ABSTRACT
Glomerular filtration rate (GFR) impairment is common both intraoperatively and in the early postoperative period of major surgeries, even elective ones. In some patients, such impairment is subtle and short-lasting, not even detected by increases in serum creatinine (sCr) and, consequently, not of sufficient magnitude to fulfill acute kidney injury (AKI) sCr-based criteria. In patients with a GFR decrease of greater magnitude, significant increases in sCr will occur but, unfortunately, usually at a late time in its progression. Both urinary and serum biomarkers have been proposed to be capable of anticipating AKI development but they are not widely available nor cost-effective in most centers. In this context, a urine biochemical approach using urinary sodium concentration (NaU) and the fractional excretion of potassium (FeK) has been proposed, anticipating the level of renal microcirculatory stress and decreases in GFR. An educational postoperative case example is presented highlighting the relevance that this approach can have in the correct interpretation of sCr values, bringing more dynamism to renal function monitoring. How to cite this article: Maciel AT. Optimizing Postoperative Acute Kidney Injury Monitoring Using a Urine Biochemical Approach-Time to Bring More Dynamism to Serum Creatinine Evaluation! Indian J Crit Care Med 2024;28(8):729-733.
ABSTRACT
Urine biochemistry (UB) remains a controversial tool in acute kidney injury (AKI) monitoring, being considered to be of limited value both in terms of AKI diagnosis and prognosis. However, many criticisms can be made to the studies that have established the so called "pre-renal paradigm" (used for decades as the essential physiological basis for UB assessment in AKI) as well as to more recent studies suggesting that UB has no utility in daily clinical practice. The aim of this article is to describe our hypothesis on how to interpret simple and widely recognized urine biochemical parameters from a novel perspective, propose the rationale for their sequential assessment and demonstrate their usefulness in AKI monitoring, especially in the critical care setting.
ABSTRACT
Introducción: La variación del magnesio y de indicadores bioquímicos del metabolismo óseo-mineral según la tasa de filtración glomerular en jóvenes sin enfermedad renal es poco conocida por lo que es necesario considerarla para delimitar lo no atribuible a enfermedad renal crónica. El papel que desempeña el magnesio está en estudio. En la enfermedad renal crónica hay una alteración progresiva del metabolismo óseo-mineral que comienza tempranamente. Objetivos: Evaluar valores séricos de magnesio, calcio, fósforo, fosfatasa alcalina y parathormona, excreciones urinarias de 24 h y excreción fraccional de estos electrolitos según categoría G de tasa de filtración glomerular estimada por clearance de creatinina: G1 (normal a alta) y G2 (levemente disminuida) en estudiantes sin enfermedad renal crónica. Material y métodos: Estudio analítico y corte transversal con una muestra de 55 estudiantes voluntarios sin enfermedad renal en el periodo 2018 a 2019. Los analitos se determinaron en suero y algunos en orina de 24 h. Resultados: Solamente magnesio sérico y excreción fraccional de magnesio excreción fraccional de magnesio mostraron diferencias significativas según la categoría G (p < 0,05). Los valores de magnesio sérico magnesio sérico estuvieron dentro de los valores de referencia para el método. En G2, magnesio sérico, descendido respecto a G1 y excreción fraccional de magnesio aumentada, inversamente relacionados. El magnesio sérico disminuyó en promedio 0,26 mg/dL por unidad de aumento de excreción fraccional de magnesio (p = 0,0502). Conclusiones: Se observaron diferencias en magnesio sérico y excreción fraccional de magnesio al comparar los resultados en G1 y G2. Los demás indicadores bioquímicos estudiados no mostraron diferencias por categoría G. Diseños de corte longitudinal en muestras mayores pueden confirmar o no estos hallazgos. Tales estudios pueden aportar a la comprensión de cambios bioquímicos del metabolismo óseo-mineral en etapas iniciales de disminución de la tasa de filtración glomerular(AU)
Introduction: Not much is known about the variation in magnesium and biochemical indicators of the osseous-mineral metabolism according to glomerular filtration rate testing in young people without kidney disease. This variation should therefore be considered to delimit whatever is not attributable to chronic kidney disease. The role played by magnesium is currently under study. In chronic kidney disease a progressive alteration of the osseous-mineral metabolism starts early. Objectives: Evaluate serum values of magnesium, calcium, phosphorus, alkaline phosphatase and parathormone, 24-hour urinary excretion and fractional excretion of these electrolytes according to category G of the glomerular filtration rate estimated by creatinine clearance: G1 (normal to high) and G2 (slightly reduced) in students without chronic kidney disease. Methods: An analytical cross-sectional study was conducted of a sample of 55 student volunteers without kidney disease in the period 2018-2019. The analytes were determined in serum and some in 24-hour urine. Results: Only serum magnesium and magnesium fractional excretion displayed significant differences according to category G (p < 0.05). Serum magnesium values were within the reference values for the method. In G2, serum magnesium was lower than in G1, whereas magnesium fractional excretion was higher, i.e. an inverse relation is observed. Serum magnesium reduction averaged 0.26 mg/dl per unit of magnesium fractional excretion increase (p = 0.0502). Conclusions: Comparison of G1 and G2 results revealed differences in serum magnesium and magnesium fractional excretion. The remaining biochemical indicators studied did not show any differences in category G. Longitudinal studies with larger samples may or may not confirm these findings, thus contributing to a better understanding of the biochemical changes in osseous-mineral metabolism occurring in the initial stages of glomerular filtration rate reduction(AU)
