Fluidoterapia reflexiva: desde la fisiología a la práctica clínica / Reflexive fluid therapy: From physiology to clinical practice

Introducción. La fluidoterapia es una intervención ampliamente usada en la práctica clínica. No obstante, su aplicación no está exenta de riesgos y demanda una evaluación cuidadosa de la tolerancia del paciente y su respuesta al volumen. La práctica empírica de la reanimación con líquidos puede ser potencialmente letal. El propósito de esta revisión fue proporcionar una visión general de los principios fisiológicos y terapéuticos para la administración de líquidos intravenosos en pacientes críticamente enfermos, abordando poblaciones especiales, como los pacientes quirúrgicos, sépticos y politraumatizados. Métodos. Se hizo una revisión narrativa a partir de artículos publicados en PUBMED, ScienceDirect y LILACS, entre 2001 y 2023. Para la búsqueda se emplearon los términos MESH fluid therapy, crystalloid solutions y colloids. Resultados. Se encontraron 371 artículos, de los cuales se seleccionaron los estudios clínicos aleatorizados, las revisiones narrativas, las revisiones sistemáticas y los metaanálisis que analizaron el rol de los cristaloides y coloides. Se incluyeron manuscritos publicados en fechas por fuera del rango de búsqueda, que se consideraron relevantes para la descripción de la fisiopatología y los fundamentos del uso de líquidos endovenosos. Conclusión. La reanimación reflexiva se fundamenta en un entendimiento holístico de la fisiología y la individualización de la fluidoterapia. El uso liberal de líquidos endovenosos tiene potenciales efectos nocivos y las estrategias de reanimación deben ser guiadas por medidas dinámicas y estáticas individuales, que proporcionan un panorama seguro para el manejo de los líquidos.

Introduction. Fluid therapy is an intervention widely used in clinical practice. However, its application is not without risks and requires a careful evaluation of patient's tolerance and response to volume. The empirical practice of fluid resuscitation can be potentially lethal. The purpose of this review was to provide an overview of the physiological and therapeutic principles for the administration of intravenous fluids in critically ill patients, addressing special populations, such as surgical, septic, and trauma patients. Methods. A narrative review was carried out based on articles published in PUBMED, ScienceDirect, and LILACS between 2001 and 2023. MESH terms fluid therapy, crystalloid solutions, and colloids were employed. Results. A total of 371 articles were found, of which randomized clinical trials studies, narrative reviews, systematic reviews, and meta-analyses that analyzed the role of crystalloids and colloids were selected. Manuscripts published on dates outside the search range, which were considered relevant for the description of the pathophysiology and the rationale for the use of intravenous fluids, were included. Conclusion. Reflective resuscitation is based on a holistic understanding of physiology and individualization of fluid therapy. The liberal use of intravenous fluids has potential harmful effects and resuscitation strategies should be guided by individual dynamic and static measures, which provide a safe framework for fluid management

Use of the cardiac power index to predict fluid responsiveness in the prone position: a proof-of-concept study.

BACKGROUND: The primary aim of this proof-of-concept study was to investigate whether the Cardiac Power Index (CPI) could be a novel alternative method to assess fluid responsiveness in the prone position. METHODS: Patients undergoing scheduled elective lumbar spine surgery in the prone position under general anesthesia were enrolled in the criteria of patients aged 19-75 years with American Society of Anesthesiologists (ASA) physical status I-II. The hemodynamic variables were evaluated before and after changes in posture after administering a colloid bolus (5 mL.kg-1) in the prone position. Fluid responsiveness was defined as an increase in the Stroke Volume Index (SVI) ≥ 10%. RESULTS: A total of 28 patients were enrolled. In responders, the CPI (median [1/4Q-3/4Q]) decreased to 0.34 [0.28-0.39] W.m-2 (p = 0.035) after the prone position. After following fluid loading, CPI increased to 0.48 [0.37-0.52] W.m-2 (p < 0.008), and decreased SVI (median [1/4Q-3/4Q]) after prone increased from 26.0 [24.5-28.0] mL.m-2 to 33.0 [31.0-37.5] mL.m-2 (p = 0.014). Among non-responders, CPI decreased to 0.43 [0.28-0.53] W.m-2 (p = 0.011), and SVI decreased to 29.0 [23.5-34.8] mL.m-2 (p < 0.009). CPI exhibited predictive capabilities for fluid responsiveness as a receiver operating characteristic curve of 0.78 [95% Confidence Interval, 0.60-0.95; p = 0.025]. CONCLUSION: This study suggests the potential of CPI as an alternative method to existing preload indices in assessing fluid responsiveness in clinical scenarios, offering potential benefits for responders and non-responders.

Predictive value of dynamic arterial elastance for vasopressor withdrawal: a systematic review and meta-analysis.

