrados. Este artículo describe varios procedimientos en el consultorio, incluida la biopsia, las inyecciones de cuerdas vocales y la cirugía con láser. También se discutieron los factores que podrían contribuir a que los procedimientos en el consultorio se realicen con más frecuencia en algunos países que en otros. Conclusión: Las intervenciones con pacientes despiertos ofrecen numerosos beneficios, incluido un tiempo de procedimiento más corto, costos reducidos y una menor morbilidad para el paciente. Estas ventajas han transformado significativamente el tratamiento de las enfermedades laríngeas en la práctica de la laringología moderna a nivel mundial.

Should videolaryngoscopy be routinely used for airway management? An approach from different scenarios in medical practice

During the past two decades, the videolaryngoscope (VDL) has become a valuable and effective tool for the management of the airway, not just in the realm of anesthesiology, but also in other medical specialties in clinical scenarios requiring tracheal intubation. In countries such as the United States, this represents over 15 million cases in the operating room and 650,000 outside the OR. The overall accumulated incidence of difficult airway is 6.8% events in routine practice and between 0.1 and 0.3 % of failed intubations, both associated with complications such as desaturation, airway injury, hemodynamic instability and death. Notwithstanding the fact that the VDL has proven advantages such as improved visualization of the glottis, higher first attempt success rates, and a shortened learning curve, most of the time its use is limited to rescue attempts or as a secondary option. The aim of this article is to comment the advantages and limitations of the VDL vs. the direct laryngoscope in a wide range of clinical settings, including the operating room, intensive care units, emergency departments, pediatrics, obstetrics, and Covid-19 to consider its routine use.

En las últimas dos décadas, el videolaringoscopio (VDL) se ha convertido en una herramienta valiosa y eficaz para el manejo de la vía aérea no solo en el ámbito de anestesiología, sino en otras especialidades médicas durante escenarios clínicos que requieren la intubación traqueal y las cuales, en países como Estados Unidos corresponden anualmente a más de 15 millones dentro de salas de cirugía y 650.000 fuera de ella. Aproximadamente, hay una incidencia global acumulada de 6,8 % de eventos de vía aérea difícil en la práctica rutinaria y 0,1 al 0,3 % de intubaciones fallidas, ambas asociadas a complicaciones como desaturación, daño en la vía aérea, inestabilidad hemodinámica y muerte. Pese a que el VDL ha demostrado ventajas como mejoría de la visualización de la glotis, aumento de tasa de éxito al primer intento y menor curva de aprendizaje, su uso en la mayoría de las veces se ve limitado como dispositivo de rescate o de manera secundaria. El propósito de este artículo es comentar acerca de las ventajas y limitaciones del VDL vs. el laringoscopio directo en un variado número de escenarios clínicos, como salas de cirugía, unidades de cuidado intensivo, emergenciología, pediatría, obstetricia y covid-19, con el fin de considerar si su uso debiera hacerse de manera rutinaria.

Recommendations from the Brazilian Society of Anesthesiology (SBA) for difficult airway management in pediatric care

Abstract Difficult airway management in pediatrics during anesthesia represents a major challenge, requiring a careful approach, advanced technical expertise, and accurate protocols. The task force of the Brazilian Society of Anesthesiology (SBA) presents a report containing updated recommendations for the management of difficult airways in children and neonates. These recommendations have been developed based on the consensus of a panel of experts, with the objective of offering strategies to overcome challenges during airway management in pediatric patients. Grounded in evidence published in international guidelines and expert opinions, the report highlights crucial steps for the appropriate management of difficult airways in pediatrics, encompassing assessment, preparation, positioning, pre-oxygenation, minimizing trauma, and, paramountly, the maintenance of arterial oxygenation. The report also delves into additional strategies involving the use of advanced tools, such as video laryngoscopy, flexible intubating bronchoscopy, and supraglottic devices. Emphasis is placed on the simplicity of implementing the outlined recommendations, with a focus on the significance of continuous education, training through realistic simulations, and familiarity with the latest available technologies. These practices are deemed essential to ensure procedural safety and contribute to the enhancement of anesthesia outcomes in pediatrics.

