Hyperlacticaemia in children with status asthmaticus. The Stewart approach.

BACKGROUND: Patients with status asthmaticus (SA) frequently present with lactic acidosis (LA). Our goal is to identify the nature of this LA using the Stewart physicochemical model and to identify the independent factors associated with LA in children with SA. METHODS: Analytical study of a retrospective cohort using a nested case-control design. Twenty-eight episodes of SA in 24 children were included. Patients admitted to a paediatric intensive care unit (PICU) for SA over a 9-year period were recruited consecutively. Data were analysed using the Stewart model and the Strong Ion Calculator. Data were analysed using descriptive statistics and regression models were fitted within the general linear model. RESULTS: Hyperlacticaemia (Lact[mM/L] = 3.905 [95% CI = 3.018-4.792]) and acidosis (pH = 7.294 [95% CI = 7.241-7.339]) were observed in 18 episodes (15 patients; 62.5%). According to the Stewart model, acidosis was caused by a decrease in strong ion difference. Initially, pCO2 was high (pCO2[mmHg] = 45.806 [95% CI = 37.314-54.298]) but the net unmeasured ion (NUI) component was normal (NUI=-4,461 [95% CI=-3.51 - -5.412]), and neither changed significantly over the clinical course. There was no need to determine pyruvate, as the NUI was normal and the LA was type B (non-hypoxic, lactate / pyruvate < 25). We observed a correlation (p = 0.023) between LA and intramuscular epinephrine administered on arrival at hospital, but not between LA and the cumulative dose of nebulized salbutamol. CONCLUSIONS: Most patients with SA presented LA. The Stewart model confirmed that LA is not hypoxic, probably due to sympathomimetic-related glycolysis.

¿Bicarbonato de sodio en terapia intensiva es útil o no?

La acidosis metabólica se ha convertido en un problema muy serio, tanto en las áreas críticas, como de medicina interna y emergencias, sobre todo por la innumerable cantidad de patologías que la presentan; que ha encaminado a muchos profesionales a usar el bicarbonato de Na (NaHCO3-), que definitivamente tiene un efecto en el ascenso del pH y el HCO3-, asociado a un sosiego inverosímil del profesional médico y probablemente a un escaso beneficio por parte de los pacientes; este estudio trata de explicar en forma concisa a la etiología de la acidosis metabólica y la real indicación de esta droga, que hasta el momento podría tener más perjuicios que beneficios.

Metabolic acidosis has become a very serious problem, both in critical areas, such as internal medicine and emergencies, especially due to the innumerable number of pathologies that present it; which has led many professionals to use Na bicarbonate (NaHCO3-), which definitely has an effect on the rise in pH and HCO3-, associated with an unlikely calmness of the medical professional and probably with little benefit on the part of the patients. patients; This study tries to concisely explain the etiology of metabolic acidosis and the real indication of this drug, which up to now could have more harm than good.

Control de la ventilación y regulación del estado ácido-base del pez al hombre / Control of ventilation and regulation of acid-base status from fish to man

RESUMEN Este artículo analiza ciertos aspectos evolutivos en el intercambio gaseoso, el desa rrollo pulmonar, la bomba respiratoria, el estado ácido-base y el control de la ventila ción en relación con un evento trascendente: el pasaje de la vida acuática a la terres tre. Su estudio puede permitir comprender ciertos aspectos con los que lidiamos en la práctica clínica: ¿Por qué las personas con debilidad muscular respiratoria extrema respiran como ranas (respiración frog)?, ¿Por qué los recién nacidos con dificultad respiratoria tienen aleteo nasal y quejido espiratorio?, ¿cómo es posible que los mús culos abdominales, típicamente espiratorios, asistan a la inspiración en casos de la parálisis diafragmática?, ¿por qué en la insuficiencia respiratoria el patrón respiratorio tiene menos variabilidad y se torna más rígido? y, por último, ¿es posible imaginar un pH neutro que no tenga el valor de 7,0, para qué sirve este conocimiento y como se deben interpretar los gases en hipotermia? La transición del agua a la tierra es una de las más importantes e inspiradoras de las grandes transiciones en la evolución de los vertebrados. Ante la sorprendente diversi dad de organismos vivos, es tentador imaginar una cantidad enorme de adaptaciones evolutivas para resolver los diferentes desafíos que cada especie tiene para la vida en la tierra. Hay desarrollos tempranos que comparten algunos factores cruciales y algunas de las redes genéticas regulatorias cercanas y lejanas están conservadas. Somos testigos de hallazgos clínicos que son el testimonio de especies que han vivido en épocas remotas y nos han legado su historia evolutiva.

ABSTRACT This article analyzes certain evolutionary aspects of gas exchange, lung development, the respiratory pump, the acid-base status and control of ventilation in relation to a significant event: the passing from aquatic to terrestrial life. By studying this, we can understand certain aspects that are present in the clinical practice: Why do people with extreme respiratory muscle weakness breathe as frogs? (frog breathing); why do newborns with breathing difficulties have nasal flaring and expiratory grunting?; how is it possible that abdominal muscles, which are typically expiratory, assist with inspira tion in cases of diaphragmatic paralysis?; why does the breathing pattern of respiratory failure has less variability and becomes more rigid? and, finally, is it possible to imagine a neutral pH that doesn't have the 7.0 value?; what's the use of this knowledge, and how should gases in hypothermia be interpreted? Water-to-land transition is one of the most important and inspiring major transitions of vertebrate evolution. Given the amazing diversity of living organisms, it is tempting to imagine an enormous amount of evolutionary adaptation processes to solve the different challenges of living on earth faced by each species. There are certain early development processes that share some crucial factors, and some of the close and distant gene regulatory networks are conserved. We are witnesses of clinical findings that serve as testimony of the species that lived in remote times and left us their evo lutionary history.

Physiological variables of the "metabolic component" of acid-base balance and mortality in intensive care patients / Variables fisiológicas del "componente metabólico" del estado ácido base y mortalidad en pacientes de cuidados intensivos

Abstract Introduction: Metabolic acidosis is a frequent pathophysiological condition in critically ill patients. It can be assessed using different physiological variables, but their prognostic value has not yet been well established. Objective: To evaluate the association between the variables that allow assessing the metabolic component of acid-base balance (ABB) and 28-day mortality in patients admitted to an intensive care unit (ICU) in Bogotá, D.C., Colombia. Materials and methods: Prospective cohort study conducted in 122 patients admitted to an ICU between January and June 2013 and with a stay >24 hours. On admission to the ICU, blood samples were taken, and an arterial blood gas test was performed in order to calculate the following variables: anion gap (AG), corrected anion gap (AGc), standard base excess (BEst), metabolic H+, base excess-unmeasurable anions (BEua), arterial pH, arterial lactate, standard HCO3-st, and strong ion difference (SID). APACHE II and SOFA scores were also calculated. A bivariate analysis was performed in which ORs and their respective 95%CI were calculated, and then a multivariate analysis was conducted using a logistic regression model to identify the variables associated with 28-day mortality; a significance level of p<0.05 was considered. Results: Out of the 122 patients, 33 (27.05%) died at 28 days and 51 (48.80%) were women. Participants' mean age was 46.5 years (±15.7). The following variables were significantly associated with 28-day mortality in the bivariate analysis: SID (OR=1.150; p=0.008), BEua (OR=0.897; p=0.023), AG (OR=1.231; p=0.002), AGc (OR=1.232; p=0.003), blood pH (OR=0.001; p=0.023), APACHE II (OR=1.180; p=0.001), HCO3-st (OR=0.841; p=0.015). In the multivariate analysis, only the APACHE II score variable was significantly associated with 28-day mortality (OR=1.188; p=0.008). Conclusion: The physiological variables that allow assessing the metabolic component of ABB, both from the Henderson model and the Stewart model, were not significantly associated with 28-day mortality.

