Bicarbonato de sodio intravenoso ¿Cuándo, cómo y por qué utilizarlo? / Intravenous sodium bicarbonate. When, how and why to use it?

Severe metabolic acidosis is defined by a pH < 7.2 with HCO3− < 8 mE- q/L in plasma. Its best treatment is to correct the underlying cause. However, acidemia produces multiple complications such as resistance to the action of catecholamines, pulmonary vasoconstriction, impaired cardiovascular function, hyperkalemia, immunological dysregulation, respiratory muscle fatigue, neurological impairment, cellular dysfunction, and finally, it contributes to multisystemic failure. Intravenous NaHCO3 buffers severe acidemia, preventing the associated damage and gains time while the causal disease is corrected. Its indication requires a risk-benefit assessment, considering its complications. These are hypernatremia, hypokalemia, ionic hypocalcemia, rebound alkalosis, and intracellular acidosis. For this reason, therapy must be "adapted" and administered judiciously. The patient will require monitoring with serial evaluation of the internal environment, especially arterial blood gases, plasma electrolytes, and ionized calcium. Isotonic solutions should be preferred instead of hypertonic bicarbonate. The development of hypernatremia must be prevented, calcium must be provided for hypocalcemia to improve cardiovascular function. Furthermore, in mechanically ventilated patients, a respiratory response similar to the one that would develop physiologically, must be established to be able to extract excess CO2 and thus avoid intracellular acidosis. It is possible to estimate the bicarbonate deficit, speed, and volume of its infusion. However, the calculations are only for reference. More important is to start intravenous NaHCO3 when needed, administer it judiciously, manage its side effects, and continue it to a safe goal. In this review we address all the necessary elements to consider in the administration of intravenous NaHCO3, highlighting why it is the best buffer for the management of severe metabolic acidosis.

Ressuscitação direcionada ao tempo de enchimento capilar baseada em fenótipo hemodinâmico no choque séptico precoce: protocolo de estudo do ensaio clínico randomizado ANDROMEDA-SHOCK-2 / Hemodynamic phenotype-based, capillary refill time-targeted resuscitation in early septic shock: The ANDROMEDA-SHOCK-2 Randomized Clinical Trial study protocol

RESUMO Introdução: A reversão precoce da hipoperfusão tecidual induzida é essencial para a sobrevida no choque séptico. No entanto, falta consenso sobre a melhor estratégia de ressuscitação inicial, uma vez que intervenções destinadas a toda a população com choque séptico podem produzir administração desnecessária de líquidos. Este artigo relata a justificativa, o delineamento e o plano de análise do estudo ANDROMEDA-2, que visa determinar se uma estratégia guiada por perfusão periférica, que consiste na ressuscitação guiada pelo tempo de enchimento capilar com base em fenótipos clínicos e hemodinâmicos, está associada a uma diminuição no desfecho composto de mortalidade, tempo até a interrupção ao suporte de órgãos e tempo de internação em comparação com o atendimento padrão em pacientes com choque séptico precoce (< 4 horas do diagnóstico). Metódos: O estudo ANDROMEDA-2 é um ensaio clínico randomizado controlado multinacional e multicêntrico. No grupo de intervenção, o tempo de enchimento capilar será medido a cada hora, durante 6 horas. Se estiver anormal, os pacientes serão alocados em um algoritmo, começando com a avaliação da pressão de pulso. Pacientes com pressão de pulso inferior a 40mmHg serão testados quanto à capacidade de resposta a líquidos e receberão líquidos de acordo. Em pacientes com pressão de pulso > 40mmHg, norepinefrina será titulada para manter a pressão arterial diastólica > 50mmHg. Os pacientes que não normalizarem o tempo de enchimento capilar após as etapas anteriores serão submetidos à ecocardiografia de cuidados intensivos para avaliação da disfunção cardíaca e posterior manejo. Por fim, serão realizados testes com vasopressores e inodilatadores para otimizar ainda mais a perfusão. Um tamanho de amostra de 1.500 pacientes fornecerá 88% de poder para demonstrar a superioridade da estratégia direcionada ao tempo de enchimento capilar. Conclusão: Se for demonstrado que o direcionamento ao tempo de enchimento capilar é uma estratégia melhor, os processos de atendimento na ressuscitação do choque séptico podem ser otimizados com ferramentas usadas à beira do leito.

