Total intravenous anesthesia vs inhalational anesthesia in patients undergoing surgery under general anesthesia. Cost-minimization study / Anestesia total endovenosa vs. anestesia basada en halogenados en pacientes llevados a cirugía bajo anestesia general. Estudio de minimización de costos

Abstract Introduction: The methods most frequently used at the present time in Colombia for the administration of general anesthesia are based on halogenated and intravenous drugs. However, in view of the lack of differential clinical outcomes, the existence of cost variations between the two is not clear. Objective: To determine the expected cost of the use of both techniques in patients taken to surgery, within the framework of the Colombian national health system. Methods: A cost minimization study was carried out using the decision tree as the analytical model. A time frame of 6 postoperative hours was used as the assumption. Only direct healthcare-related costs were included using a case study approach. An econometric model was used based on the frequency with which each technology is applied and the type of drug used, and a deterministic and probabilistic sensitivity analysis was performed. Results: For the case study, total intravenous anesthesia (TIVA) is more costly than the inhalational technique, with an incremental cost of $102,718 per patient. The deterministic analysis shows that both the incidence of postoperative nausea and vomiting (PONV) as well as the use of target controlled infusion (TCI) techniques are the main cost determinants. The probabilistic analysis shows that the cost difference can even be nil in more than 50% of the simulated settings, when the difference in the risk of PONV is higher. Conclusions: Although the total intravenous technique can be more costly than the inhalational technique, this difference is offset by a lower cost of the postanesthesia care unit, given the lower risk of postoperative nausea and vomiting.

Resumen Introducción: Actualmente, los métodos más usados en Colombia para la administración de anestesia general son las técnicas basadas en halogenados y en medicamentos intravenosos. No obstante, y ante la falta de desenlaces clínicos diferenciales, no es claro si existe una variación en los costos. Objetivo: Determinar el costo esperado del uso de ambas técnicas en pacientes llevados a cirugía bajo la perspectiva del sistema nacional de salud colombiano. Métodos: Se realizó un estudio de minimización de costos. Se empleó el árbol de decisión como modelo analítico. Se asumió un horizonte temporal de 6 horas postoperatorio. Se incluyeron solo los costos sanitarios directos mediante un caso tipo. Se empleó un modelo econométrico basado en la frecuencia de uso de cada tecnología y medicamento empleado y se realizó análisis de sensibilidad determinístico y probabilístico. Resultados: Para el caso tipo, la técnica total endovenosa es más costosa que la técnica basada en halogenados, con un costo incremental de $102.718 por paciente. El análisis determinístico muestra que tanto la incidencia de náuseas y vómito postoperatorio como el uso de tecnologías TCI (targetcontrolled infution) son los principales determinantes de estos costos. El análisis probabilístico muestra que la diferencia de costos puede ser incluso de cero pesos en más del 50 % de los escenarios simulados cuando se tiene una mayor diferencia del riesgo de náuseas y vómito postoperatorio. Conclusiones: Aunque la técnica total endovenosa puede ser más costosa que la basada en halogenados, esto se compensa con un costo inferior en la unidad de recuperación postanestésica debido a un menor riesgo de náuseas y vómito postoperatorio.

¿Anestesia halogenada o anestesia total endovenosa en neurocirugía? / Volatile or total intravenous anesthesia for neurosurgery?

Total intravenous anesthesia (TIVA) with propofol/remifentanil appears in the literatura as a good option for neurosurgical patients who have increased intracranial pressure (ICP),risk of postoperative nausea and vomiting (PONV), need for neuromonitoring, and in those with impaired brain self-regulation. On the other hand, in patients with normal neurological status, normal ICP, a technique with volatile (halogenated) agents plus an opiiid can be used. This review describes two anesthetic techniques available for use in neurosurgery, highlighting the neurophysiological changes, advantages and disadvantages of each technique. MATERIAL AND METHOD: PubMed search engine was used for bibliographic search. DISCUSSION: The search for an ideal anesthetic in neurosurgery is still a matter of debate. There are numerous investigations aimed at finding an optimal agent that ensure the coupling between cerebral flow (CBF) and metabolism, keeping self-regulation intact without increasing the CBF and intracerebral pressure (ICP). CONCLUSIONS: Both anesthetic techniques, TIVA and volatile agents (halogenated), can be used in neurosurgical procedures and should provide neuroprotection, brain relaxation and a rapid awakening.