Resumen Introducción. La acidosis metabólica es una condición fisiopatológica frecuente en pacientes críticamente enfermos. Esta alteración es evaluada mediante diferentes variables fisiológicas; sin embargo, su valor pronóstico aún no está bien definido. Objetivo. Evaluar la asociación entre, por una parte, las variables del componente metabólico que permiten valorar el estado ácido base (EAB) y, por la otra, la mortalidad a 28 días en pacientes hospitalizados en una unidad de cuidados intensivos (UCI) en Bogotá D.C., Colombia. Materiales y métodos. Estudio de cohorte prospectivo realizado en 122 pacientes hospitalizados en una UCI entre enero y junio de 2013 y con una estancia mayor a 24 horas. Se tomaron muestras sanguíneas y gases arteriales de ingreso a UCI para el cálculo de las siguientes variables: anion gap (AG), anion gap corregido (AGc), base exceso estándar (BEst), H+ metabólicos, base exceso-aniones no medibles (BEua), pH arterial, lactato arterial, HCO3-st y brecha de iones fuertes (BIF). También se calcularon el puntaje APACHE II y el puntaje SOFA. Se realizó un análisis bivariado en el que se calcularon OR y sus respectivos IC95%, y luego uno multivariado, mediante un modelo de regresión logística, para identificar las variables asociadas con la mortalidad a 28 días; se consideró un nivel de significancia de p<0.05 Resultados. De los 122 pacientes, 33 (27.05%) fallecieron a 28 días y 51 (48.80%) eran mujeres. La edad promedio fue 46.5 años (±15.7). En el análisis bivariado, las siguientes variables se asociaron significativamente con la mortalidad a 28 días: BIF (OR=1.150; p=0.008), BEua (OR=0.897; p=0.023), AG (OR=1.231; p=0.002), AGc (OR=1.232; p=0.003), pH arterial (OR=0.001; p=0.023), APACHE II (OR=1.180;p=0.001), HCO3-st (OR=0.841;p=0.015). En el análisis multivariado, solo el puntaje APACHE II se asoció significativamente con la mortalidad a 28 días (OR=1.188; p=0.008). Conclusión. Las variables fisiológicas que permiten evaluar el componente metabólico del EAB, tanto las del modelo de Henderson, como las del modelo de Stewart, no se asociaron significativamente con la mortalidad a 28 días.

A comparison of dietary acid load between team, endurance, and strength sports

ABSTRACT Purpose: Since the dietary acid load (PRAL) may affect the acid-base balance of the body, there is an increasing interest in its role in sports performance. Typical nutritional requirements of different sports, associated with its physiological demands, might be reflected in the acid load of their diet. Thus, the purpose of this study is to compare the dietary acid load between team, endurance, and strength athletes and to determine the associations between PRAL and hydration status. Methods: Fifty-one healthy recreational male athletes (age: 18-39 yrs) from team, endurance, and strength sports participated in the study. A 3-day food diary was recorded and dietary PRAL values (mEq/day) were calculated. Urine pH and specific gravity were measured. One-way ANOVA with Bonferroni post-hoc analysis and Pearson correlation coefficient (r) were used for data analysis. Results: PRAL in endurance athletes (25.34 mEq/day) was lower compared to team and strength athletes (46.12 and 46.47 mEq/day, respectively) (p= 0.023). Percentage of high PRAL diet (≥15 (mEq/day)) was highest in team sports (89.5%), followed by strength (83.3%) and endurance sports (60%). PRAL was not associated with hydration status. Conclusion: Typical nutritional requirements of sport disciplines are reflected in the PRAL, thus PRAL should be considered when preparing nutritional strategies to improve performance.

RESUMEN Objetivo: Dado que la carga ácida de la dieta (PRAL) puede afectar el equilibrio ácido-base del cuerpo, existe un interés creciente en su papel en el rendimiento deportivo. Los requerimientos nutricionales típicos de diferentes deportes, asociados con sus demandas fisiológicas, pueden reflejarse en la carga ácida de su dieta. Por lo tanto, el propósito de este estudio fue comparar la carga ácida de la dieta entre atletas de equipo, de resistencia y de fuerza, y determinar las asociaciones entre PRAL y el estado de hidratación. Métodos: Participaron en el estudio 51 atletas masculinos sanos (edad: 18-39 años) de deportes de equipo, de resistencia y de fuerza. Se registró un diario de alimentación de 3 días y se calcularon los valores de PRAL dietético (mEq/día). Se midieron el pH y la gravedad específica de la orina. Para el análisis de datos se utilizó ANOVA de una vía con análisis post-hoc de Bonferroni y coeficiente de correlación de Pearson (r). Resultados: PRAL en los atletas de resistencia (25,34 mEq/día) fue menor en comparación con los atletas de equipo y de fuerza (46,12 y 46,47 mEq/día, respectivamente) (p= 0,023). El porcentaje de dieta alta en PRAL (≥15 mEq/día) fue más alto en los deportes de equipo (89,5%), seguido de los deportes de fuerza (83,3%) y de resistencia (60%). PRAL no se asoció con el estado de hidratación. Conclusión: Los requerimientos nutricionales típicos de las disciplinas deportivas se reflejan en el PRAL, por lo que se debe considerar el PRAL al preparar estrategias nutricionales para mejorar el rendimiento.

