Effects of higher dietary acid load: a narrative review with special emphasis in children.

Metabolic effects of high diet acid load (DAL) have been studied for years in adults, although only recently in children. Contemporary diets, especially those of Western societies, owe their acidogenic effect to high animal-origin protein content and low contribution of base-forming elements, such as fruits and vegetables. This imbalance, where dietary acid precursors exceed the body's buffering capacity, results in an acid-retaining state known by terms such as "eubicarbonatemic metabolic acidosis," "low-grade metabolic acidosis," "subclinical acidosis," or "acid stress". Its consequences have been linked to chronic systemic inflammation, contributing to various noncommunicable diseases traditionally considered more common in adulthood, but now have been recognized to originate at much earlier ages. In children, effects of high DAL are not limited to growth impairment caused by alterations of bone and muscle metabolism, but also represent a risk factor for conditions such as obesity, insulin resistance, diabetes, hypertension, urolithiasis, and chronic kidney disease (CKD). The possibility that high DAL may be a cause of chronic acid-retaining states in children with growth impairment should alert pediatricians and pediatric nephrologists, since its causes have been attributed traditionally to inborn errors of metabolism and renal pathologies such as CKD and renal tubular acidosis. The interplay between DAL, overall diet quality, and its cascading effects on children's health necessitates comprehensive nutritional assessments and interventions. This narrative review explores the clinical relevance of diet-induced acid retention in children and highlights the potential for prevention through dietary modifications, particularly by increasing fruit and vegetable intake alongside appropriate protein consumption.

Consensus of the Brazilian association of hematology, hemotherapy and cellular therapy on patient blood management: Anemia tolerance mechanisms.

Understanding the physiological concepts of oxygen delivery is essential to discern the mechanisms that influence its increase, reduction or maintenance in the body. This text explores the different mechanisms that help maintain oxygen delivery even in the face of reduced hemoglobin levels. Adequate oxygen delivery ensures tissue and metabolic balance, which is crucial to avoid harmful consequences such as metabolic acidosis and cellular dysoxia. The complex interaction between variables such as cardiac output, hemoglobin and heart rate (HR) plays a fundamental role in maintaining oxygen delivery, allowing the body to temporarily adjust to situations of anemia or high metabolic demand. It is important to emphasize that blood transfusions should not be based on fixed values, but rather on individual metabolic needs. Strategies to reduce myocardial consumption and monitor macro and micro hemodynamics help in making rational decisions. Individualizing treatment and considering factors such as blood viscosity in relation to the benefits of transfusion are increasingly relevant to optimize therapy and minimize risks, especially in complex clinical scenarios, such as neurocritical patients and trauma victims.

Serum bicarbonate levels and kidney outcomes in critically ill patients: a prospective cohort study.

BACKGROUND: The interplay between serum bicarbonate levels and kidney outcomes is not fully understood. We conducted a prospective cohort study in three intensive care units (ICUs) to evaluate the association of serum bicarbonate levels with acute kidney injury (AKI) and kidney function recovery in critically ill patients. METHODS: A prospective cohort study in three intensive care units (ICUs) was performed. The serum bicarbonate level in the first 24 h after ICU admission was categorized as low (< 22 mEq/L), normal (22-26 mEq/L), or high (> 26 mEq/L). Serum creatinine (SCr) levels according to the KDIGO AKI guideline were used for defining AKI within the first 7 days of ICU stay. At ICU admission, SCr ≥ 1.1 for women and ≥ 1.3 mg/dL for men were indicative of impaired kidney function. Mortality outcome was tracked up to 28 days, and kidney function recovery was assessed at hospital discharge. RESULTS: A total of 2732 patients (66 ± 19 years and 55% men) were analyzed, with 32% having impaired kidney function at ICU admission. Overall, 26% of patients had low bicarbonate levels, while 32% had high bicarbonate levels. Notably, patients with preserved kidney function showed a lower prevalence of low bicarbonate levels compared to those with impaired kidney function (20% vs. 39%, p < 0.001), while higher rates were observed for high bicarbonate (35% vs. 24%, p < 0.001). Compared with patients with normal serum bicarbonate levels, those with low bicarbonate were 81% more likely to develop AKI (OR = 1.81; 95% CI 1.10-2.99), whereas those with high bicarbonate were 44% less likely (OR = 0.56; 95% CI 0.32-0.98) in the adjusted model for confounders. Neither those with high nor low serum bicarbonate levels were associated with an increased risk of mortality (HR = 1.03; 95% CI 0.68-1.56 and 0.99; 95% CI 0.68-1.42, respectively). In subgroup analysis, regardless of the kidney function at ICU admission, serum bicarbonate levels were not associated with the development of AKI and all-cause mortality. Regarding kidney function recovery, higher non-recovery rates were found for those with low bicarbonate. CONCLUSION: In critically ill ICU patients, low bicarbonate levels were associated with the more likely development of AKI and subsequent non-recovery of kidney function, while high bicarbonate levels showed no such association. Therefore, low bicarbonate levels may be considered a risk factor for adverse kidney outcomes in critically ill patients.