Recommendations from the Brazilian Society of Anesthesiology (SBA) for difficult airway management in adults

Abstract Difficult airway management represents a major challenge, requiring a careful approach, advanced technical expertise, and accurate protocols. The task force of the Brazilian Society of Anesthesiology (SBA) presents a report with updated recommendations for the management of difficult airway in adults. These recommendations were developed based on the consensus of a group of expert anesthesiologists, aiming to provide strategies for managing difficulties during tracheal intubation. They are based on evidence published in international guidelines and opinions of experts. The report underlines the essential steps for proper difficult airway management, encompassing assessment, preparation, positioning, pre-oxygenation, minimizing trauma, and maintaining arterial oxygenation. Additional strategies for using advanced tools, such as video laryngoscopy, flexible bronchoscopy, and supraglottic devices, are discussed. The report considers recent advances in understanding crisis management, and the implementation seeks to further patient safety and improve clinical outcomes. The recommendations are outlined to be uncomplicated and easy to implement. The report underscores the importance of ongoing education, training in realistic simulations, and familiarity with the latest technologies available.

Effect of oral clonidine premedication on attenuating haemodynamic response to laryngoscopy and intubation during general anaesthesia

Background: Laryngoscopy with or without tracheal intubation evokes a defense mechanism that in turn alters patients’ haemodynamic responses in terms of increased heart rate (HR) and arterial blood pressure (ABP). Aim of current investigation was to study the efficacy of orally administered clonidine in a dose of 3-3.5 µg/kg given 90 minutes prior to scheduled time of the surgery, in attenuating the adverse haemodynamic responses to laryngoscopy and intubation of the trachea. Methods: Eighty normotensive patients between 20-60 years of age and having ASA grade I/II physical status were subdivided in two groups with 40 patients in each; test group received clonidine in a dose of 3-3.5 mcg/kg of body weight orally, 90 min before surgery and control group did not receive clonidine premedication. Induction was done with Thiopentone intravenous injection (5 mg/kg), followed by succinylcholine (1-1.5 mg/kg). Results: Haemodynamic responses in terms of parameters like HR, systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) were recorded at pre induction and at 1, 2, 3, 5 minutes following laryngoscopy. The 1-minute post induction values of SBP, DBP, MAP were significantly less in clonidine group (p<0.001) and the significance in listed parameters between two groups persisted until 5 minutes. Increase in HR was less in clonidine group than in control group. Conclusions: Premedication with oral clonidine 3-3.5 mcg/kg of body weight, 90 minutes before laryngoscopy and intubation is an efficient, simple and inexpensive method in attenuating the haemodynamic response generated due to laryngoscopy and intubation.

Attenuation of hemodynamic responses to laryngoscopy and intubation by pre-operative oral melatonin

Background: Laryngoscopy and endotracheal intubation are usually associated with tachycardia and hypertension. Pre-administration of melatonin has anxiolytic and sedative property which can reduce the tachycardia and hypertension during the surgical procedures. Aims and Objectives: The present study aimed to evaluate the melatonin effect on hemodynamic changes during laryngoscopy and intubation. Materials and Methods: This prospective study was done in the department of anesthesia, Sri Jayadeva Institute of Cardiovascular Sciences and Research, Bengaluru, Karnataka. Total 80 patients were included in the study based on the inclusion and exclusion criteria. Patients were divided into two groups. Group-A treated with placebo and Group-B treated with melatonin (6 mg) and demographic, clinical, and hemodynamic parameters were recorded. The data were analyzed with unpaired t-test with the use SPSS (20.0) version software. Results: Comparison of number and percentage of age, gender, and blood groups between the Group-I and Group-II not showed any significant difference. Group-I and Group-II mean age, height, and weight not showed any significant difference. Mean heart rate, systolic blood pressure, diastolic blood pressure, and mean arterial pressure were compared between the Group-I and Group-II at basal, during, after 1, 3, 5, and 10 min showed significant difference. Conclusion: Pre-administration melatonin showed significant reduction of hemodynamic changes compared to placebo group.