Alteraciones del estado ácido básico en pacientes adultos con insuficiencia renal crónica / Acid-base status alterations in adult patients with chronic renal failure

RESUMEN Introducción: el portador de insuficiencia renal crónica puede presentar diversas alteraciones del estado ácido básico, siendo la acidosis metabólica la más frecuente. Objetivos: describir las características demográficas y clínicas y las alteraciones del estado ácido básico de pacientes adultos que ingresan con insuficiencia renal crónica en dos centros hospitalarios del Paraguay. Metodología: se aplicó un diseño observacional, descriptivo, transversal. Se incluyó a sujetos adultos de ambos sexos, portadores de insuficiencia renal crónica, que acudieron al Hospital Nacional (Itauguá) y Hospital Militar (Asunción) entre abril y noviembre del 2021. Se midieron variables antropométricas, clínicas y laboratoriales al ingreso. Los datos se sometieron a estadística descriptiva con el programa Epi Info 7™. El estudio contó con la aprobación del Comité de Ética de la Universidad Privada del Este, Paraguay. Resultados: se incluyó a 148 sujetos, siendo 78 (52,7 %) varones con edad media 58 ± 16 años y 70 (47,3 %) mujeres con edad media 54 ± 17 años. Las etiologías más frecuentes de la insuficiencia renal crónica fueron la diabetes mellitus e hipertensión arterial (44,5 %). Se detectó 12 sujetos (8,1 %) con gasometría normal. La alteración del estado ácido básico más frecuente fue la acidosis metabólica (87,2 %), predominando en este grupo los casos con brecha aniónica normal. Conclusiones: las alteraciones del estado ácido básico predominantes en pacientes con insuficiencia renal crónica fue la acidosis metabólica con brecha aniónica normal. Se sugiere aplicar los cálculos de los mecanismos compensadores para llegar al diagnóstico certero de estas alteraciones metabólicas.

ABSTRACT Introduction: the carrier of chronic renal failure can present various alterations of the basic acid state, being the metabolic acidosis the most frequent. Objectives: to describe the demographic and clinical characteristics and alterations in the acid-base status of adult patients admitted with chronic renal failure in two hospitals in Paraguay. Methodology: an observational, descriptive, cross-sectional design was applied. Adult subjects of both sexes, carriers of chronic renal failure, who attended the National Hospital (Itauguá) and the Military Hospital (Asunción) between April and November 2021 were included. Anthropometric, clinical and laboratory variables were measured at admission. The data was submitted to descriptive statistics with the Epi Info 7™ program. The study was approved by the Ethics Committee of the Universidad Privada del Este, Paraguay. Results: 148 subjects were included, being 78 (52.7 %) men with a mean age of 58 ± 16 years and 70 (47.3 %) women with a mean age of 54 ± 17 years. The most frequent etiologies of chronic renal failure were diabetes mellitus and arterial hypertension (44.5 %). 12 subjects (8.1 %) with normal blood gases were detected. The most frequent alteration of the acid-base status was metabolic acidosis (87.2 %), with cases with normal anion gap predominating in this group. Conclusions: the predominant acid-base status alterations in patients with chronic renal failure was metabolic acidosis with normal anion gap. It is suggested to apply the calculations of the compensatory mechanisms to arrive at the accurate diagnosis of these metabolic alterations.

Iatrogenic alkalosis in goats with the use of intravenous electrolyte solution containing 84 mEq/L of lactate / Alcalose iatrogênica em cabras após infusão intravenosa de solução eletrolítica contendo 84mEq/L de lactato

ABSTRACT: This study investigated the alkalinizing potential of an intravenous polyionic solution containing 84 mEq/L of lactate on hydroelectrolyte and acid-base balances in healthy goats.Four solutions, containing 28 and 84 mEq/L of lactate (L28 and L84) or bicarbonate (B28 and B84), were formulated. Six healthy Saanen goats were used. All four solutions were infused intravenously in each animal, one at a time, with an interval of 4-5 days between the infusions, at a speed of 33.3 mL/kg/h and totaling a volume equivalent to 10% of their body weight, in 3 h of continuous administration. Samples of venous blood and urine were collected at 0h (start of the infusion), 1.5h (middle of the infusion), 3h (end of the infusion), and 4.5h, 6h, and 24 h from the start of the infusion. The laboratory tests includeddetermination of blood pH, pCO2,HCO3 -, base excess (BE), Na+, K+, Cl-, total plasmatic protein, L-lactate, and creatinine. In urine samples, pH, Na+, K+, Cl-, L-lactate, and creatinine were measured. The L28 solution, equivalent to lactated Ringer's solution, caused a slight increase in the alkaline reserve and did not change the electrolyte balance. The L84 solution resulted in a greater increase in the alkaline reserve, equivalent to the B84 solution, with return to baseline values within 24 h from the start of the infusion.The L84 solution proved to be safe and produced iatrogenic alkalization when infused into healthy goats, without causing side effects.

RESUMO: O objetivo deste trabalho foi investigar o potencial alcalinizante de uma solução poli-iônica intravenosa contendo 84mEq/L de lactato no equilíbrio hidroeletrolítico e ácido base de cabras saudáveis. Quatro soluções contendo 28 e 84 mEq/L de lactato (L28 e L84) ou bicarbonato (B28 e B84) foram formuladas. Seis cabras, adultas, da raça Saanen, saudáveis receberam as quatro soluções por via intravenosa, uma de cada vez, com intervalo de quatro a cinco dias entre as infusões, a velocidade de 33,3 ml/kg/h, totalizando um volume equivalente a 10% do seu peso corporal, em três horas de administração contínua. Foram coletadas amostras de sangue venoso e urina antes do início da infusão (0h), na metade (1,5h), no fim (3h) e às 4,5h, 6h e 24h após o início da infusão. Os exames laboratoriais consistiram na determinação do pH sanguíneo, pCO2, HCO3 -, BE, Na+, K+, Cl-, proteína plasmática total, lactato L e creatinina. Nas amostras de urina foram medidos o pH, Na+, K+, Cl-, lactato L e creatinina. A solução L28, equivalente à solução de Ringer com lactato, causou um aumento leve na reserva alcalina e não alterou o equilíbrio eletrolítico. A solução L84 resultou em maior aumento da reserva alcalina, equivalente à solução B84, com retorno dos parâmetros avaliados aos valores basais em até 24 horas após o início da infusão. A solução L84 provou-se segura e produziu alcalose iatrogência em cabras sadias, sem causar qualquer efeito colateral.

Princípios analíticos da gasometria arterial / Analytical principles of arterial gasometry

Gasometria arterial (GA) é um exame que permite avaliar a condição respiratória e metabólica do paciente, sendo uma das formas mais comuns de investigação clínica em casos emergenciais e de cuidados críticos. É utilizada para medir as concentrações de oxigênio e também para avaliação do distúrbio do equilíbrio ácido-base, da oxigenação do sangue arterial e da ventilação alveolar. O presente estudo tem como objetivo apontar e avaliar os princípios da técnica de gasometria arterial, fases analíticas, principais doenças em que se utiliza o exame e inovações da técnica ao longo dos anos, baseado em dados de artigos científicos e banco de dados do Scielo (Scientific Eletronic Library Online) e Lilacs (Literatura Latino-Americana e do Caribe em Ciências da Saúde). A coleta de sangue arterial para gasometria ocorre através de um procedimento invasivo realizado por intermédio de uma punção arterial. Tal procedimento é executado pelo profissional enfermeiro e exige qualificações técnicas e científicas. O estudo mostrou que as informações acerca do exame constituem uma importante ferramenta para que se possam compreender a complexidade da técnica bem como os distúrbios ácido-base envolvidos na clínica do paciente.