Subject(s)
Humans , Students , Calcium , Glomerular Filtration Rate , Kidney Diseases , Magnesium , Metabolism , Cross-Sectional Studies , Longitudinal StudiesABSTRACT
Introducción: El ensayo de muestras matutinas de orina pudiera mejorar el estudio de la función tubular en niños y adolescentes. Objetivo: Describir las tubulopatías diagnosticadas en niños y adolescentes después del ensayo de muestras matutinas de orina. Métodos: Se completó un estudio retrospectivo y analítico en el Laboratorio de Estudio de la Función Renal, Servicio de Laboratorio Clínico, Hospital Pediátrico Docente "Juan Manuel Márquez", con 70 informes de la función tubular hechos en muestras matutinas de orina de 56 probandos (varones: 50,0 por ciento; edad promedio: 4,3 ± 5,5 años; edades < 12 meses: 41,1 por ciento) atendidos entre 2015-2019 (ambos inclusive) que contenían los valores del filtrado glomerular, la excreción urinaria absoluta y fraccional de las sustancias de interés, la brecha aniónica, la presión parcial de los gases, y la acidez titulable, el pH, la densidad y la osmolaridad de los fluidos pertinentes. Los resultados obtenidos se integraron dentro de las construcciones de caso de varias tubulopatías. Resultados: La función tubular estaba conservada en el 41,1 por ciento de los probandos. La inmadurez tubular explicó los hallazgos en otros dos niños. La hipercalciuria idiopática (16,0 por ciento), la diabetes insípida de causa nefrogénica (8,9 por ciento) y la insuficiencia renal aguda (5,3 por ciento) fueron los hallazgos más frecuentes. En 14 de los probandos se diagnosticaron 10 tubulopatías que recorrieron el raquitismo carencial, la hipofosfatasia, la enfermedad de Leigh, el síndrome de Bartter, la enfermedad de Dent y la acidosis tubular I, II y IV. Conclusiones: El estudio tubular en muestras matutinas de orina permite el diagnóstico de importantes tubulopatías en las edades pediátricas(AU)
Introduction: The morning urine sample assay may improve the study of tubular function in children and adolescents. Objective: Describe the tubulopathies diagnosed in children and adolescents after the trial of morning urine samples. Methods: A retrospective and analytical study was completed at the Renal Function´s Study Laboratory, in the Clinical Laboratory Service at "Juan Manuel Marquez" Teaching Pediatric Hospital, with 70 reports of tubular function made in morning urine samples of 56 testees (males: 50.0 percent; average age: 4.3 ± to 5.5 years; ages< 12 months: 41.1 percent) attended from 2015 to 2019 (both inclusive) containing glomerular filtration values, absolute and fractional urinary excretion of substances of interest, anionic gap, partial gas pressure, and titrable acidity, pH, density and osmolarity of relevant fluids. The results obtained were integrated into the case constructions of various tubulopathies. Results: Tubular function was preserved in 41.1 percent of the testees. Tubular immaturity explained the findings in two other children. Idiopathic hypercalciuria (16.0 percent), nephrogenic diabetes insipidus (8.9 percent) and acute renal failure (5.3 percent) were the most frequent findings. In 14 of the testees, 10 tubulopathies were diagnosed were through deficiency rickets, hypophosphatasia, Leigh's disease, Bartter syndrome, Dent disease and tubular acidosis I, II and IV.. Conclusions: The tubular study with morning urine samples allows the diagnosis of important tubulopathies in the pediatric ages(AU)
Subject(s)
Humans , Male , Female , Infant , Child, Preschool , Osmolar Concentration , Diabetes Insipidus, Nephrogenic , Acute Kidney Injury , Clinical Laboratory Services , Hydrogen-Ion ConcentrationABSTRACT
BACKGROUND: Type 2 diabetes (T2DM) has been associated with deficiencies in serum magnesium level, decreasing insulin sensitivity and glucose metabolism. Glycosylated hemoglobin (Hb1Ac) is a biomarker of glucose values within the half-life of the erythrocyte, that is, 3 months. Low circulating and intracellular magnesium levels can modify glucose metabolism and insulin sensitivity. Renal solute management is a parameter little used to estimate circulating and excreted concentrations of elements such as magnesium. OBJECTIVE: The purpose of this study was to assess and associated fractional excretion of magnesium (FEMg) and serum magnesium with metabolic parameters, especially Hb1Ac percent, in a group of well characterized subjects with T2DM and non-diabetics subjects (ND). METHODS: According to Hb1Ac, two groups were compared and associated with existing biochemical parameters, included Hb1Ac, fasting glucose, lipid profile, serum creatinine, serum magnesium and urinary creatinine for FEMg. RESULTS: HbA1c levels were explained by serum magnesium in 25%. Serum magnesium levels in the ND group were higher than in the T2DM group and this was a statistically significant difference. Serum magnesium ≤1.8 is a risk factor (OD 16.1; P=0.021) for an HbA1c ≥ 6.5%. CONCLUSION: In this study, hypomagnesemia was a parameter strongly associated with the diagnosis and progression of T2DM, while FEMg showed no significant association.