BACKGROUND: Dynamic arterial elastance (Eadyn) has been investigated for its ability to predict hypotension during the weaning of vasopressors. Our study focused on assessing Eadyn's performance in the context of critically ill adult patients admitted to the intensive care unit, regardless of diagnosis. MAIN BODY: Our study was conducted in accordance with the Preferred Reported Items for Systematic Reviews and Meta-Analysis checklist. The protocol was registered in PROSPERO (CRD42023421462) on May 26, 2023. We included prospective observational studies from the MEDLINE and Embase databases through May 2023. Five studies involving 183 patients were included in the quantitative analysis. We extracted data related to patient clinical characteristics, and information about Eadyn measurement methods, results, and norepinephrine dose. Most patients (76%) were diagnosed with septic shock, while the remaining patients required norepinephrine for other reasons. The average pressure responsiveness rate was 36.20%. The synthesized results yielded an area under the curve of 0.85, with a sensitivity of 0.87 (95% CI 0.74-0.93), specificity of 0.76 (95% CI 0.68-0.83), and diagnostic odds ratio of 19.07 (95% CI 8.47-42.92). Subgroup analyses indicated no variations in the Eadyn based on norepinephrine dosage, the Eadyn measurement device, or the Eadyn diagnostic cutoff to predict cessation of vasopressor support. CONCLUSIONS: Eadyn, evaluated through subgroup analyses, demonstrated good predictive ability for the discontinuation of vasopressor support in critically ill patients.

Microcirculation, endothelium and glycocalyx changes associated with the use of milrinone in children with septic shock.

Background: The goal of fluid resuscitation and the use of inotropes in septic shock has traditionally focused on improving blood pressure and cardiac output, without considering the microcirculatory changes. Reaching macrocirculatory goals but with persistent microcirculatory abnormalities (hemodynamic incoherence) in septic shock has been associated with greater organ dysfunction and mortality. The objective of this study was to evaluate the microcirculation (flow and capillary density) and endothelial glycocalyx changes associated with the use of milrinone in children with septic shock, as well as their relationship with clinical variables and organ dysfunction. Methods: A prospective cohort study from February 2022 to January 2023 at a university hospital (Fundación Cardioinfantil-Instituto de Cardiología). Sublingual video microscopy was used to evaluate capillary density, microvascular flow rates and perfused boundary region (PBR-inverse parameter of glycocalyx thickness-abnormal if >2.0 microns). The primary outcome was the association between microcirculation and endothelial glycocalyx changes related to the use of milrinone. Results: A total of 140 children with a median age of two years [interquartile range (IQR) 0.58-12.1] were included. About 57.9% (81/140) of the patients received milrinone infusions. Twenty-four hours after receiving milrinone, the patients maintained functional capillary density (P<0.01) and capillary recruitment capacity (P=0.04) with no changes in capillary blood volume versus those who did not receive milrinone. Children under two years old who received milrinone had better 4-6-micron capillary density than older children [odds ratio (OR) 0.33; 95% confidence interval (95% CI): 0.12-0.89; P=0.02] and less endothelial glycocalyx degradation [adjusted OR (aOR) 0.34 95% CI: 0.11-0.99; P=0.04]. These changes persisted despite elevated ferritin (aOR 0.41; 95% CI: 0.18-0.93; P=0.03). Prolonged capillary refill and elevated lactate were correlated with microcirculation changes in both groups. The patients who died had the highest PBR levels (P=0.04). Conclusions: Children with septic shock who receive milrinone infusions have microcirculation changes compared with those who do not receive them. The group that received milrinone was found to maintain functional capillary density and capillary recruitment capacity and have less endothelial glycocalyx degradation 24 hours after administration. These changes were present despite the inflammatory response and were more significant in those under two years of age.

Fluids in the treatment of diabetic ketoacidosis in children: A systematic review.

AIM: To determine the comparative effectiveness of fluid schemes for children with diabetic ketoacidosis (DKA). METHODS: We conducted a systematic review with an attempt to conduct network meta-analysis (NMA). We searched MEDLINE, EMBASE, CENTRAL, Epistemonikos, Virtual Health Library, and gray literature from inception to July 31, 2022. We included randomized controlled trials (RCTs) in children with DKA evaluating any intravenous fluid schemes. We planned to conduct NMA to compare all fluid schemes if heterogeneity was deemed acceptable. RESULTS: Twelve RCTs were included. Studies were heterogeneous in the population (patients and DKA episodes), interventions with different fluids (saline, Ringer's lactate (RL), and polyelectrolyte solution-PlasmaLyte®), tonicity, volume, and administration systems. We identified 47 outcomes that measured clinical manifestations and metabolic control, including single and composite outcomes and substantial heterogeneity preventing statistical combination. No evidence was found of differences in neurological deterioration (main outcome), but differences were found among interventions in some comparisons to normalize acid-base status (∼2 h less with low vs. high volume); time to receive subcutaneous insulin (∼1 h less with low vs. high fluid rate); length of stay (∼6 h less with RL vs. saline); and resolution of the DKA (∼3 h less with two-bag vs. one-bag scheme). However, available evidence is scarce and poor. CONCLUSIONS: There is not enough evidence to determine the best fluid therapy in terms of fluid type, tonicity, volume, or administration time for DKA treatment. There is an urgent need for more RCTs, and the development of a core outcome set on DKA in children.