Consensus of the Brazilian association of hematology, hemotherapy and cellular therapy on patient blood management: Anemia tolerance mechanisms

Abstract Understanding the physiological concepts of oxygen delivery is essential to discern the mechanisms that influence its increase, reduction or maintenance in the body. This text explores the different mechanisms that help maintain oxygen delivery even in the face of reduced hemoglobin levels. Adequate oxygen delivery ensures tissue and metabolic balance, which is crucial to avoid harmful consequences such as metabolic acidosis and cellular dysoxia. The complex interaction between variables such as cardiac output, hemoglobin and heart rate (HR) plays a fundamental role in maintaining oxygen delivery, allowing the body to temporarily adjust to situations of anemia or high metabolic demand. It is important to emphasize that blood transfusions should not be based on fixed values, but rather on individual metabolic needs. Strategies to reduce myocardial consumption and monitor macro and micro hemodynamics help in making rational decisions. Individualizing treatment and considering factors such as blood viscosity in relation to the benefits of transfusion are increasingly relevant to optimize therapy and minimize risks, especially in complex clinical scenarios, such as neurocritical patients and trauma victims.

Renal toxicity caused by diethylene glycol: an overview.

Diethylene glycol (DEG) is nephrotoxic, potentially resulting in high morbidity and mortality. Its main nephrotoxic by-product is diglycolic acid (DGA). This narrative overview summarizes selected literature with a focus on clinical findings, pathophysiology, diagnosis including morphological features of renal biopsies, and management. The kidney injury in DEG poisoning is secondary to proximal tubular necrosis caused by DGA. Marked vacuolization and edema of epithelial cells obstruct the lumen, reducing urine flow and, consequently, resulting in anuria and uremia. The clinical alterations due to DEG poisoning are dose-dependent. Patients may present with gastrointestinal symptoms and anion gap metabolic acidosis, followed by renal failure, and, later, encephalopathy and neuropathy. Although this three-phase pattern has been described, signs and symptoms may be overlapping. Data about DEG intoxication is scarce. Sometimes the diagnosis is challenging. The management includes supportive care, gastric decontamination, correction of acid-base disorders, and hemodialysis. The understanding of the metabolic processes related to DEG poisoning may contribute to its management, preventing death, serious sequels, or irreversible lesions.

Effects of pre-analytical sample care and analysis methodology on measures of metabolic acidosis in hemodialysis patients.

INTRODUCTION: We evaluated the effects of pre-analytical care on total carbon dioxide (tCO2 ) in hemodialysis patients, as calculated by blood gas analysis (ctCO2 ) or measured by an enzymatic assay (mtCO2 ). METHODS: Blood samples were collected via vascular access before dialysis sessions. For blood gas analysis, eight aliquots were collected, refrigerated or non-refrigerated, and analyzed at 0, 4, 8, and 24 h after collection. A blood sample was then collected for the enzymatic method and distributed into 14 aliquots. Half of the aliquots were refrigerated. The samples analyzed at time point 0 were centrifuged immediately. The remaining aliquots of both the refrigerated and non-refrigerated clusters were centrifuged before storage. Samples were analyzed at 4, 8, and 24 h post-collection. FINDINGS: By blood gas analysis, no significant change was found in bicarbonate values over time, either in the non-refrigerated or refrigerated samples. ctCO2 values during the experiment showed a minor but statistically significant increase of questionable clinical relevance in both non-refrigerated and refrigerated aliquots. In the enzymatic assay, the reduction in mtCO2 levels during the experiment was negligible. The median absolute reductions at the end of the experiment were 1.77, 1.21, 1.04, and 1.12 mmol/L for the non-centrifuged/non-refrigerated, centrifuged/non-refrigerated, non-centrifuged/refrigerated, and centrifuged/refrigerated aliquots, respectively. DISCUSSION: Our results suggest that measured or calculated tCO2 levels of capped and cooled samples are adequate for analyzing the acid-base status of hemodialysis patients, even when such determination is not performed immediately after collection.

