¿Cómo realizar una revisión sistemática o un metaanálisis? / How to perform a systematic review and/or a meta-analysis?

La práctica de la medicina basada en la evidencia consiste en la utilización de la mejor evidencia científi ca clínica disponible para tomar decisiones sobre el cuidado de pacientes concretos. Sin embargo, frecuentemente las respuestas obtenidas resultan decepcionantes, o las mejores evidencias científi cas resultan inaplicables para un paciente concreto, lo que obliga al clínico a intervenir tomando una actitud «bayesiana», basada en su experiencia. Existen herramientas metodológicas para la investigación de fuentes, herramientas que son cada vez más perfectas y sofi sticadas, pero de uso más especializado y complejo. Lo lógico sería dejarlas en manos de metodólogos, mientras que los clínicos colaborarían en el proyecto aplicando su experiencia. Primero con la identificación del problema y la formulación de los objetivos a partir de la pregunta clínica estructurada, y posteriormente, tras recibir las respuestas, con la valoración de su calidad y aplicabilidad, y la elaboración de las recomendaciones apropiadas. En este artículo, dedicado al clínico, se insistirá en el desarrollo de las reuniones de consenso, ya que consideramos que es donde éste tiene un mayor protagonismo. Sin olvidar el protagonismo secundario, pero irreemplazable, que los clínicos desarrollan en otras etapas de cualquier revisión sistemática (AU)

Evidence-based medicine practice aims to apply the best clinical scientific evidence available for decision taking in individualized patient care. But frequently, achieved responses are disappointing or excellent evidences cannot be applied to specific patients, forcing the clinician to act, adopting a bayesian attitude, based on his own experience. There are continuously improved and more complex methodological tools for the research of bibliographic resources, but their use is more specialized and difficult. The logical attitude would be to leave them in the hands of methodologists, while clinician’s would collaborate in the project applying their own experience. Firstly, identifying the problem and formulating specific goals by means of the structured clinical question and then, after having received the responses, evaluating the quality and feasibility, and elaborating appropriate recommendations. In this paper, addressed to clinicians, the developing of a consensus meeting, in which they may play a greater role, is emphasized. Without forgetting secondary roles, but un replaceable, of clinicians to develop in earlier stages of whatever systematic reviews (AU)

Evaluación del riesgo nutricional e instauración de soporte nutricional en pacientes oncológicos, según el protocolo del grupo español de Nutrición y Cáncer / Nutricional risk evaluation and establishment of nutricional support in oncology patients according to the protocol of the spanish nutrition and cancer group

Introducción: El cáncer, los tratamientos que lo acompañan y los síntomas consecuentes que a su vez generan, aumentan en los pacientes el riesgo de sufrir malnutrición. La cual produce un gran deterioro del estado de salud, con el consecuente aumento de complicaciones, disminución de la tolerancia al tratamiento oncológico y una disminución de la calidad de vida del paciente. Por este motivo, un grupo de profesionales sanitarios de diferentes puntos de España se reunieron con el objetivo de mejorar la intervención nutricional en pacientes oncológicos, con el apoyo de la Sociedad Española de Nutrición Básica y Aplicada (SENBA). Metodología: Este grupo multidisciplinar de profesionales elaboró un documento de consenso basado en la literatura y en la experiencia personal, creando un protocolo de evaluación y de intervención nutricional en forma de algoritmos. Se clasifican los pacientes en tres pasos: 1. según el tipo de tratamiento oncológico que reciben, ya sea de tipo curativo o paliativo; 2. riesgo nutricional de la terapia antineoplásica (bajo, mediano, o alto riesgo), y 3. de acuerdo a la Valoración Global Subjetiva-Generada por el paciente (VGS-gp), que clasifica a los pacientes en: A. pacientes con adecuado estado nutricional, B. pacientes con malnutrición o a riesgo de malnutrición y C. pacientes con malnutrición severa. Durante un año el protocolo se puso en marcha en 226 pacientes mayores de 18 años de ambos sexos, escogidos al azar en las consultas externas de Radioterapia Oncológica y Oncología Médica. Resultados: Más de la mitad sufren malnutrición (64%), y este valor se incrementa llegando hasta un 81% en pacientes con tratamiento paliativo. La mayoría de los pacientes tienen tratamiento de intención curativa (83%) y reciben tratamiento oncológico de intensidad moderada o de alto riesgo nutricional (69%). Un 68% de los pacientes tienen algún tipo de dificultad en la alimentación. La media en el porcentaje de pérdida de peso es del 6,64% ± 0,87 (min 0, máx 33%). El 32% de la población presenta cifras de albúmina entre 3 y 3,5 g/dl, existiendo una correlación negativa entre ésta y las dificultades con la alimentación p = 0,001. El IMC no mostró ser un parámetro significativo para detectar malnutrición (sólo un 10% se encontraba por debajo de 19,9 kg/m2), pero tiene una tendencia lineal significativa con las dificultades en la alimentación, de forma tal que a medida que disminuye el IMC aumentan las dificultades p = 0,001. Más de la mitad de la población, requirió recomendaciones dietéticas específicas para el control de los síntomas que dificultaban la ingesta y una tercera parte de la población necesitó la indicación de suplementos nutricionales. Tras la intervención nutricional más de la mitad (60%) mantuvo su peso y una sexta parte lo aumentó. Conclusión: La aplicación de este protocolo es útil, sencillo y podría facilitar la detección de malnutrición en los pacientes oncológicos. Seleccionando a los pacientes que realmente se podrían beneficiar de una intervención nutricional específica, pero debería aplicarse al inicio coincidiendo si fuera posible con el diagnóstico de la enfermedad. El soporte nutricional resulta eficaz en la mayoría de los pacientes (AU)