ABSTRACT Background: Early reversion of sepsis-induced tissue hypoperfusion is essential for survival in septic shock. However, consensus regarding the best initial resuscitation strategy is lacking given that interventions designed for the entire population with septic shock might produce unnecessary fluid administration. This article reports the rationale, study design and analysis plan of the ANDROMEDA-2 study, which aims to determine whether a peripheral perfusion-guided strategy consisting of capillary refill time-targeted resuscitation based on clinical and hemodynamic phenotypes is associated with a decrease in a composite outcome of mortality, time to organ support cessation, and hospital length of stay compared to standard care in patients with early (< 4 hours of diagnosis) septic shock. Methods: The ANDROMEDA-2 study is a multicenter, multinational randomized controlled trial. In the intervention group, capillary refill time will be measured hourly for 6 hours. If abnormal, patients will enter an algorithm starting with pulse pressure assessment. Patients with pulse pressure less than 40mmHg will be tested for fluid responsiveness and receive fluids accordingly. In patients with pulse pressure > 40mmHg, norepinephrine will be titrated to maintain diastolic arterial pressure > 50mmHg. Patients who fail to normalize capillary refill time after the previous steps will be subjected to critical care echocardiography for cardiac dysfunction evaluation and subsequent management. Finally, vasopressor and inodilator tests will be performed to further optimize perfusion. A sample size of 1,500 patients will provide 88% power to demonstrate superiority of the capillary refill time-targeted strategy. Conclusions: If hemodynamic phenotype-based, capillary refill time-targeted resuscitation demonstrates to be a superior strategy, care processes in septic shock resuscitation can be optimized with bedside tools.

La criticidad de las Unidades de Intensivo. Ampliando las Unidades en tiempos de pandemia / Expanding ICU facilities in a pandemic scenario

Our country is suffering the effects of the ongoing pandemic of coronavirus disease (COVID-19). Because the vulnerability of healthcare systems, especially the intensive care areas they can rapidly be overloaded. That challenge the ICUs simultaneously on multiple fronts making urgent to increase the number of beds, without lowering the standards of care. The purpose of this article is to discuss some aspects of the national situation and to provide recommendations on the organizational management of intensive care units such as isolation protocols, surge in ICU bed capacity, ensure adequate supplies, protect and train healthcare workers maintaining quality clinical management.

Trabajando y enseñando en Chad / Working and teaching in Chad

Anesthesiologists from different centers of our country have been involved in an international cooperation program in Chad. this article shows the experience of a group of them, as well as a brief account of the work that different organizations have carried out to reduce the world wide deficit of anesthetists.

Anestesiólogos de distintos centros de nuestro país se han involucrado en un programa de cooperación internacional en Chad. este artículo muestra la experiencia de un grupo de ellos, así como un breve resumen del trabajo que distintas organizaciones han llevado a cabo para disminuir el déficit global de anestesistas.

Cooperación internacional ¿en qué estamos y hacia dónde vamos? / International cooperation. Where are we, and where are we heading to?

Unmet needs in global health are important issues, not yet solved by the international community. A variety of individuals, non-governmental organizations (NGO) and government institutions have tried to address this situation, developing multiple types of international cooperation (IC), such as humanitarian aid (HA), cooperation for development (CD) and medical missions (MM). In the last decades, we have witnessed an exponential growth in the creation and participation of these projects. Moreover, in the last 20 years, Chile has experimented a real paradigm switch, from a receiver to a provider of IC. Due to the recent surge in interest and relevance of the topic, we performed a narrative revision of the literature related with IC. In the present article, we characterize the different types of IC, with emphasis in MM: we address the risks, controversies and ethical problems associated with these activities. We finally propose some guidelines for the future development and promotion of MM.