Consensus of the Brazilian association of hematology, hemotherapy and cellular therapy on patient blood management: Intraoperative hemostasis and volume replacement.

Hemostasis plays a critical role in surgical procedures and is essential for a successful outcome. Advances in hemostatic agents offer new approaches to controlling bleeding thereby making surgeries safer. The appropriate choice of these agents is crucial. Volume replacement, another integral part of Patient Blood Management (PBM), maintains adequate tissue perfusion, preventing cellular damage. Individualization in fluid administration is vital with the choice between crystalloids and colloids depending on each case. Colloids, unlike crystalloids, increase oncotic pressure, contributing to fluid retention in the intravascular space. Understanding these aspects is essential to ensure safe and effective surgery, minimizing complications related to blood loss and maintaining the patient's hemodynamic status.

Feasibility of Goal-Directed Fluid Therapy in Patients with Transcatheter Aortic Valve Replacement - An Ambispective Analysis.

INTRODUCTION: Goal-directed fluid therapy (GDFT) has been shown to reduce postoperative complications. The feasibility of GDFT in transcatheter aortic valve replacement (TAVR) patients under general anesthesia has not yet been demonstrated. We examined whether GDFT could be applied in patients undergoing TAVR in general anesthesia and its impact on outcomes. METHODS: Forty consecutive TAVR patients in the prospective intervention group with GDFT were compared to 40 retrospective TAVR patients without GDFT. Inclusion criteria were age ≥ 18 years, elective TAVR in general anesthesia, no participation in another interventional study. Exclusion criteria were lack of ability to consent study participation, pregnant or nursing patients, emergency procedures, preinterventional decubitus, tissue and/or extremity ischemia, peripheral arterial occlusive disease grade IV, atrial fibrillation or other severe heart rhythm disorder, necessity of usage of intra-aortic balloon pump. Stroke volume and stroke volume variation were determined with uncalibrated pulse contour analysis and optimized according to a predefined algorithm using 250 ml of hydroxyethyl starch. RESULTS: Stroke volume could be increased by applying GDFT. The intervention group received more colloids and fewer crystalloids than control group. Total volume replacement did not differ. The incidence of overall complications as well as intensive care unit and hospital length of stay were comparable between both groups. GDFT was associated with a reduced incidence of delirium. Duration of anesthesia was shorter in the intervention group. Duration of the interventional procedure did not differ. CONCLUSION: GDFT in the intervention group was associated with a reduced incidence of postinterventional delirium.

Fluid therapy and pulmonary complications in abdominal surgeries: randomized controlled trial.

BACKGROUND: There is no consensus on the most effective strategy for Postoperative Pulmonary Complication (PPC) reduction. This study hypothesized that a Goal-Directed Fluid Therapy (GDFT) protocol of infusion of predetermined boluses reduces the occurrence of PPC in patients undergoing elective open abdominal surgeries when compared with Standard of Care (SOC) strategy. METHODS: Randomized, prospective, controlled study, conducted from May 2012 to December 2014, with ASA I, II or III patients undergoing open abdominal surgeries, lasting at least 120 min, under general anesthesia, randomized into the SOC and the GDFT group. In the SOC, fluid administration was according to the anesthesiologist's discretion. In the GDFT, the intervention protocol, based on bolus infusion according to blood pressure and delta pulse pressure, was applied. Patients were postoperatively evaluated by an anesthesiologist blinded to the group allocation regarding PPC incidence, mortality, and Length of Hospital Stay (LOHS). RESULTS: Forty-two patients in the SOC group and 43 in the GDFT group. Nineteen patients (45%) in the SOC and 6 in the GDFT (14%) had at least one PPC (p = 0.003). There was no difference in mortality or LOHS between the groups. Among the patients with PPC, four died (25%), compared to two deaths in patients without PPC (3%) (p = 0.001). The LOHS had a median of 14.5 days in the group with PPC and 9 days in the group without PPC (p = 0.001). CONCLUSION: The GDFT protocol resulted in a lower rate of PPC; however, the LOHS and mortality did not reduce.

Assessment of the components of fluid balance in patients with septic shock: a prospective observational study.

