Actualización en el abordaje de la vía respiratoria del paciente obeso / Update on the approach to the obese patient respiratory tract

RESUMEN El manejo de la vía respiratoria es uno de los aspectos más importantes en Anestesia. Entre el 50 y 70 % de los paros cardiacos durante la anestesia general obedecen a dificultades en la intubación. Los pacientes obesos tienen un 30 % más de probabilidades de presentar intubación difícil con respecto a pacientes normopesos. También desarrollan desaturación de oxígeno más rápido, lo que aumenta el riesgo de complicaciones. Teniendo en cuenta lo anterior, se decidió realizar este trabajo, con el objetivo de actualizar sobre el uso de los métodos para el abordaje de la vía respiratoria en dichos pacientes. Se mostraron los criterios y resultados de investigaciones de autores sobre el tema. Se concluye que, a pesar de que el método más utilizado para abordar la vía aérea en obesos es la intubación orotraqueal con visión directa, se debe considerar el uso de máscara laríngea de intubación, fibroscopio flexible y videolaringoscopios, sobre todo en personas superobesas (AU).

ABSTRACT The respiratory tract management is one of the most important topics in anesthesia. Between 50 and 70 % of the heart arrests occurring during general anesthesia are due to intubation difficulties. Obese patients are 30 % more likely of presenting difficult intubation with respect to normal weight patients. They also develop oxygen desaturation faster, increasing the complication risk. Taking into consideration the above reasons, the authors decided to write this article, with the aim of updating on the methods to approach the respiratory tract in those patients. The authors' criteria and research outcomes on the theme are showed. It was concluded that even though the most used method to approach the airway in obese patients is the orotracheal intubation with direct vision, the use of a laryngeal intubation mask, flexible fiberscope and video laryngoscopes should be considered, especially in superobese patients (AU).

Craneotomía en el paciente despierto / Awake craniotomy

Introducción: La craneotomía con el paciente despierto es útil para lograr resecciones cerebrales amplias de lesiones de áreas elocuentes. Objetivo: Presentar un caso al que se le realizó la técnica dormido- despierto. Método: Se realizó la inducción de la anestesia con propofol/fentanilo/rocuronio y se colocó una mascarilla laríngea. Después del bloqueo de escalpe se mantuvo la infusión de propofol/fentanilo y lidocaína hasta que se realizó la craneotomía. Se disminuyó la velocidad de infusión y se mantuvo de esta manera hasta finalizada la intervención. Resultados: Se logró el despertar del paciente a los 13 minutos de reducida la infusión. Se mantuvo buena estabilidad hemodinámica, sin depresión respiratoria ni otras complicaciones. El paciente se mantuvo colaborador, respondió preguntas y movilizó sus extremidades. No presentó complicaciones posoperatorias. Discusión: Dentro de las técnicas anestésicas utilizadas en el mundo la dormido- despierto-dormido es la más popular; sin embargo, constituye una alternativa no dormir nuevamente al paciente ni reinstrumentar la vía respiratoria. Los medicamentos más empleados son el propofol/remifentanilo, aunque la comparación con otros opioides no arrojan diferencias significativas; aunque sí supone un beneficio adicional la dexmedetomidina. Conclusiones: La craneotomía con el paciente despierto es posible de realizar en el entorno hospitalario siempre que exista un equipo multidisciplinario que consensue las mejores acciones médicas para el paciente(AU)

Introduction: Awake craniotomy is useful to achieve wide brain resections of lesions in eloquent areas. Objective: To present the case of a patient who was operated on with the asleep-awake-asleep technique. Method: Anesthesia was induced with propofol-fentanyl-rocuronium and a laryngeal mask was placed. After scalp block, the propofol-fentanyl and lidocaine infusion was maintained until craniotomy was performed. The infusion rate was decreased and remained this way until the end of the intervention. Results: The patient was awakened thirteen minutes after the infusion was reduced. Good hemodynamic stability was maintained, without respiratory depression or other complications. The patient remained collaborative, answered questions, and mobilized his limbs. He had no postoperative complications. Discussion: Among the anesthetic techniques used in the world, asleep-awake-asleep is the most popular. However, it is an alternative not to put the patient back to sleep or re-instrument the airway. The most commonly used drugs are propofol-remifentanil, although the comparison with other opioids does not show significant differences, except for dexmedetomidine, which does represent an additional benefit. Conclusions: Awake craniotomy is possible to be performed in the hospital setting as long as there is a multidisciplinary team that agrees on the best medical actions for the patient(AU)