A prospective validation and comparison of three multivariate models for prediction of difficult intubation in adult patients

Abstract Purpose Several bedside clinical tests have been proposed to predict difficult tracheal intubation. Unfortunately, when used alone, these tests show less than ideal prediction performance. Some multivariate tests have been proposed considering that the combination of some criteria could lead to better prediction performance. The goal of our research was to compare three previously described multivariate models in a group of adult patients undergoing general anesthesia. Methods This study included 220 patients scheduled for elective surgery under general anesthesia. A standardized airway evaluation which included modified Mallampati class (MM), thyromental distance (TMD), mouth opening distance (MOD), head and neck movement (HNM), and jaw protrusion capacity was performed before anesthesia. Multivariate models described by El-Ganzouri et al., Naguib et al., and Langeron et al. were calculated using the airway data. After anesthesia induction, an anesthesiologist performed the laryngoscopic classification and tracheal intubation. The sensitivity, specificity, and receiver operating characteristic (ROC) curves of the models were calculated. Results The overall incidence of difficult laryngoscopic view (DLV) was 12.7%. The area under curve (AUC) for the Langeron, Naguib, and El-Ganzouri models were 0.834, 0.805, and 0.752, respectively, (Langeron > El-Ganzouri, p= 0.004; Langeron = Naguib, p= 0.278; Naguib = El-Ganzouri, p= 0.101). The sensitivities were 85.7%, 67.9%, and 35.7% for the Langeron, Naguib, and El-Ganzouri models, respectively. Conclusion The Langeron model had higher overall prediction performance than that of the El-Ganzouri model. Additionally, the Langeron score had higher sensitivity than the Naguib and El-Ganzouri scores, and therefore yielded a lower incidence of false negatives.

A randomized comparative study of preoperative fentanyl and dexmedetomidine nebulization on the hemodynamic response to endotracheal intubation

Background: Intense sympathetic activity is linked to laryngoscopy and endotracheal intubation, which could lead to intraoperative problems. We undertook this study to compare the effects of preoperative nebulized Fentanyl and Dexmedetomidine on hemodynamic response to laryngoscopy and endotracheal intubation, taking advantage of their high bioavailability and better absorption through nasal mucosa. Aim and Objectives: The objectives of the study were (i) to compare the effect of preoperative nebulization on the hemodynamic response to laryngoscopy and intubation; and (ii) to assess intraoperative requirement of anesthetic agents. Materials and Methods: This prospective, randomized, and comparative study was conducted among 100 American Society of Anesthesiologists (ASA) I, II patients (of either gender) undergoing elective surgeries and requiring tracheal intubation, were randomized in two groups. Group A was given Fentanyl Nebulization (2 ?g/kg in 4 ml of 0.9% saline) and Group B was given Dexmedetomidine nebulization (1 ?g/kg in 4 ml of 0.9% saline) 10 min before anesthesia induction. Hemodynamic parameters were noted before and immediately after induction, 1 min, 5 min and 10 min after intubation. The main goal was to assess how Fentanyl and dexmedetomidine nebulization affect the laryngoscopy and intubation-induced stress response. The secondary outcome was to assess the intraoperative requirement of anesthetic agents, observe adverse effects of study drug and sedation score. Results: Dexmedetomidine nebulization was found to be more effective in blunting rise in heart rate post laryngoscopy compared to Fentanyl Nebulization (P < 0.0001) as well as in MAP after 10 min of intubation (P < 0.0001). Requirement of propofol was seen to be significantly reduced in Group B compared to Group A (P < 0.05). Sedation scores were significantly higher in Group B (P < 0.05). No evidence of side effects was observed in any group. Conclusion: Nebulisation of dexmedetomidine was found to be more effective in attenuation of stress response of laryngoscopy and intubation compared to nebulisation of fentanyl, with stable intraoperative hemodynamic and no significant side effects.

Comparative Study Between Intravenous Clonidine and Preservative Free Intravenous Lignocaine in Attenuation of Pressor Response to Laryngoscopy and Endotracheal Intubation