Subject(s)
Diabetes Mellitus, Type 2 , Magnesium , Blood Glucose , Creatinine , Glycated Hemoglobin , HumansABSTRACT
Obstructive urolithiasis is highly prevalent disease in feedlot sheep. Urinary acidification is effective for disease prevention. Forty-five healthy 3-4 month-old male Santa Inês crossbred feedlot lambs were distributed into three groups of 15 animals each. Ammonium chloride (GA) at 400 mg/kg/day/animal, vitamin C (GC) at 4 mg/kg/day/animal, and a combination of the two (GAC) were administered orally for 21 d. Blood and urine samples were taken 7 d before beginning treatment (M0), immediately before (M1), and weekly for 21 d (M2, M3, and M4) for renal function tests, levels of Ca, P, and Mg in serum and urine, urinalysis, and fractional excretion (FE) analysis in these minerals. In groups GA and GAC, pH decreased in M2 and remained acidic throughout the experiment. A significant decrease in serum P and a urinary increase in Ca and Mg occurred in GA. The FE of Ca increased during treatments, but there was no interference with Mg. The FE of P was significantly lower in GA. Ammonium chloride was an effective urinary acidifier in sheep, but vitamin C administered orally did not provide stable results. Thus, based on our results, vitamin C supplementation may not effective for urinary acidification to prevent obstructive urolithiasis.(AU)
A urolitíase obstrutiva é uma enfermidade de alta incidência em ovinos confinados. A acidificação urinária é um dos métodos mais eficazes para a prevenção da doença. Utilizaram-se 45 cordeiros clinicamente sadios, machos, mestiços Santa Inês, com três a quatro meses de idade, em confinamento, distribuídos em três grupos de 15 animais cada. Foi administrado 400mg/kg/dia/animal de cloreto de amônio (GA), 4mg/kg/dia/animal de vitamina C (GC) e associação dos dois produtos (GAC), durante 21 dias, ambos por via oral. As colheitas de sangue e urina foram realizadas sete dias antes do início do tratamento (M0), imediatamente antes (M1) e depois, semanalmente, até 21 dias após (M2, M3 e M4) para realização de exames de função renal (ureia e creatinina), dosagem de Ca, P e Mg no soro e na urina, urinálise e cálculo de EF desses minerais. Nos grupos GA e GAC, houve diminuição do pH no M2, permanecendo ácido até o final do experimento. Houve diminuição significativa do P sérico no GA, além de aumento urinário nos teores de Ca e Mg nesse grupo. A EF de Ca aumentou após o início dos tratamentos, porém não houve interferência para Mg. A EF de P foi significativamente menor somente no GA. O cloreto de amônio se mostrou eficaz como acidificante urinário em ovinos, porém a vitamina C, por via oral, apresentou oscilação e não atingiu estabilidade. Portanto, a suplementação com vitamina C não foi eficaz para acidificação urinária e, por isso, não deve ser utilizada na prevenção de urolitíase obstrutiva.(AU)
Subject(s)
Animals , Ascorbic Acid/analysis , Ascorbic Acid/therapeutic use , Ammonium Chloride/analysis , Ammonium Chloride/therapeutic use , Sheep/physiology , Urolithiasis/therapy , Urolithiasis/veterinary , Acidification , Urinalysis/veterinaryABSTRACT
Obstructive urolithiasis is highly prevalent disease in feedlot sheep. Urinary acidification is effective for disease prevention. Forty-five healthy 3-4 month-old male Santa Inês crossbred feedlot lambs were distributed into three groups of 15 animals each. Ammonium chloride (GA) at 400 mg/kg/day/animal, vitamin C (GC) at 4 mg/kg/day/animal, and a combination of the two (GAC) were administered orally for 21 d. Blood and urine samples were taken 7 d before beginning treatment (M0), immediately before (M1), and weekly for 21 d (M2, M3, and M4) for renal function tests, levels of Ca, P, and Mg in serum and urine, urinalysis, and fractional excretion (FE) analysis in these minerals. In groups GA and GAC, pH decreased in M2 and remained acidic throughout the experiment. A significant decrease in serum P and a urinary increase in Ca and Mg occurred in GA. The FE of Ca increased during treatments, but there was no interference with Mg. The FE of P was significantly lower in GA. Ammonium chloride was an effective urinary acidifier in sheep, but vitamin C administered orally did not provide stable results. Thus, based on our results, vitamin C supplementation may not effective for urinary acidification to prevent obstructive urolithiasis.
A urolitíase obstrutiva é uma enfermidade de alta incidência em ovinos confinados. A acidificação urinária é um dos métodos mais eficazes para a prevenção da doença. Utilizaram-se 45 cordeiros clinicamente sadios, machos, mestiços Santa Inês, com três a quatro meses de idade, em confinamento, distribuídos em três grupos de 15 animais cada. Foi administrado 400mg/kg/dia/animal de cloreto de amônio (GA), 4mg/kg/dia/animal de vitamina C (GC) e associação dos dois produtos (GAC), durante 21 dias, ambos por via oral. As colheitas de sangue e urina foram realizadas sete dias antes do início do tratamento (M0), imediatamente antes (M1) e depois, semanalmente, até 21 dias após (M2, M3 e M4) para realização de exames de função renal (ureia e creatinina), dosagem de Ca, P e Mg no soro e na urina, urinálise e cálculo de EF desses minerais. Nos grupos GA e GAC, houve diminuição do pH no M2, permanecendo ácido até o final do experimento. Houve diminuição significativa do P sérico no GA, além de aumento urinário nos teores de Ca e Mg nesse grupo. A EF de Ca aumentou após o início dos tratamentos, porém não houve interferência para Mg. A EF de P foi significativamente menor somente no GA. O cloreto de amônio se mostrou eficaz como acidificante urinário em ovinos, porém a vitamina C, por via oral, apresentou oscilação e não atingiu estabilidade. Portanto, a suplementação com vitamina C não foi eficaz para acidificação urinária e, por isso, não deve ser utilizada na prevenção de urolitíase obstrutiva.
Subject(s)
Animals , Ammonium Chloride/analysis , Ammonium Chloride/therapeutic use , Sheep/physiology , Urolithiasis/therapy , Urolithiasis/veterinary , Ascorbic Acid/analysis , Ascorbic Acid/therapeutic use , Acidification , Urinalysis/veterinaryABSTRACT
A urolitíase é uma doença importante de cordeiros confinados. A acidificação da urina, pela ingestão de cloreto de amônio, é o método preventivo mais frequentemente empregado. Devido à falta de informação específica em ovinos, este estudo foi realizado para avaliar as alterações que ocorrem nos eletrólitos urinários de cordeiros, que receberam cloreto de amônio na dieta. Foram utilizados 100 cordeiros, com 3 meses de idade, que foram mantidos em confinamento durante 56 dias, e distribuídos em 3 grupos: G1 (n=40) que receberam 400mg/kg de peso vivo (PV) de cloreto de amônio/dia, durante 21 dias; G2 (n=40) que receberam 400mg/kg de PV de cloreto de amônio/dia durante 42 dias; e G3 (n=20) que não receberam cloreto de amônio. Os cordeiros foram examinados e as amostras de sangue e urina foram colhidas a cada 7 dias: 0 (antes do início da ingestão de cloreto de amônio), 7, 14, 21, 28, 35, e 42 dias. As concentrações séricas e urinárias de sódio (Na+), potássio (K+), cloreto (Cl-), e de creatinina foram mensuradas em todos os momentos de colheita. A excreção fracionada urinária (EFu) de eletrólitos e a diferença de íons fortes (SID) na urina [(Na+ + K+) - Cl] foram calculadas. A EFu de Na+, K+ e Cl- não variou ao longo do tempo em G3, provando que a dieta de confinamento, por si só, não influenciou a excreção urinária destes eletrólitos. A ingestão de cloreto de amônio, pelo grupo G1 e G2, influenciou a EFu sobre o tempo de confinamento. A SID urinária foi mais precisa do que a EFu de Cl- para demonstrar que a concentração de Cl- aumentou na urina, o que destacou a relevância desta variável.(AU)