BACKGROUND: The optimal amount for initial fluid resuscitation is still controversial in sepsis and the contribution of non-resuscitation fluids in fluid balance is unclear. We aimed to investigate the main components of fluid intake and fluid balance in both survivors and non-survivor patients with septic shock within the first 72 hours. METHODS: In this prospective observational study in two intensive care units, we recorded all fluids administered intravenously, orally, or enterally, and losses during specific time intervals from vasopressor initiation: T1 (up to 24 hours), T2 (24 to 48 hours) and T3 (48 to 72 hours). Logistic regression and a mathematical model assessed the association with mortality and the influence of severity of illness. RESULTS: We included 139 patients. The main components of fluid intake varied across different time intervals, with resuscitation and non-resuscitation fluids such as antimicrobials and maintenance fluids being significant contributors in T1 and nutritional therapy in T2/T3. A positive fluid balance both in T1 and T2 was associated with mortality (p = 0.049; p = 0.003), while nutritional support in T2 was associated with lower mortality (p = 0.040). The association with mortality was not explained by severity of illness scores. CONCLUSIONS: Non-resuscitation fluids are major contributors to a positive fluid balance within the first 48 hours of resuscitation. A positive fluid balance in the first 24 and 48 hours seems to independently increase the risk of death, while higher amount of nutrition seems protective. This data might inform fluid stewardship strategies aiming to improve outcomes and minimize complications in sepsis.

Intracellular and extracellular water content with carbohydrate-loading diets / Contenido de agua intracelular y extracelular con dietas de carga de carbohidratos / Conteúdo de água intracelular e extracelular com dietas de carregamento de carboidratos

ABSTRACT Introduction: In prolonged physical activities, water replacement and muscle glycogen content are limiting factors in marathon runners. Carbohydrate-loading (CHO) in the days prior to endurance competition is a commonly employed method to optimise muscle glycogen stores and optimise exercise performance. Since each gram of muscle glycogen binds ∼2.7-4 grams of water, water retention may occur during carbohydrate-loading diets. Objective: To evaluate differences between CHO loading strategies (Bergström and Sherman) on intracellular (ICW) and extracellular (ECW) water content. Methods: Twenty-three runners were randomly allocated to two interventions (Bergström and Sherman) in a crossover design. Participants underwent a baseline evaluation before 3 days of glycogen depletion followed by 3 days of carbohydrate loading with a washout of 30 days consisting of normal diet and training. Multifrequency bioimpedance (BIS) was used to assess ICW and ECW at Baseline, Post-depletion and Post-CHO to determine any differences between Bergström and Sherman protocols. Blood samples were also obtained to assess potassium levels. Associations between ICW and ECW and muscle glycogen were determined. Results: There were no differences in ICW or ECW content between the two interventions at any moment. There was an effect of time for ICW, with an increase from Post-depletion to Post-CHO without any difference between interventions. Plasma potassium decreased from Baseline to Post-depletion in both conditions. There was no difference in muscle glycogen content between interventions or moments. Conclusion: There were no differences in ICW and ECW content between the Bergström and Sherman interventions at any moment. Level of Evidence I; Tests of Previously Developed Diagnostic Criteria.

RESUMEN Introducción: En actividades físicas prolongadas, la reposición de agua y el glucógeno muscular son factores limitantes en los corredores de maratón. La carga de carbohidratos (CHO) en los días previos a la competencia de resistencia es un método empleado para optimizar las reservas de glucógeno muscular y el rendimiento del ejercicio. Cómo cada gramo de glucógeno muscular se une a ≈ 2,7 a 4 gramos de agua, puede producirse retención de agua durante las dietas ricas en carbohidratos. Objetivo: Evaluar las diferencias entre las estrategias de carga de carbohidratos (Bergström y Sherman) en el contenido de agua intracelular (AIC) o extracelular (AEC). Métodos: Veintitrés corredores fueron asignados aleatoriamente a dos intervenciones (Bergström y Sherman) en un diseño cruzado. Los participantes se sometieron a una evaluación inicial antes de los 3 días de agotamiento del glucógeno, seguido de 3 días de carga de carbohidratos con un tiempo de "washout" de 30 días que consistía en una dieta y entrenamiento normales. Se utilizó bioimpedancia multifrecuencia (BIS) para evaluar AIC y AEC al inicio, después del agotamiento y después de CHO para determinar cualquier diferencia entre las dos intervenciones. También se obtuvieron muestras de sangre para evaluar el potasio. Se determinaron asociaciones entre AIC, AEC y glucógeno muscular. Resultados: No hubo diferencias en el contenido de AIC o AEC entre las dos intervenciones en ningún momento. Hubo un efecto de tiempo para AIC, con un aumento desde Post-agotamiento hasta Post-CHO sin ninguna diferencia entre las intervenciones. El potasio plasmático disminuyó entre el inicio y el post-agotamiento en ambas condiciones. No hubo diferencia en el contenido de glucógeno muscular entre las intervenciones o momentos. Conclusión: No hubo diferencias en el contenido de AIC y AEC entre las dos intervenciones en ningún momento. Nivel de Evidencia I; Pruebas de Criterios Diagnóstico Desarrollados Previamente.