La anestesia total endovenosa (TIVA) con propofol/remifentanilo aparece en la literatura como una buena opción para pacientes neuroquirúrgicos que tienen aumento de la presión intracraneana (PIC), riesgo de náuseas y vómitos posoperatorios (NVPO), necesidad de neuromonitoreo, y en aquellos con alteración de la autorregulación cerebral. Por otra parte, en pacientes con estado neurológico normal, PIC normal puede usarse una técnica con agentes volátiles (halogenados) más un opioide. Esta revisión describe dos técnicas anestésicas disponibles para su uso en neurocirugía, destaca los cambios neurofisiológicos, ventajas y desventajas de cada técnica. MATERIAL Y MÉTODO: Para búsqueda bibliográfica se usó buscador PubMed. DISCUSIÓN: La búsqueda de un anestésico ideal en neurocirugía sigue siendo tema de debate. Existen numerosas investigaciones destinadas a buscar un agente óptimo que asegure el acoplamiento entre flujo sanguíneo cerebral (FSC) y metabolismo, manteniendo la autorregulación intacta sin aumentar el FSC y presión intracerebral (PIC). CONCLUSIONES: Ambas técnicas anestésicas, TIVA y agentes volátiles (halogenados), pueden ser usadas en procedimientos neuroquirúrgicos y deben brindar neuroprotección, relajación cerebral y un despertar rápido.

Caso de hipertermia maligna en paciente intervenida de apendicectomía laparoscópica / Malignant Hyperthermia after a laparoscopic appendicectomy: Case report

Malignant hyperthermia is an hypermetabolic syndrome in which the intracellular calcium receptors are altered. Patients who present compatible symptoms with this symdrome are genetically predisposed. Many of the cases have been described in the surgical area, due to the use of anesthesic drugs and neuromuscular blockers. However, there are some cases with an unknown trigger. The prevalence of the syndrome is very difficult to estimate. The diagnosis and early treatment are pronostic factors predicting the evolution of the syndrome.

La hipertermia maligna es conocida como un síndrome de estimulación masiva del metabolismo, debido a la alteración en la liberación de calcio intracelular. Muchos pacientes que presentan clínica compatible con este síndrome están genéticamente predispuestos. La mayoría de los casos se describen en el ámbito quirúrgico, con el empleo de fármacos anestésicos y determinados relajantes neuromusculares, aunque también existen casos en los que no se halla desencadenante. De prevalencia difícil de estimar, la sospecha diagnóstica y el tratamiento precoz marcan el pronóstico evolutivo de estos pacientes.

Caracterización de los episodios de agitación durante la emergencia de la anestesia general en pediatría / Characterization of agitation episodes during the emergence from general anesthesia in Pediatrics

RESUMEN Introducción: la agitación durante la emergencia de la anestesia general es una complicación frecuente en pediatría que puede causar daños físicos, retrasar el alta y aumentar los costos. Objetivo: caracterizar los episodios anestesia general en el paciente pediátrico. Materiales y métodos: se realizó un estudio descriptivo, prospectivo, longitudinal de 246 pacientes que presentaron anestesia general en el Hospital "Eliseo Noel Caamaño" entre septiembre de 2015 y diciembre de 2018. Se estudiaron las variables: edad, género, ASA, tiempo quirúrgico y tiempo anestésico, tipo de cirugía, método de anestesia, agentes usados para la inducción y el mantenimiento, severidad de los episodios y necesidad de tratamiento. Resultados: la mayoría de los pacientes que presentaron anestesia general tenían entre 2 y 6 años (63,4%), eran masculinos (67,9%), ASA I (78,1%) y fueron operados de excéresis de lesiones de partes blandas (27,6%). El tiempo quirúrgico fue de 31,2 ± 10,4 minutos y el anestésico 43,5±8,8 minutos. El método anestésico más indicado fue la anestesia balanceada (84,2%), como inductor el propofol (86,2%) y para el mantenimiento isoflurano (34,1%) y sevoflurano (26,4%). Predominaron los episodios severos (51,2%) y el 56,9% necesitó intervención farmacológica. Conclusiones: esta anestesia fue más frecuente en los menores de seis años, masculinos, sanos, a los cuales se les realizaron procederes cortos, con anestesia balanceada, se usó propofol para la inducción e isoflurano y sevoflurano para el mantenimiento de la anestesia. Prevalecieron los episodios severos y la mayoría requirió tratamiento farmacológico.