Objectives To compare the attenuation of pressor responses by intravenous clonidine and preservative-free lignocaine to laryngoscopy and endotracheal intubation. Materials and Methods A randomized, prospective, comparative, double-blinded study was conducted in 80 adult patients who were randomized into two groups of 40 each, group clonidine (Group C) and group lignocaine (Group L). Group C patients were given 2 µg/kg clonidine in 20 ml of normal saline as a slow infusion over 10 min prior to intubation. Group L patients were given 1.5 mg/kg of preservative-free 2% lignocaine in 20 ml of normal saline as a single-dose infusion over 3 min prior to intubation. Baseline vital and hemodynamic parameters were monitored during the perioperative period at 1-, 5-, and 10-min post-intubation. Results The attenuation of heart rate (HR) after intubation was much better with clonidine than lignocaine as there is statistically significant difference in the mean HR between the two groups at 1, 5, and 10 min after intubation with the HR significantly lesser in the Group C than the Group L at all times after intubation. Both clonidine and lignocaine were effective in attenuating systolic blood pressure response after intubation, but clonidine was more effective than lignocaine as systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) in the Group C remained much lower than the Group L and the difference between the two groups was statistically significant at all times after intubation. Conclusion Premedicating with a single slow infusion of 2 µg/kg i.v. clonidine has been proven to be effective in maintaining perioperative hemodynamic stability at 1, 5, and 10 min post-intubation than lignocaine.

A quantitative study of airway ultrasound in predicting difficult laryngoscopy: A prospective study / 中华创伤杂志(英文版)

PURPOSE@#As common clinical screening tests cannot effectively predict a difficult airway, and unanticipated difficult laryngoscopy remains a challenge for physicians. We herein used ultrasound to develop some point-of-care predictors for difficult laryngoscopy.@*METHODS@#This prospective observational study included 502 patients who underwent laryngoscopy and a detailed sonographic assessment. Patients under 18 years old, or with maxillofacial deformities or fractures, limited mouth opening, limited neck movement or history of neck surgery were excluded from the study. Laryngoscopic views of all patients were scored and grouping using the modified Cormack-Lehane (CL) scoring system. The measurements acquired comprised tongue width, the longitudinal cross-sectional area of the tongue, tongue volume, the mandible-hyoid bone distance, the hyoid bone-glottis distance, the mandible-hyoid bone-glottis angle, the skin-thyrohyoid membrane distance, the glottis-superior edge of the thyroid cartilage distance (DGTC), the skin-hyoid bone distance, and the epiglottis midway-skin distance. ANOVA and Chi-square were used to compare differences between groups. Logistic regression was used to identify risk factors for difficult laryngoscopy and it was visualized by receiver operating characteristic curves and nomogram. R version 3.6.3 and SPSS version 26.0 were used for statistical analyses.@*RESULTS@#Difficult laryngoscopy was indicated in 49 patients (CL grade Ⅲ - Ⅳ) and easy laryngoscopy in 453 patients (CL grade Ⅰ - Ⅱ). The ultrasound-measured mandible-hyoid bone-glottis angle and DGTC significantly differed between the 2 groups (p < 0.001). Difficult laryngoscopy was predicted by an area under the curve (AUC) of 0.930 with a threshold mandible-hyoid bone-glottis angle of 125.5° and by an AUC of 0.722 with a threshold DGTC of 1.22 cm. The longitudinal cross-sectional area of the tongue, tongue width, tongue volume, the mandible-hyoid distance, and the hyoid-glottis distance did not significantly differ between the groups.@*CONCLUSION@#Difficult laryngoscopy may be anticipated in patients in whom the mandible-hyoid bone-glottis angle is smaller than 125.5° or DGTC is larger than 1.22 cm.

Construction of three image recognition models of manikin′s glottis using visual laryngoscopy based on deep-learning algorithm / 中华麻醉学杂志

Objective:To construct three image recognition models of manikin′s glottis using visual laryngoscopy based on deep-learning algorithm.Methods:The tracheal intubation manikin′s epiglottis was visualized using a videolaryngoscope, and then epiglottis was elevated to expose the glottis and acquire glottic images. A total of 149 images were obtained from various angles and orientations and randomly divided into training set and test set, and the annotation of image data was completed. Three glottal image recognition models of CenterNet, YOLOv3 and YOLOv4 were developed. The training set was used to complete the training of the models, and finally the test set was used to evaluate the model performance.Results:CenterNet, YOLOv3 and YOLOv4 three models were successfully constructed, the mean average precision of CenterNet, YOLOv3 and YOLOv4 was 92.33%, 89.52% and 89.02% respectively, the recall rates were 87.50%, 90.00% and 90.00% respectively, the precision rates reached 97.22%, 94.74% and 94.74% respectively, and the accuracy rates were 90.91%, 85.11% and 88.89% respectively. All three algorithms demonstrated an identical F1 score of 91.00%.Conclusions:The CenterNet, YOLOv3 and YOLOv4 models are successfully constructed, and three recognition models can accurately identify the glottis in the image, with the CenterNet model demonstrating the highest recognition precision.

