Intubación orotraqueal por medio de fibrobroncoscopio flexible sin conductor vs guiada con máscara laríngea AuraGain en simuladores pediátricos: Ensayo clínico cross over

Antecedentes: La incidencia de intubación difícil en población pediátrica es de 2 a 11 casos por 1000 pacientes llevados a anestesia general, lo que conlleva riesgos potenciales como hipoxemia, parada cardíaca y muerte. Dentro de las estrategias para el manejo de la vía aérea difícil en los niños se encuentra el uso de fibroscopia flexible para guiar la intubación, que se puede combinar con un dispositivo supraglótico con la finalidad de facilitar su inserción, superar obstrucciones de la vía aérea superior y permitir una ventilación simultánea. El objetivo de este estudio fue comparar la intubación orotraqueal en simuladores pediátricos, utilizando fibrobroncoscopio flexible sin conductor versus el uso de la máscara laríngea AuraGain como conductor, con el fin de demostrar si el uso de dicho dispositivo supra glótico tiene alguna ventaja comparado con intubar sin conductor. Métodos: 41 anestesiólogos y residentes de anestesiología, fueron asignados al azar para realizar una intubación orotraqueal en un simulador pediátrico, utilizando fibrobroncoscopio flexible sin conductor o utilizando como guía la máscara laríngea AuraGain. Resultados: La intubación exitosa en el primer intento se consiguió en 38 de 41 intubaciones en el grupo de fibrobroncoscopia sin conductor y en 32 de 41 intubaciones en el grupo de fibrobroncoscopia con AuraGain, sin encontrar diferencias estadísticamente significativas. El grupo de fibrobroncoscopia sin conductor tuvo una mediana de tiempo de intubación significativamente más corta (41 segundos), comparado con el grupo de fibrobroncoscopia y AuraGain (67.5 segundos). Conclusiones: Usar el dispositivo AuraGain como conductor para intubar simuladores pediátricos con fibra óptica no mejora la intubación al primer intento, la intubación global, ni la visualización glótica, comparado con intubar solo con fibra óptica. Usar AuraGain aumenta los tiempos de intubación, sin embargo, dichos hallazgos deben ser confirmados en estudios con humanos. Background: The incidence of difficult intubation in pediatric population is 2 to 11 cases per 1000 patients brought to general anesthesia, which carries potential risks such as hypoxemia, cardiac arrest and death. Among the strategies for the management of difficult airway in children is the use of flexible fiberscopy to guide intubation, which can be combined with a supraglottic device in order to facilitate its insertion, overcome upper airway obstructions and allow simultaneous ventilation. The aim of this study was to compare orotracheal intubation in pediatric simulators, using a flexible fibrobronchoscope without driver versus using the AuraGain laryngeal mask as a driver, in order to demonstrate whether the use of such a supraglottic device has any advantage compared to intubating without a driver. Methods: 41 anesthesiologists and anesthesiology residents were randomly assigned to perform orotracheal intubation in a pediatric simulator using either a flexible fibrobronchoscope without a driver or the AuraGain laryngeal mask as a guide. Results: Successful intubation on the first attempt was achieved in 38 of 41 intubations in the driverless fibrobronchoscopy group and in 32 of 41 intubations in the fibrobronchoscopy with AuraGain group, with no statistically significant differences. The driverless fibrobronchoscopy group had a significantly shorter median intubation time (41 seconds) compared to the fibrobronchoscopy and AuraGain group (67.5 seconds). Conclusions: Using the AuraGain device as a driver to intubate pediatric simulators with fiberoptics does not improve first-attempt intubation, overall intubation, or glottic visualization compared with intubating with fiberoptics alone. Using AuraGain increases intubation times, however, such findings need to be confirmed in human studies.