ABSTRACT Introduction: agitation during the emergence from general anesthesia is a frequent complication in Pediatrics that can cause physical damages, delay discharge and increase costs. Objective: to characterize the episodes of general anesthesia in the pediatric patient. Materials and methods: a descriptive, prospective, longitudinal study was carried out with 246 patients who presented general anesthesia in the Hospital "Eliseo Noel Caamaño" from September 2015 to December 2018. The studied variables were age, gender, ASA, surgical time, anesthetic time, kind of surgery, anesthetic method, agents used for the induction and maintenance, episodes severity and treatment necessity. Results: most of patients treated with general anesthesia were aged 2-6 years (63.4 %), male (67.9 %), ASA I (78.1 %), and underwent the removal of soft parts lesions (27.6 %). The average surgical time was 31,2 ± 10,4 minutes and the anesthetics one was 43,5±8,8 minutes. The most used anesthetics method was balanced anesthesia (84.2 %), the most used inductor was propofol (86.2 %) and for the maintenance isoflurane (34,1%) and sevoflurane (26,4%). Severe episodes (51,2%) predominated, and 56.9 % needed pharmacologic intervention. Conclusions: this kind of anesthesia is more frequently used in children aged less than 6 years, male, healthy, who underwent short procedures with balanced anesthesia and the use of propofol for the induction and isoflurane and sevoflurane for maintaining it. Severe episodes predominated, and most of them required pharmacologic treatment.

Aplicacao da tecnica por cromatografia a gas para investigacao da formacao de sub produtos da desinfeccao em agua potavel / Application of gas chromatographic technique for investigation of the formation of by products in drinking water disinfection

O uso do cloro para a desinfecção e/ou oxidação nas estações de tratamento de água favorece a formação de subprodutos orgânicos halogenados (SOH), muitos deles carcinogênicos. O objetivo desta pesquisa foi validar uma metodologia analítica proposta para a quantificação simultânea de 12 subprodutos da desinfecção por cromatografia a gás com detector de captura de elétrons (CG-DCE). O método apresentou linearidade (r>0,998), repetibilidade menor que 0,15%, limites de detecção de 1 a 6 µg.L-1 e de quantificação de 3 a 21 Î1/4g.L-1, precisão (<10%), exatidão (93-120%) e recuperação (87-117%). Os resultados indicam que o método pode ser empregado para a investigação de SOH em água, garantindo confiabilidade analítica nos resultados.

The use of chlorine for disinfection and/or oxidation at drinking water treatment plants favors the formation of halogenated organic by-products (HOB), many of them carcinogenic. The purpose of this research was to validate an analytical method for the simultaneous quantification of 12 HOB from disinfection by gas chromatograph with electrons capture detector (GC-ECD). The method provided linearity (r>0.998), repeatability lower than 0.15%, limits of detection from 1 to 6 Î1/4g.L-1 and of quantification from 3 to 21 Î1/4g.L-1, precision (<10%), accuracy (93-120%) and recovery (87-117%). The results indicate that the method can be employed to investigate the formation of HOB in water, yielding analytically reliable results.

Tratamento de água de reservatórios por dupla filtração, oxidação e adsorção em carvão ativado granular / Double filtration, oxidation and granular activated carbon adsorption for treating lake water

Este trabalho teve como objetivo avaliar o tratamento de água bruta proveniente de um reservatório de água, utilizando instalação piloto de dupla filtração (DF), composta por filtro ascendente de pedregulho (FAP) e filtro rápido descendente de areia (FRD), seguida de uma unidade de pós-tratamento com carvão ativado granular (CAG). Adicionalmente, foi verificado o efeito da pré e interoxidação (entre o FAP e o FRD) na eficiência global do tratamento e na formação de subprodutos orgânicos halogenados (SOH). Em função dos resultados obtidos, foi observado que a pré-oxidação melhorou a qualidade do efluente do FAP e a interoxidação favoreceu que resultassem valores menores de turbidez e cor no efluente do FRD. O processo de tratamento por adsorção em carvão ativado granular, utilizado como pós-tratamento, mostrou-se eficiente para assegurar a qualidade dos efluentes finais nos ensaios realizados, especialmente, em relação à remoção de matéria orgânica, cianobactérias e cor. As concentrações máximas de SOH encontrados nos efluentes do FRD e do FCAG não ultrapassaram os valores limites da Portaria nº 2.914/2011 do Ministério da Saúde.

This study evaluated the treatment of raw lake water using a double filtration (DF) pilot plant consisting of an up-flow gravel filter (UGF) in series with a down-flow sand filter (DSF) and followed by a post-treatment granular activated carbon (GAC) unit. Additionally, the study examines the effect of pre and inter-oxidation (between UGF and DSF) on overall efficiency in the treatment and the formation of halogenated organic byproducts (HOB). According to the results obtained, it was observed that the pre-oxidation improved the quality of the UGF effluent and the inter-oxidation favored lower values of turbidity and color in the DSF effluent. Also, the treatment process by adsorption on granular activated carbon, used as a post-treatment, was efficient to ensure the quality of final effluent in the tests, especially regarding the removal of organic matter, cyanobacteria, and color. The maximum concentrations of HOB found in the effluents from the DSF and GAC did not exceed the limits of the Brazilian drinking water standards (Portaria nº 2.914/2011).