RESUMO Introdução: Em atividades físicas prolongadas a reposição hídrica e o conteúdo de glicogênio muscular são fatores limitantes em corredores de maratonas. O carregamento de carboidrato (CHO) nos dias anteriores à competição de resistência é um método comumente empregado para otimizar os estoques de glicogênio muscular e o desempenho no exercício. Uma vez que cada grama de glicogênio muscular liga-se a ≈2,7 a 4 gramas de água, a retenção hídrica pode ocorrer durante dietas de carregamento de carboidrato. Objetivo: Avaliar diferenças entre as estratégias de carregamento de carboidratos (Bergström e Sherman) no teor de água intracelular (AIC) ou água extracelular (AEC). Métodos: Vinte e três corredores foram alocados aleatoriamente para duas intervenções (Bergström e Sherman) num delineamento em "crossover". Os participantes foram submetidos a uma avaliação inicial antes dos 3 dias de depleção de glicogênio, seguidos por 3 dias de carga de carboidratos com tempo de "washout" de 30 dias consistindo em dieta e treinamento normais. Utilizou-se a bioimpedância multifrequencial (BIS) para avaliar AIC e AEC na Etapa Inicial, Pós-depleção e Pós-CHO para determinar quaisquer diferenças entre os protocolos de Bersgstrom e Sherman. Também foram obtidas coletas de sangue para avaliar o potássio. Foram determinadas associações entre AIC, AEC e glicogênio muscular. Resultados: Não houve diferenças no conteúdo de AIC ou AEC entre as duas intervenções em qualquer momento. Houve um efeito do tempo para AIC, com aumento da etapa Pós-depleção para Pós-CHO sem qualquer diferença entre as intervenções. O potássio plasmático diminuiu entre a Linha de base e Pós-depleção em ambas condições. Não houve diferença no conteúdo de glicogênio muscular entre intervenções ou momentos. Conclusão: Não houve diferenças no conteúdo de AIC e AEC entre as intervenções de Bergström e Sherman em qualquer momento. Nível de Evidência I; Testes de Critérios Diagnósticos Desenvolvidos Anteriormente.

Assessment of the components of fluid balance in patients with septic shock: a prospective observational study

Abstract Background: The optimal amount for initial fluid resuscitation is still controversial in sepsis and the contribution of non-resuscitation fluids in fluid balance is unclear. We aimed to investigate the main components of fluid intake and fluid balance in both survivors and non-survivor patients with septic shock within the first 72 hours. Methods: In this prospective observational study in two intensive care units, we recorded all fluids administered intravenously, orally, or enterally, and losses during specific time intervals from vasopressor initiation: T1 (up to 24 hours), T2 (24 to 48 hours) and T3 (48 to 72 hours). Logistic regression and a mathematical model assessed the association with mortality and the influence of severity of illness. Results: We included 139 patients. The main components of fluid intake varied across different time intervals, with resuscitation and non-resuscitation fluids such as antimicrobials and maintenance fluids being significant contributors in T1 and nutritional therapy in T2/T3. A positive fluid balance both in T1 and T2 was associated with mortality (p = 0.049; p = 0.003), while nutritional support in T2 was associated with lower mortality (p = 0.040). The association with mortality was not explained by severity of illness scores. Conclusions: Non-resuscitation fluids are major contributors to a positive fluid balance within the first 48 hours of resuscitation. A positive fluid balance in the first 24 and 48 hours seems to independently increase the risk of death, while higher amount of nutrition seems protective. This data might inform fluid stewardship strategies aiming to improve outcomes and minimize complications in sepsis.

Feasibility of Goal-Directed Fluid Therapy in Patients with Transcatheter Aortic Valve Replacement - An Ambispective Analysis

ABSTRACT Introduction: Goal-directed fluid therapy (GDFT) has been shown to reduce postoperative complications. The feasibility of GDFT in transcatheter aortic valve replacement (TAVR) patients under general anesthesia has not yet been demonstrated. We examined whether GDFT could be applied in patients undergoing TAVR in general anesthesia and its impact on outcomes. Methods: Forty consecutive TAVR patients in the prospective intervention group with GDFT were compared to 40 retrospective TAVR patients without GDFT. Inclusion criteria were age ≥ 18 years, elective TAVR in general anesthesia, no participation in another interventional study. Exclusion criteria were lack of ability to consent study participation, pregnant or nursing patients, emergency procedures, preinterventional decubitus, tissue and/or extremity ischemia, peripheral arterial occlusive disease grade IV, atrial fibrillation or other severe heart rhythm disorder, necessity of usage of intra-aortic balloon pump. Stroke volume and stroke volume variation were determined with uncalibrated pulse contour analysis and optimized according to a predefined algorithm using 250 ml of hydroxyethyl starch. Results: Stroke volume could be increased by applying GDFT. The intervention group received more colloids and fewer crystalloids than control group. Total volume replacement did not differ. The incidence of overall complications as well as intensive care unit and hospital length of stay were comparable between both groups. GDFT was associated with a reduced incidence of delirium. Duration of anesthesia was shorter in the intervention group. Duration of the interventional procedure did not differ. Conclusion: GDFT in the intervention group was associated with a reduced incidence of postinterventional delirium.