Urolithiasis is an important disease of lambs confined. The urine acidification, by ammonium chloride intake, is the preventive method most frequently employed. Due to the lack of specific information in sheep, this study was performed to evaluate the electrolyte changes that occur in the urine of lambs receiving ammonium chloride in the diet. One hundred male lambs, 3 months old, were kept in a feedlot during 56 days, and distributed in 3 groups: G1 (n=40) receiving 400mg/kg BW of ammonium chloride/day during 21 days; G2 (n=40) receiving 400mg/kg BW of ammonium chloride/day during 42 days; and G3 (n=20) that did not receive ammonium chloride. The lambs were examined and blood and urine samples were collected every 7 days: 0 (the beginning of ammonium chloride intake), 7, 14, 21, 28, 35, and 42 days. Serum and urine sodium (Na+), potassium (K+), chloride (Cl-), and creatinine concentrations were measured. The urinary fractional excretion (FE) of electrolytes and the urine strong ion difference [(Na+ + K+) - Cl-] were calculated. FEs of Na+, K+, and Cl- did not vary over time in G3, proving that the feedlot diet, by itself, did not influence the urinary excretion of these electrolytes. The ingestion of ammonium chloride, instead, influenced FEs over the time of feedlot. The urinary SID was more accurate than the FE of Cl- to demonstrate that the concentration of Cl- increased in the urine. It highlights the relevance of this variable.(AU)
Subject(s)
Animals , Urine/chemistry , Sheep/physiology , Potassium/analysis , Sodium/analysis , Chlorides/analysis , Urolithiasis/veterinaryABSTRACT
A urolitíase é uma doença importante de cordeiros confinados. A acidificação da urina, pela ingestão de cloreto de amônio, é o método preventivo mais frequentemente empregado. Devido à falta de informação específica em ovinos, este estudo foi realizado para avaliar as alterações que ocorrem nos eletrólitos urinários de cordeiros, que receberam cloreto de amônio na dieta. Foram utilizados 100 cordeiros, com 3 meses de idade, que foram mantidos em confinamento durante 56 dias, e distribuídos em 3 grupos: G1 (n=40) que receberam 400mg/kg de peso vivo (PV) de cloreto de amônio/dia, durante 21 dias; G2 (n=40) que receberam 400mg/kg de PV de cloreto de amônio/dia durante 42 dias; e G3 (n=20) que não receberam cloreto de amônio. Os cordeiros foram examinados e as amostras de sangue e urina foram colhidas a cada 7 dias: 0 (antes do início da ingestão de cloreto de amônio), 7, 14, 21, 28, 35, e 42 dias. As concentrações séricas e urinárias de sódio (Na+), potássio (K+), cloreto (Cl-), e de creatinina foram mensuradas em todos os momentos de colheita. A excreção fracionada urinária (EFu) de eletrólitos e a diferença de íons fortes (SID) na urina [(Na+ + K+) - Cl] foram calculadas. A EFu de Na+, K+ e Cl- não variou ao longo do tempo em G3, provando que a dieta de confinamento, por si só, não influenciou a excreção urinária destes eletrólitos. A ingestão de cloreto de amônio, pelo grupo G1 e G2, influenciou a EFu sobre o tempo de confinamento. A SID urinária foi mais precisa do que a EFu de Cl- para demonstrar que a concentração de Cl- aumentou na urina, o que destacou a relevância desta variável.(AU)
Urolithiasis is an important disease of lambs confined. The urine acidification, by ammonium chloride intake, is the preventive method most frequently employed. Due to the lack of specific information in sheep, this study was performed to evaluate the electrolyte changes that occur in the urine of lambs receiving ammonium chloride in the diet. One hundred male lambs, 3 months old, were kept in a feedlot during 56 days, and distributed in 3 groups: G1 (n=40) receiving 400mg/kg BW of ammonium chloride/day during 21 days; G2 (n=40) receiving 400mg/kg BW of ammonium chloride/day during 42 days; and G3 (n=20) that did not receive ammonium chloride. The lambs were examined and blood and urine samples were collected every 7 days: 0 (the beginning of ammonium chloride intake), 7, 14, 21, 28, 35, and 42 days. Serum and urine sodium (Na+), potassium (K+), chloride (Cl-), and creatinine concentrations were measured. The urinary fractional excretion (FE) of electrolytes and the urine strong ion difference [(Na+ + K+) - Cl-] were calculated. FEs of Na+, K+, and Cl- did not vary over time in G3, proving that the feedlot diet, by itself, did not influence the urinary excretion of these electrolytes. The ingestion of ammonium chloride, instead, influenced FEs over the time of feedlot. The urinary SID was more accurate than the FE of Cl- to demonstrate that the concentration of Cl- increased in the urine. It highlights the relevance of this variable.(AU)
Subject(s)
Animals , Urine/chemistry , Sheep/physiology , Potassium/analysis , Sodium/analysis , Chlorides/analysis , Urolithiasis/veterinaryABSTRACT
ABSTRACT: Urolithiasis is an important disease of lambs confined. The urine acidification, by ammonium chloride intake, is the preventive method most frequently employed. Due to the lack of specific information in sheep, this study was performed to evaluate the electrolyte changes that occur in the urine of lambs receiving ammonium chloride in the diet. One hundred male lambs, 3 months old, were kept in a feedlot during 56 days, and distributed in 3 groups: G1 (n=40) receiving 400mg/kg BW of ammonium chloride/day during 21 days; G2 (n=40) receiving 400mg/kg BW of ammonium chloride/day during 42 days; and G3 (n=20) that did not receive ammonium chloride. The lambs were examined and blood and urine samples were collected every 7 days: 0 (the beginning of ammonium chloride intake), 7, 14, 21, 28, 35, and 42 days. Serum and urine sodium (Na+), potassium (K+), chloride (Cl-), and creatinine concentrations were measured. The urinary fractional excretion (FE) of electrolytes and the urine strong ion difference [(Na+ + K+) - Cl-] were calculated. FEs of Na+, K+, and Cl- did not vary over time in G3, proving that the feedlot diet, by itself, did not influence the urinary excretion of these electrolytes. The ingestion of ammonium chloride, instead, influenced FEs over the time of feedlot. The urinary SID was more accurate than the FE of Cl- to demonstrate that the concentration of Cl- increased in the urine. It highlights the relevance of this variable.