Arterial blood gas (GA) is an exam that allows the assessment of respiratory and metabolic condition, being one of the most common forms of clinical investigation in emergency cases and critical care. It is used to measure oxygen concentrations, as well as for evaluation of acid-base balance disorder, arterial blood oxygenation and alveolar ventilation. This study aims to point out and evaluate the principles of arterial blood gas technique, analytical phases, main diseases in which the examination is used and innovations of the technique over the years, based on data from scientific articles and SciELO database (Scientific Electronic Library Online) and Lilacs (Latin American and Caribbean Health Sciences Literature). The collection of arterial blood for blood gas analysis occurs through an invasive procedure in which an arterial puncture is performed. Such procedure is performed by the professional nurse and requires technical and scientific qualifications. The study showed that the information about the exam is an important tool to understand the complexity of the technique, as well as the acid-base disorders involved in the patient's clinic.

Distúrbios ácido-base nas doenças hepáticas / Acid-base disorders in liver diseases

O objetivo deste artigo foi abordar as controvérsias científicas acerca dos distúrbios ácido-base nas doenças hepáticas. Nos estágios avançados da doença hepática, os distúrbios ácido-base atuam de forma complexa, comprometendo a qualidade de vida do paciente e desafiando o manejo clínico. A literatura apresenta a alcalose respiratória como uma das principais alterações, porém há uma longa discussão sobre o mecanismo fisiopatológico; em especial, citam-se a hipóxia, a hipocapnia e o nível de progesterona. Nas desordens metabólicas, com destaque para a acidose, os estudos apontam principalmente o lactato, os unmeasured ions ou íons não medidos e as alterações hidroeletrolíticas, mas cada componente desse sobressai-se dependendo da fase da doença estudada, compensada ou descompensada. As controvérsias dos distúrbios ácido-base nas doenças hepáticas devem-se ora à complexidade da fisiopatologia da própria doença, ora à necessidade de mais estudos esclarecedores.

The aim of this study is to address the scientific controversy about acid-base disorders in liver diseases. In the end stage of liver diseases, the acid-base disorder has a complex performance, impairing the patient's quality of life and challenging the clinic management. Although the literature shows respiratory alkalosis as one of the main alterations, there is a long discussion about the pathophysiological mechanism, specially regarding hypoxia, hypocapnia, and progesterone level. In metabolic disorders, especially acidosis, the studies mainly indicate the lactate, unmeasured ions, and hydroelectrolytic alterations, but, depending on the disease phase, either compensated or decompensated, each element has a particular action. The controversy about acid-base disorders in liver diseases is associated with the complexity of this condition, as well as with the necessity of more specialized research.

Comparative analysis of acid-base balance in patients with severe sepsis and septic shock: traditional approach vs. physicochemical approach / Análisis comparativo del equilibrio ácido-base en pacientes con sepsis severa y choque séptico: enfoque tradicional versus enfoque físico-químico

Abstract Introduction: The evaluation of metabolism and the diagnostic classification of acid-base disorders has generated great controversy. Acid-base balance (ABB) is approached by means of the physicochemical and Henderson's models. Objective: To compare two diagnostic approaches to ABB in patients with severe sepsis. Materials and methods: Prospective, descriptive study conducted in patients with severe sepsis. ABB was analyzed within the first 24 hours. The diagnosis was compared according to each model and the causes of the disorders were compared according to the physicochemical model. Results: 38 patients were included in the study, of which 21 (55%) were women; the mean age was 49 years, the median APACHE II, 13.28, and the mortality at 28 days, 24.3%. The traditional approach identified 8 patients with normal ABB, 20 with metabolic acidosis, and 10 with other disorders. Based on the physicochemical model, all subjects had acidosis and metabolic alkalosis. Increased strong ion difference (SID) was the most frequently observed disorder. Conclusion: The physicochemical model was useful to diagnose more patients with acid-base disorders. According to these results, all cases presented with acidosis and metabolic alkalosis; the most frequent proposed mechanism of acidosis was elevated SID. The nature of these disorders and their clinical relevance is yet to be established.

Resumen Introducción. Existe gran controversia en la evaluación del componente metabólico y en la clasificación diagnóstica de las alteraciones del equilibrio ácido-base (EAB), el cual se aborda mediante los modelos físico-químico y de Henderson. Objetivo. Comparar dos enfoques diagnósticos del EAB en pacientes con sepsis severa. Materiales y métodos. Estudio descriptivo prospectivo realizado en pacientes con sepsis severa. Se analizó el EAB en las primeras 24 horas; el diagnóstico se comparó según cada modelo y las causas de alteraciones, según el modelo físico-químico. Resultados. Se analizaron 38 pacientes (55% mujeres) con edad promedio de 49 años, mediana APACHE II de 13 y mortalidad a 28 días del 24.3%. El enfoque tradicional identificó 8 pacientes con EAB normal, 20 con acidosis metabólica y 10 con otros trastornos. En el modelo físico-químico, los 38 pacientes tuvieron alteraciones denominadas acidosis y alcalosis metabólica; el aumento de la brecha de iones fuertes (SIG, por su sigla en inglés) fue la más frecuente. Conclusión. El modelo físico-químico diagnosticó más pacientes con alteraciones ácido-base. Según este, todos tuvieron acidosis y alcalosis metabólica y el mecanismo propuesto más frecuente de acidosis fue el SIG elevado. La naturaleza de estas alteraciones y su significado clínico está por definirse.

Nivel del magnesio sérico y su relación con el medio interno en pacientes incidentes al servicio de emergencia médica de un hospital general / Serum magnesium level and its relationship with internal medium in incident patients attending an emerging service of a public hospital

El magnesio participa en múltiples procesos metabólicos y diversos estudios han mostrado que sus niveles alterados se asocian a enfermedades crónicas, alteraciones del medio interno y en unidades de cuidados críticos, está asociado a mayor mortalidad. Objetivos: Determinar la relación entre el nivel de magnesio sérico y las alteraciones del medio interno, en pacientes incidentes al servicio de emergencia de un hospital general de Lima, Perú. Material y métodos: Se incluyeron 201 pacientes con medida del magnesio, creatinina y electrolitos séricos, así como gasometría arterial al ingreso a emergencia del Hospital Cayetano Heredia (HCH) durante los años 2017-2018. Se analizó los valores del magnesio sérico y su asociación con las demás variables electrolíticas y clínicas. Resultados: La edad media de la población fue 60,1 ± 20,1 años. El magnesio sérico promedio fue 2,05±0,57 mg/dl. La hipomagnesemia e hipermagnesemia tuvieron una frecuencia de 20,4% y 21,9% respectivamente. La regresión lineal bivariado mostró correlación del magnesio con la creatinina, el potasio, el fósforo, el pH y HCO -. En la regresión lineal múltiple, sólo el pH se asoció significativamente con el magnesio. En el análisis del magnesio estratificado, el pH mostró la mayor significancia estadística. No hubo relación con la edad, sexo y variables clínicas. Conclusión: El magnesio es una alteración frecuente en la población que acude a la emergencia del HCH y tiene correlación con el bicarbonato, la creatinina, el potasio, el fósforo y el pH; siendo el último la variable más relevante.