Application of upright seated and head down tongue protrusion technique in the completely exposure of the epiglottic surface under electronic laryngoscopy / 局解手术学杂志

Objective To study the clinical application value of the upright seated + head down(30° to 45°)+ tongue protrusion technique for the completely exposure of the epiglottic surface under electronic laryngoscopy.Methods Based on the clinical examination process of electronic laryngoscopy in the laryngoscopy room,two methods were applied for the patients with difficulty in exposing the epiglottic surface:① upright seated + tongue protrusion;② upright seated + head down(30° to 45°)+ tongue protrusion.The proportions of patients exposed to the epiglottic surface by these two methods were compared.Results The electronic laryngoscopy examination used the upright seated + tongue protrusion technique allowed for the clear exposure of the epiglottic surface in approximately 73.91%of patients with exposure difficulty.By using the upright seated + head down(30° to 45°)+ tongue protrusion technique,combined with the operator's control over the free movement of the laryngoscope's front end lens into the epiglottic vallecula space for close-range exploration,a 100%clear exploration of the epiglottic surface was achieved.Conclusion The upright seated + head down(30° to 45°)+ tongue protrusion technique for electronic laryngoscopy examination in patients with difficulty in exposing the epiglottic surface can completely expose the epiglottic surface,with significantly clinical effect.It can be used as a supplementary examination method for patients with difficulty in exposing the epiglottic surface in the ordinary upright seated or upright seated + tongue protrusion technique,and has certain clinical application value.

Visual-perceptive assessment of glottic characteristics of vocal nodules by means of high-speed videoendoscopy

Abstract Objective Visual-perceptive assessment of glottic characteristics of vocal nodules by means of high-speed videoendoscopy. Methods Descriptive observational research with convenience sampling of five laryngeal videos of women with an average age of 25 years. The diagnosis of vocal nodules was defined by two otolaryngologists, with 100% intra-rater agreement and 53.40% inter-rater agreement and five otolaryngologists as judge assessed the laryngeal videos based on an adapted protocol. The statistical analysis calculated measures of central tendency and dispersion, as well as percentage. The AC1 coefficient was used for agreement analysis. Results In high-speed videoendoscopy imaging, vocal nodules are characterized by amplitude of the mucosal wave and muco-undulatory movement with magnitude between 50% and 60%. Non-vibrating segments of vocal folds are scarce, and the glottal cycle does not show a predominant phase, it is symmetric and periodic. Glottal closure is characterized by the presence of a mid-posterior triangular chink (double chink or isolated mid-posterior triangular chink), without movement of supraglottic laryngeal structures, with irregular contour of the free edge of vocal folds, which are vertically on-plane. Conclusion Vocal nodules present mid-posterior triangular chink and irregular free edge contour. Amplitude and mucosal wave were partially reduced. Level of evidence: Level 4 (Case-series).

Dispositivo com câmera para treinamento de intubação orotraqueal: possibilidade de ensino médico em período pandêmico / Device with camera in orotracheal intubation training: possibility of medical education a pandemic period

Resumo: Introdução: A intubação orotraqueal é um procedimento importante no manejo da via aérea, principalmente quando realizada em situações de emergência. A videolaringoscopia é um artificio que facilita a visualização da glote ao auxiliar a intubação. Objetivo: Este estudo teve como objeto acoplar uma câmera de vídeo a um laringoscópio convencional do tipo Macintosh para possibilitar e orientar o treinamento da intubação orotraqueal. Método: O uso de uma câmera acoplada a um laringoscópio convencional permite a visibilização direta e indireta da glote. As imagens da câmera podem ser transmitidas por wi-fi e compartilhadas para dispositivos e plataformas eletrônicos, visando ao ensino presencial ou remoto da intubação orotraqueal. Resultado: A utilização do dispositivo artesanal como método de ensino de intubação orotraqueal permite ao docente ensinar a teoria do procedimento e orientar e corrigir a execução realizada pelo acadêmico. Esse feedback no treinamento prático pode ser realizado presencialmente ou por via remota. Conclusão: O uso do dispositivo artesanal de videolaringoscopia no ensino médico é uma ferramenta de baixo custo para aperfeiçoar o treinamento de intubação orotraqueal convencional.