RESUMO: A urolitíase é uma doença importante de cordeiros confinados. A acidificação da urina, pela ingestão de cloreto de amônio, é o método preventivo mais frequentemente empregado. Devido à falta de informação específica em ovinos, este estudo foi realizado para avaliar as alterações que ocorrem nos eletrólitos urinários de cordeiros, que receberam cloreto de amônio na dieta. Foram utilizados 100 cordeiros, com 3 meses de idade, que foram mantidos em confinamento durante 56 dias, e distribuídos em 3 grupos: G1 (n=40) que receberam 400mg/kg de peso vivo (PV) de cloreto de amônio/dia, durante 21 dias; G2 (n=40) que receberam 400mg/kg de PV de cloreto de amônio/dia durante 42 dias; e G3 (n=20) que não receberam cloreto de amônio. Os cordeiros foram examinados e as amostras de sangue e urina foram colhidas a cada 7 dias: 0 (antes do início da ingestão de cloreto de amônio), 7, 14, 21, 28, 35, e 42 dias. As concentrações séricas e urinárias de sódio (Na+), potássio (K+), cloreto (Cl-), e de creatinina foram mensuradas em todos os momentos de colheita. A excreção fracionada urinária (EFu) de eletrólitos e a diferença de íons fortes (SID) na urina [(Na+ + K+) - Cl] foram calculadas. A EFu de Na+, K+ e Cl- não variou ao longo do tempo em G3, provando que a dieta de confinamento, por si só, não influenciou a excreção urinária destes eletrólitos. A ingestão de cloreto de amônio, pelo grupo G1 e G2, influenciou a EFu sobre o tempo de confinamento. A SID urinária foi mais precisa do que a EFu de Cl- para demonstrar que a concentração de Cl- aumentou na urina, o que destacou a relevância desta variável.
ABSTRACT
In the past, urine biochemistry was a major tool in acute kidney injury (AKI) management. Classic papers published some decades ago established the values of the urine indices which were thought to distinguish "pre-renal" (functional) AKI attributed to low renal perfusion and "renal" (structural) AKI attributed to acute tubular necrosis (ATN). However, there were a lot of drawbacks and limitations in these studies and some recent articles have questioned the utility of measuring urine electrolytes especially because they do not seem to adequately inform about renal perfusion nor AKI duration (transient vs. persistent). At the same time, the "pre-renal" paradigm has been consistently criticized because hypoperfusion followed by ischemia and ATN does not seem to explain most of the AKI developing in critically ill patients and distinct AKI durations do not seem to be clearly related to different pathophysiological mechanisms or histopathological findings. In this new context, other possible roles for urine biochemistry have emerged. Some studies have suggested standardized changes in the urine electrolyte composition preceding increases in serum creatinine independently of AKI subsequent duration, which might actually be due to intra-renal microcirculatory changes and activation of sodium-retaining mechanisms even in the absence of impaired global renal blood flow. In the present review, the points of controversy regarding urine biochemistry assessment were evaluated as well as future perspectives for its role in AKI monitoring. An alternative approach for the interpretation of measured urine electrolytes is proposed which needs further larger studies to be validated and incorporated in daily ICU practice.
Subject(s)
Acute Kidney Injury/diagnosis , Acute Kidney Injury/urine , Critical Care/trends , Critical Illness , Forecasting , Urinalysis/methods , Urinalysis/trends , Biomarkers/urine , Critical Care/methods , Evidence-Based Medicine , Humans , Reproducibility of Results , Sensitivity and Specificity , Technology Assessment, BiomedicalABSTRACT
BACKGROUND: Acute kidney injury (AKI) is a common complication after cardiac surgery (CS). Recently, neutrophil gelatinase-associated lipocalin (NGAL) was shown to predict AKI development earlier than serum creatinine, but it is not widely used in clinical practice. Fractional excretion of urea (FeU) has been referred to as a useful tool to discriminate between prerenal and established AKI. The aim of our study is to evaluate the sensitivity and specificity of FeU, in the early diagnosis of AKI in patients undergoing CS. METHODS: We performed a prospective study on adults undergoing CS. AKI was defined by AKIN criteria. Individuals suffering from CKD, were excluded. Sensitivity and specificity of FeU, fractional excretion of sodium (FeNa) and urine NGAL, measured at 1, 6 and 24 h following CS, were assessed. RESULTS: We included 66 patients (26% female) aging 68 ± 11 years. AKI prevalence was 24% and mortality was 3.28%. Patients with AKI had a significantly lower FeU compared to those without AKI (23.89 ± 0.67% vs. 34.22 ± 0.58%; p < 0.05) 6 h after CS, but not at the 1- and 24-h time points. NGAL was also statistically significant between both groups. FeU showed a 75% sensitivity and 79.5% specificity; the AUC was 0.786. ROC analysis of FeU and NGAL yielded similar values (p = NS). CONCLUSION: FeU is useful as an early biomarker to predict AKI after CS and it is comparable to the new biomarker NGAL.