Consensus of the Brazilian association of hematology, hemotherapy and cellular therapy on patient blood management: Intraoperative hemostasis and volume replacement

Abstract Hemostasis plays a critical role in surgical procedures and is essential for a successful outcome. Advances in hemostatic agents offer new approaches to controlling bleeding thereby making surgeries safer. The appropriate choice of these agents is crucial. Volume replacement, another integral part of Patient Blood Management (PBM), maintains adequate tissue perfusion, preventing cellular damage. Individualization in fluid administration is vital with the choice between crystalloids and colloids depending on each case. Colloids, unlike crystalloids, increase oncotic pressure, contributing to fluid retention in the intravascular space. Understanding these aspects is essential to ensure safe and effective surgery, minimizing complications related to blood loss and maintaining the patient's hemodynamic status.

Dimensão ética da alimentação e hidratação artificiais no doente terminal / Ethics, artificial nutrition, and hydration in terminal patients / Dimensión ética de la nutrición e hidratación artificial en los pacientes terminales

Resumo Dada a insuficiente evidência científica, decisões relativas à utilização de nutrição e hidratação artificiais em pacientes terminais configuram um importante dilema ético. Identifica-se um conflito entre as perspetivas de "tratar" e "cuidar", com variação quanto a sua utilização conforme o contexto legal e cultural de diferentes países. O intuito deste estudo é esclarecer se essa prática constitui uma medida de cuidado básico ou um tratamento fútil e desproporcionado. Procede-se a uma revisão das diretrizes e dos códigos deontológicos de diferentes países europeus. Em Portugal, na Itália e na Polônia, tal prática é vista como uma medida de cuidado básico; já em países como França, Inglaterra, Noruega, Irlanda, Alemanha, Finlândia, Holanda, Bélgica e Suíça, é considerada um tratamento fútil. Na Romênia, na Croácia e na Hungria, verifica-se um enquadramento ético e legal insuficiente. As diferenças de abordagem a doentes terminais podem ser reflexo das diferentes perspetivas culturais.

Abstract Given the lack of scientific evidence, decisions regarding the administration of artificial nutrition and hydration in terminally ill patients constitute an important ethical dilemma due to the conflict between "treat" and "care" perspectives and the varying usage depending on the legal and cultural background across countries. This study aims to explain whether this practice configures a basic care intervention or a futile medical treatment. Therefore, we review the national guidelines and codes of ethics from several European countries. Countries such as Portugal, Italy, and Poland view it as a basic care intervention, whereas France, England, Norway, Ireland, Germany, Finland, Netherlands, Belgium, and Switzerland, as a medical treatment. Moreover, countries such as Romania, Croatia, and Hungary lack such legal framework. The different approaches regarding the care of terminally ill patients can reflect differences on cultural perspectives.

Resumen Dada la insuficiente evidencia científica, las decisiones sobre el uso de la nutrición e hidratación artificiales en los pacientes terminales constituyen un importante dilema ético. Se identifica un conflicto entre las perspectivas de "tratar" y "cuidar", con variaciones en su uso según el contexto legal y cultural de los diferentes países. El objetivo de este estudio es dilucidar si esta práctica constituye una medida de atención básica o un tratamiento fútil y desproporcionado. Se realiza una revisión de las directrices y códigos deontológicos de diferentes países europeos. En Portugal, Italia y Polonia, se considera esta práctica como una medida de atención básica; mientras que en países como Francia, Inglaterra, Noruega, Irlanda, Alemania, Finlandia, Holanda, Bélgica y Suiza, se considera un tratamiento fútil. En Rumanía, Croacia y Hungría, el marco ético y jurídico es insuficiente. Las diferencias en el tratamiento de los pacientes terminales pueden reflejar diferentes perspectivas culturales.

Hemodynamic and respiratory support in pulmonary embolism: a narrative review.

Pulmonary embolism is a common and potentially fatal disease, with a significant burden on health and survival. Right ventricular dysfunction and hemodynamic instability are considered two key determinants of mortality in pulmonary embolism, which can reach up to 65% in severe cases. Therefore, timely diagnosis and management are of paramount importance to ensure the best quality of care. However, hemodynamic and respiratory support, both major constituents of management in pulmonary embolism, associated with cardiogenic shock or cardiac arrest, have been given little attention in recent years, in favor of other novel advances such as systemic thrombolysis or direct oral anticoagulants. Moreover, it has been implied that current recommendations regarding this supportive care lack enough robustness, further complicating the problem. In this review, we critically discuss and summarize the current literature concerning the hemodynamic and respiratory support in pulmonary embolism, including fluid therapy, diuretics, pharmacological support with vasopressors, inotropes and vasodilators, oxygen therapy and ventilation, and mechanical circulatory support with veno-arterial extracorporeal membrane oxygenation and right ventricular assist devices, while also providing some insights into contemporary research gaps.