Serum magnesium participates in multiple metabolic processes; several studies have shown that alterations in its serum levels are associated with chronic illnesses, alterations in the internal medium and the critical care units these alterations are associated with higher mortality. Objectives: To determine the relationship between serum magnesium level and alterations in the internal medium in incident patients attending an emerging service of a public hospital. Methods: 201 patients were included who had measurements of serum magnesium, creatinine, serum electrolytes and blood gases on admission to the emergency room at Hospital Cayetano Heredia (CHH) between 2017-2018. Results: Mean age was 60.1 ± 20.1 years. Mean serum magnesium level was 2.05 ± 0.57 mg/dl. Hypo and hypermagnesemia were observed in 20.4% and 21.9%, respectively. Bivariate lineal analysis showed correlation of magnesium with creatinine, potassium, phosphorus, pH and bicarbonate. The multiple lineal regression showed association of magnesium with pH only, which was corroborated in the stratified analysis, no association with age, gender and clinical variables was found. Conclusions: Serum magnesium levels are frequently altered in patients attending the emergency room at CHH and correlates with bicarbonate, creatinine, potassium, phosphorus and pH, with the latter being more relevant.

Alterações dos valores gasométricos decorrentes do tempo de exposição da amostra / Changes in gasometric values around the sample exposure time / Enmiendas de los valores gasométricos desde el tiempo de exposición de la muestra

Objetivos: identificar a influência do tempo, no sangue coletado, para os parâmetros gasométricos. Método: pesquisa descritiva, exploratória de abordagem quantitativa. Foram colhidas quatro amostras de sangue arterial de sessenta pacientes internados. As sessenta amostras de sangue arterial foram divididas e identificadas seguindo a sequência: pH, pCO2 e HCO3 respectivamente. Cada amostra (contida em uma seringa) foi processada na máquina para leitura quatro vezes em momentos diferentes. Resultados: foi feita uma comparação de cada um dos principais dados gasométricos, colocando os resultados de cada tempo pré-determinado, revelando as alterações ocorridas no tempo entre a coleta e a realização do exame de gases. O pH apresentou alterações tendendo para uma acidose, o pCO2 houve um ganho na sua concentração, o HCO3 houve queda na média de sua concentração Conclusão: a amostra para gasometria arterial se apresenta instável e de rápida mudança nos valores dos gases no decorrer do tempo.(AU)

Objectives: identify the influence of time, in the blood collected, for the gasometrical parameters. Method: descriptive, exploratory, quantitative approach research Four arterial blood samples were collected from sixty inpatients. Sixty arterial blood samples were divided and identified following the sequence: pH, pCO2 and HCO3 respectively. Each sample (contained in a syringe) was processed in the machine to read four times at different times. Results: a comparison of each of the main gasometrical data was made, placing the results of each predetermined time, revealing the changes occurred in the time between the collection and the gas examination. The pH presented alterations tending to an acidosis, the pCO2 had a gain in its concentration, the HCO3 had a decrease in the mean of its concentration Conclusion: the sample for arterial blood gases shows an unstable and rapidly changing gas values over time.(AU)

Objetivos: identificar la influencia del tiempo, en la sangre recogida, para los parámetros gasométricos. Método: investigaccíon, descriptiva, exploratória de enfoque cuantitativo. Se tomaron cuatro muestras de sangre arterial de sesenta pacientes internados. Las sesenta muestras de sangre arterial fueron divididas e identificadas siguiendo la secuencia: pH, pCO2 y HCO3 respectivamente. Cada muestra (contenida en una jeringa) fue procesada en la máquina para lectura cuatro veces en momentos diferentes. Resultados: se hizo una comparación de cada uno de los principales datos gasométricos, colocando los resultados de cada tiempo predeterminado, revelando los cambios ocurridos en el tiempo entre la recolección y la realización del examen de gases. El pH presentó alteraciones tendientes a una acidosis, el pCO2 hubo una ganancia en su concentración, el HCO3 hubo caída en la media de su concentración. Conclusión: la muestra para gasometría arterial se presenta inestable y de rápido cambio en los valores de los gases en el transcurso del tiempo.(AU)

Experimental protocol for metabolic acidosis induction by intravenous administration of hydrochloric acid in sheep / Protocolo de indução experimental de acidose metabólica por administração intravenosa de ácido clorídrico em ovinos

The aim of this study was to assess the magnitude and duration of blood and urine changes and the side effects of hyperchloremic acidosis induced by the intravenous administration of hydrochloric acid in sheep. Five healthy, crossbred adult ewes, with a mean body weight of 44±2.9kg were used. The hydrochloric acid solution was administered intravenously at a rate of 25mL/kg/h for 4 hours continuously. Venous blood and urine samples were collected and pH values, blood carbon dioxide partial pressure, bicarbonate, base excess, strong ion difference, anion gap, total concentration of nonvolatile buffers, creatinine, plasma L-lactate, plasma and urine sodium, potassium, and chloride were determined. The experimental protocol induced severe hyperchloremic acidosis at the end of the infusion, with a decreased plasma strong ion difference. The fractional excretion of sodium and chloride remained increased during 4 hours after the infusion. Aciduria was observed at approximately 24 hours. Twenty-four hours after the infusion, the animals showed mild and compensated metabolic acidosis. This protocol was effective in inducing severe and long-lasting hyperchloremic acidosis and did not cause serious side effects. Therefore, this protocol can be used safely in adult sheep for studies on the treatment of this condition.(AU)

O objetivo deste estudo foi avaliar a magnitude e a duração das alterações sanguíneas e urinárias, bem como os efeitos colaterais da acidose hiperclorêmica induzida por administração intravenosa de ácido clorídrico, em ovinos. Foram utilizadas cinco ovelhas mestiças, adultas, sadias, com peso médio de 44±2,9kg. A solução de ácido clorídrico foi administrada por via intravenosa, na velocidade de 25mL/kg/h, totalizando quatro horas de administração contínua. Amostras de sangue venoso e de urina foram colhidas, e determinaram-se os valores de pH, pressão parcial de dióxido de carbono, bicarbonato, excesso de bases, diferença dos íons fortes, ânion-gap, creatinina, lactato L, sódio, potássio e cloro. O protocolo de indução experimental foi capaz de induzir acidose hiperclorêmica grave ao término da infusão, com diminuição da diferença dos íons fortes plasmáticos. Houve aumento da excreção fracionada de sódio e cloro por até quatro horas após o término da infusão. A acidúria foi observada por cerca de 24 horas. Após 24 horas do início da infusão, os animais apresentaram acidose metabólica leve e compensada. Esse protocolo foi eficaz na indução da acidose hiperclorêmica grave e duradoura e não causou efeitos colaterais. Conclui-se que o protocolo pode ser usado com segurança em ovelhas adultas, para estudos sobre tratamento dessa condição.(AU)

Concordance of the ions and GAP anion obtained by gasometry vs standard laboratory in critical care. / Concordancia de los iones y anión GAP obtenidos mediante gasometría vs laboratorio estándar en cuidados críticos.

