Anesthetic induction and endotracheal intubation in the sitting position due to the fixed forearm caught by a meat grinder

Abstract A male patient was scheduled for urgent amputation of his right forearm. His right forearm was stuck inside the insertion slot of a meat grinder, resulting in severe pain to his injured arm. His upper body could not move to sit in a semi-upright position. An endotracheal tube was successfully placed after rapid sequence intubation using a video laryngoscope from behind the patient on the first attempt. This case report is the first documentation of successful anesthetic induction with subsequent endotracheal intubation using a video laryngoscope from behind an injured patient whose upper body was upright with limited positioning.

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.

Aplicaciones diagnósticas y terapéuticas del videolaringoscopio C-MAC® en cirugía de vía aérea pediátrica / Diagnostic and therapeutic applications of the C-MAC® videolaryngoscope in pediatric airway surgery

Resumen La patología quirúrgica de la vía aérea pediátrica suele ser desafiante. Una visualización adecuada de las estructuras faríngeas y laríngeas es absolutamente necesaria para su correcto diagnóstico y tratamiento. Distintos instrumentos, como laringoscopios de intubación, laringoscopios de suspensión y broncoscopios flexibles o rígidos, permiten acceder a la vía aérea. Muchas veces se requiere el uso de una combinación de ellos para abordar con éxito estos problemas. En esta revisión, discutimos el uso de videolaringoscopios en el manejo de condiciones como estenosis subglótica, lesiones de vía aérea y cuerpos extraños. Aunque los anestesiólogos los utilizan frecuentemente para intubaciones difíciles debido a su cámara incorporada que facilita la visión de las estructuras laríngeas, existen escasos informes sobre su uso por cirujanos de vía aérea. Las ventajas sobre la laringoscopía convencional incluyen una mejor visualización, la capacidad de supervisar el procedimiento a través de una pantalla, una mejor ergonomía, que es portátil y que permite una rápida inserción de diferentes instrumentos. Consideramos que es particularmente útil en la dilatación de estenosis subglóticas. Presentamos un método fácil, barato y reproducible para realizarla.

Abstract Surgical pediatric airway diseases are often challenging, and an adequate visualization of pharyngeal and laryngeal structures is absolutely necessary for their correct diagnosis and treatment. Different instruments such as intubation laryngoscopes, suspension laryngoscopes and flexible and rigid bronchoscopes allow for access to the airway, and using a combination of them, is usually required to successfully address these problems. In this review, we discuss the use of videolaryngoscopes in the management of conditions such as subglottic stenosis, airway lesions and foreign bodies. Although commonly used by anesthesiologists for difficult intubations because of their built-in cameras that facilitate the view of laryngeal structures, there are scarce reports on its use by airway surgeons. Advantages over standard laryngoscopy include improved visualization and the ability to supervise the procedure through a screen. We also consider that it allows for improved ergonomics, portability and fast insertion of different instruments. We have found it to be particularly useful in subglottic stenosis dilation and an easy, cheap and reproducible method is also presented.

Time comparison of artificial airway establishment in operating room and on slope using endotracheal intubation and laryngeal mask / 北京大学学报(医学版)

OBJECTIVE@#To compare the completion time of endotracheal intubation and laryngeal mask implantation in operating room and on slope of ski resort, and to discuss the optimal method of estab-lishing artificial airway on slope of ski resort.@*METHODS@#The simulator was placed with the head under the feet on slope of ski resort. The artificial airway was established by tracheal intubation assisted by video laryngoscope (endotracheal intubation group) and laryngeal mask placement (laryngeal mask group) respectively by an anesthesiologist who wore full set of ski suits, helmets, goggles, gloves and ski boots. Each method was repeated 5 times, and the operation time of artificial airway establishment was recorded. While the simulated human was placed flat on the operating table in an operating room of a hospital, and the artificial airway was established by the same anesthesiologist using the same methods. Time was recorded and repeated for 5 times. The completion time of endotracheal intubation and laryngeal mask placement in the operating room and on the ski slope were compared.@*RESULTS@#The operating time of tracheal intubation in the operating room was longer than that of laryngeal mask placement [(79.8±10.4) s vs. (53.4±2.7) s, P=0.005], and the operating time of endotracheal intubation on the ski slope was longer than that of laryngeal mask placement [(209.2±32.7) s vs. (72.2±3.1) s, P=0.001]. The time of endotracheal intubation group on the slope of the ski resort was longer than that in the opera-ting room(t=-7.851, P=0.001). The time of laryngeal mask group on the slope was longer than that in the operating room (t=-19.391, P < 0.001).@*CONCLUSION@#On ski slope, both of tracheal intubation assisted by video laryngoscope and laryngeal mask placement can quickly complete the establishment of artificial airway, but the time required is longer than that in the operating room. The time of laryngeal mask placement to establish artificial airway is shorter than that of tracheal intubation assisted video laryngoscope, which may have a certain advantage in ski rescue.

