A mathematical description for the nutrition therapy ecosystem.

Introduction: Background: nutrition therapy is a complex area of healthcare systems that encompasses patient characteristics, medical decision making, nutritional formula characteristics, and costs, composing a complex ecosystem. The integration of these different domains is actualized in medical prescription in a heuristic and iterative way, taking into account patient characteristics and formulas, with a limited capacity for in-scale calculations and inclusion of factors involved in the prescription of nutritional formulas and other ecosystem elements. From a practical standpoint, depicting the four areas as equalities could provide the necessary equivalence to study dependence and consequence from left- and right-side terms. Objectives: the objective of this theoretical study is to provide a mathematical model that describes and integrates different aspects of nutrition therapy. Methods: in this theoretical study, we deducted a mathematical representation for nutrition therapy using first-grade equations and simple calculus techniques. Results: a formula that coordinates four elements of the nutrition therapy ecosystem was found: cashflow, compliance adherence, patient, and macronutrient mass, formula density and unitary cost. Conclusion: factors involving decision-making in nutrition therapy can be unified in a mathematical model.

Introducción: Antecedentes: la terapia nutricional es un área compleja de los sistemas de salud que abarca las características del paciente, la toma de decisiones médicas, las características de la fórmula nutricional y los costos, componiendo un ecosistema complejo. La integración de estos diferentes dominios se actualiza en la prescripción médica de forma heurística e iterativa, teniendo en cuenta las características y fórmulas del paciente, con una capacidad limitada para cálculos a escala e inclusión de otros factores relacionados con la prescripción de la terapia nutricional y los elementos del ecosistema. Desde un punto de vista práctico, describir las cuatro áreas como igualdades podría proporcionar la equivalencia necesaria para estudiar la dependencia y la consecuencia de los términos del lado izquierdo y derecho. Objetivos: el objetivo de este estudio teórico es brindar un modelo matemático que describa e integre diferentes aspectos de la terapia nutricional. Métodos: en este estudio teórico se dedujo una representación matemática para la terapia nutricional utilizando ecuaciones de primer grado y técnicas de cálculo simple. Resultados: se encontró una fórmula que coordina cuatro elementos del ecosistema de la terapia nutricional: flujo de caja, adherencia al cumplimiento, masa del paciente y macronutrientes, densidad de la fórmula y costo unitario. Conclusión: los factores que involucran la toma de decisiones en la terapia nutricional se pueden unificar en un modelo matemático.

Clinical nutrition prescription using a mathematical method to assess industrialized formulas.

INTRODUCTION: Background: the planning of nutritional therapy depends restrictions defined by the prescriber, in a way that nutrients and calories levels are placed at appropriate intervals. Since industrialized formulas (IF) have fixed compositions of macro and micronutrients, there is a high risk of not meeting the set of restrictions in a given clinical scenario, i.e., attendance of the caloric, but not of the protein target. Objective: the objective of this study is to identify under what conditions it is possible an industrialized formula to meet the clinical restrictions of calories, macro and micronutrients. Methods: we deduced a mathematical relationship that must be met in order to satisfy such constraints. Using as variables: a) the necessary volume of an FI to meet the energy goal; b) the energy density of the FI; c) upper limit of calorie or nutrient; and d) the lower limit of calorie or nutrient. Results: a first degree inequality was developed that if attended allows to discriminate if a prescribed volume v of an IF meets the set of restrictions placed by the prescriber, in order to previously select viable formulas among a portfolio. Clinical vignettes are presented. Conclusion: the viability condition of an industrialized formula for the attendance of a system of constraints can be identified with the aid of a mathematical formula of the first-degree inequality type.