OBJECTIVE: To evaluate the differences observed in ion and GAP anion determinations obtained by point-of-care (POC) blood gas versus laboratory biochemical testing, and to analyze the possible errors according to the limits of normality. MATERIAL AND METHODS: A descriptive, cross-sectional retrospective study was made to assess concordance between two diagnostic tests in patients admitted to the Critical Care Unit of Ourense University Hospital Complex (Spain), between July and November 2015, involving at least one coinciding biochemical test and POC determination. Patients under 18years of age were excluded. RESULTS: A total of 1,073 samples were analyzed. Lin's concordance correlation coefficients for sodium, potassium and chlorine were 0.87, 0.84 and 0.72, respectively. Kappa concordance of the normality limits for sodium, potassium and chlorine was 0.63, 0.74 and 0.32. The results indicated poor correlation of the anion GAP and null concordance between POC and biochemical testing, including the value corrected for albumin. CONCLUSIONS: Poor concordance was observed between the ion values as determined by biochemistry and blood gases; the two methods are therefore not interchangeable. Kappa agreement with normality limits was good for sodium and potassium, and weak for chlorine. Possible validity was noted in orienting the classification within the ion limits, with the exception of chlorine. No agreement was recorded in relation to the anion GAP, even that corrected for albumin.

Trastornos del equilibrio Acido Base / Balance disorders Acido Base

Las alteraciones del equilibro ácido base pueden ocurrir con carácter primario pero, en general, derivan de la complicación de una enfermedad preexistente. Por ello, no es raro que una caracterización correcta del trastonno ácido base sea la pista causal insospechado hasta entonces. La frecuencia de estas anomalias es eelevada, especialmente en pacientes hospitalizados y su apración tiene claras implicaciones pron´soticas. La alteraciones mixtas del equilibrio acido básico, definidas por la presencia simultánea de dos o más trastornos, son también muy frecuentes, especialmene en determinadas situaciónes

Gasometría arterial en adultos jóvenes en una altura promedio de 1605 msnm. Armenia, Colombia 2016 / Arterial blood gas in young adults at an average altitude of 1605-m above sea level: Armenia, Colombia 2016

Abstract Introduction: Arterial blood gas measurement is an essential quick test in clinical practice to evaluate oxygenation and for the identification and diagnosis of acid-base and metabolic disorders. Arterial blood gas reference values vary as a result of altitude changes associated with barometric pressure (bp). Objectives: To determine the PaCO2, PaO2, HCO3, and SaO2% values for a young population without lung disease in a city located at an average altitude of 1605-m above sea level and a bp of 624mm Hg. Materials and methods: Descriptive cross-sectional study in 137 arterial blood gas samples from male and female healthy volunteers aged between 18 and 40 years old. An COPD® point of care blood analysis portable system was used for readings with single-use individual cards. Results and conclusion: The 95% confidence interval (CI) limits were pH between 7.43 and 7.45, PaO2 between 86.23 and 88.83, PaCO2 between 32.64 and 33.87, and SatO2% between 97.13 and 97.38. No gender or age differences were found. When comparing the findings against other trials conducted over 2640-m above sea level, some differences were identified: PaO2 between 18 and 26 mm Hg lower at an altitude of 1605 m (Armenia), PCO2 between 2.0 and 2.7 mm Hg higher in Armenia, and also the SaO2% was between 3.6% and 6.2% higher. PaO2 and HCO3~ were mildly higher as compared with a study conducted in Medellin. The oxygenation index (PaO2/FIO2) was 416.83 (95% CI 410.63-23.03)- as expected-considering the difference in altitude due to the geographic location, pursuant to the referenced studies.

Resumen Introducción: La gasometría arterial es una prueba rápida indispensable en la práctica clínica para la evaluación de la oxigenación y para identificar y diagnosticar desórdenes metabólicos, por alteración en el equilibrio ácido base. Los valores de referencia varían por los cambios de altitud relacionados con la presión barométrica (pb). Objetivos: Determinar los valores de PaCO2, PaO2, HCO3- y SaO2% en población joven sin enfermedad pulmonar en una ciudad con altura promedio de 1605 msnm y pb de 624 mmHg. Materiales y métodos: Estudio descriptivo transversal en 137 muestras de sangre arterial de voluntarios sanos de 18 a 40 años ambos sexos. Para la lectura se utilizó un equipo portátil "point of care en sangre EPOC®" con tarjetas individuales de un solo uso. Resultados y conclusiones: Los límites de intervalos de confianza del 95% de las medias fueron: pH entre 7,43 y 7,45; PaO2 86,23 y 88,83; PaCO2 32,64 y 33,87 y SaO2% 97,13 y 97,38. No se encontraron diferencias por sexo ni edad. Al comparar los hallazgos con estudios realizados por encima de los 2640 msnm, se observaron diferencias: PaO2 entre18y 26 mm de Hg menor que a 1605 msnm (Armenia), PCO2 entre 2,0 y 2,7 mm Hg mayor en Armenia al igual que la SaO2% entre 3,6 y 6,2%. La PaO2 y el HCO3- fueron levemente mayores que un estudio realizado en Medellín. El índice de oxigenación (PaO2/FIO2) fue de 416,83 (IC 95% 410,63-423,03), resultados esperados, teniendo en cuenta la diferencia de altura por la ubicación geográfica, según los estudios referenciados.

One-step laparoscopic abomasopexy versus abomasopexy via right paralumbar fossa to treat left abomasal displacement in dairy cows / Abomasopexia por laparoscopia em um passo em comparação à abomasopexia via laparotomia pelo flanco direito no tratamento do deslocamento de abomaso à esquerda em vacas leiteiras

This study aimed to compare the clinical and metabolic results obtained by use of one-step laparoscopic abomasopexy and right paralumbar fossa abomasopexy for the treatment of left displaced abomasum in dairy cows. Thirty Holstein-Friesian dairy cows were randomly placed in two groups: G1, with 15 animals treated by one-step laparoscopic abomasopexy; and G2, with 15 animals treated by right paralumbar fossa ventral abomasopexy. Concentrations of sodium, potassium, chloride, bicarbonate, base excess (BE), pH, partial pressure of carbon dioxide (pCO2) strong ion difference (SID), anion gap (AG), glucose, β-hydroxybutyrate (BHBA) and non-esterified fatty acids (NEFA) were measured before (M0) and 24 (M1), 48 (M2) and 72 (M3) hours following surgery. Laparotomy was statistically faster than laparoscopy. Hypochloremia was observed only in G2 at M0. Hypokalemia and hypocalcemia were observed in both groups at M0, increasing after surgery. Metabolic alkalosis in both groups before surgery was characterized by high bicarbonate, pCO2, and BE, which decreased in subsequent time points, as well as blood pH. Glucose was statistically increased and NEFA and BHBA were statistically decreased in G2 compared to G1. In G1, NEFA and BHBA decreased significantly following surgery. Both surgical techniques restored abomasal flow and feed intake in both groups. Based in acid-base status, one-step laparoscopy showed no additional advantage in comparison with abomasopexy via right paralumbar fossa.(AU)