Simulación de intubación pediátrica con videolaringoscopio de bajo costo en contexto de pandemia por COVID-19 / Simulation of pediatric intubation using a low-cost videolaryngoscope in the setting of the COVID-19 pandemic

En pacientes con infección por SARS-CoV-2 la intubación endotraqueal es un procedimiento con riesgo elevado de contagio. La videolaringoscopia complementa la protección del profesional, pero los videolaringoscopios comerciales son caros y no siempre están disponibles en las terapias intensivas pediátricas argentinas. El objetivo fue describir la práctica de intubación en un modelo de cabeza de simulación de lactante con un videolaringoscopio artesanal de bajo costo.Quince pediatras sin experiencia previa con el dispositivo participaron de una práctica de intubación en una cabeza de simulación con un videolaringoscopio artesanal. El tiempo promedio del primer intento fue de 116,4 segundos (intervalo de confianza del 95 % [IC95 %]: 84,8-148,0) y, el del siguiente fue de 44,2 segundos (IC95 %: 27,7­60,6). El tiempo disminuyó de forma significativa en el segundo intento (p : 0,0001). El dispositivo permitió la intubación exitosa en todos los intentos acortando la duración del procedimiento en la segunda práctica

In patients with SARS-CoV-2 infection, endotracheal intubation is a procedure with a high risk for transmission. A videolaryngoscopy is a supplementary level of health care provider protection, but commercial videolaryngoscopes are expensive and not always available in pediatric intensive care units in Argentina. Our objective was to describe intubation practice using an infant head mannequin with a low-cost, handcrafted videolaryngoscope.Fifteen pediatricians with no prior experience using the device participated in an intubation practice in a head mannequin with a handcrafted videolaryngoscope. The average time for the first attempt was 116.4 seconds (95 % confidence interval [CI]: 84.8-148.0) and, for the second one, 44.2 seconds (95 % CI: 27.7-60.6). Time decreased significantly for the second attempt (p: 0.0001).A successful intubation was achieved with the device in all attempts, and the procedure duration decreased with the second practice

Changing the view: impact of simulation-based mastery learning in pediatric tracheal intubation with videolaryngoscopy

Abstract Objective: To determine the effect of a training program using simulation-based mastery learning on the performance of residents in pediatric intubations with videolaryngoscopy. Method: Retrospective cohort study carried out in a tertiary pediatric hospital between July 2016 and June 2018 evaluating a database that included the performance of residents before and after training, as well as the outcome of tracheal intubations. A total of 59 pediatric residents were evaluated in the pre-training with a skills' checklist in the scenario with an intubation simulator; subsequently, they were trained individually using a simulator and deliberate practice in the department itself. After training, the residents were expected to have a minimum passing grade (90/100) in a simulated scenario. The success of the first attempted intubation, use of videolaryngoscopy, and complications in patients older than 1 year of age during the study period were also recorded in clinical practice. Results: Before training, the mean grade was 77.5/100 (SD 15.2), with only 23.7% (14/59) of residents reaching the minimum passing grade of 90/100. After training, 100% of the residents reached the grade, with an average of 94.9/100 (SD 3.2), p < 0.01, with only 5.1% (3/59) needing more practice time than that initially allocated. The success rate in the first attempt at intubation in the emergency department with videolaryngoscopy was 77.8% (21/27). The rate of adverse events associated with intubations was 26% (7/27), representing a serious event. Conclusions: Simulation-based mastery learning increased residents' skills related to intubation and allowed safe tracheal intubations with video laryngoscopy.