Abstract: Introduction: The orotracheal intubation is an important procedure in airway management, especially when performed in emergency situations. Video-laryngoscopy is an artifice that facilitates visualization of the glottis, aiding intubation. Objective: This study aimed to attach a video camera to a conventional Macintosh-type laryngoscope to enable and train intubation or otracheal training. Method: The use of a camera coupled to a conventional laryngoscope allows direct and indirect visualization of the glottis. Camera images can be transmitted over wi-fi and shared to electronic devices and platforms, aiming at teaching in person or remotely about orotracheal intubation. Result: The use of the device as a method of teaching intubation or otracheal, allows teaching to teach the theory of procedure and training the execution performed by the artisanal method. This feedback in the practical training of orotracheal intubation in mannequins can be performed in person or remotely. Conclusion: The use of handcrafted video laryngoscopy device in medical education is a low-cost tool to improve conventional orotracheal intubation training.

Preoperative airway ultrasound assessment in the sniffing position: a prospective observational study

Abstract Background: Clinical airway screening tests intend to predict difficult airways, but none have a high predictive value. Recent systematic reviews correlate ultrasound with difficult laryngoscopy. This study aimed primarily to correlate ultrasound measurements of anatomical upper airway structures in the sniffing position with difficult direct laryngoscopy. The secondary aim was to observe gender-based differences. Methods: This prospective, cross-sectional, single-center observational study included 209 patients requiring general anesthesia for elective surgery. Preoperatively, we performed six clinical airway assessments and three ultrasound measurements, which were the Distance from Skin to the Hyoid Bone (DSHB), to the Epiglottis (DSE), and to the anterior commissure of the vocal cords (DSAC) in a sniffing position. Benumof's criteria for the "best view at the first attempt" for direct laryngoscopy assessed the difficulty of laryngoscopy. Results: The distance from skin to the epiglottis was the best predictor of direct difficult laryngoscopy (defined as Cormack-Lehane grade > 2b) with a minimum thickness cut-off at 2.70 ± 0.19 cm (sensitivity 91.3%; specificity 96.9%). The skin to the hyoid bone distance cut-off was 1.41 ± 0.30 cm with moderate correlation (sensitivity 80.4%; specificity 60.1%). No correlation was found for the distance to the anterior commissure of the vocal cords. In women compared to men, the skin to the epiglottis distance was more sensitive (92.3% vs. 90.9%) and specific (98.8% vs. 95.2%). Conclusions: DSE in the sniffing position is the most reliable parameter for preoperative airway ultrasound assessment in the Caucasian population, with higher sensitivity and specificity in women, and might be considered as an independent predictor for direct difficult laryngoscopy.

Upper airway angle and glottic height: a prospective cohort to evaluate two new features for airway prediction

Abstract Background: Predicting difficult direct laryngoscopies remains challenging and improvements are needed in preoperative airway assessment. We conceived two new tests (the upper airway angle and the glottic height) and assessed their association with difficult direct laryngoscopies as well as their predictive performance. Methods: A prospective cohort was conducted with 211 patients undergoing general anesthesia for surgical procedures. We assessed the association between difficult laryngoscopies and modified Mallampati Test (MMT), Upper Lip Bite Test (ULBT), Mandibular Length (ML), Neck Circumference (NC), Mouth Opening (MO), Sternomental Distance (SMD), Thyromental Distance (TMD), Upper Airway Angle (UAA), and Glottic Height (GH). We also estimated their predictive values. Results: Difficult laryngoscopy was presented by 12 patients (5.7%). Six tests were significantly associated with difficult laryngoscopies and their area under the ROC curve, and 95% CIs were as follows: UAA = 88.82 (81.86-95.78); GH = 86.43 (72.67-100); ML = 83.75 (72.77-94.74); NC = 79.17 (64.98-93.36); MO = 65.58 (45.13-86.02); and MMT = 77.89 (68.37-87.41). Conclusion: We have found two new features (the UAA and the GH) to be significantly associated with the occurrence of difficult direct laryngoscopies. They also presented the best predictive performance amongst the nine evaluated tests in our cohort of patients. We cannot ensure, however, these tests to be superior to other regularly used bedside tests based on our estimated 95% CIs.