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.

Effects of total parenteral nutrition associated with glutamine, enteral fluid therapy with or without glutamine, and fluid therapy on the acid-base and electrolyte balance of horses starved after exploratory laparotomy.

This study aimed to evaluate the effects of the total parenteral nutrition associated with glutamine, enteral fluid therapy with or without glutamine, and fluid therapy on the acid-base and electrolyte balance of horses starved after exploratory laparotomy. Sixteen healthy male and female adult horses of mixed breed, aged between 4 and 14 years, and having a mean body weight of 248.40 ± 2.28 kg and a body score index of 3-4 (scale of 1-5) were divided into four groups with four animals per group. After an adaptation period of 30 days, they were randomly divided into four experimental groups: enteral fluid therapy, enteral fluid therapy associated with glutamine, total parenteral nutrition associated with glutamine, and parenteral fluid therapy. The experiment was further divided into two phases: Phase 1 and Phase 2. In Phase 1, an exploratory laparotomy was performed, treatments were administered to the groups and the horses received no food or water other than those given to their respective groups. In Phase 2, the animals were re-fed. Each phase had a total duration of 144 h. Venous blood samples were collected every 24 h throughout the experimental period for blood gas and electrolyte analyses. The following parameters were evaluated: pH, partial pressure of carbon dioxide, total carbon dioxide, bicarbonate, base shift, anion gap, sodium, potassium, chloride, total calcium and magnesium. Completely randomized designs with a 4 × 7 factorial scheme (groups × harvest time) in Phase 1 and a 4 × 6 factorial scheme (groups × harvest time) in Phase 2 were used with four replications. All values were considered significant when p≤0.05 (95% probability). Blood pH, bicarbonate concentration, and base shift in the PARGL group decreased, indicating metabolic acidosis. Changes in the acid-base and electrolyte balance were more intense in the PARGL group than in the other groups. These results demonstrated the need to monitor blood gas and electrolyte balance in horses with food restriction under nutritional support or prolonged fluid therapy so that such changes are promptly corrected.

Este estudo teve como objetivo avaliar os efeitos da nutrição parenteral total associada à glutamina, fluidoterapia enteral com ou sem glutamina e fluidoterapia no equilíbrio ácido-base e eletrolítico de equinos submetidos à inanição após laparotomia exploratória. Dezesseis cavalos adultos saudáveis, machos e fêmeas, sem raça definida, com idade entre 4 e 14 anos, com peso corporal médio de 248,40 ± 2,28 kg e índice de escore corporal de 3 a 4 (escala de 1 a 5) foram divididos em quatro grupos com quatro animais por grupo. Após um período de adaptação de 30 dias, foram divididos aleatoriamente em quatro grupos experimentais: fluidoterapia enteral, fluidoterapia enteral associada à glutamina, nutrição parenteral total associada à glutamina e fluidoterapia parenteral. O experimento foi ainda dividido em duas fases: Fase 1 e Fase 2. Na Fase 1, os tratamentos foram administrados aos grupos, a laparotomia exploratória foi realizada e os cavalos não receberam alimentos ou água além daqueles dados aos seus respectivos grupos. Na Fase 2, os animais foram realimentados. Cada fase teve uma duração total de 144 h. Amostras de sangue venoso foram coletadas a cada 24 h durante todo o período experimental para análises gasométricas e eletrolíticas. Foram avaliados os seguintes parâmetros: pH, pressão parcial de dióxido de carbono, dióxido de carbono total, bicarbonato, desvio de base, anion gap, sódio, potássio, cloreto, cálcio total e magnésio. Delineamentos inteiramente casualizados com esquema fatorial 4 × 7 (grupos × época de colheita) na Fase 1 e esquema fatorial 4 × 6 (grupos × época de colheita) na Fase 2 foram utilizados com quatro repetições. Todos os valores foram considerados significativos quando p≤0,05 (95% de probabilidade). O pH sanguíneo, a concentração de bicarbonato e o desvio de base no grupo PARGL diminuíram, indicando acidose metabólica. As alterações no equilíbrio ácido-base e eletrolítico foram mais intensas no grupo PARGL do que nos outros grupos. Esses resultados demonstraram a necessidade de monitorar o equilíbrio hemogasométrico e eletrolítico em equinos com restrição alimentar sob suporte nutricional ou fluidoterapia prolongada para que tais alterações sejam prontamente corrigidas.