Laringoscopio híbrido: Una opción de costo razonable para el abordaje de la vía aérea difícil. Reporte de un caso / Hybrid laryngoscope: A reasonable option cost for approaching the airway difficulty. A case report

The laryngoscope is a primary tool that every medical professional who performs in airway care should know how to use. Although it's an irreplaceable tool, in the last decade have been considered transformations and modifications in them that have allowed the medical professional, especially the anesthesiologist to perform successfully for critical management especially in the context of unanticipated difficult airway, because most of the time the only available resource at hand is the laryngoscope and a malleable stylet that guides the orotracheal. The new technological age of visual instruments such as video cameras and photographs many of these with small sizes, has been used in the manufacture of video laryngoscopes that today are used, which have managed to approach the aerea in a minimally traumatic way and also safeguard lives. Our hydrid video laryngoscope is a handcrafted tool made of high-quality elements, strength, durability and low cost.

El laringoscopio es una herramienta primordial que todo profesional médico que se desempeña en la atención de la vía aérea debería saber utilizar. Pese a ser un dispositivo insustituible, en la última década se han considerado transformaciones y modificaciones en los mismos que le han permitido al profesional de la medicina, fundamentalmente al anestesiólogo, desempeñarse exitosamente durante el manejo crítico especialmente en el contexto de vía aérea difícil no anticipada, en el que la mayoría de las veces el único recurso disponible a la mano es el laringoscopio y un estilete maleable que sirve de guía para dirigir la sonda orotraqueal. La nueva era tecnológica de los instrumentos visuales como cámaras de video y fotografía, (muchos de estos con tamaños reducidos) han sido empleados en la fabricación de videolaringoscopios que hoy en día se utilizan y que han logrado abordar la vía aérea de manera mínimamente traumática, así mismo, salvaguardar vidas. Nuestro videolaringoscopio híbrido es una herramienta artesanal fabricada con elementos de alta calidad, resistencia, durabilidad y bajo costo.

Use of video laryngoscope for tracheal intubation in patient with oral cavity mass: case report / Uso de videolaringoscópio para intubação traqueal em paciente com massa tumoral na cavidade oral: relato de caso

Abstract Background and objectives When planning the management of a predicted difficult airway, it is important to determine which strategy will be followed. Video laryngoscopy is a major option in scenarios with factors suggesting difficult airway access. It is also indicated in rescue situations, when there is tracheal intubation failure with direct laryngoscopy. The objective of the present report was to show the efficacy of using the video laryngoscope as the first device for a patient with a large tumor that occupied almost the entire anterior portion of the oral cavity. Case report An 85 year-old male patient, 162 cm, 70 kg, ASA Physical Status II, Mallampati IV classification, was scheduled for resection of an angiosarcoma located in the right maxillary sinus that invaded much of the hard palate and the upper portion of the oropharynx. He was conscious and oriented, with normal blood pressure, heart and respiratory rates and, despite the large tumor in the oral cavity, he showed no signs of respiratory failure or airway obstruction. After intravenous cannulation and monitoring, sedation was performed with 1 mg of intravenous midazolam, and a nasal cannula was placed to provide oxygen, with a flow of 2 L min−1. Then, the target-controlled infusion of remifentanil with an effect site concentration of 2 ng mL−1 was initiated, according to Minto's pharmacokinetic model. Ventilation was maintained spontaneously during airway handling. A trans-cricothyroid block was performed, with 8 mL of 1% lidocaine solution injected into the tracheal lumen. Slight bleeding did not prevent the use of an optical method for performing tracheal intubation. The entire oral cavity was sprayed with 1% lidocaine. The McGraph video laryngoscope with the difficult intubation blade was used, and an armored tube with a guide wire inside was used for tracheal intubation, performed on the first attempt with appropriate glottis visualization. Conclusion The video laryngoscope occupies a prominent position in cases in which access to the airway is difficult. In the present case it was useful. It can be used as first choice or as a rescue technique. The video laryngoscope is an appropriate alternative and should be available for facing the ever-challenging difficult airway patient.