Subject(s)
Acute Kidney Injury/diagnosis , Acute Kidney Injury/etiology , Cardiac Surgical Procedures/adverse effects , Urea/blood , Urea/urine , Acute Kidney Injury/blood , Acute Kidney Injury/urine , Acute-Phase Proteins/urine , Aged , Biomarkers/blood , Biomarkers/urine , Early Diagnosis , Female , Humans , Lipocalin-2 , Lipocalins/urine , Male , Prospective Studies , Proto-Oncogene Proteins/urine , Sensitivity and SpecificityABSTRACT
Introducción: la fracción de excreción de los electrólitos puede constituir un marcador temprano de daño renal en las glomerulopatías. Objetivo: identificar la posible relación existente entre variables clínicas, fracción de excreción de magnesio y estado del túbulo-intersticio, en pacientes con proteinuria nefrótica a los que se les realizó biopsia renal en el Instituto de Nefrología entre abril de 2012 y junio de 2013. Métodos: se realizó un estudio observacional analítico, transversal, en el que se excluyeron los pacientes con factores que modificaran la fracción de excreción de magnesio. A los 40 pacientes incluidos en el estudio se les recogieron datos antropométricos, demográficos y clínicos, se les midió la fracción de excreción de magnesio, se les practicó biopsia renal y se les cuantificó el porcentaje de fibrosis con el programa Image J. La información fue procesada mediante el paquete estadístico SPSS 15.0. Se utilizó la técnica estadística de análisis de distribución de frecuencias, en las variables cuantitativas se calcularon estadígrafos descriptivos. Fueron empleados los tests de Wilcoxon, de Kruskal Wallis y el coeficiente de correlación de Spearman's-rho, en las pruebas de hipótesis. Resultados: se encontró correlación estadísticamente significativa de la fibrosis intersticial con la fracción de excreción de magnesio (r sp= 0,37, p= 0,02) y con la tasa de filtración glomerular (r sp= -0,56, p= 0,00). No fue encontrada asociación de la fracción de excreción de magnesio con el empleo de medicamentos, ni con el antecedente de hipertensión arterial. Conclusión: la fibrosis intersticial se relaciona con la fracción de excreción de magnesio y con la tasa de filtración glomerular en pacientes con proteinuria nefrótica.(AU)
Introduction: fractional excretion of electrolytes can be used as an early marker of renal damage in glomerulopathies. Objective: to identify the possible relationship between some clinical variables, the fractional excretion of magnesium and the tubulointerstitial status in patients with nephrotic proteinuria assisted at The National Institute of Nephrology from April 2012 to June 2013. Methods: an observational analytical study was conducted. Patients with conditions that modify the fractional excretion of magnesium were excluded. 40 patients were included in this study at the Institute of Nephrology from April 2012 until June 2013, and their demographic, anthropometric and clinical data were collected; the fractional excretion of magnesium was measured as well. Renal biopsies were practiced to all patients and the percent of fibrosis was measured with the aid of image J program. Data were processed with Statistical package for Social Science (SPSS) version 15.0. The statistical technique of frequency distribution analysis was used; quantitative variables descriptive statistics were calculated. Wilcoxon tests, Kruskal Wallis and correlation coefficient Spearman's- rho were used in hypothesis tests. Results: the percent of interstitial fibrosis was related to fractional excretion of magnesium (rsp= 0,37, p= 0,02) and glomerular filtration rate (rsp= -0,56, p= 0,00). No association of the fractional excretion of magnesium with the use of drugs or with history of hypertension was found. Conclusions: tubulointerstitial fibrosis is related to the fractional excretion of magnesium and glomerular filtration rate in patients with nephrotic proteinuria.(AU)
Subject(s)
Humans , Nephritis, Interstitial/diagnosis , Proteinuria/pathology , Magnesium , Nephrotic Syndrome/diagnosis , Modalities, Secretion and ExcretionABSTRACT
INTRODUCCIÓN: la fracción de excreción de los electrólitos puede constituir un marcador temprano de daño renal en las glomerulopatías. OBJETIVO: identificar la posible relación existente entre variables clínicas, fracción de excreción de magnesio y estado del túbulo-intersticio, en pacientes con proteinuria nefrótica a los que se les realizó biopsia renal en el Instituto de Nefrología entre abril de 2012 y junio de 2013. MÉTODOS: se realizó un estudio observacional analítico, transversal, en el que se excluyeron los pacientes con factores que modificaran la fracción de excreción de magnesio. A los 40 pacientes incluidos en el estudio se les recogieron datos antropométricos, demográficos y clínicos, se les midió la fracción de excreción de magnesio, se les practicó biopsia renal y se les cuantificó el porcentaje de fibrosis con el programa Image J. La información fue procesada mediante el paquete estadístico SPSS 15.0. Se utilizó la técnica estadística de análisis de distribución de frecuencias, en las variables cuantitativas se calcularon estadígrafos descriptivos. Fueron empleados los tests de Wilcoxon, de Kruskal Wallis y el coeficiente de correlación de Spearman's-rho, en las pruebas de hipótesis. RESULTADOS: se encontró correlación estadísticamente significativa de la fibrosis intersticial con la fracción de excreción de magnesio (rsp= 0,37, p= 0,02) y con la tasa de filtración glomerular (rsp= -0,56, p= 0,00). No fue encontrada asociación de la fracción de excreción de magnesio con el empleo de medicamentos, ni con el antecedente de hipertensión arterial. CONCLUSIÓN: la fibrosis intersticial se relaciona con la fracción de excreción de magnesio y con la tasa de filtración glomerular en pacientes con proteinuria nefrótica.
INTRODUCTION: fractional excretion of electrolytes can be used as an early marker of renal damage in glomerulopathies. OBJECTIVE: to identify the possible relationship between some clinical variables, the fractional excretion of magnesium and the tubulointerstitial status in patients with nephrotic proteinuria assisted at The National Institute of Nephrology from April 2012 to June 2013. METHODS: an observational analytical study was conducted. Patients with conditions that modify the fractional excretion of magnesium were excluded. 40 patients were included in this study at the Institute of Nephrology from April 2012 until June 2013, and their demographic, anthropometric and clinical data were collected; the fractional excretion of magnesium was measured as well. Renal biopsies were practiced to all patients and the percent of fibrosis was measured with the aid of image J program. Data were processed with Statistical package for Social Science (SPSS) version 15.0. The statistical technique of frequency distribution analysis was used; quantitative variables descriptive statistics were calculated. Wilcoxon tests, Kruskal Wallis and correlation coefficient Spearman's- rho were used in hypothesis tests. RESULTS: the percent of interstitial fibrosis was related to fractional excretion of magnesium (rsp= 0,37, p= 0,02) and glomerular filtration rate (rsp= -0,56, p= 0,00). No association of the fractional excretion of magnesium with the use of drugs or with history of hypertension was found. CONCLUSIONS: tubulointerstitial fibrosis is related to the fractional excretion of magnesium and glomerular filtration rate in patients with nephrotic proteinuria.