Dosis efectiva 90 de oxitocina profiláctica en infusión luego del alumbramiento durante operación cesárea en pacientes en trabajo de parto o cesárea primaria: Un estudio dosis-respuesta con distribución secuencial arriba-abajo

Introducción: La administración profiláctica de oxitocina es parte del manejo activo de la tercera etapa del trabajo de parto y reduce el riesgo de hemorragia posparto. Objetivo: estimar con un modelo dosis-respuesta la dosis de oxitocina endovenosa en infusión continua, efectiva en 90% (ED90) para contracción uterina adecuada luego de trabajo de parto fracasado en pacientes que serán sometidas a operación cesárea versus aquellas sometidas a cesárea electiva. Métodos: Estudio dosis-respuesta, ciego único, de dos ramas utilizando la metodología de la moneda sesgada en relación 9:1 para determinar la DE90. El grupo experimental fueron parturientas sometidas a operación cesárea, secundaria a fracaso en la progresión del trabajo de parto y que habían recibido oxitocina. El grupo control, pacientes sometidas a cesárea electiva. Se les administró oxitocina en infusión continua inmediatamente post nacimiento, de acuerdo a la metodología de la moneda sesgada. Posteriormente, a los 4 minutos del nacimiento, el cirujano estimó si el tono uterino era satisfactorio o no. Los desenlaces secundarios incluyeron requerimientos de uterotónicos adicionales y efectos colaterales maternos. Los datos se analizaron por medio de un modelo de regresión logística y la estimación de la DE90 fue derivada del ajuste de curvas. Resultados: Participaron 38 pacientes sometidas a cesárea electiva y 32 que venían de un trabajo de parto. La DE90 de oxitocina estimada fue significativamente mayor para las pacientes en trabajo de parto (44,2 IU/h, iC95% 33,8-55,6), comparadas con las sometidas a cesárea electiva (16,2 IU/h (iC95% 13,1-19,3)). Significativamente más mujeres en el grupo experimental requirieron uterotónicos suplementarios (34% vs/ 8%, p=0,008). La incidencia global de efectos colaterales fue mayor en el grupo experimental (69% vs/ 34%, p=0.004). Conclusión: La mujeres con exposición previa a oxitocina exógena requieren una mayor dosis de infusión inicial de oxitocina para prevenir atonía uterina post operación cesárea que aquellas sin exposición previa.

Comentario sobre "Estudio aleatorio sobre el efecto de la profilaxis antibiótica en la fiebre epidural durante el trabajo de parto" / Comment on "A randomized trial of the effects of antibiotic prophylaxis on epidural-related fever in labor"

This work presents a critical analysis of the article by Sharma et al.

Evaluación para el aprendizaje: experiencia en un curso teórico de pregrado en medicina / Assessment for learning: experience in an undergraduate medical theoretical course

Background: Assessment for learning is a paradigm that is taking shape in the field of medical education. This approach aims to embed the assessment process within the educational and learning process. Aim: To evaluate the impact of curricular changes, from a focus of assessment of learning to one of assessment for learning, in the perception of undergraduate students of medicine and their final grades obtained in a theoretical course (TCG). Material and Methods: In the year 2011 lectures were reduced and intermediate assessments followed by a feedback session were introduced. The activities of each program course, surveys about student perceptions of the course and the final grades of students (assessments with multiple choice questions) were compared between the periods prior and after curricular changes (2005-2010 and 2011-2013). Results: As a consequence of curricular changes, time for lectures was reduced by 19.5%, time for summative assessments was increased by 8.5%, and feedback activity, occupying 7.3% of the course time was added. There were significant improvements in student is perceptions in all areas assessed by surveys, emphasizing feedback and assessments. The overall grade assigned to the course dictated after implementing the changes increased from 6.18 to 6.59 (p < 0.001, 1-7 scale). The grades of students also improved from an average of 5.78 to 6.43 (p < 0.001, 1-7 scale). Conclusions: Assessment for learning achieved the desired educational impact without increasing the assigned curricular time. Programmatic assessment is favorably perceived by students.