Effect of an Albumin Infusion Treatment Protocol on Delayed Cerebral Ischemia and Relevant Outcomes in Patients with Subarachnoid Hemorrhage.

BACKGROUND: An institutional management protocol for patients with subarachnoid hemorrhage (SAH) based on initial cardiac assessment, permissiveness of negative fluid balances, and use of a continuous albumin infusion as the main fluid therapy for the first 5 days of the intensive care unit (ICU) stay was implemented at our hospital in 2014. It aimed at achieving and maintaining euvolemia and hemodynamic stability to prevent ischemic events and complications in the ICU by reducing periods of hypovolemia or hemodynamic instability. This study aimed at assessing the effect of the implemented management protocol on the incidence of delayed cerebral ischemia (DCI), mortality, and other relevant outcomes in patients with SAH during ICU stay. METHODS: We conducted a quasi-experimental study with historical controls based on electronic medical records of adults with SAH admitted to the ICU at a tertiary care university hospital in Cali, Colombia. The patients treated between 2011 and 2014 were the control group, and those treated between 2014 and 2018 were the intervention group. We collected baseline clinical characteristics, cointerventions, occurrence of DCI, vital status after 6 months, neurological status after 6 months, hydroelectrolytic imbalances, and other SAH complication. Multivariable and sensitivity analyses that controlled for confounding and considered the presence of competing risks were used to adequately estimate the effects of the management protocol. The study was approved by our institutional ethics review board before study start. RESULTS: One hundred eighty-nine patients were included for analysis. The management protocol was associated with a reduced incidence of DCI (hazard ratio 0.52 [95% confidence interval 0.33-0.83] from multivariable subdistribution hazards model) and hyponatremia (relative risk 0.55 [95% confidence interval 0.37-0.80]). The management protocol was not associated with higher hospital or long-term mortality, nor with a higher occurrence of other unfavorable outcomes (pulmonary edema, rebleeding, hydrocephalus, hypernatremia, pneumonia). The intervention group also had lower daily and cumulative administered fluids compared with historic controls (p < 0.0001). CONCLUSIONS: A management protocol based on hemodynamically oriented fluid therapy in combination with a continuous albumin infusion as the main fluid during the first 5 days of the ICU stay appears beneficial for patients with SAH because it was associated with reduced incidence of DCI and hyponatremia. Proposed mechanisms include improved hemodynamic stability that allows euvolemia and reduces the risk of ischemia, among others.

Enteral hydration in cows: Comparison between continuous flow and bolus administration.

BACKGROUND: Enteral hydration in cattle is most commonly performed as a bolus (B) via the ororuminal route, although continuous flow (CF) administration via the nasoesophageal route represents a viable alternative. Currently, no study has compared the effectiveness of these two methods. This study aimed to compare the efficiency of enteral hydration using CF and B to correct water, electrolyte and acid-base imbalances in cows. METHODS: Protocols for the induction of dehydration were applied twice to eight healthy cows, with an interval of 1 week. In a crossover design, two types of enteral hydration were performed using the same electrolyte solution and volume equal to 12% of bodyweight (BW): CF (10 mL/kg/h, between 0 and 12 hours) and B (6% BW, twice, at 0 and 6 hours). Clinical and blood variables were determined at -24, 0, 6, 12 and 24 hours and compared using repeated-measures ANOVA. RESULTS: Induced moderate dehydration and hypochloremic metabolic alkalosis were corrected after 12 hours using the two hydration methods, with no differences observed between the methods. LIMITATIONS: The study was conducted with induced rather than natural imbalances, so the findings should be interpreted cautiously. CONCLUSION: Enteral CF hydration is as effective as B hydration in reversing dehydration and correcting electrolyte and acid-base imbalances.

Point-of-care ultrasonography to predict fluid responsiveness in children: A systematic review and meta-analysis.

BACKGROUND: Point-of-care ultrasonography (POCUS) is proposed as a valuable method for hemodynamic monitoring and several ultrasound-based predictors of fluid responsiveness have been studied. The main objective of this study was to assess the accuracy of these predictors in children. METHODS: PubMed, Embase, Scopus, ClinicalTrials.gov, and Cochrane Library databases were searched for relevant publications through July 2022. Pediatric studies reporting accuracy estimates of ultrasonographic predictors of fluid responsiveness were included since they had used a standard definition of fluid responsiveness and had performed an adequate fluid challenge. RESULTS: Twenty-three studies involving 1028 fluid boluses were included, and 12 predictors were identified. A positive response to fluid infusion was observed in 59.7% of cases. The vast majority of participants were mechanically ventilated (93.4%). The respiratory variation in aortic blood flow peak velocity (∆Vpeak) was the most studied predictor, followed by the respiratory variation in inferior vena cava diameter (∆IVC). The pooled sensitivity and specificity of ∆Vpeak were 0.84 (95% CI, 0.76-0.90) and 0.82 (95% CI, 0.75-0.87), respectively, and the area under the summary receiver operating characteristic curve (AUSROC) was 0.89 (95% CI, 0.86-0.92). The ∆IVC presented a pooled sensitivity and specificity of 0.79 (95% CI, 0.62-0.90) and 0.70 (95% CI, 0.51-0.84), respectively, and an AUSROC of 0.81 (95% CI, 0.78-0.85). Significant heterogeneity in accuracy estimates across studies was observed. CONCLUSIONS: POCUS has the potential to accurately predict fluid responsiveness in children. However, only ∆Vpeak was found to be a reliable predictor. There is a lack of evidence supporting the use of POCUS to guide fluid therapy in spontaneously breathing children.