Resumo Justificativa e objetivos No planejamento da abordagem a uma via aérea difícil prevista, é importante determinar qual será a estratégia a ser seguida. A videolaringoscopia é uma ótima opção em situações em que existam fatores indicadores de dificuldade de acesso à via aérea. Também é indicada em situações de resgate, quando houve insucesso na tentativa de intubação com a laringoscopia direta. O objetivo deste relato é mostrar a eficácia da utilização do videolaringoscópio como primeiro dispositivo diante de paciente com grande tumor que ocupava quase a totalidade da porção anterior da cavidade oral. Relato do caso Paciente com 85 anos, sexo masculino, 162 cm, 70 kg, estado físico ASA II, classificação de Mallampati IV, foi escalado para a ressecção de um angiossarcoma localizado no seio maxilar direito que invadia grande parte do palato duro e da porção superior da orofaringe. Apresentava-se lúcido, consciente e orientado, com valores de pressão arterial, frequência cardíaca e respiratória normais e, apesar do grande tumor na cavidade oral, não apresentava qualquer sinal de insuficiência respiratória ou de obstrução das vias aéreas. Após venóclise, foi feita monitorização e sedação com 1 mg de midazolam, por via venosa, e colocado cateter nasal para administração de oxigênio, com fluxo de 2 L.min-1. Em seguida, foi iniciada a infusão alvo-controlada de remifentanil com concentração efeito de 2 ng.mL-1 segundo o modelo farmacocinético de Minto. A ventilação foi mantida em espontânea durante a manipulação da via aérea. Foi realizado bloqueio transcricotireóideo, sendo injetados 8 mL de solução de lidocaína a 1% na luz traqueal. Um pequeno sangramento não impediu que um método óptico fosse utilizado para realizar a intubação traqueal. Toda a cavidade oral recebeu o spray de lidocaína tópica a 1%. Foi utilizado o videolaringoscópio McGraph com a lâmina de intubação difícil, e um tubo aramado com fio guia no seu interior, foi utilizado para a intubação traqueal, que foi realizada na primeira tentativa, com boa visualização da glote. Conclusão O videolaringoscópio ocupa uma posição de destaque nos casos em que o acesso à via aérea é difícil. No presente caso, a sua utilização foi útil. Ele pode ser utilizado como primeira opção ou como técnica de resgate. Nas condições sempre preocupantes diante de um paciente com via aérea difícil, o videolaringoscópio deve estar disponível, constituindo-se uma boa opção.

Comparison of channelled videolaryngoscope and intubating laryngeal mask airway for tracheal intubation in obese patients: a randomised clinical trial / Comparação de videolaringoscópio com canal e máscara laríngea na intubação traqueal de pacientes obesos: estudo clínico randomizado

Abstract Background: Obesity causes various difficulties in intubation and ventilation, which are confronted due to increased fat tissue in the upper airway and diminished compliance in the chest wall. Videolaryngoscopes and Intubating Laryngeal Mask Airway (ILMA) are good options as recommended by the American Society of Anesthesologists (ASA) difficult airway guidelines. We aimed to compare ILMA and Airtraq (a channeled videolaryngoscope) in obese patients. Methods: Eighty patients with ASA physical status 1-3, aged between 18 and 65 years and with a body mass index greater than 35 kg.m-2, who were undergoing elective surgery requiring orotracheal intubation, were included in the study. Patients were intubated with one of the devices cited. Results: There was no difference between the number of intubation attempts, insertion times and need for optimisation manoeuvres of Airtraq and ILMA. The intubation with Airtraq was accomplished in a shorter period of time than in that in the ILMA group (29.9 ± 22.1s vs. 50.7 ± 21.2s; p < 0.001). A significant difference was found when the times of total intubation were compared (29.9 ± 22.1s vs. 97.4 ± 42.7s; p < 0.001). The mean arterial pressure statistically increased after device insertion in the ILMA group (p < 0.05). Conclusions: Airtraq appears to be superior to ILMA in obese patients, with a total of time intubation of less than 60 seconds and with low mean arterial pressure changes. However, ILMA is still a useful tool that provides both ventilation and intubation throughout the whole intubation process.