Hipertermia severa post cirugía cardiaca: presentación de un caso / Severe hyperthermia present after a heart surgery

Introducción: La hipertermia maligna es una miopatía hereditaria causada por un trastorno del receptor rianodine del retículo sarcoplásmico rugoso del músculo estriado; se manifiesta en pacientes susceptibles por la exposición a agentes halogenados o succinilcolina. Objetivo: Presentar la evolución de una paciente con hiperpirexia severa post cirugía cardiaca. Caso clínico: Paciente de 56 años, anunciada para reemplazo valvular aórtico, ASA III, clase funcional NYHA II-III, sin otros antecedentes. A su llegada a la Unidad de Cuidados Intensivos Postoperatorios se constató gran contractura muscular, generalizada y en particular de los músculos maseteros, incremento progresivo del CO2 arterial (105 mmHg), acidosis metabólica, bajas relaciones paO2/FiO2, orinas de color rojo vino, hiperpotasemia, taquicardia sinusal con contracciones ventriculares prematuras frecuentes, salvas autolimitadas de taquicardia ventricular, bajo gasto cardiaco severo e hiperpirexia mantenida de 41ºC para lo cual se tomaron medidas sintomáticas. Después de 8 horas, disminuyó la fiebre, se restableció el medio interno, el aclaró el color de la orina, la hemodinámica se estabilizó y se constató elevación de la creatinina sérica, que disminuyó progresivamente en los días siguientes. A las 48 horas se destetó de la ventilación mecánica. Se dio el alta de la UCIP al quinto día. Conclusiones: Independientemente, que no se realizaron pruebas específicas para hipertermia maligna, se trata de un caso complejo con una hiperpirexia severa y evolución satisfactoria.

Introduction: Malignant hyperthermia is a hereditary myopathy caused by a rianodine receptor disorder of rugous sarcoplasmic reticulum of the skeletal muscle becomes clear in patients oversensitive to exposition to halogen agents or to succinylcholine. Objective: To present the course of patient presenting with a severe hyperpyrexia after a heart surgery. Clinical case: Patient aged 56 programmed for an aortic valvular replacement, ASA III, functional class NYHA-II-III without other backgrounds. At her arrival to Postperative Intensive Care Unit (POICU) it was noted a significant widespread muscular contracture mainly in masseter muscles, a progressive increase of the arterial CO2 (105 mm Hg), metabolic acidosis, low paO2/FiO2 relations, urine of red wine color, hyperpotassemia, sinus tachycardia with frequent early ventricular contractions, self-limited of ventricular tachycardia, a sever and low cardiac output and sustained hyperpyrexia if 41°C taking measures related to symptoms. At 8 hours fever decreased with restoration of internal environment, urine color cleared, hemodynamics was stable verifying a rise of serum creatinine which decreased progressively after few days. At 48 hours patient was weaned of the mechanical ventilation. At 5 days she was discharged from the POICU. Conclusions: Apart from there were not specific tests to malignant hyperthermia, it is a complex case presenting with a severe hyperpyrexia and a satisfactory course.

Formação de subprodutos orgânicos halogenados nas operações de pré-oxidação com cloro, ozônio e peroxônio e pós-cloração em água conténdo subtância húmica / Formation of halogenated organic byproducts using preoxidation with chlorine, ozone and peroxone and post-chlorination of water containing humic substances

Dentre os compostos orgânicos halogenados que podem ser encontrados na água distribuída à população, destacam-se: trialometanos, ácidos haloacéticos, haloaldeídos, halocetonas, halofenóis e halopicrinas. O presente trabalho teve como objetivo avaliar o efeito da formação de 22 subprodutos com a utilização dos pré-oxidantes: cloro, ozônio e peroxônio. A formação de subprodutos foi observada em água preparada com adição de substâncias húmicas extraídas de solo turfoso, por meio do uso da pré-oxidação, presença e ausência de coagulação, filtração e pós-cloração. Os subprodutos foram quantificados por cromatografia gasosa com detetor de captura de elétrons. Os resultados obtidos mostraram que o uso de pré-oxidantes alternativos, ozônio e peroxônio, associados à coagulação, filtração e pós-cloração, formam quantidades pequenas de subprodutos.

When chlorine is used as preoxidant, the formation of halogenated organic byproducts found in water treated and distriduted to the population, are: trihalometane, haloacetic acids, haloaldehyde, haloketone, halophenol and halopicrin. This research was performed to evaluate the formation potential of 22 byproducts using the following preoxidants: chlorine, ozone and peroxone. The formation of byproducts was simulated in water prepared with the addition of humic substances extracted from peat soil by the use of preoxidants, coagulation, filtration, and post-chlorination. Byproducts have quantified by gas chromatography with electron capture detector. The results obtained showed that the use of alternative preoxidants, such as ozone and peroxone, associated with coagulation, filtration, and post-chlorination form a low concentration of byproducts.