[RETRACTED ARTICLE] Comparison of Arndt-endobronchial blocker plus laryngeal mask airway with left-sided double-lumen endobronchial tube in one-lung ventilation in thoracic surgery in the morbidly obese

This study aimed to evaluate the feasibility and performance of Arndt-endobronchial blocker (Arndt) combined with laryngeal mask airway (LMA) compared with left-sided double-lumen endobronchial tube (L-DLT) in morbidly obese patients in one-lung ventilation (OLV). In a prospective, randomized double-blind controlled clinical trial, 80 morbidly obese patients (ASA I-III, aged 20-70) undergoing general anesthesia for elective thoracic surgeries were randomly allocated into groups Arndt (n=40) and L-DLT (n=40). In group Arndt, a LMA™ Proseal was placed followed by an Arndt-endobronchial blocker. In group L-DLT, patients were intubated with a left-sided double-lumen endotracheal tube. Primary endpoints were the airway establishment, ease of insertion, oxygenation, lung collapse and surgical field exposure. Results showed similar ease of airway establishment and tube/device insertion between the two groups. Oxygen arterial pressure (PaO2) of patients in the Arndt group was significantly higher than L-DLT (154±46 vs 105±52 mmHg; P<0.05). Quality of lung collapse and surgical field exposure in the Arndt group was significantly better than L-DLT (effective rate 100 vs 90%; P<0.05). Duration of surgery and anesthesia were significantly shorter in the Arndt group (2.4±1.7 vs 3.1±1.8 and 2.8±1.9 vs 3.8±1.8 h, respectively; P<0.05). Incidence of hoarseness of voice and incidence and severity of throat pain at the post-anesthesia care unit and 12, 24, 48, and 72 h after surgery were significantly lower in the Arndt group (P<0.05). Findings suggested that Arndt-endobronchial blocker combined with LMA can serve as a promising alternative for morbidly obese patients in OLV in thoracic surgery.

Comparison of Arndt-endobronchial blocker plus laryngeal mask airway with left-sided double-lumen endobronchial tube in one-lung ventilation in thoracic surgery in the morbidly obese

This study aimed to evaluate the feasibility and performance of Arndt-endobronchial blocker (Arndt) combined with laryngeal mask airway (LMA) compared with left-sided double-lumen endobronchial tube (L-DLT) in morbidly obese patients in one-lung ventilation (OLV). In a prospective, randomized double-blind controlled clinical trial, 80 morbidly obese patients (ASA I-III, aged 20-70) undergoing general anesthesia for elective thoracic surgeries were randomly allocated into groups Arndt (n=40) and L-DLT (n=40). In group Arndt, a LMA™ Proseal was placed followed by an Arndt-endobronchial blocker. In group L-DLT, patients were intubated with a left-sided double-lumen endotracheal tube. Primary endpoints were the airway establishment, ease of insertion, oxygenation, lung collapse and surgical field exposure. Results showed similar ease of airway establishment and tube/device insertion between the two groups. Oxygen arterial pressure (PaO2) of patients in the Arndt group was significantly higher than L-DLT (154±46 vs 105±52 mmHg; P<0.05). Quality of lung collapse and surgical field exposure in the Arndt group was significantly better than L-DLT (effective rate 100 vs 90%; P<0.05). Duration of surgery and anesthesia were significantly shorter in the Arndt group (2.4±1.7 vs 3.1±1.8 and 2.8±1.9 vs 3.8±1.8 h, respectively; P<0.05). Incidence of hoarseness of voice and incidence and severity of throat pain at the post-anesthesia care unit and 12, 24, 48, and 72 h after surgery were significantly lower in the Arndt group (P<0.05). Findings suggested that Arndt-endobronchial blocker combined with LMA can serve as a promising alternative for morbidly obese patients in OLV in thoracic surgery.