A protocol for the multi-method evaluation of novel externally applied suction-based airway clearance devices in the treatment of foreign body airway obstructions

Background: Foreign body airway obstructions (FBAO, choking) are a significant cause of preventable mortality. Abdominal thrusts, back blows, and chest compressions are traditional interventions; however, suction-based airway clearance devices (anti-choking devices, ACDs) have recently been marketed as an alternative. Of note, there is limited published evidence regarding their efficacy and safety. Our research has two aims: 1) To investigate what situational and patient factors are frequently identified, and which are associated with relief of the FBAO, and survival, in individuals with a FBAO treated with an ACD; and 2) To describe the experience of individuals who have used ACDs in response to a FBAO and identify facilitators and barriers to the use of ACDs compared to traditional interventions. Methods and analysis: All ACD case reports collected a priori by manufacturers will be analyzed up to July 1st, 2021. Following, a prospective database will be developed using an online reporting system to capture future ACD use from July 1st, 2021 to Dec 31st, 2023. Descriptive statistics will be used to summarize cases, 58 outcomes, and adverse events. Where possible, bivariable and multivariable analysis will be employed to assess for predictors of outcomes (relief of FBAO, survival, and survival with good neurological function). Semi-structured interviews will be conducted with a subset of ACD users to describe in detail their experience using the device. Themes from these interviews will be assessed using the Theoretical Domains Framework. Ethics and dissemination: This study has ethics approval from the University of New South Wales Human Research Ethics Committee (HC210242). Findings from this multi-year, multi-method study will be published in peer reviewed literature, presented at conferences and contribute to informing future resuscitation guidelines. Data on ACDs are urgently needed as these devices are already being used by parents, caregivers, lay rescuers, and healthcare professionals

Safety of Laser and Thermal Therapy During Rigid Bronchoscopy Using Manual Hand Jet Ventilation

Introduction: Thermal ablative therapies (laser, radiofrequency ablation, electrocautery, argon plasma coagulation) are often used during rigid bronchoscopy for the treatment of central airway obstructions (CAO). An airway fire is a feared complication that can occur during endobronchial thermal ablation. Materials and Methods: This was a single-center, retrospective, observational study. A total of 175 patients were reviewed undergoing rigid bronchoscopy in the operating room and bronchoscopy suite requiring manual hand jet ventilation and thermal therapy between September 2014 and September 2018. The study objective was to determine the safety of manual hand jet ventilation during endobronchial thermal therapies with rigid bronchoscopy. Results: Over a five-year period, 175 patients underwent endobronchial thermal therapy during rigid bronchoscopy with manual hand jet ventilation for the treatment CAOs. Immediately prior to thermal therapy activation, jet ventilation was paused. No incidences (0/175) of airway fires occurred despite immediate delivery of thermal energy following a jet ventilation hold. Conclusions: Results of our study show that performing thermal ablative therapy during rigid bronchoscopy with jet ventilation using a breath-hold technique is safe.

Using individualized three-dimensional printed airway models to guide airway stent implantation

Airway stents are used to manage central airway obstructions by restoring airway patency. Current manufactured stents are limited in shape and size, which pose issues in stent fenestrations needed to be manually created to allow collateral ventilation to airway branches. The precise location to place these fenestrations can be difficult to predict based on 2-dimensional computed tomography images. Inspiratory computed tomography scans were obtained from 3 patients and analysed using 3D-Slicer™, Blender™ and AutoDesk® Meshmixer™ programmes to obtain working 3D-airway models, which were 3D printed. Stent customizations were made based on 3D-model dimensions, and fenestrations into the stent were cut. The modified stents were then inserted as per usual technique. Two patients reported improved airway performance; however, stents were later removed due to symptoms related to in-stent sputum retention. In a third patient, the stent was removed a few weeks later due to the persistence of fistula leakage. The use of a 3D-printed personalized airway model allowed for more precise stent customization, optimizing stent fit and allowing for cross-ventilation of branching airways. We determine that an airway model is a beneficial tool for stent optimization but does not prevent the development of some stent-related complications such as airway secretions.