Introduction: Cancer and its oncological treatment cause symptoms which increase the patients risk to suffer from malnutrition. This affects the patients health status negatively by increasing the number of complications, reducing the tolerance to the oncology treatment and a decrease of the patients quality of life. Motivated by this, a group of health professionals from several spanish regions met with the backing of the Sociedad Española de Nutrición Básica y Aplicada (SENBA) to address strategies to improve the quality of nutritional intervention in cancer patients. Methods: This multidisciplinary group developed a protocol describing nutritional assessment and intervention in form of algorithms based on literature and personal experience. The patients are classified in a three step process: 1. type of their oncology treatment (curative or palliative); 2. nutritional risk of the antineoplastic therapy (low, medium or high risk) and 3. depending on the Subjective Global Assessment patient-generated (SGApg). The patients are classified as: A. patients with adequate nutritional state, B. patients with malnutrition or risk of malnutrition and C. patients suffering from severe malnutrition. During one year, the protocol has been used for 226 randomly chosen female and male patients older than 18 years. They were treated by the Medical and Radiotherapy Oncology outpatient clinic. Results: More than a half of the patients were suffering from malnutrition (64%) increasing up to 81% for patients undergoing palliative treatment. Most of them were treated curatively (83%) and received oncology treatment with moderate or high nutritional risk (69%). 68% of patients were affected by some feeding difficulty. The mean percentage of weight loss has been 6.64% ± 0.87 (min 0%, max 33%). Albumin values of 32% of the patients were between 3 and 3.5 g/dl and negatively correlated with feeding difficulties (p = 0.001). The body mass index (BMI) has not found to be a significant parameter for detecting malnutrition (only in 10% of the patients, the value was below 19.9 kg/m2). But a significant linear tendency when compared to feeding problems could be shown, such that in patients with less feeding problems a higher BMI has been found (p = 0.001). More than a half of the patients required nutritional counselling to control symptoms which made food intake difficult. One third of the patients needed oral nutritional supplementation. Following the nutritional intervention the weight of about 60% of the patients could be maintained and of one sixth it could be increased. Conclusion: The application of this protocol is useful, easy and could help detecting malnutrition in oncology patients. It provides the possibility to select those patients who can benefit from a specific nutritional intervention. If possible, the application of the protocol should be started immediatly after cancer is diagnosed. Nutritional support proves efficient for most of the patients (AU)

[Nutritional risk evaluation and establishment of nutritional support in oncology patients according to the protocol of the Spanish Nutrition and Cancer Group]. / Evaluación del riesgo nutricional e instauración de soporte nutricional en pacientes oncológicos, según el protocolo del grupo Español de Nutrición y Cáncer.