The impact of introducing a videolaryngoscope in the initial training of laryngoscopy for undergraduate medical students: a simulation randomized trial

Abstract Introduction: Adequate and continuous airway management by health professionals is fundamental to ensure patient safety and protection. Among several techniques, laryngoscopy for orotracheal intubation is considered a basic skill, so it is taught and learned in medical school and used during the future years of professional practice. However, in some clinical scenarios, physical and anatomical characteristics can make laryngoscopy exceedingly difficult. In the last decade, some new devices have emerged to apply indirect or video-assisted imaging systems, so-called videolaryngoscopes. They have shown great efficiency in difficult intubation cases and have improved teaching and training. Our study introduced a videolaryngoscope, the McGrathTM MAC, in the regular laryngoscopy training rotation for 3rd-year undergraduate medical students and evaluated whether there was any associated optimization of the students' performance. Method: Students from two different classes and years (2017 and 2018) were randomly divided into two groups and received theoretical and practical training in the techniques of Direct Laryngoscopy (DL) and Videolaryngoscopy (VL). The students in each group applied the manoeuvres and simulated three tracheal intubation attempts on mannequins. They were evaluated for their success rate on the first attempt, the time required to finalize the intubation, and the visualization of the glottic structures according to the classification of Cormack-Lehane (C&L). Results: Two hundred and four students with an average age of 21 ± 2 years participated in the study; the groups were similar. There was a significant difference between the VL and DL groups in the 1st attempt success rate (97% and 89.4%, respectively, p = 0.0497 - 95% CI), but such a difference was not seen for the other attempts or regarding the number of oesophageal intubations (3% and 7.7%). The students in the VL group were faster than those in the DL group in all intubation attempts; in parallel, the vast majority of the VL group reported excellent visualization conditions, with 75% of the attempts classified as Cormack-Lehane grade 1. Conclusion: The introduction of a videolaryngoscope in medical students' training improved the visualization of anatomical structures and allowed tracheal intubation maneuvers to be performed faster and with a higher success rate on the first attempt. Thus, under the conditions of this prospective study, the videolaryngoscope had a positive impact on training and proved to be a promising tool for teaching laryngoscopy.

Role of melatonin in attenuation of hemodynamic response to intubation and anesthetic requirements: a randomized, controlled, double-blind study

Abstract Background Melatonin has been studied to have anxiolytic, sedative, and analgesic effects. However, there is limited data on the effect of melatonin in the attenuation of hemodynamic response to intubation. We aimed to study whether preanesthetic oral melatonin attenuates hemodynamic responses to intubation and anesthetic requirements. Methods Sixty-four patients scheduled for laparoscopic cholecystectomy were randomized into melatonin or placebo group (n = 32 each). Melatonin group received two tablets (3 mg each) of melatonin, and the placebo group received two tablets of vitamin D3 120 min before induction. Hemodynamic parameters were recorded during induction and postintubation for 15 minutes. Total induction dose of propofol, total intraoperative fentanyl consumption, and adverse effects of melatonin were also noted. Results Postintubation rise in heart rate (HR) was less in the melatonin group compared to the placebo group (10.59% vs. 37.08% at 1 min, respectively) (p< 0.0001). Maximum percentage increase in systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean blood pressure (MBP) was lesser in melatonin group than placebo group (SBP 9.25% vs. 37.73%, DBP 10.58% vs. 35.51%, MBP 9.99% vs. 36.45% at 1 min postintubation. respectively) (p< 0.0001). Induction dose of propofol (1.42 mg.kg-1 vs. 2.01 mg.kg-1) and the number of patients requiring additional fentanyl intraoperatively (3 vs. 11) were also significantly reduced in the melatonin group. Conclusion Premedication with 6 mg of oral melatonin resulted in significant attenuation of postintubation rise in HR, SBP, DBP, and MBP. It also reduced the induction dose of propofol, total intraoperative fentanyl consumption without any adverse effects.