Airflow restriction mask induces greater central fatigue after a non-exhaustive high-intensity interval exercise.

The airflow restriction mask (ARM) is a practical and inexpensive device for respiratory muscle training. Wearing an ARM has recently been combined with high-intensity interval exercise (HIIE), but its effect on neuromuscular fatigue is unknown. The present study investigated the effects of ARM wearing on neuromuscular fatigue after an HIIE session. Fourteen healthy men performed two HIIE sessions (4 × 4 min at 90% HRmax , 3 min recovery at 70% HRmax ) with or without an ARM. Neuromuscular fatigue was quantified via pre- to post-HIIE changes in maximal voluntary contraction (MVC), voluntary activation (VA, central fatigue), and potentialized evoked twitch force at 100, 10, and 1 Hz (peripheral fatigue). Blood pH and lactate were measured before and after the HIIE session, while HR, SpO2 , dyspnea, physical sensation of effort (P-RPE), and Task Effort and Awareness (TEA) were recorded every bout. The exercise-induced decrease in MVC was higher (p < 0.05) in the ARM (-28 ± 12%) than in the Control condition (-20 ± 11%). The VA decreased (p < 0.05) in the ARM (-11 ± 11%) but not in the control condition (-4 ± 5%, p > 0.05). Pre- to post-HIIE declines in evoked twitch at 100, 10, and 1 Hz were similar (p > 0.05) between ARM and control conditions (ARM: -18 ± 10, -43 ± 11 and -38 ± 12%; Control: -18 ± 14, -43 ± 12 and -37 ± 17%). When compared with the control, the HIIE bout wearing ARM was marked by higher heart rate, plasma lactate concentration, dyspnea, P-RPE and TEA, as well as lower SpO2 and blood pH. In conclusion, ARM increases perceptual and physiological stress during a HIIE, which may lead to a greater post-exercise central fatigue.

Comparison of a modified Story approach to traditional evaluation of acid-base disturbances in patients with shock: a cohort study.

To compare whether the diagnostic evaluation of metabolic acidosis can be improved by using a modified Story method compared to the traditional evaluation in a population of critically ill patients with shock. This prospective cohort study included shock patients admitted to the ICU of a tertiary hospital in Brazil between May 2018 and November 2019. We collected laboratory data necessary for traditional evaluation and the simplified Stewart's method. During the study period, 149 patients were included in the final analysis. Of the 17 patients with a normal SBE and AGcorrected, 13 (76.5%) presented with metabolic acidosis according to the modified Story assessment. Therefore, of the 149 patients included in the study, the traditional approach failed to identify metabolic acidosis that was identified by the modified Story assessment in 13 (8.7%) patients. In addition, the determination of the severity of metabolic acidosis also differed between the two methods by a mean of - 7.8 mEq/L. We found that a modified Story method can identify and quantify metabolic acidosis in patients with disorders that were not revealed by the traditional approach.