INTRODUCTION: Cancer and its oncological treatment cause symptoms which increase the patients risk to suffer from malnutrition. This affects the patients health status negatively by increasing the number of complications, reducing the tolerance to the oncology treatment and a decrease of the patients quality of life. Motivated by this, a group of health professionals from several spanish regions met with the backing of the Sociedad Española de Nutrición Básica y Aplicada (SENBA) to address strategies to improve the quality of nutritional intervention in cancer patients. METHODS: This multidisciplinary group developed a protocol describing nutritional assessment and intervention in form of algorithms based on literature and personal experience. The patients are classified in a three step process: 1. type of their oncology treatment (curative or palliative); 2. nutritional risk of the antineoplastic therapy (low, medium or high risk) and 3. depending on the Subjective Global Assessment patient-generated (SGA-pg). The patients are classified as: A. patients with adequate nutritional state, B. patients with malnutrition or risk of malnutrition and C. patients suffering from severe malnutrition. During one year, the protocol has been used for 226 randomly chosen female and male patients older than 18 years. They were treated by the Medical and Radiotherapy Oncology outpatient clinic. RESULTS: More than a half of the patients were suffering from malnutrition (64%) increasing up to 81% for patients undergoing palliative treatment. Most of them were treated curatively (83%) and received oncology treatment with moderate or high nutritional risk (69%). 68% of patients were affected by some feeding difficulty. The mean percentage of weight loss has been 6.64% +/- 0.87 (min 0%, max 33%). Albumin values of 32% of the patients were between 3 and 3.5 g/dl and negatively correlated with feeding difficulties (p = 0.001). The body mass index (BMI) has not found to be a significant parameter for detecting malnutrition (only in 10% of the patients, the value was below 19.9 kg/m2). But a significant linear tendency when compared to feeding problems could be shown, such that in patients with less feeding problems a higher BMI has been found (p = 0.001). More than a half of the patients required nutritional counselling to control symptoms which made food intake difficult. One third of the patients needed oral nutritional supplementation. Following the nutritional intervention the weight of about 60% of the patients could be maintained and of one sixth it could be increased. CONCLUSION: The application of this protocol is useful, easy and could help detecting malnutrition in oncology patients. It provides the possibility to select those patients who can benefit from a specific nutritional intervention. If possible, the application of the protocol should be started immediatly after cancer is diagnosed. Nutritional support proves efficient for most of the patients.

Cirugía

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[Women and children first?....]. / Las mujeres y los niños primero?....

The goal of the National Health System (SNS in its Spanish acronym) does not consist in distributing to everyone an identical dose of health services but in establishing a balance between those who are ill and those who are healthy in the course of their lives, and concentrating its interventions on those who are worse. In an advanced health care system, there are very few actions by health personnel that can be assessed as "lives saved": more often than not, these actions manage to delay the end and are occasionally limited to improving the quality of the years patients live, without extending their number. It is therefore clearly necessary to find appropriate units of measurement to assess the benefits and utility of all health-related procedures. When effecting a cost-effectiveness study and assessing the results obtained, it is necessary to differentiate between quality of life (personal), utility (personal) and the utility of the procedure or process when applied to our patients. This utility is determined by means of the additional quality and quantity of life, measured in a single unit, QALY, but this cost-effectiveness analysis would be constrained in patients with a shortened life expectancy and/or reduced quality of life due to old age or degenerative disease, thus skewing the distribution of resources in favour of younger population groups. In order to redress this situation, the use of corrective measurements such as EQALY is proposed. We believe that neither age nor illness in themselves limit the application of resources, providing that we can prove a useful result for the patient.

¿Las mujeres y los niños primero? / Women and kids first?

El fin del Sistema Nacional de Salud (SNS), no consiste en distribuir a todo el mundo una dosis idéntica de servicio sanitario, sino en establecer un equilibrio entre los que están enfermos y los que están sanos en el curso de su vida, concentrando su intervención en aquellos que están peor. En un sistema sanitario avanzado son muy pocas las intervenciones sanitarias que pueden ser valoradas en "vidas salvadas", la mayor parte de las veces, éstas logran retrasar el final y, en ocasiones, se limitan a mejorar la calidad de los años de vida, sin alargarla. Se manifiesta, por tanto, la necesidad de encontrar unidades de medida adecuadas para valorar los beneficios y la utilidad de todos los procedimientos sanitarios. Al realizar un estudio coste/utilidad, y al valorarlos resultados obtenidos, hay que diferenciar entre la calidad de vida (personal), la utilidad (personal) y la utilidad del procedimiento o proceso al aplicarlo a nuestros enfermos. Esa utilidad se determina en calidad y cantidad de vida ganados, y se mide utilizando una única unidad: AVAC o QALY, pero en los pacientes que por su edad avanzada o enfermedad degenerativa tienen una calidad y/o esperanza de vida acortada el análisis coste/eficacia se verá condicionado, induciendo la distribución de los recursos a favor de los jóvenes. Para equilibrar esta situación, se propone el empleo de medidas correctoras como el EQALY. Consideramos que la edad ni la enfermedad son, por sí mismas, limitaciones para la aplicación de un recurso siempre que demostremos que éste resulta útil para el paciente (AU)