INTRODUCCIÓN: Introducción: la planificación de la terapia nutricional depende de las restricciones definidas por el prescriptor, de manera que los niveles de nutrientes y calorías se coloquen a intervalos apropiados. Como las fórmulas industrializadas (IF) tienen composiciones fijas tanto de macronutrientes como de micronutrientes, existe un alto riesgo de no cumplir con el conjunto de restricciones en un escenario clínico dado; es decir, la consecución del objetivo calórico, pero no del objetivo proteico. Objetivo: el objetivo de este estudio es identificar bajo qué condiciones una fórmula industrializada puede cumplir con las restricciones clínicas de calorías, macronutrientes y micronutrientes. Métodos: dedujimos una relación matemática que debe cumplirse para satisfacer tales restricciones. Usando como variables: a) el volumen necesario de un FI para alcanzar la meta energetic; b) la densidad de energía del FI; c) el límite superior de calorías o nutrientes; y d) el límite inferior de calorías o nutrientes. Resultados: se desarrolló una desigualdad de primer grado que, si se atiende, permite discriminar si un volumen prescrito v de un IF cumple con el conjunto de restricciones impuestas por el prescriptor para seleccionar previamente fórmulas viables entre una cartera. Se presentan viñetas clínicas. Conclusión: la condición de viabilidad de una fórmula industrializada para el cumplimiento de un sistema de restricciones puede identificarse con la ayuda de una fórmula matemática del tipo de desigualdad de primer grado.

Protein requirements, morbidity and mortality in critically ill patients: fundamentals and applications.

Recent evidence suggests that a negative protein balance secondary to severe disease is associated with increased morbidity. A loss of total body protein is inevitable in this scenario, even with an aggressive nutritional approach, primarily due to the catabolism of skeletal muscle fibers. The ubiquitin-proteasome system is the primary metabolic and biochemical mechanism involved in this process; paradoxically, this system consumes adenosine triphosphate as its energy source. It is possible that a neutral protein balance in these clinical situations is important for improving outcomes and achieving the caloric goals estimated or measured by indirect calorimetry. Recent studies have suggested that the use of higher protein concentrations in nutritional therapy for critically ill patients may help to reduce mortality. The purpose of this study was to review some of the nutrition therapy principles related to protein metabolism, evaluate the main assertions of the guidelines of specialty societies and review the recent studies that address these issues using critical insights from the authors' clinical experience.

Necessidades proteicas, morbidade e mortalidade no paciente grave: fundamentos e atualidades / Protein requirements, morbidity and mortality in critically ill patients: fundamentals and applications

Evidências recentes sugerem que o balanço proteico negativo secundário à doença grave se associa ao aumento de morbidade. A perda da proteína corporal total é inevitável nesse cenário, mesmo com uma abordagem nutricional agressiva, e resulta, principalmente, do catabolismo da fibra muscular esquelética. O principal mecanismo bioquímico e metabólico envolvido nesse processo é o sistema ubiquitina-proteassoma, que, paradoxalmente, consome a adenosina trifosfatocomo fonte energética e motriz. É possível que a neutralidade do balanço proteico nessas instâncias clínicas, seja tão importante na melhora dos desfechos quanto atingir a meta calórica estimada ou medida pela calorimetria indireta. Estudos recentes apontam a utilização de concentrações mais elevadas de proteínas na terapia nutricional do paciente grave como importante para um impacto positivo na mortalidade. A proposta deste trabalho foi revisar alguns princípios da terapia nutricional relativos ao metabolismo proteico, sinalizar para as principais assertivas das diretrizes das sociedades especializadas e comentar estudos recentes, que abordam a questão em tela, sob a visão crítica da experiência clínica dos autores.

Recent evidence suggests that a negative protein balance secondary to severe disease is associated with increased morbidity. A loss of total body protein is inevitable in this scenario, even with an aggressive nutritional approach, primarily due to the catabolism of skeletal muscle fibers. The ubiquitin-proteasome system is the primary metabolic and biochemical mechanism involved in this process; paradoxically, this system consumes adenosine triphosphate as its energy source. It is possible that a neutral protein balance in these clinical situations is important for improving outcomes and achieving the caloric goals estimated or measured by indirect calorimetry. Recent studies have suggested that the use of higher protein concentrations in nutritional therapy for critically ill patients may help to reduce mortality. The purpose of this study was to review some of the nutrition therapy principles related to protein metabolism, evaluate the main assertions of the guidelines of specialty societies and review the recent studies that address these issues using critical insights from the authors' clinical experience.