Valores de la gasometría arterial en pacientes embarazadas con preeclampsia severa / Arterial blood gas parameters in pregnant patients with severe preeclampsia

Resumen OBJETIVO: Determinar e interpretar los valores de la gasometría arterial en pacientes embarazadas con preeclampsia severa. MATERIALES Y MÉTODOS: Estudio observacional, transversal, retrospectivo y descriptivo llevado a cabo en pacientes con más o menos 20 semanas de embarazo y diagnóstico establecido de preeclampsia severa atendidas en la unidad de cuidados intensivos entre el 1 de julio y el 31 de diciembre del 2019. Los datos generales, la condición obstétrica, los estudios de laboratorio clínico y los valores de la gasometría arterial se documentaron conforme a lo registrado en los expedientes clínicos. Se utilizó estadística descriptiva y los datos se procesaron en el programa SPSS versión 20. RESULTADOS: Se estudiaron 30 pacientes con media de edad de 31.6 ± 6.85 años, mediana de paridad 1, todas con feto único de 33.89 ± 3.43 semanas y residencia en la Ciudad de México. Los valores de la gasometría arterial fueron: pH 7.41 ± 0.08, presión parcial de dióxido de carbono 25.51 ± 6.12 mmHg, presión parcial de oxígeno 85.24 ± 41.81 mmHg, hematocrito 33.86 ± 7.51%, ión carbonato 16.95 ± 5.13 mmol/L, patrón de bicarbonato estandarizado 19.04 ± 2.50 mmol/L, gases de efecto invernadero 16.94 ± 2.51 mmHg, exceso de base del fluido extracelular -7.72 ± 5.60 mmol/L, BE (B) -7.36 ± 3.07 mmol/L, porcentaje de saturación de oxígeno 93 ± 8.29, hemoglobina total en la gasometría arterial 10.64 ± 2.36 g/dL, gradiente alvéolo-arterial de oxígeno 49.43 ± 10.98 mmHg, presión parcial de oxígeno 140.43 ± 106.93 mmHg, concentraciones de dióxido de carbono 0.79 ± 0.28 mmHg e Índice respiratorio 0.95 ± 2.57. CONCLUSIONES: Los resultados corresponden a un patrón gasométrico de acidosis metabólica compensada.

Abstract OBJECTIVE: To determine and interpret arterial blood gas values in pregnant patients with severe preeclampsia. MATERIALS AND METHODS: study carry out in a series of 30 patients with a pregnancy ≥ 20 weeks and an established diagnosis of SP admitted to the Intensive Care Unit from July 1 to December 31, 2019, in whom arterial blood gases are part of the routine studies upon admission to the ICU. Patients with recurrence of preeclampsia, eclampsia and HELLP syndrome or with metabolic, respiratory, cardiological and renal morbidities affecting arterial blood gas values were excluded. The general data, obstetric condition, clinical laboratory and arterial blood gas values were documented from the clinical records. Statistical analysis: descriptive statistics were used with the statistical package SPSS version 20. RESULTS: Thirty patients were studied, with a mean age of mean age 31.6 ± 6.85 years, median parity 1, all with a single product of 33.89±3.43 weeks and residence in Mexico City 31.37 ± 7 years. Arterial blood gas values were: pH 7.41 ± 0.08, PCO2 25.51 ± 6.12 mmHg, PO2 85.24 ± 41.81 mmHg, Hct 33.86 ± 7.51%, HCO3- 16.95 ± 5.13 mmol/L, HCO3- std 19.04 ± 2.50 mmol/L, TCO2 16.94 ± 2.51 mmHg, BE ecf -7.72 ± 5.60 mmol/L, BE (B) -7.36 ± 3.07 mmol/L, SO2c% 93 ± 8.29%, THbc 10.64 ± 2.36 g/dL, Aa DO2 49.43 ± 10.98 mmHg, pAO2 140.43 ± 106.93 mmHg, PaO2/PAO2 0.79 ± 0.28 mmHg and Respiratory Index 0.95 ± 2.57. CONCLUSIONS: The results correspond to a gasometric pattern of compensated metabolic acidosis.