Resumo Justificativa: A obesidade dificulta a ventilação manual e intubação traqueal devido ao acúmulo de tecido adiposo na via aérea superior e a complacência diminuída na caixa torácica. Os videolaringoscópios e as Máscaras Laríngeas para Intubação (MLI) são alternativas boas para o manuseio da via aérea difícil, de acordo com as diretrizes da Sociedade Americana de Anestesologia (ASA). O objetivo do estudo foi comparar o uso da MLI e do Airtraq, um videolaringoscópio com canal, em pacientes obesos. Método: Estudamos 80 pacientes com classificação ASA I-III, com idades entre 18 e 65 anos e índice de massa corporal acima de 35 kg.m-2, submetidos a cirurgia eletiva com indicação de intubação orotraqueal. Os pacientes foram intubados empregando-se um dos seguintes dispositivos: MLI ou Airtraq. Resultados: Não houve diferença entre o número de tentativas de intubação, tempo de inserção do dispositivo e necessidade de manobras de otimização para o Airtraq e MLI. A intubação com Airtraq foi realizada mais rapidamente do que no Grupo MLI (29,9 ± 22,1 s vs. 50,7 ± 21,2 s; p < 0,001). Houve diferença significante na comparação do tempo total para intubação (29,9 ± 22,1 s vs. 97,4 ± 42,7 s; p < 0,001). Houve aumento estatisticamente significante da pressão arterial média após a inserção do dispositivo no Grupo MLI (p < 0,05). Conclusões: Airtraq parece ser superior a MLI em pacientes obesos, apresentando tempo total de intubação abaixo de 60 segundos e com menor variação na pressão arterial média. Todavia, a MLI ainda é ferramenta útil que propicia tanto ventilação quanto intubação durante todo o processo de manejo da via aérea.

Consistent Technique Limits Suspension Laryngoscopy Complications

Abstract Introduction Suspension laryngoscopy (SL) is a commonly performed procedure among otolaryngologists. Several studies have shown that adverse effects occur regularly with SL. Objective To evaluate the postoperative complications of SL, and to determine if protecting the dentition and the oral mucosa and limiting suspension times decrease the overall incidence of oral cavity and pharyngeal complications of SL. Methods All of the cases of SL performed by 1 surgeon from November 2008 through September 2014 were retrospectively reviewed. A consistent technique for dental and mucosal protection was utilized, and suspension times were strictly limited to 30 consecutiveminutes. The incidence of postoperative complications was calculated and analyzed with respect to gender, smoking status, dentition, laryngoscope type, and suspension system. Results A total of 213 consecutive SL cases were reviewed, including 174 patients (94 male, 80 female). The overall postoperative complication rate was of 3.8%. Four patients experienced tongue-related complications, two experienced oral mucosal alterations, one had a dental injury, and one experienced a minor facial burn. The complication incidence was greater with the Zeitels system(12.5%) compared with the Lewy suspension system (3.3%), although it was not significant (p = 0.4). Likewise, the association of complications with other patient factors was not statistically significant. Conclusion Only 8 out of 213 cases in the present series experienced complications, which is significantly less than the complication rates observed in other reports. Consistent and conscientious protection of the dentition and of the oral mucosa and limiting suspension times to 30 minutes are factors unique to our series that appear to reduce complications in endolaryngeal surgery.

Successful intubation using video laryngoscope in a child with CHARGE syndrome: A case report

CHARGE syndrome is a rare genetic disorder with CHD7 gene mutation. CHARGE is an acronym for coloboma (C), heart disease (H), atresia of choanae (A), retardation of growth (R), genitourinary malformation (G), and ear abnormalities (E). Patients with CHARGE syndrome need to undergo many surgeries due to their various congenital anomalies. Since airway abnormalities frequently accompany CHARGE syndrome, general anesthesia remains a challenge. Here we report a case of difficult intubation in a 35-month-old boy with CHARGE syndrome during general anesthesia and the experience of successful intubation using D-blade of C-MAC® video laryngoscope.

A Missed and Delayed Detected Fish Bone Impaction in Subglottis / 대한이비인후과학회지

Laryngeal foreign body can be a life-threatening emergency. Respiratory distress, aphonia, and cyanosis may occur in quick succession. However, in case of a non-obstructive laryngeal foreign body, symptoms can be indolent, but the hazardous foreign body can nevertheless put the patient in danger. To prevent life-threatening consequences, early detection based on symptoms is imperative. This case, which presented with usual symptoms of anterior neck pain and throat discomfort without respiratory symptoms and an unusual site of laryngeal foreign body, finally turned out to be an impacted fish bone in the subglottis.