Este estudo objetivou comparar as técnicas de abomasopexia por laparoscopia em um passo e abomasopexia por laparotomia pelo flanco direito, no tratamento do deslocamento de abomaso à esquerda (DAE) em vacas leiteiras quanto a recuperação clínica no pós-operatório, utilizando parâmetros clínicos, metabólicos e eletrolíticos. Trinta vacas Holandesas preto e brancas foram distribuídas de forma aleatória em dois grupos: G1 com 15 animais tratados pela técnica de abomasopexia em um passo; e G2, com 15 animais tratados pela abomasopexia por laparotomia pelo flanco direito. Foram mensuradas as concentrações séricas de sódio, potássio, cloro, bicarbonato, excesso de base (BE), pH sanguíneo, pressão parcial de gás carbônico (pCO2), diferença de íons fortes (SID), ânion gap AG), glicose, β-hidroxibutirato (BHBA) e ácidos graxos não esterificados (NEFA). As variáveis foram mensuradas antes da operação e 24, 48 e 72 horas após operação. A laparotomia foi estatisticamente mais rápida do que a laparoscopia no tratamento do DAE. Hipocloremia foi observada somente nas vacas do G2 antes da cirurgia. Alcalose metabólica em ambos os grupos antes da operação foi caracterizada pelo aumento do bicarbonato, pCO2 e BE, os quais diminuíram significativamente nos momentos subsequentes, assim como o pH sanguíneo. A concentração de glicose apresentou aumento significativo no G2 em comparação ao G1, enquanto o BHBA e o NEFA estavam estatisticamente diminuídos. Ambas as técnicas restauraram o fluxo abomasal e o consumo de alimentos em ambos os grupos. Baseado no equilíbrio ácido-base, a técnica de laparoscopia não demonstrou vantagens sobre a técnica cirúrgica tradicional.(AU)

A velocidade de infusão da solução poli-iônica intravenosa contendo 84mEq/L de lactato determina a intensidade do efeito alcalinizante em equinos / The intravenous polyionic solution with 84mEq/L of lactate infusion rate determines the intensity of the alkalizing effect in horses

O objetivo deste trabalho foi verificar os efeitos da solução poli-iônica intravenosa contendo 84mEq/L de lactato (L84) sobre os equilíbrios hidroeletrolítico e ácido-base de equinos, quando administrada de forma rápida ou lenta. Cinco equinos sadios adultos receberam a infusão contínua intravenosa da L84, em volume correspondente a 10% do peso corporal, em duas ocasiões: a) infusão rápida (16,66mL/kg/h) durante seis horas; b) infusão lenta (8,33mL/kg/h) durante 12 horas. Amostras de sangue venoso foram colhidas ao início da infusão (hora zero) e três, seis, nove, 12 e 24 horas após, e amostras de urina nas horas zero, seis, 12 e 24. Determinaram-se pH (sanguíneo e urinário), pCO2, HCO3 -, BE, PPT, lactato L, Na+, K+, Cl-, AG, SID, Atot, VVP, densidade urinária e excreções fracionadas urinárias de lactato L, Na+, K+ e Cl-. A L84 provoca efeito alcalinizante iatrogênico de menor magnitude quando administrada de forma lenta, porque os mecanismos renais, atuantes durante o período de infusão, promovem a correção gradativa do desequilíbrio. Pode-se concluir que a infusão de forma lenta da solução L84 em equinos é recomendável nos casos em que se suspeite de acidose metabólica e não seja possível quantificar o grau do desequilíbrio.(AU)

The aim of this study was to investigate the effects of an intravenous polyionic solution containing 84mEq/L of lactate (L84) on the hydroelectrolyte and acid-base balances when administered quickly or slowly in horses. Five healthy adult horses received the L84 solution, in a volume corresponding to 10% of BW, by continuous intravenous infusion, in two instants: a) rapid infusion (16.66mL/kg/h) during 6 hours; b) slow infusion (8.33mL/kg/h) during 12 hours. Venous blood samples were taken at the beginning of the infusion (hour 0) and 3, 6, 9, 12, and 24 hours after. Urine samples were taken at 0, 6, 12, and 24h. pH (blood and urine), pCO2, HCO3-, BE, TPP, L-lactate, Na+, K+, Cl-, AG, SID, Atot, PVV, urine specific gravity, and L-lactate, Na+, K+, and Cl- renal fractional clearance were determined. The L84 solution causes lower magnitude alkalizing effect when administered slowly, due to the gradual correction of the iatrogenic imbalance by the kidneys during the infusion period. The L84 solution infused at a low rate in horses could be recommended in cases where metabolic acidosis is suspected and it is not possible to quantify the imbalance degree.(AU)

Brecha de iones fuertes y su cinética de aclaramiento como marcador de mortalidad en pacientes con choque séptico / Strong ion gap and its clearance kinetics as a mortality marker in septic shock patients / Hiato de íons fortes e sua cinética de aclaramento como marcador da mortalidade em pacientes com choque séptico

Resumen: Introducción: Existe evidencia clínica de que la brecha de iones fuertes obtenida por el método de Stewart de equilibrio ácido-base es mejor predictora de mortalidad que los parámetros tradicionales en algunos pacientes críticamente enfermos. Objetivo: Evaluar la cinética de depuración de la brecha de iones fuertes en individuos con choque séptico durante las primeras 48 horas de estancia en la unidad de cuidados intensivos. Material y métodos: Se trata de un estudio retrospectivo observacional, con datos obtenidos del expediente clínico, realizado en una unidad de cuidados intensivos adultos en un hospital privado de la ciudad de Monterrey, Nuevo León. Se evaluaron variables demográficas, así como datos obtenidos de gasometrías y química sanguínea al ingreso, a las 24 y 48 horas posteriores, para calcular parámetros tradicionales del equilibrio ácido-base y los obtenidos por el método de Stewart. Se calculó también la cinética de eliminación de dichos parámetros para evaluar sus cambios a través del tiempo y su relación con la mortalidad. Resultados: Se estudiaron 91 personas con choque séptico entre junio de 2014 y junio de 2016, con una mortalidad de 28.6%. La depuración de lactato, brecha aniónica corregida y brecha de iones fuertes a 48 horas no fueron capaces de predecir mortalidad, aunque sí los niveles individuales de dichos parámetros a las 48 horas. El mejor predictor de mortalidad fue AGCOR a 48, con un área bajo la curva ROC de 0.71805, contrario a la brecha de iones fuertes (SIG por sus siglas en inglés) a 48 horas, con un área bajo la curva ROC de 0.67367. Conclusiones: Los cambios a través de las primeras 48 horas de la brecha de iones fuertes son asociados a mortalidad, pero no aportan mayor beneficio que los parámetros tradicionales en sujetos con choque séptico.