Use of enteral electrolyte solutions with different sodium acetate concentrations in weaned foals: the effects on acid-base balance, blood glucose, lactate, and urine ph / Utilização de soluções eletrolíticas enterais com diferentes concentrações de acetato em potros desmamados: efeitos sobre o equilíbrio ácido base, concentrações plasmáticas de glicose e lactato e pH urinário

The effects of acetate as an alkalinizing agent in maintenance enteral electrolyte solutions administered by nasogastric route in a continuous flow have not been previously described in weaned foals. This is the second part of a study that evaluated the effects of two electrolyte solutions of enteral therapy fluid in weaned foals. In this part, will be considered the effects of enteral electrolyte solutions containing different acetate concentrations on acid-base balance, blood glucose, lactate and urine pH of weaned foals. This was a controlled trial in a cross-over design performed in six foals with a mean age of 7.3 ± 1.4 months. After 12 h of water and food deprivation, each animal received the following two treatments by nasogastric route in a continuous flow of 15 ml/kg/h during 12 h: HighAcetate (acetate 52 mmol/l) and LowAcetate (acetate 22.6 mmol/l). The HighAcetate treatment was effective in generating a slight increase in blood pH, blood bicarbonate concentration, base excess and urinary pH.

Os efeitos da utilização de acetato como um agente alcalinizante em soluções eletrolíticas enterais de manutenção administradas por sonda nasogástrica em fluxo contínuo não foram descritos em potros desmamados. O presente estudo teve como objetivo avaliar os efeitos de soluções eletrolíticas enterais contendo diferentes concentrações de acetato sobre o equilíbrio ácido base, concentrações plasmáticas de glicose e lactato, e pH urinário de potros desmamados. Este trabalho foi um estudo controlado em um delineamento cross-over (6X2) utilizando seis potros com idade média de 7.3 ± 1.4 meses. Após 12h de restrição hídrica e alimentar, cada animal recebeu os dois tratamentos por via nasogástrica em fluxo contínuo de 15 ml/kg/h durante 12h: HighAcetate (52 mmol/l) e LowAcetate (22.6 mmol/l). O grupo HighAcetate foi eficaz em gerar um pequeno aumento no pH sanguíneo, concentração de bicarbonato sanguíneo, excesso de base e pH urinário.

Sistemática para el manejo del equilibrio ácido-base en pacientes graves / Systemization for the management of acid-base balance in seriously ill patients

Introducción: Las alteraciones del equilibrio ácido-base pueden ser de carácter primario. En la mayoría de los casos dependen de la complicación de una enfermedad preexistente. La frecuencia de estos trastornos es elevada, especialmente, en enfermos hospitalizados en las unidades de atención al paciente grave. Su aparición conlleva implicaciones pronósticas significativas. Objetivo: Sistematizar sobre el estado actual del manejo del equilibrio ácido-base. Método: Se realizó una revisión bibliográfica en la que se utilizaron las herramientas del método científico. Se examinó toda la bibliografía disponible publicada en los últimos cinco años y así, elaborar una síntesis crítica, acorde al criterio y las competencias de los autores sobre la temática. Resultados: Se expone la importancia de la evaluación clínica, que unida a los niveles de PCO2, y de exceso o déficit de bases en una gasometría arterial, permiten identificar el trastorno ácido base existente. Igualmente, se destaca que el CO2 tiene una función clave en el control de la ventilación, así como las modificaciones que produce al flujo sanguíneo cerebral, el pH y el tono adrenérgico. Otro aspecto importante fue la reciente práctica clínica de la "hipercapnia permisiva" para reducir el metabolismo tisular y de esta manera, mejorar la función del surfactante e impedir la nitración de las proteínas. Conclusiones: El manejo de los desequilibrios ácido-base debe ser del dominio de todos los profesionales vinculados a la asistencia médica, pues el retraso de su diagnóstico puede empeorar la evolución y el pronóstico de los pacientes graves(AU)

Introduction: Acid-base balance alterations can be of a primary nature. In most cases, they depend on the complication of a pre-existing disease. The frequency of these disorders is high, especially in patients hospitalized in critical care units. Its appearance carries significant prognostic implications. Objective: To systematize the current state of acid-base balance management. Method: A bibliographic review was carried out, for which the tools of the scientific method were used. All the available bibliography, published in the last five years, was examined; thus, a critical synthesis was prepared, according to the criteria and competences of the authors regarding the subject. Results: The importance of the clinical evaluation is exposed, which, together with PCO2 levels as well as excess or deficit of bases in an arterial blood gas, allow to identify the existing acid-base disorder. Likewise, it is highlighted that CO2 has a key function in ventilation control, together with the modifications it produces on cerebral blood flow, pH and adrenergic tone. Another important aspect was the recent clinical practice of "permissive hypercapnia" to reduce tissue metabolism and thus improve surfactant function and prevent protein nitration. Conclusions: The management of acid-base imbalances should be mastered by all professionals associated to medical care, since any delay in its diagnosis can worsen the evolution and prognosis of seriously ill patients(AU)

Kidney function in patients with primary distal renal tubular acidosis.

