Método de suma acumulada (CUSUM) para evaluar las curvas de aprendizaje del bloqueo femoral continuo guiado por ecografía / Use of the cumulative sum method (CUSUM) to assess the learning curves of ultrasound-guided continuous femoral nerve block

Introducción. Aunque la ecografía es una competencia básica de los residentes de anestesia (RA) hay pocos datos disponibles sobre su proceso de aprendizaje. Este estudio prospectivo observacional tiene como objetivo evaluar el proceso de aprendizaje del bloqueo del nervio femoral continuo guiado por ecografía y determinar el número de procedimientos necesarios que un RA debe realizar para ser exitoso, utilizando el método de suma acumulada (CUSUM). Método. Reclutamos 19 RA sin experiencia previa. Construimos las curvas de aprendizaje utilizando la metodología CUSUM para el bloqueo del nervio femoral continuo guiado por ecografía considerando 2 criterios de éxito: disminución del dolor>2 puntos en una escala numérica [0-10] tras 15min y el tiempo necesario para realizar la técnica. Resultados. Analizamos los datos de 17 RA, que realizaron un total de 237 bloqueos del nervio femoral continuo guiados por ecografía. Ocho de 17 RA tuvieron éxito en cuanto a la disminución del dolor, y asimismo aquellos RA que realizaron>12 bloqueos (8/8) lo consiguieron. En cuanto al tiempo de realización, 5/17 RA alcanzaron el objetivo en 12min; y todos los RA que realizaron>20 procedimientos (4/4) lo alcanzaron. Conclusiones. El número de procedimientos necesarios para alcanzar el éxito parece ser 12, sin embargo es necesario realizar un número mayor para reducir el tiempo de realización del mismo. La metodología CUSUM podría ser útil en programas de formación, permitiendo intervenciones precoces en casos de fallos repetidos, y realizar un currículo basado principalmente en las competencias (AU)

Background. Although ultrasound is a basic competence for anaesthesia residents (AR) there is few data available on the learning process. This prospective observational study aims to assess the learning process of ultrasound-guided continuous femoral nerve block and to determine the number of procedures that a resident would need to perform in order to reach proficiency using the cumulative sum (CUSUM) method. Methods. We recruited 19 AR without previous experience. Learning curves were constructed using the CUSUM method for ultrasound-guided continuous femoral nerve block considering 2 success criteria: a decrease of pain score>2 in a [0-10] scale after 15minutes, and time required to perform it. Results. We analyse data from 17 AR for a total of 237 ultrasound-guided continuous femoral nerve blocks. 8/17 AR became proficient for pain relief, however all the AR who did more than 12 blocks (8/8) became proficient. As for time of performance 5/17 of AR achieved the objective of 12minutes, however all the AR who did more than 20 blocks (4/4) achieved it. Conclusions. The number of procedures needed to achieve proficiency seems to be 12, however it takes more procedures to reduce performance time. The CUSUM methodology could be useful in training programs to allow early interventions in case of repeated failures, and develop competence-based curriculum (AU)

Visión moderna sobre una técnica antigua: revisión narrativa de técnicas de localización del espacio epidural / Modern approach to an old technique: narrative revision of techniques used to locate the epidural space

Desde la primera descripción de la técnica epidural en los años 1920, el progreso continuo en el conocimiento de la anatomía y de la fisiología del espacio epidural ha permitido desarrollar diferentes técnicas de localización de este espacio para aumentar tanto la seguridad como la eficacia del procedimiento. Las técnicas más utilizadas hoy en día se basan en las 2 principales propiedades descritas del espacio epidural: la diferencia de distensibilidad entre el ligamento amarillo y el espacio epidural y la existencia de una presión negativa en el espacio epidural. Sin embargo, en los últimos años, la evolución tecnológica ha permitido desarrollar nuevas técnicas de localización basadas en otras propiedades físicas de los tejidos. Algunas de ellas están todavía en una fase experimental, pero otras como las técnicas con ultrasonidos han alcanzado una fase clínica y se está expandiendo su uso en la práctica diaria (AU)

Since the first description of the epidural technique during the 1920s, the continuous progress of knowledge of the anatomy and physiology of the epidural space has allowed the development of different techniques to locate this space while increasing both the safety and efficacy of the procedure. The most common techniques used today are based on the two main characteristics of the epidural space: the difference in distensibility between the ligamentum flavum and the epidural space, and the existence of negative pressure within the epidural space. However, over recent years, technological advances have allowed the development of new techniques to locate the epidural space based on other physical properties of tissues. Some are still in the experimental phase, but others, like ultrasound-location have reached a clinical phase and are being used increasingly in daily practice (AU)

Modern approach to an old technique: Narrative revision of techniques used to locate the epidural space. / Visión moderna sobre una técnica antigua: revisión narrativa de técnicas de localización del espacio epidural.