An Accidental Bronchial Obstruction Caused by Detached Cuff: Case Report and Literature Review

Background The airway obstructions are usually caused by secretions, mucus plugs, blood clots, malposition of bronchial blockers (BBs) cuff or twist of the tube by oral biting. In this paper, we report a case of accidental bronchial obstruction as a result of a cuff detaching from the BBs catheter.Case presentation A 48-year-old male was admitted to our department due to small cell lung cancer. He had received two cycles of neoadjuvant chemotherapy with etoposide plus cisplatin and was scheduled a right upper lobe resection by thoracotomy. During the surgery, the patient was intubated with an 8.0-mm internal diameter BBs tube (Univent tube). When the anesthesiologist tried to remove the BBs towards the end of surgery, the cuff got detached accidentally and obstructed the airway leading to improper expansion of the middle lobe. This condition was determined later by the 6.0-mm bronchoscope and the cuff was removed with forceps. Conclusions We report this case aiming to remind other colleagues that the cuff detachment in the surgical procedure is still a potentially fatal incident even it rarely happens nowadays. It is important to check the BBs apparatus meticulously through the whole operative procedure. The routine use of 4.0-mm bronchoscope should be highly recommended during the entire airway management when a bronchial obstruction is suspected.

Impact of artificial airway resistances on regional ventilation distribution during airway closure

Electrical impedance tomography (EIT), a noninvasive and radiation-free imaging technique can be used in pulmonary function monitoring for determining regional ventilation distribution within the lung. Gold standard in pulmonary function monitoring is spirometry/body plethysmography, a method using forced breathing maneuvers to obtain global lung function parameters. However, this method is heavily dependent on the cooperation of the patients. Within this observational study, a method under normal breathing was tested with 5 healthy volunteers, which provides regional information about ventilation distribution. The occlusion method Rocc, a method for determining airway resistance, was used to create a short-term airway closure. Regional ventilation during the airway closure was examined with EIT. Simultaneously four different artificial airway resistances were used to simulate airway obstructions. Results show that EIT in combination with the ROcc method is suitable for the detection of regional differences in ventilation during airway closure for all four artificial airway resistances. Although the sum of relative impedances at the end of the shutter maneuver are smaller (nearly -0.100 AU) for the airway resistances Ø 12.5 mm, Ø 10.5 mm and Ø 9.5 mm than for the smallest one with Ø 30.0 mm (~ -0.070 AU), the changes in impedance from the start to the end of the shutter maneuver differs only slightly between the four artificial airway resistances. All impedance changes are in the range of 0.100 to 0.130 AU. The combination of EIT and the ROcc method provides not only global parameters such as airway resistance under normal breathing conditions, but also results of regional ventilation, which could enable the identification of areas affected by airway obstructions. However, the obtained results indicate that EIT might be a useful tool in the diagnosis and follow-up of obstructive lung diseases.

Normal Predicted Reference Values for Spirometry in Korean Children and Adolescents

Pulmonary function tests are useful to evaluate airway obstructions and bronchial responsiveness. We aimed to determine the reference values applicable to Korean children and adolescents. In total, 5590 (2607 males, 2983 females) healthy children aged 4 to 17 years old were recruited from three regions in Korea. Simple and multiple regression analyses were applied using age, height, and weight as variables to predict the forced vital capacity (FVC), forced expiratory volume in one second (FEV1), maximum mid-expiratory flow (MMEF) and the peak expiratory flow rate (PEFR). There were significant correlations between the variables and parameters (P < 0.001). The coefficient of determination (R2) values of polynomial equations with two variables were lower than those with two variables but higher than those of monomial equations based on height. The prediction equations by height were obtained, and the R2 value of the FEV1 was the highest. The predicted spirometric values for males were higher than those for females except for the MMEF. The R2 values for the FEV1 and FVC were higher than previous studies except for the R2 value of the FVC for males in European data. This study provided updated regression equations of normal predicted values for spirometry applicable to Korean children and adolescents.