Subject(s)
Humans , Proteinuria/pathology , Magnesium , Nephritis, Interstitial/diagnosis , Nephrotic Syndrome/diagnosis , Modalities, Secretion and ExcretionABSTRACT
O objetivo do presente trabalho foi avaliar os efeitos do tratamento com dimetilsulfóxido (DMSO) sobre aspectos pertinentes à função renal, perfil bioquímico sérico, parâmetros hematológicos e condição clínica de cães sadios e de cães com doença renal crônica (DRC). As avaliações foram feitas antes, durante e após a administração de DMSO a 10% na dose de 0,5g kg-1, cada 24h, por três dias. O DMSO resultou em alguns efeitos adversos nos cães sadios e também nos cães com DRC, nos quais os efeitos foram mais frequentes e mais graves. Apesar desses efeitos adversos, tanto em cães sadios quanto para cães com DRC 2-3, não há contraindicações para o uso do fármaco quando em curto espaço de tempo. A gravidade dos efeitos adversos relacionados ao tratamento com DMSO e possível associação com o óbito em cães com DRC em estádio 4, constituem fatores para contraindicação do fármaco nesse grupo de pacientes.
The objective of this study was to evaluate the effects of dimethyl sulfoxide (DMSO) treatment on aspects of renal function, serum profile, total blood count parameters and clinical condition of health or chronic kidney disease (CKD) dogs. The evaluations were done before, during and after the administration of DMSO 10% at a dose of 0.5g kg-1, each 24h, for three days. DMSO resulted in some adverse effects in both healthy and CKD dogs, however the effects were more frequent and worse in CKD dogs. Despite these adverse effects, both groups don't have contraindications to use the drug in a short time. The severity of adverse effects related to the DMSO and its possible association with death in stage 4 CKD dogs, are contraindications for the drug in this group of patients.
ABSTRACT
Introducción: La hiponatremia es el trastorno hidroelectrolítico más común entre pacientes internados. Conocer de manera precoz el estado del líquido extracelular (LEC) para el estudio de las causas de hiponatremia y su posterior tratamiento es de suma importancia. Se ha planteado la posibilidad de utilizar la excreción fraccional de ácido úrico (EFAU) como herramienta complemetaria para discernir LEC normal de LEC disminuído, incluso en pacientes bajo tratamiento diurético. Métodos: Se evaluaron en 45 pacientes seleccionados en forma prospectiva, parámetros clínicos y de laboratorio habituales al momento del diagnóstico de hiponatremia, para definir el estado del LEC. Una vez definido éste, se calculó la EFAU. Resultados: Se observó que en los 21 pacientes que conformaron el grupo de LEC disminuido, la tensión arterial, la natriuria, la excreción fraccional de sodio, la excreción fraccional de urea y la EFAU fueron significativamente menores (p < 0.05) que en los 24 pacientes del grupo LEC normal. Dentro de estas variables, la EFAU fue la de mayor sensibilidad y especificidad para predecir LEC disminuido, con un valor de corte < 10.9 %. Dentro del subgrupo de 15 pacientes que recibían diuréticos, la EFAU < 10.9 % tuvo una sensibilidad de 100% y una especificidad de 100% para predecir LEC disminuido. Conclusión: Así, la EFAU debería instaurarse dentro del protocolo de estudio de un paciente con hiponatremia, dado que, realizada con muestra aislada de sangre y orina, es un método sencillo y eficaz para efectuar en la urgencia, sobre todo en pacientes con diuréticos.(AU)
Introduction: Hyponatremia is the most common hydroelectrolitic disorder in hospitalized patients. It is essential to acquire an early understanding of the extracellular liquid (ECL) status for the study of the causes of hyponatremia and its subsequent treatment. The possibility of using the fractional excretion of uric acid (FEUA) as a supplementary tool to distinguish normal ECL from reduced ECL has been considered, including patients undergoing diuretic treatment. Methods: The typical clinical and laboratory parameters were examined at the time of the diagnosis of hyponatremia in 45 patients prospectively selected, to define the status of ECL. Once defined, the FEUA was estimated. Results: For the 21 patients within the reduced ECL group, blood pressure, natriuria, fractional excretion of sodium, fractional excretion of urea and FEUA were significantly lower (p < 0.05) than for the 24 patients within the normal ECL group. Among these variables, the FEUA was the one which showed more sensitivity and specificity to predict a reduced ECL, with a cutoff value < 10.9 %. Within the of 15 patients on diuretic treatment, FEUA < 10.9 % had a 100% sensitivity and a 100% specificity to predict a reduced ECL. Conclusion: Therefore, the FEUA should be included in the study protocol of a patient with hyponatremia,since when performed in an isolated sample of blood andurine, it constitutes a simple and efficient method to be implemented under emergency situations, especially in patients receiving diuretics.(AU)
Subject(s)
Uric Acid , HyponatremiaABSTRACT
Introducción: La hiponatremia es el trastorno hidroelectrolítico más común entre pacientes internados. Conocer de manera precoz el estado del líquido extracelular (LEC) para el estudio de las causas de hiponatremia y su posterior tratamiento es de suma importancia. Se ha planteado la posibilidad de utilizar la excreción fraccional de ácido úrico (EFAU) como herramienta complemetaria para discernir LEC normal de LEC disminuído, incluso en pacientes bajo tratamiento diurético. Métodos: Se evaluaron en 45 pacientes seleccionados en forma prospectiva, parámetros clínicos y de laboratorio habituales al momento del diagnóstico de hiponatremia, para definir el estado del LEC. Una vez definido éste, se calculó la EFAU. Resultados: Se observó que en los 21 pacientes que conformaron el grupo de LEC disminuido, la tensión arterial, la natriuria, la excreción fraccional de sodio, la excreción fraccional de urea y la EFAU fueron significativamente menores (p < 0.05) que en los 24 pacientes del grupo LEC normal. Dentro de estas variables, la EFAU fue la de mayor sensibilidad y especificidad para predecir LEC disminuido, con un valor de corte < 10.9 %. Dentro del subgrupo de 15 pacientes que recibían diuréticos, la EFAU < 10.9 % tuvo una sensibilidad de 100% y una especificidad de 100% para predecir LEC disminuido. Conclusión: Así, la EFAU debería instaurarse dentro del protocolo de estudio de un paciente con hiponatremia, dado que, realizada con muestra aislada de sangre y orina, es un método sencillo y eficaz para efectuar en la urgencia, sobre todo en pacientes con diuréticos.