The goal of the National Health System (SNS in its Spanish acronym) does not consist in distributing to everyone an identical dose of health services but in establishing a balance between those who are ill and those who are healthy in the course of their lives, and concentrating its interventions on those who are worse. In an advanced health care system, there are very few actions by health personnel that can be assessed as “lives saved”: more often than not, these actions manage to delay the end and are occasionally limited to improving the quality of the years patients live, without extending their number. It is therefore clearly necessary to find appropriate units of measurement to assess the benefits and utility of all health-related procedures. When effecting a cost-effectiveness study and assessing the results obtained, it is necessary to differentiate between quality of life (personal), utility (personal) and the utility of the procedure or process when applied to our patients. This utility is determined by means of the additional quality and quantity of life, measured in a single unit, QALY, but this cost-effectiveness analysis would be constrained in patients with a shortened life expectancy and/or reduced quality of life due to old age or degenerative disease, thus skewing the distribution of resources in favour of younger population groups. In order to redress this situation, the use of corrective measurements such as EQALY is proposed. We believe that neither age nor illness in themselves limit the application of resources, providing that we can prove a useful result for the patient (AU)

La información "predigerida". A propósito de la calidad de la información / "Pre-digested" information. A propos of data quality

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Soporte nutrometabólico en el paciente quirúrgico crítico / Nutrometabolic support in the critical surgical patient

La agresión provoca una fase aguda de estimulación neuroendocrina, neuropeptídica y de mediadores lipídicos, que puede superarse espontáneamente, o bien perpetuarse y evolucionar hacia situaciones de disfunción y fracaso uni o multiorgánico. El soporte nutrometabólico en el paciente crítico plantea una serie de interrogantes todavía no resueltos: necesidades cuanti y cualitativas. La respuesta hipermetabólica propia del paciente en situación de estrés no se correlaciona con un aumento proporcional del gasto energético. Un aporte excesivo, por sobrestimación, puede añadir un factor de estrés secundario causado por la hipernutrición y la sobrecarga de sustratos. Por otra parte, el aporte de un sustrato considerado adecuado no garantiza necesariamente, en el paciente agredido, una eficaz utilización metabólica, ya que ésta, en la situación de estrés, depende del contexto neuroendocrino, de la acción de los mediadores y del mantenimiento de variables fisiológicas alteradas en el paciente crítico. Consideramos que el soporte nutricional resulta menos eficaz a medida que aumenta la gravedad de la respuesta al estrés. Debe ser instaurado precozmente, y su constitución estará gobernada tanto por la respuesta conseguida como por la condición clínica cambiante del paciente. Nuestra meta es conseguir en este complejo medio un adecuado aporte de hidratos de carbono (glucosa o no glucosa), lípidos, aminoácidos y otros nutrientes esenciales (vitaminas, micronutrientes y elementos traza), sin olvidar las nuevas posibilidades de aporte de sustratos: nucleótidos, péptidos, arginina, glutamina, ácido oleico (w-9) y aceites de pescado (w-3), cuyos efectos terapéuticos en algunos de ellos no han pasado, por el momento, de la fase del "razonamiento fisiopatológico" Parece posible que con un mejor conocimiento de las interacciones entre el hipotálamo, hormonas convencionales, mediadores celulares, moléculas de adhesión y óxido nítrico en la fisiopatología de la enfermedad pueda ser factible desarrollar alternativas terapéuticas basadas tanto en un adecuado soporte nutricional (cuanti, cualitativo y temporal), como hormonal (GH, IGF-1, insulina, esteroides anabólicos), y farmacológico que actúen como moduladores del metabolismo de los sustratos nutrientes durante la compleja fase metabólica de la enfermedad crítica (AU)

[Perioperative nutrition]. / Nutrición perioperatoria.

The incidence of malnutrition in hospitalized patients is high in our environment, and sometimes it worsens during the hospital stay (67%). In surgical patients who will be subjected to a surgical intervention and whose ingestion will be suppressed for digestive repose after the post-operative period, the situation becomes more complicated as in addition to their malnutrition there is an increased energetic-proteineic need due to the aggression. The direct relationship between severe malnutrition and an immune deficiency is translated into an increased morbidity (78%), into some extreme cases of mortality (24%), and always into longer hospitalizations. Implementing an adequate nutrition early will favorably influence the surgical results like any other therapeutic support measure. On the other hand, with the increased knowledge of the physiopathology of the gastrointestinal tract and its immunological function (GALT), the theoretical beneficial effect of intestinal repose has changed signs, with it being recommended to implement enteral nutrition rapidly post-operatively, with the physiological and practical advantages of enteral nutrition as opposed to parenteral nutrition being accepted unanimously. Immunomodulatory diets have shown their beneficial effect in specific situations: critical patients, septicemics, poly-traumatized patients, digestive tumor disease, etc., with infectious, scarring, and hospitalization complications decreasing significantly. When indicating peri-operative nutrition we must assess the disease and the characteristics hereof (benign, malignant, acute, or chronic), the surgical procedure used (aggression), the patient's prior nutritional status, the energetic needs (degree of aggression), the expected post-operative period, the expected fasting period (in function of the recommended intestinal repose and the expected complications), the available artificial nutrition routes (by patient limitations or strategic limitations of our environment), and finally, whenever possible, to use the enteral pathway.