Atitutes e percepções em terapia nutricional entre médicos intensivistas: um inquérito via internet / Intensive care physicians' attitudes and perceptions on nutrition therapy: a web-based survey

OBJETIVO: Terapia nutricional é elemento importante no cuidado ao paciente grave. Mesmo reconhecida enquanto especialidade, a existência de equipes multidisciplinares ainda é escassa nas unidades terapia intensiva. Possivelmente a aplicação de cuidados em terapia nutricional seja variada entre intensivistas. O objetivo do estudo foi descrever percepções destes especialistas sobre atitudes e práticas em terapia nutricional enteral. MÉTODOS: Elaboramos questionário em plataforma on-line. Após fase de pré-validação, o instrumento foi distribuído via eletrônica. Após 30 dias as respostas foram computadas, considerando-se apenas os formulários completos. RESULTADOS: Cento e quatorze formulários foram devolvidos, 112 foram analisados. Os respondedores concentraram-se predominantemente na região sudeste do país. Sobre a instituição do suporte enteral, a maioria das respostas reflete percepções coadunadas às orientações de sociedades de especialistas. Os respondedores percebem frequentemente a aplicação de protocolos assistenciais relativos aos cuidados nutricionais. Após o início dos cuidados nutricionais, a percepção dos respondedores sobre a participação em modificações no plano terapêutico nutricional aparenta ser menor. O auto-conhecimento sobre o tema "terapia enteral" entre os respondedores foi quantificado em 6,0 (média aritmética), em escala de 1 a 10. CONCLUSÕES: Mais estudos para avaliação de práticas nutricionais entre médicos intensivistas são necessários. Alternativas à distribuição via plataforma on-line devem ser consideradas. Possivelmente intensivistas lidam melhor com as fases iniciais de instituição dos cuidados com nutrição enteral do que em relação à continuidade dos cuidados ou mudança na programação nutricional. Médicos intensivistas percebem em geral conhecimento sub-ótimo sobre o tema terapia nutricional enteral.

OBJECTIVE: Nutritional therapy is an important element in critical ill patient care. Although recognized as specialty, multidisciplinary teams in nutrition support are scarce in our country. Possibly, nutrition support therapy is applied by intensive care physicians and this may vary. The aim of the study is describe these specialists perceptions about theirs attitudes in enteral nutrition support. METHODS: A questionnaire was elaborated in an on-line platform. After pre-validation, it was sent by electronic mail to intensivists. In 30 days answers were collected, considering only the full-filled questionnaires. RESULTS: One hundred an fourteen forms were returned, 112 were analyzed. The responders were localized at majority in southeastern region. About beggining of nutritional support, the majority of answers reflect perceptions in accord to specialists societies recommendations. The responders' perception the frequent utilization of assistentials protocols in nutrition care. After support beginning, the responders perceptions about theirs participation in changes in therapeutic plan seems to be lower. The self-knowledge about the theme among the responders was 6.0 (arithmetic media) in a 1 to 10 scale. CONCLUSIONS: More studies are necessary to evaluate nutritional support practices among intensive care physicians. Alternatives to on-line platform should be considered. Possibly, intensive care physicians do better in the initial phases of enteral support than in continuity of care. Intensive care physicians knowledge about the issue is suboptimal.

Intensive care physicians' attitudes and perceptions on nutrition therapy: a web-based survey. / Atitutes e percepções em terapia nutricional entre médicos intensivistas: um inquérito via internet.

OBJECTIVE: Nutritional therapy is an important element in critical ill patient care. Although recognized as specialty, multidisciplinary teams in nutrition support are scarce in our country. Possibly, nutrition support therapy is applied by intensive care physicians and this may vary. The aim of the study is describe these specialists perceptions about theirs attitudes in enteral nutrition support. METHODS: A questionnaire was elaborated in an on-line platform. After pre-validation, it was sent by electronic mail to intensivists. In 30 days answers were collected, considering only the full-filled questionnaires. RESULTS: One hundred an fourteen forms were returned, 112 were analyzed. The responders were localized at majority in southeastern region. About beggining of nutritional support, the majority of answers reflect perceptions in accord to specialists societies recommendations. The responders' perception the frequent utilization of assistentials protocols in nutrition care. After support beginning, the responders perceptions about theirs participation in changes in therapeutic plan seems to be lower. The self-knowledge about the theme among the responders was 6.0 (arithmetic media) in a 1 to 10 scale. CONCLUSIONS: More studies are necessary to evaluate nutritional support practices among intensive care physicians. Alternatives to on-line platform should be considered. Possibly, intensive care physicians do better in the initial phases of enteral support than in continuity of care. Intensive care physicians knowledge about the issue is suboptimal.