Foreign body aspiration during dental treatment under general anesthesia: A case report

Foreign body aspiration in dental clinics is the most common cause of respiratory emergencies. There are no reports on foreign body aspiration during dental treatment under stable general anesthesia because the patient neither has voluntary movements nor reflex actions. This is a case report on the fall of a prosthesis in the larynx, which occurs rarely under general anesthesia. During the try-in procedure, the prosthesis slid from the surgeon's hand and entered the retromylohyoid space, and while searching for it, it passed down the larynx to the endotracheal tube balloon, leading to a dangerous situation. The prosthesis was promptly removed using video-assisted laryngoscope and forceps, and the patient was discharged without any complications.

Fibreoptic intubation in airway management: a review article

Since the first use of the flexible fibreoptic bronchoscope, a plethora of new airway equipment has become available. It is essential for clinicians to understand the role and limitations of the available equipment to make appropriate choices. The recent 4th National Audit Project conducted in the United Kingdom found that poor judgement with inappropriate choice of equipment was a contributory factor in airway morbidity and mortality. Given the many modern airway adjuncts that are available, we aimed to define the role of flexible fibreoptic intubation in decision-making and management of anticipated and unanticipated difficult airways. We also reviewed the recent literature regarding the role of flexible fibreoptic intubation in specific patient groups who may present with difficult intubation, and concluded that the flexible fibrescope maintains its important role in difficult airway management.

Impacts of Different Nostril for Nasotracheal Intubation with Video Laryngoscopy / 中国医学科学院学报

Objective To compare the impacts of different nostril on nasotracheal intubation with video laryngoscopy.Methods Totally 120 ASA grade I maxillofacial surgery patients were equally randomized into two groups:group A(left nostril)and group B(right nostril).After rapid induction of anesthesia,the nasal intubation was completed by Tosight video laryngoscope,and the success rate of the first attempt of the tube passing through the nasal cavity was recorded and compared between these two groups.In addition,time of tube through nasal cavity,time of glottis exposure,total intubation time,intubation success rate,and nasal bleeding were recorded.Results The success rate of the first attempt of tube passing through the nasal cavity was not significantly different between groups A and B(84.7% . 81.7%;=0.202,=0.653).The time of tube passing through nasal cavity [(7.3±4.6)s .(7.5±4.1)s;=-0.223,=0.824] and the time of glottic exposure [(6.6±1.4)s .(6.7±1.4)s;=-0.348,=0.728] had no significant differences between two groups.The success rates of first intubation attempt were 100% in both groups.The total intubation time was(35.1±9.2)s in group A and(34.0±7.8)s in group B(=0.663,=0.509).Intubation-related epistaxis was found in 16 cases(27.1%)in group A and in 17 cases(28.3%)in group B( =0.022,=0.882).Conclusion Different nasal approaches have no effect on nasal intubation.

Study on the effect of a cold environment on the quality of three video laryngoscopes: McGrath MAC, GlideScope Ranger, and Pentax Airway Scope

OBJECTIVE: Several environmental factors influence the prehospital use of video laryngoscopes (VLs). For example, fogging of the VL lens can occur in cold environments, and the low temperature can cause the VLs to malfunction. As relevant research on the effect of environment on VLs is lacking, we aimed to study the effect of a cold environment on three commonly used VLs.METHODS: McGrath MAC, Pentax Airway Scope (AWS), and GlideScope Ranger were exposed to temperatures of -5°C, -10°C, -20°C, and -25°C for 1 hour each and then applied to a manikin in a thermohydrostat room 5 times. Immediately after turning on the power and inserting the blade, the time until an appropriate glottic image appeared on the screen was measured.RESULTS: McGrath MAC was able to accomplish immediate intubation regardless of the temperature drop. However, GlideScope Ranger required an average of 4.9 seconds (-5°C to -20°C) and 10.1 seconds (-25°C) until appropriate images were obtained for intubation. AWS showed adequate image acquisition immediately after blade insertion despite slight fogging at -20°C, but at -25°C, images suitable for intubation did not appear on the screen for an average of 4.7 minutes.CONCLUSION: All three devices appear to be usable without any limitations up to -20°C. However, GlideScope Ranger and AWS may not produce images immediately at temperatures below -25°C. Thus, medical practitioners performing VL in a cold environment should be aware of the characteristics of the VL devices in advance.