Evaluación de la concordancia entre las variaciones de la velocidad pico aórtico y velocidad pico carotídeo con la ventilación mecánica en una población pediátrica sometida a cirugía electiva bajo anestesia general / Evaluation of the agreement between variations in aortic peak velocity and carotid peak velocity with mechanical ventilation in a pediatric population undergoing elective surgery under general anesthesia

Introducción. La variación de la velocidad máxima aórtica con la ventilación mecánica (ΔVpeakAo) ha demostrado ser el mejor predictor de respuesta a volumen en pediatría. Existe evidencia en adultos de que la variación de velocidad máxima de flujo carotídeo (ΔVpeakCar) es predictor de respuesta a fluidos. Al momento es escasa la información sobre este índice en pediatría. Su beneficio se basa en la no-invasividad, y que para su medición no es necesaria la ecocardiografía ni el acceso al tórax del paciente. Objetivo. El objetivo general de este trabajo fue estudiar la correlación y la concordancia de ΔVpeakCar con ΔVpeakAo en una población pediátrica bajo ventilación mecánica. Metodología. Se incluyeron pacientes de 0 a 12 años. Se registraron flujos aórtico y carotídeos máximos y mínimos y se calculó ΔVpeakCar y ΔVpeakAo. Para analizar correlación y concordancia entre las variables se utilizó el test de Pearson, análisis de Bland-Altman y análisis de los 4-cuadrantes. Resultados. Se estudiaron 58 pacientes, 13 lactantes (menores 12 meses), 21 preescolares (12-60 meses) y 24 escolares (mayores a 60 meses). Se observó una correlación significativa entre ΔVpeakAo y ΔVpeakCar (r=0,85; p<0,05) con un coeficiente de determinación de r2=0,72. El análisis de Bland-Altman mostró un sesgo del 0,15% (IC95%, -0.7-1.0) con un límite de concordancia del -6,1 a 6,2%. La concordancia fue 85%, con un sesgo angular de 4,5°±31°. El análisis por subgrupos mostró un r2 de 0.89 en escolares, 0.56 en preescolares y 0.45 en lactantes. La concordancia fue de 100% en escolares, 95% en prescolares y 93% en lactantes. Discusión y conclusiones. El registro de ΔVpeakCar fue viable. Al analizar la capacidad de ΔVpeakCar de sustituir a ΔVpeakAo en el total de la muestra, no es buena La correlación y concordancia son mejores en escolares. Es necesario continuar estudiando este nuevo índice.

Introduction. The variation in maximum aortic velocity with mechanical ventilation (ΔVpeakAo) has proven to be the most effective predictor of fluid response in pediatrics. While there is evidence in adults that the variation in maximum carotid flow velocity (ΔVpeakCar) predicts fluid response, information on this index in pediatrics remains limited. Its advantage lies in its non-invasive nature, eliminating the need for echocardiography or thoracic access for recording. Objective. This study aims to examine the correlation and concordance between ΔVpeakCar and ΔVpeakAo in a pediatric population. Methodology. The study included patients aged 0 to 12 years. Maximum and minimum aortic and carotid flows were recorded, and ΔVpeakCar and ΔVpeakAo were calculated. Correlation and agreement between variables were analyzed using the Pearson test, Bland Altman analysis, and 4-quadrant analysis. Results. A total of 58 patients were studied, comprising 13 infants (under 12 months), 21 preschoolers (12-60 months), and 24 school-aged children (over 60 months). A significant correlation was observed between ΔVpeakAo and ΔVpeakCar (r=0.85; p<0.05) with a coefficient of determination, r²=0.72. The Bland-Altman analysis revealed a bias of 0.15% (95% CI, -0.7-1.0) with an agreement limit of -6.1% to 6.2%. The concordance rate was 85%, with an angular bias of 4.5°±31°. Subgroup analysis showed r² values of 0.89 in school-aged children, 0.56 in preschoolers, and 0.45 in infants. Concordance rates were 100% in school-aged children, 95% in preschoolers, and 93% in infants. Discussion and Conclusions. The measurement of ΔVpeakCar proved feasible. However, when considering its ability to replace ΔVpeakAo, the results are suboptimal. Correlation and concordance are stronger in school-aged children. Further investigation into this new index is warranted.