Abstract: Introduction: There is clinical evidence that the strong ion gap obtained by Stewart's acid-base approach is a better predictor of mortality than those obtained by the traditional approach in some critically ill patients. Objective: To evaluate the strong ion gap clearance kinetics in patients with septic shock during the first 48 hours in the intensive care unit. Material and methods: A retrospective, observational study obtained from a patient database in a private intensive care unit in Monterrey, Nuevo León. Patient's demographics were analyzed, along with data collected from their laboratory work at admission and at 24 and 48 hours to calculate traditional acid-base parameters and parameters obtained by the Stewart's method. Clearance at 48 hours was also calculated to track their changes over time and to evaluate their relation to patient mortality. Results: Data from 91 patients with septic shock admitted between June 2014 and June 2016 were studied, with a 28.6% mortality rate. Lactate clearance, corrected anion gap clearance and strong ion gap clearance at 48 hours were not related to patient mortality, although their individual values at 48 hours were able to predict mortality. The best predictor of mortality was AGCOR at 48, with an area under the ROC curve of 0.71805, compared with an area under the ROC curve of 0.67367 for SIG at 48 hours. Conclusions: Strong ion gap changes over the first 48 hours were associated with mortality; however, they do not offer any advantage over traditional acid-base parameters in patients with septic shock.

Resumo: Introdução: Existe evidência clínica que o hiato de íons fortes, obtido pelo método de Stewart de ácido-base, é melhor preditor de mortalidade que os parâmetros tradicionais em alguns pacientes graves. Objetivo: Avaliar a cinética de depuração do hiato de íons fortes em pacientes com choque séptico durante as primeiras 48 horas de estadia na unidade de terapia intensiva. Material e métodos: Um estudo retrospectivo, observacional com dados obtidos a partir do prontuário médico. Realizado na UTI de um hospital particular na cidade de Monterrey, em Nuevo León. Foram avaliadas as variáveis ​​demográficas e os dados obtidos a partir da gasometria e química sanguínea na admissão, 24 horas e 48 horas posteriores para calcular os parâmetros tradicionais do equilíbrio ácido-base e os obtidos pelo método de Stewart. Calculou-se também as cinéticas de eliminação destes parâmetros e assim avaliar as alterações ao longo do tempo e a sua relação com a mortalidade. Resultados: Foram estudados 91 pacientes com choque séptico entre junho de 2014 e junho de 2016, com uma taxa de mortalidade de 28.6%. A depuração de lactato, hiato aniônico corrigido e hiato de íons fortes às 48 horas não foram capazes de prever a mortalidade, se bem que previram os níveis individuais de estes parâmetros às 48 horas. O melhor preditor de mortalidade foi AGCOR às 48 com uma área sob a curva ROC de 0.71805, contrário ao SIG às 48 horas com uma área sob a curva ROC de 0.67367. Conclusões: As alterações através das primeiras 48 horas do hiato de íons fortes está associada com a mortalidade, mas não fornecem maior benefício que os parâmetros tradicionais em pacientes com choque séptico.

Estratégias para minimizar os efeitos de um ambiente térmico adverso para frangos de corte / Strategies to minimize the adverse thermal environment in broiler chickens

O calor limita a produção de frangos de corte. Este trabalho avaliou as interações entre o termocondicionamento precoce (TCP) e o uso do equilíbrio eletrolítico (EE) sobre o desempenho e as características da carcaça das aves. Assim, o balanço eletrolítico (BE = Na + K - Cl) foi ajustado em 350mEq/kg, e a relação eletrolítica (K+Cl)/Na em 3:1, pelo programa PPFR. O experimento foi realizado no setor de Zootecnia da Faculdade de Medicina Veterinária de Araçatuba/Unesp. Alojaram-se 240 pintos machos de um dia de idade, linhagem Cobb-500(r), em bateria metálica com 24 divisões e aquecimento elétrico automático. O delineamento experimental foi inteiramente ao acaso, em arranjo fatorial 2x2, totalizando quatro tratamentos com seis repetições e 10 aves por parcela experimental. O TCP ocorreu no quinto dia de idade, por 24 horas, a 36,5°C, em metade do lote. Posteriormente, as aves foram transferidas para um galpão climatizado e alojadas em boxes, da mesma forma que a outra parcela que não passou pelo TCP. Avaliaram-se os efeitos do estresse calórico crônico (seis horas a 32°C) aplicado do 35º ao 39º dia de idade. Foram monitoradas a temperatura e a umidade do ar, bem como a temperatura de globo negro. Alimentação e água foram fornecidas ad libitum. Calcularam-se os dados de desempenho zootécnico e a taxa de mortalidade das aves. Submeteram-se os resultados à análise de variância e à comparação de médias pelo teste de Tukey. Não houve interação entre o TCP e o EE sobre o desempenho e as características da carcaça das aves. As estratégias, TCP e EE, mostraram-se ineficazes para amenizar os efeitos do estresse calórico crônico em frangos de corte.

Heat limits the production of broilers. This study evaluated the interactions between early thermal conditioning (ETC) and the electrolyte balance (EB) on performance and characteristics of birds' carcass. Thus, the electrolyte balance (BE = Na+ + K+ - Cl-), was set to 350mEq/kg and electrolyte ratio (K+ + Cl-)/ Na+ in 3:1 by the PPFR program. The experiment was carried out at the Animal Science department of the Faculty of Veterinary Medicine of Araçatuba / UNESP. 240 1 day old Cobb-500(r) male chicks were used, lodged in metal batteries with 24 divisions and automatic electric heating. The experimental design was completely randomized in a 2x2 factorial arrangement, totaling 4 treatments with 6 replicates and 10 birds per experimental plot. ETC occurred on the 5th day of age for 24 hours at 36.5°C in half of the batch. Subsequently, these birds were transferred to an environmentally controlled shed and were grown in boxes, in the same way as the other half that had not received ETC treatment. The effects of chronic heat stress (6 hours at 32°C) applied from the 35th through the 39th day of age were evaluated. Temperature and air humidity, as well black-globe temperature were monitored electronically. Food and water were provided ad libitum. The growth performance data and the mortality rate of birds were measured. The results were subjected to analysis of variance and comparison of means was done by Tukey test. There were no interaction effects between ETC and EB on performance and characteristics of birds' carcass. The ETC and EB strategies proved to be ineffective to mitigate the effects of chronic heat stress in broilers.