Predictive performance of thyromental height for difficult laryngoscopies in adults: a systematic review and meta-analysis

Abstract Background Thyromental height (TMH) was first reported as a great single test for prediction of difficult laryngoscopies, although further studies have shown variable estimates of its accuracy. We thus performed this meta-analysis to summarize the predictive values of TMH mainly for prediction of difficult laryngoscopies. Methods A search in PubMed, EMBASE, LILACS, and Scielo was conducted in June 2020. We included prospective cohorts fully reported with patients ≥ 16 years old, providing data on predictive values of TMH for prediction of either difficult laryngoscopies or difficult intubations. Diagnostic properties and association between TMH and Cormack and Lehanes's classification by direct laryngoscopy were evaluated. A random-effects meta-analysis using hierarchical models was performed. Results Eight studies evaluating 2844 patients were included. All included studies had high risk of bias and low concern regarding applicability. There was significant heterogeneity among the studies. The pooled diagnostic odds ratio (DOR) and positive (LR+) and negative (LR-) likelihood ratios were as follows: DOR, 57.94 (95% CI: 18.19-184.55); LR+, 11.32 (95% CI: 4.28-29.92); and LR-, 0.23 (95% CI: 0.15-0.35). Summary sensitivity and specificity for studies with common threshold were 82.6 (95% CI: 74-88.8%) and 93.5 (95% CI: 79-98.2%), respectively. The estimated AUC was 81.1%. Conclusion TMH arises as a good predictor of difficult laryngoscopies in adult patients from diverse populations presenting better predictive values than most previously reported bedside tests. However, the high risk of bias throughout the studies may have skewed the results of the individual research as well as the summary points of the present meta-analysis.

Vocal rehabilitation in singers with vocal complaints: a digital kymography analysis / Reabilitação vocal em cantoras com queixa vocal: análise da videoquimografia digital

ABSTRACT Purpose: to evaluate the effects of the Comprehensive Vocal Rehabilitation Program associated with the application of transcutaneous electrical nerve stimulation through digital kymography in singers with vocal complaints. Methods: an experimental intrasubject comparative study in 24 singers, who underwent the rehabilitation program associated with transcutaneous electrical nerve stimulation. They were assessed with laryngeal high-speed videoendoscopy before and after vocal rehabilitation. The paired t-test and Wilcoxon test were used to compare the two assessments. The significance level was set at 5%. Results: significant differences were found in the maximum opening, dominant amplitude of the opening variation and dominant frequency of the opening variation of the right vocal fold in the posterior glottic region, and in maximum opening, mean opening, dominant amplitude of the opening variation of the left vocal fold and dominant frequency of the opening variation of both vocal folds in the anterior glottic region. Conclusion: the results showed that the Comprehensive Vocal Rehabilitation Program associated with transcutaneous electrical stimulation decreased the opening amplitude of the vocal fold, increased the vibration frequency, and improved glottal closure in the anterior and posterior glottic regions.

RESUMO Objetivo: avaliar os efeitos do Programa Integral de Reabilitação Vocal associado à aplicação da estimulação elétrica nervosa transcutânea por meio da videoquimografia digital em cantoras com queixa vocal. Métodos: estudo experimental comparativo intrassujeitos com 24 cantoras, que realizaram o programa de reabilitação associado à estimulação elétrica nervosa transcutânea. A avaliação, por meio da videolaringoscopia de alta velocidade, foi realizada antes e após a reabilitação vocal. Os testes T pareado e de Wilcoxon foram utilizados para comparação das duas avaliações. Considerou-se o nível de significância de 5%. Resultados: diferenças significantes foram identificadas quanto aos parâmetros de abertura máxima, amplitude dominante de variação de abertura e frequência dominante de abertura da prega vocal direita na região posterior da glote, além dos parâmetros de abertura máxima, abertura média, amplitude dominante de variação de abertura da prega vocal esquerda e frequência dominante de abertura de ambas as pregas vocais na região anterior da glote. Conclusão: os resultados mostraram que o Programa Integral de Reabilitação Vocal associado à estimulação elétrica transcutânea promoveu uma diminuição da amplitude de abertura da prega vocal e aumento da frequência de vibração, além de um melhor fechamento glótico nas regiões anterior e posterior da glote.