Introduction: Hyponatremia is the most common hydroelectrolitic disorder in hospitalized patients. It is essential to acquire an early understanding of the extracellular liquid (ECL) status for the study of the causes of hyponatremia and its subsequent treatment. The possibility of using the fractional excretion of uric acid (FEUA) as a supplementary tool to distinguish normal ECL from reduced ECL has been considered, including patients undergoing diuretic treatment. Methods: The typical clinical and laboratory parameters were examined at the time of the diagnosis of hyponatremia in 45 patients prospectively selected, to define the status of ECL. Once defined, the FEUA was estimated. Results: For the 21 patients within the reduced ECL group, blood pressure, natriuria, fractional excretion of sodium, fractional excretion of urea and FEUA were significantly lower (p < 0.05) than for the 24 patients within the normal ECL group. Among these variables, the FEUA was the one which showed more sensitivity and specificity to predict a reduced ECL, with a cutoff value < 10.9 %. Within the of 15 patients on diuretic treatment, FEUA < 10.9 % had a 100% sensitivity and a 100% specificity to predict a reduced ECL. Conclusion: Therefore, the FEUA should be included in the study protocol of a patient with hyponatremia,since when performed in an isolated sample of blood andurine, it constitutes a simple and efficient method to be implemented under emergency situations, especially in patients receiving diuretics.
Subject(s)
Hyponatremia , Uric AcidABSTRACT
The objective of this study was to evaluate the effects of dimethyl sulfoxide (DMSO) treatment on aspects of renal function, serum profile, total blood count parameters and clinical condition of health or chronic kidney disease (CKD) dogs. The evaluations were done before, during and after the administration of DMSO 10% at a dose of 0.5g kg-1, each 24h, for three days. DMSO resulted in some adverse effects in both healthy and CKD dogs, however the effects were more frequent and worse in CKD dogs. Despite these adverse effects, both groups don't have contraindications to use the drug in a short time. The severity of adverse effects related to the DMSO and its possible association with death in stage 4 CKD dogs, are contraindications for the drug in this group of patients.
O objetivo do presente trabalho foi avaliar os efeitos do tratamento com dimetilsulfóxido (DMSO) sobre aspectos pertinentes à função renal, perfil bioquímico sérico, parâmetros hematológicos e condição clínica de cães sadios e de cães com doença renal crônica (DRC). As avaliações foram feitas antes, durante e após a administração de DMSO a 10% na dose de 0,5g kg-1, cada 24h, por três dias. O DMSO resultou em alguns efeitos adversos nos cães sadios e também nos cães com DRC, nos quais os efeitos foram mais frequentes e mais graves. Apesar desses efeitos adversos, tanto em cães sadios quanto para cães com DRC 2-3, não há contraindicações para o uso do fármaco quando em curto espaço de tempo. A gravidade dos efeitos adversos relacionados ao tratamento com DMSO e possível associação com o óbito em cães com DRC em estádio 4, constituem fatores para contraindicação do fármaco nesse grupo de pacientes.
ABSTRACT
The objective of this study was to evaluate the effects of dimethyl sulfoxide (DMSO) treatment on aspects of renal function, serum profile, total blood count parameters and clinical condition of health or chronic kidney disease (CKD) dogs. The evaluations were done before, during and after the administration of DMSO 10% at a dose of 0.5g kg-1, each 24h, for three days. DMSO resulted in some adverse effects in both healthy and CKD dogs, however the effects were more frequent and worse in CKD dogs. Despite these adverse effects, both groups don't have contraindications to use the drug in a short time. The severity of adverse effects related to the DMSO and its possible association with death in stage 4 CKD dogs, are contraindications for the drug in this group of patients.
O objetivo do presente trabalho foi avaliar os efeitos do tratamento com dimetilsulfóxido (DMSO) sobre aspectos pertinentes à função renal, perfil bioquímico sérico, parâmetros hematológicos e condição clínica de cães sadios e de cães com doença renal crônica (DRC). As avaliações foram feitas antes, durante e após a administração de DMSO a 10% na dose de 0,5g kg-1, cada 24h, por três dias. O DMSO resultou em alguns efeitos adversos nos cães sadios e também nos cães com DRC, nos quais os efeitos foram mais frequentes e mais graves. Apesar desses efeitos adversos, tanto em cães sadios quanto para cães com DRC 2-3, não há contraindicações para o uso do fármaco quando em curto espaço de tempo. A gravidade dos efeitos adversos relacionados ao tratamento com DMSO e possível associação com o óbito em cães com DRC em estádio 4, constituem fatores para contraindicação do fármaco nesse grupo de pacientes.
ABSTRACT
The objective of this study was to evaluate the effects of dimethyl sulfoxide (DMSO) treatment on aspects of renal function, serum profile, total blood count parameters and clinical condition of health or chronic kidney disease (CKD) dogs. The evaluations were done before, during and after the administration of DMSO 10% at a dose of 0.5g kg-1, each 24h, for three days. DMSO resulted in some adverse effects in both healthy and CKD dogs, however the effects were more frequent and worse in CKD dogs. Despite these adverse effects, both groups don't have contraindications to use the drug in a short time. The severity of adverse effects related to the DMSO and its possible association with death in stage 4 CKD dogs, are contraindications for the drug in this group of patients.
O objetivo do presente trabalho foi avaliar os efeitos do tratamento com dimetilsulfóxido (DMSO) sobre aspectos pertinentes à função renal, perfil bioquímico sérico, parâmetros hematológicos e condição clínica de cães sadios e de cães com doença renal crônica (DRC). As avaliações foram feitas antes, durante e após a administração de DMSO a 10% na dose de 0,5g kg-1, cada 24h, por três dias. O DMSO resultou em alguns efeitos adversos nos cães sadios e também nos cães com DRC, nos quais os efeitos foram mais frequentes e mais graves. Apesar desses efeitos adversos, tanto em cães sadios quanto para cães com DRC 2-3, não há contraindicações para o uso do fármaco quando em curto espaço de tempo. A gravidade dos efeitos adversos relacionados ao tratamento com DMSO e possível associação com o óbito em cães com DRC em estádio 4, constituem fatores para contraindicação do fármaco nesse grupo de pacientes.