BACKGROUND: Recent reports indicate that chronic reduction of glomerular filtration rate (GFR) is common in patients with distal renal tubular acidosis (DRTA). Factors responsible for decreased GFR need clarification. METHODS: We reviewed records of 25 patients with genetically confirmed DRTA included in the RenalTube database. Patients < 18 years at diagnosis and having at least one annual follow-up were selected and classified in two groups according to GFR ≥ 90 (normal GFR) or < 90 mL/min/1.73 m2 (low GFR) after median follow-up of 8.8 years. RESULTS: Eighteen and seven patients had normal and low GFR (X ± SEM, 121.16 ± 28.87 and 71.80 ± 10.60 mL/min/1.73 m2, respectively, p < 0.01). At diagnosis, these 2 subgroups did not differ in sex, age, underlying mutated gene, GFR, height SDS, or percentage of ultrasound nephrocalcinosis. Serum creatinine (SCr) was different but likely due to median ages of presentation being 0.6 and 4.0 in normal and low GFR patients, respectively. On the last recorded visit, no differences between both groups were found in serum bicarbonate, serum potassium, or alkali dosage. Height SDS of patients with normal GFR was - 0.15 ± 0.47 whereas it was - 1.06 ± 0.60 in the low GFR group (p = 0.27). Interestingly, 23% of the whole group had low birth weight (LBW; < 2500 g), equating to 20% and 29% in the normal and low GFR patients, respectively (p = 0.65). CONCLUSIONS: Our findings confirm the risk of kidney function reduction in patients with DRTA of pediatric age onset, suggesting that low GFR is related with less favorable growth outcome and discloses the high frequency of LBW in primary DRTA, a hitherto unrecognized feature.

Potential Novel Benefits of Sodium Restriction in Chronic Kidney Disease.

Chronic kidney disease is a global public health issue, and it has been considered as the epidemic of the 21st century. Therefore, all initiatives addressed to slow down the evolution and complications of this condition should be well received. While the effects of salt reduction on cardiovascular disease have some controversial issues, in chronic kidney disease, such a policy is beneficial in multiple aspects. In chronic kidney disease patients, dietary sodium restriction is regularly recommended to control extracellular fluid expansion, hypertension and cardiovascular risk. Instead, the effects of sodium reduction on chronic kidney disease progression are still controversial. In the last years, potentially beneficial effects of a low sodium diet on chronic kidney disease evolution have emerged. Firstly, recent magnetic resonance-based findings of increased Na depots in skin and muscle associated with renal function, ageing and sodium intake open a vast body of investigation as a potential tool for monitoring effects of sodium restriction. In this narrative review, we also discussed novel aspects of sodium restriction in chronic kidney disease to manage metabolic acidosis as well as renal effects on fibroblast growth factor 23 or gut microbiota. Beyond current evidence, these approaches showed that common findings of kidney failure environment such as sodium -sensitivity, micro-inflammation, arterial stiffness metabolic acidosis and sarcopenia could be delayed controlling dietary sodium. Additional studies are now needed in populations with chronic kidney disease to confirm these new findings, addressed to slow down the evolution and complications of this condition.

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.

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 84 mEq/L de lactato

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 included determination 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.

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.

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 84 mEq/L de lactato

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 included determination 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.(AU)

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.(AU)

Metabolic acidosis and hyperkalemia differentially regulate cation HCN3 channel in the rat nephron.