Since the first description of the epidural technique during the 1920s, the continuous progress of knowledge of the anatomy and physiology of the epidural space has allowed the development of different techniques to locate this space while increasing both the safety and efficacy of the procedure. The most common techniques used today are based on the two main characteristics of the epidural space: the difference in distensibility between the ligamentum flavum and the epidural space, and the existence of negative pressure within the epidural space. However, over recent years, technological advances have allowed the development of new techniques to locate the epidural space based on other physical properties of tissues. Some are still in the experimental phase, but others, like ultrasound-location have reached a clinical phase and are being used increasingly in daily practice.

Use of the cumulative sum method (CUSUM) to assess the learning curves of ultrasound-guided continuous femoral nerve block. / Método de suma acumulada (CUSUM) para evaluar las curvas de aprendizaje del bloqueo femoral continuo guiado por ecografía.

BACKGROUND: Although ultrasound is a basic competence for anaesthesia residents (AR) there is few data available on the learning process. This prospective observational study aims to assess the learning process of ultrasound-guided continuous femoral nerve block and to determine the number of procedures that a resident would need to perform in order to reach proficiency using the cumulative sum (CUSUM) method. METHODS: We recruited 19 AR without previous experience. Learning curves were constructed using the CUSUM method for ultrasound-guided continuous femoral nerve block considering 2 success criteria: a decrease of pain score>2 in a [0-10] scale after 15minutes, and time required to perform it. RESULTS: We analyse data from 17 AR for a total of 237 ultrasound-guided continuous femoral nerve blocks. 8/17 AR became proficient for pain relief, however all the AR who did more than 12 blocks (8/8) became proficient. As for time of performance 5/17 of AR achieved the objective of 12minutes, however all the AR who did more than 20 blocks (4/4) achieved it. CONCLUSIONS: The number of procedures needed to achieve proficiency seems to be 12, however it takes more procedures to reduce performance time. The CUSUM methodology could be useful in training programs to allow early interventions in case of repeated failures, and develop competence-based curriculum.

Protocolo clínico asistencial de manejo de la hipertermia maligna / Clinical protocol for the management of malignant hyperthermia

La hipertermia maligna es un síndrome hipermetabólico que ocurre en pacientes susceptibles, tras la exposición a un fármaco anestésico desencadenante (succinilcolina, anestésicos inhalatorios). En España, se presenta en uno de cada 40.000 en adultos, con una mortalidad estimada del 10%. Está inducido por una regulación anormal de los receptores de rianodina, que produce una liberación masiva del calcio del retículo sarcoplasmático del músculo. Las manifestaciones clínicas son variadas y consisten en: elevación del CO2, taquicardia e inestabilidad hemodinámica, acidosis metabólica y respiratoria, sudoración profusa, hiperpirexia, elevación de CPK, mioglobinuria, fallo renal, CID y finalmente parada cardiorrespiratoria. El tratamiento con dantroleno sódico inhibe la liberación de calcio al antagonizar los receptores de rianodina. El diagnóstico definitivo se realiza con el test de contracción de fibra muscular expuesta a cafeína y halotano. Ante este grave evento la protocolización del manejo ayuda a garantizar que el paciente reciba una atención fiable y segura (AU)

Malignant hyperthermia is a hypermetabolic syndrome that appears in susceptible patients after exposure to certain anaesthetic drugs (succinylcholine, inhalation anaesthetics). Its incidence in Spain is 1 in 40,000 adults, with a 10% mortality rate. It is induced by an abnormal regulation of the ryanodine receptors, producing a massive release of calcium from the sarcoplasmic reticulum in the striate muscle. Clinical manifestations include: CO2 increase, tachycardia, haemodynamic instability, metabolic and respiratory acidosis, profuse sweating, hyperpyrexia, CPK increase, myoglobinuria, kidney failure, disseminated intravascular coagulation (DIC), and ending in cardiac arrest. Dantrolene sodium is a ryanodine receptor antagonist, and inhibits the release of intracellular calcium. Definitive diagnosis is achieved by the exposure of muscle fibres to caffeine and halothane. Protocols can help guarantee a reliable and secure management when this severe event occurs (AU)

Clinical protocol for the management of malignant hyperthermia. / Protocolo clínico asistencial de manejo de la hipertermia maligna.

Malignant hyperthermia is a hypermetabolic syndrome that appears in susceptible patients after exposure to certain anaesthetic drugs (succinylcholine, inhalation anaesthetics). Its incidence in Spain is 1 in 40,000 adults, with a 10% mortality rate. It is induced by an abnormal regulation of the ryanodine receptors, producing a massive release of calcium from the sarcoplasmic reticulum in the striate muscle. Clinical manifestations include: CO2 increase, tachycardia, haemodynamic instability, metabolic and respiratory acidosis, profuse sweating, hyperpyrexia, CPK increase, myoglobinuria, kidney failure, disseminated intravascular coagulation (DIC), and ending in cardiac arrest. Dantrolene sodium is a ryanodine receptor antagonist, and inhibits the release of intracellular calcium. Definitive diagnosis is achieved by the exposure of muscle fibres to caffeine and halothane. Protocols can help guarantee a reliable and secure management when this severe event occurs.