La vía respiratoria en la reanimación cardiopulmonar y cerebral / Respiratory airway in brain and cardiopulmonary resuscitation

Introducción: acceder a la vía respiratoria constituye un elemento de vital importancia en la parada cardiaca. Tanto cuando los principios básicos establecidos para la reanimación eran el ABC por sus siglas en inglés (airway, breathing and circulation), como los del actual CAB (circulation, airway and breathing). Existen controversias entre la técnica utilizar de manera que se garantice de la mejor forma la ventilación: ¿intubación orotraqueal o dispositivos supraglóticos? Objetivo: realizar una actualización sobre las técnicas para acceder a la vía respiratoria en la reanimación cardiopulmonar y cerebral. Método: se visitó la página web de la Biblioteca Médica Nacional de los Estados Unidos (PubMed), con las siguientes palabras clave en inglés: airway AND reanimation y con el filtro activado para los últimos cinco años, en humanos y a texto completo. Conclusiones: la intubación traqueal requiere entrenamiento y práctica regular para evitar complicaciones. El personal poco entrenado no siempre tiene suficientes habilidades para lograrlo y no deberían perder tiempo realizando estos procedimientos y sí centrarse en las compresiones torácicas de alta calidad, la ventilación con bolsa y mascarilla, hasta la llegada de reanimadores expertos(AU)

Introduction: Accessing the airway is an element of vital importance in cases of cardiac arrest. Both when the basic principles established for resuscitation were the ABC (English acronym for airway, breathing and circulation), and for those of the current CAB (circulation, airway and breathing). There are controversies between the technique used to ensure ventilation the best way: orotracheal intubation or supraglottic devices? Objective: To carry out an update on the techniques to access the airway in cardiopulmonary and cerebral resuscitation. Method: We visited the website of the National Medical Library of the United States ( PubMed) with the following keywords in English: airway AND reanimation, and with the filter activated for the last five years, in humans and in full text. Conclusions: Tracheal intubation requires regular training and practice to avoid complications. The untrained staff members do not always have enough skills to achieve it and should not waste time doing these procedures, but focus on high-quality chest compressions, the ventilation bag and mask, instead, until the arrival of rescuer experts(AU)

Síndrome serotoninérgico / Serotonin syndrome

Introducción: el síndrome serotoninérgico es una rara afección, con reacción adversa a la administración de determinado grupo farmacológico. Objetivo: demostrar la evolución clínico-anestesiológica de un paciente con síndrome serotoninérgico. Caso clínico: paciente de 37 años con antecedentes de epilepsia, tratado con valproato de sodio. Ingresó al hospital por quemaduras de segundo y tercer grado en ambos miembros inferiores para debridamiento e implante de piel. Lleva tratamiento con tramadol 50 mg/6 h, ácido fólico 5 mg/d, fluoxetina 20 mg/d, tiamina 100 mg/d y vitamina C 500 mg/d. Se administró anestesia general con máscara laríngea. Inducción con fentanilo 100 µg, ketamina 20 mg, propofol 150 mg. Se colocó máscara laríngea 4. Respiración espontánea en modalidad PSVPro con O2 + aire + sevoflurane (CAM 0,6 por ciento). Cuando comenzó la asepsia quirúrgica se evidenció clonus en ambos miembros inferiores. No cambios hemodinámicos, ni de la temperatura (36,1 °C). Gasometría: alcalosis metabólica. Ionograma normal. Se administró 5 mg de midazolam. En el posoperatorio se retiró la máscara laríngea. TA: 106/60. Pulso: 95 lat/min. Temperatura: 35,8 °C, Sat Hb: 98 por ciento. Se constató clonus sostenido inducible al estímulo mínimo bilateral, clonus orbital e hiperreflexia. Se mantuvo en la sala de recuperación por dos horas. Se dio alta para la sala de cuidados especiales con indicaciones. Conclusiones: la evolución fue satisfactoria. Ante un paciente que llega de urgencia, se recomienda evaluar las enfermedades coexistentes y su tratamiento; no hacerlo puede traer consecuencias fatales(AU)