The kidney controls body fluids, electrolyte and acid-base balance. Previously, we demonstrated that hyperpolarization-activated and cyclic nucleotide-gated (HCN) cation channels participate in ammonium excretion in the rat kidney. Since acid-base balance is closely linked to potassium metabolism, in the present work we aim to determine the effect of chronic metabolic acidosis (CMA) and hyperkalemia (HK) on protein abundance and localization of HCN3 in the rat kidney. CMA increased HCN3 protein level only in the outer medulla (2.74 ± 0.31) according to immunoblot analysis. However, immunofluorescence assays showed that HCN3 augmented in cortical proximal tubules (1.45 ± 0.11) and medullary thick ascending limb of Henle's loop (4.48 ± 0.45) from the inner stripe of outer medulla. HCN3 was detected in brush border membranes (BBM) and mitochondria of the proximal tubule by immunogold electron and confocal microscopy in control conditions. Acidosis did not alter HCN3 levels in BBM and mitochondria but augmented them in lysosomes. HCN3 was also immuno-detected in mitoautophagosomes. In the distal nephron, HCN3 was expressed in principal and intercalated cells from cortical to medullary collecting ducts. CMA did not change HCN3 abundance in these nephron segments. In contrast, HK doubled HCN3 level in cortical collecting ducts and favored its basolateral localization in principal cells from the inner medullary collecting ducts. These findings further support HCN channels contribution to renal acid-base and potassium balance.

Acute effect of sodium bicarbonate supplementation by resistant training practices / Efeito agudo da suplementação de bicarbonato de sódio por práticas de treinamento de resistência

Currently, the use of sodium bicarbonate (SB) as an ergogenic supplement has been linked to improved performance in several high-intensity and short time interval modalities because it is a natural buffer of the body fluids of the human body. This study aimed to evaluate the acute effect of SB supplementation on muscle strength endurance of resistance training practitioners. Crossover clinical trial, placebo-controlled (PL), and single-masked, included 10 trained adult men. The maximum repetition (1RM) and exhaustion tests with 80% 1RM were performed in the extensor chair and direct thread. In all sessions, the volunteers were verbally stimulated, the total maximum repetitions in the exercises and the blood lactate concentration were measured. SB was supplemented at a dose of 0.3 g/kg body mass. Statistical analysis was performed using SPSS version 25.0. The Shapiro­Wilktest was used to evaluate the normality of the data, and the Student's t-test was used for independent and paired samples. The size of the Cohen's effect was calculated, and the significance level was set at p<0.05. Comparing the supplements, no significant differences were found in all variables tested. However, when comparing pretest and posttest periods, significant differences were found between lactate concentrations, with considerably large effect sizes (> 1.00).SB supplementation by endurance training practitioners induces blood alkalosis, which reduces fatigue and possibly improves muscle strength endurance

Atualmente, o uso de bicarbonato de sódio (SB) como suplemento ergogênico tem sido associado a um melhor desempenho em várias modalidades de alta intensidade e intervalos de tempo curtos, pois é um amortecedor natural dos fluidos corporais do corpo humano. Este estudo teve como objetivo avaliar o efeito agudo da suplementação de SB na resistência da força muscular de praticantes de treinamento de resistência. Ensaio clínico cruzado, controlado por placebo (PL) e com máscara única, incluiu 10 homens adultos treinados. Os testes de repetição máxima (1RM) e exaustão com 80% de 1RM foram realizados na cadeira extensora e na rosca direta. Em todas as sessões, os voluntários foram estimulados verbalmente, foram medidas as repetições máximas totais nos exercícios e a concentração de lactato sanguíneo. O SB foi suplementado na dose de 0,3 g / kg de massa corporal. A análise estatística foi realizada no SPSS versão 25.0. O teste Shapiro-Wilk foi usado para avaliar a normalidade dos dados, e o teste t de Student foi usado para amostras independentes e emparelhadas. O tamanho do efeito de Cohen foi calculado e o nível de significância foi estabelecido em p <0,05. Comparando os suplementos, não foram encontradas diferenças significativas em todas as variáveis testadas. No entanto, ao comparar os períodos pré e pós-teste, foram encontradas diferenças significativas entre as concentrações de lactato, com tamanhos de efeito consideravelmente grandes (> 1,00). A suplementação de SB por praticantes de treinamento de resistência induz alcalose no sangue, o que reduz a fadiga e possivelmente melhora a resistência da força muscular.