Ventilación con mascarilla facial en decúbito prono para tratamiento radioterápico en niños / Ventilation with facial mask in the prone position for radiotherapy procedures in children

Objetivos. La ventilación de los pacientes para procedimientos en decúbito prono representa un reto para el anestesiólogo, especialmente cuando se intenta evitar la intubación endotraqueal. Presentamos un estudio concebido para comprobar la efectividad y la seguridad de un prototipo diseñado para ventilación con mascarilla facial en decúbito prono en niños. Material y métodos. Estudio descriptivo prospectivo de 105 sedaciones realizadas en 3 niños programados para tratamiento radioterápico en decúbito prono por meduloblastoma desmoplásico de fosa posterior (2 pacientes de 4 y 6 años de edad) y neuroblastoma en área temporal (un paciente de 4 años). La inducción y el mantenimiento de la sedación se realizaron con sevoflurano en oxígeno, manteniendo ventilación espontánea. Tras la pérdida de consciencia e inmovilidad del paciente se procedía a colocarlo en decúbito prono y a fijar su cabeza con frente y cara apoyadas en un prototipo creado con un molde de poliexpan que contenía la mascarilla facial (conectada a un circuito Mapleson D,) y la parte posterior de la cabeza inmovilizada con una capa de material termoplástico. Se recogieron variables de tiempo y posibles complicaciones. Resultados. Las 105 sedaciones se realizaron según el protocolo previsto. No se produjeron desaturaciones por debajo del 95%, movimientos durante el procedimiento ni otras complicaciones. El tiempo de estancia en el hospital incluyendo procedimiento y recuperación postanestésica fue de 54,4 ± 7,9 min (media ± DE). Conclusiones. El prototipo y técnica de sedación con mascarilla facial en decúbito prono empleados fueron efectivos y seguros permitiendo la realización del tratamiento radioterápico, asegurando la vía aérea de forma mínimamente invasiva, manteniendo la ventilación adecuada, una sedación superficial y posibilitando un alta a domicilio precoz (AU)

Objectives. Ventilation of patients undergoing procedures in the prone position represents a challenge for the anesthesiologist, especially when trying to avoid tracheal intubation. This study aimed to test the effectiveness and safety of a prototype designed for pediatric facial mask ventilation in the prone position. Material and methods. A prospective descriptive study was conducted on 105 sedations performed in 3 children scheduled for radiotherapy treatment of posterior fossa desmoplastic medulloblastoma (6 and 4 y.o. males), and neuroblastoma in temporal area (4 y.o. male). Induction and maintenance of sedation were conducted with sevoflurane in oxygen, maintaining spontaneous ventilation. After achieving loss of consciousness and immobility, the patients were placed in the prone position. Their heads were fixed with the forehead and face supported by a prototype made with a cast of expanded polystyrene (EPS), which held the facial mask (connected to a Mapleson D circuit), and the back of the head immobilized with a layer of thermoplastic material. Time variables and complications were recorded. Results. All sedations were performed according to the planned protocol. All patients maintained oxygen saturation levels above 95%, and no complications were reported. Daily hospital length of stay including the procedure and post anesthetic recovery was 54.4±7.9 min (mean ± SD). Conclusions. The prototype and the sedation technique with face mask in the prone position employed were effective and safe, allowing the completion of the radiotherapy sessions and securing the airway in a minimally invasive way, maintaining adequate ventilation, light sedation and enabling early hospital discharge (AU)

Ventilation with facial mask in the prone position for radiotherapy procedures in children.

OBJECTIVES: Ventilation of patients undergoing procedures in the prone position represents a challenge for the anesthesiologist, especially when trying to avoid tracheal intubation. This study aimed to test the effectiveness and safety of a prototype designed for pediatric facial mask ventilation in the prone position. MATERIAL AND METHODS: A prospective descriptive study was conducted on 105 sedations performed in 3 children scheduled for radiotherapy treatment of posterior fossa desmoplastic medulloblastoma (6 and 4 y.o. males), and neuroblastoma in temporal area (4 y.o. male). Induction and maintenance of sedation were conducted with sevoflurane in oxygen, maintaining spontaneous ventilation. After achieving loss of consciousness and immobility, the patients were placed in the prone position. Their heads were fixed with the forehead and face supported by a prototype made with a cast of expanded polystyrene (EPS), which held the facial mask (connected to a Mapleson D circuit), and the back of the head immobilized with a layer of thermoplastic material. Time variables and complications were recorded. RESULTS: All sedations were performed according to the planned protocol. All patients maintained oxygen saturation levels above 95%, and no complications were reported. Daily hospital length of stay including the procedure and post anesthetic recovery was 54.4±7.9 min (mean±SD). CONCLUSIONS: The prototype and the sedation technique with face mask in the prone position employed were effective and safe, allowing the completion of the radiotherapy sessions and securing the airway in a minimally invasive way, maintaining adequate ventilation, light sedation and enabling early hospital discharge.