Introduction: The serotonin syndrome is a rare condition and includes an adverse reaction to the administration of a certain pharmacological group. Objective: To show the clinical-anesthesiological evolution of a patient with serotonin syndrome. Clinical case: A 37-year-old patient with a history of epilepsy, treated with sodium valproate. The patient was admitted to the hospital for second and third degree burns on both lower limbs for debridement and skin implant. The patient was treated with tramadol (50 mg every 6 hours), folic acid (5 mg every d), fluoxetine (20 mg every day), thiamin (100 mg every day), and vitamin C (500 mg every day). General anesthesia with laryngeal mask was administered. Induction with fentanyl (100 µg), ketamine (20 mg), propofol (150 mg). Laryngeal mask number 4 was placed. Spontaneous respiration in PSVPro modality with O2, air and sevoflurane (CAM 0.6 percent). When the surgical asepsis began, clonus was evident in both lower limbs. No hemodynamic or temperature changes (36.1 °C). Gasometry: metabolic alkalosis. Normal Ionogram. 5 mg of midazolam were administered. In the postoperative period, the laryngeal mask was removed. TA: 106/60. Pulse: 95 beats/min. Temperature: 35.8 °C, sat Hb: 98 percent. Sustained clonus inducible to minimal bilateral stimulus, orbital clonus and hyperreflexia was found. The patient remained in the recovery room for two hours and was released for the special care room with instructions. Conclusions: The evolution was satisfactory. When a patient arrives urgently, it is recommended to assess the coexisting diseases and their treatment; not doing so can bring fatal consequences(AU)

Optimal size selection of laryngeal mask airway in Malaysian female adult population

BACKGROUND: The summary of various studies done looking at size selection of the laryngeal mask airway (LMA) in adults is that, selection based on sex is appropriate, and that both sizes 4 or 5 are adequate for adult females. However, in our local population these sizes may be too large especially the size 5 for adult females. OBJECTIVE: To determine the optimal size of LMA in Malaysian female adults. METHOD: 135 ASA 1 or 2 adult female patients coming for elective surgery, requiring general anaesthesia suitable for LMA insertion were randomised into 3 groups to receive either a size 3, 4 or 5 LMA. Optimal size of the LMA was assessed based on 4 parameters, the number of attempts at placement, the oropharyngeal leak pressure (OLP), fibre optic score and the percentage of the vocal cords seen. RESULTS: The 3 groups were demographically similar. There was no difference in the 3 groups in terms of number of attempts of placement, OLP and fibre-optic score. The percentage of vocal cords seen with the size 3 LMA was significantly less than for the size 4 and size 5 (p = 0.009). For the size 5 LMA group in 10/45 patients, the size 5 LMA was too big making it incorrectly positioned after successful insertion and in another 3/45 patients it was difficult to pass the size 5 LMA past the open mouth during insertion. There were no such problems with the size 3 or 4 LMA groups. CONCLUSION: The optimal size of LMA for the female Malaysian adult is size 4.

Máscara laríngea / The laringeal mask

Se describe la construcción de la máscara y su mecanismo de acción. Se precisa el procedimiento, sus indicaciones y la técnica de inserción. Se mencionan las contraindicaciones y las precauciones durante el funcionamiento. Se enumeran las ventajas y desventajas

laryngeal mask airway versus endotracheal tube for intraocular surgery

The use of the laryngeal mask was compared with tracheal intubation in 20 patients who underwent intraocular ophthalmic surgery and received standardized anesthesia. The changes in intraocular pressure was significantly less in the LMA group at all time points after airway instrumentation. The change in mean arterial pressure was significant between the two groups but the heart rate changes were insignificant. The mean rate pressure product was significantly smaller in LMA group compared with ETT group after both insertion and removal. At the end of the procedure, a significantly higher percentage of patients tracheal tube coughed, reacted to head movement and suffered breath holding as they also complained of postoperative sore throat more than patients with LMA