[Evaluation of the quality of life in artificial nutrition]. / La evaluación de la calidad de vida en nutrición artificial.

If we define quality of life as being the social, physiological, mental intellectual, and general well being of people, we realize that there is no known health care system that is able to guarantee that well being in all its possible aspects. When we as clinicians assess the positive effects of a treatment applied to a patient, we are not only assessing the offered quality of life, but also the quantity of life, so what we are really assessing is the usefulness. We could say, therefore, that while the quality of life is subjective, not exact, and cannot be quantified, the usefulness on the other hand, can and should be measured and quantified, even though, as this is a subjective assessment, it is somewhat difficult to quantify. The object of our publication is to find an appropriate method for assessing this parameter in the area that concerns us: artificial nutrition. Artificial nutrition is indicated when the patient cannot does not want to, or does not know how to eat in the natural manner. Therefore, in principle it could seem inhuman and even unethical to deny a vital support measure that is practically without any risks in a patient who cannot feed him-or herself. However, in a situation of limited resources, if the treatment were inappropriate we should consider that possibility. Under these circumstances we could consider that even a concept as essential as nutrition (in this case artificial) would lose its inalienable character. In order to assess usefulness, one must include parameters that can be quantified in percentages and whose results can be set out in units of time (years, months, or days). We use the concept of the individual usefulness, whose unit of time is the QALY (Quality Adjusted Life Years). In 1996 we made a personal modification of Rosser's Index, which was specific for evaluating the quality of life obtained by means of artificial nutrition. This consisted of substituting the assessment parameters of intensity of pain, by other that are specific in function of the limitation of the ingestion capacity presented by the patient who was subjected to AN. The third factor that corresponds to the concept of usefulness would be the index of beneficial applicability percentage of patients who benefit from the support. The combination of these three factors, applicability, life expectancy, and quality of life, would yield the usefulness of the procedure. In order to assess usefulness in all its aspects, one must also define intention, as this can be applied with three goals: essential or curative, complementary or adjuvant, and maintenance or merely palliative. We can say that the economical limitations and the cost of the therapeutic resources leads to rationing by the administration. In the face of this action, we would recommend a rational and reasonable restriction of the available resources, which lead to the so-called rationalization, a term that is more correct ethically and esthetically, than rationing. As a final conclusion we could state that ethics and economics help us to use the resources appropriately, without any contradictions, as the economy attempts to give the society the greatest possible degree of well being based on the available resources, and that is an ethical objective, The quantification of the benefits obtained by applying a treatment using measureable units, involves socio-economic concepts such as usefulness, cost/benefit, quality of life, etc. should not elicit rejection as though we were dealing with a merchandising of our ethical values. We clinicians are capable of assessing this together, both with regard to the obtained costs and benefits, and with regard to the final results, both intra- and extra-hospital, and using the appropriate tools, we can reach conclusions that can guide us objectively in making decisions, with the aim of optimizing our therapeutic actions.

[Structured lipids in nutritional support]. / Lípidos estructurados en el soporte nutricional.

Currently there are many studies in international medical literature which show the effectiveness and safety of the different lipid emulsions existing on the market, both in clinical and experimental studies. When referring to lipid emulsions, we mean those based exclusively on LCT and those which provide physical combinations of LCT/MCT oils, and especially the new presentations of chemical combinations known as structured lipid emulsions. These structured lipids generated in a random structuring of LCT and MCT inside the same trialcylglycerol molecule should be considered not only from the standpoint of their nutrient effects, but also from the standpoint of their particular properties and future pharmacological possibilities. These exceed the nutrient effect itself as well as the tolerance, since they open up a field towards the intake of fatty acids, amino acids or drugs in one single molecule of triglyceride. Structured lipids also have great possibilities in the field of enteral nutrition, and it has been shown that the structuring of more conventional lipids with omega-3 series lipids has a great future in immuno-nutrition.