Análisis clínicos en pediatría: la necesidad de minimizar las horas de ayuno / Clinical analysis in pediatrics: the need to minimize fasting hours

Los informes de laboratorio tienen impacto en las decisiones médicas. El ayuno es un factor preanalítico "controlable" que influye en los distintos parámetros bioquímicos. El objetivo del presente trabajo es poner en discusión la realización en pediatría de análisis clínicos con la indicación de un ayuno fisiológico , analizando resultados obtenidos por diferentes autores y evaluando las diferencias clínicas encontradas según los criterios de calidad establecidos por el laboratorio de Química Clínica. La mayoría de los individuos durante el día se encuentran en estado postprandial. Los resultados del perfil lipídico en ayunas no representan las concentraciones reales promedios de los lípidos plasmáticos de un paciente. El ayuno no sería crítico en la etapa de pesquisa , pero puede ser relevante para establecer un diagnóstico certero o inicio de tratamiento. En el caso de la glucemia si se indica en el control rutinario del paciente, y no hay sospecha de alteraciones en el metabolismo de los hidratos de carbono la glucemia sin ayuno puede ser solicitada comparando la misma con valores de corte adecuado. Las diferentes guías nacionales e internacionales recomiendan que la elección de la métrica para la evaluación, control y seguimiento de pacientes con diagnóstico de diabetes se realicen según el objetivo terapéutico. En los trabajos analizados, observamos que varios parámetros bioquímicos presentaron diferencias estadísticas, aunque las diferencias clínicas no fueron relevantes y permanecieron dentro de los intervalos de referencia. El factor limitante para evaluar parámetros bioquímicos sin ayuno es la falta de valores de referencia adecuados. Hay evidencia suficiente para que tanto el perfil lipídico, la glucemia como el resto de los parámetros bioquímicos del laboratorio de química clínica, sean solicitados con la indicación de un ayuno fisiológico de 2, 4 o 6 horas, dependiendo siempre del motivo de consulta y/o la edad del paciente. Es esencial extender la evaluación a otros analitos en población pediátrica, así como evaluar nuevos puntos de corte para parámetros bioquímicos sin ayuno (AU)

Laboratory reports have an impact on medical decision-making. Fasting is a "controllable" preanalytical factor that influences the different biochemical parameters. The aim of this study is to discuss the performance of clinical analyses in pediatrics with the indication of physiological fasting, analyzing results obtained in different disciplines, and evaluating the clinical differences found according to the quality criteria established by the clinical chemistry laboratory. During the day, most patients are in a postprandial state. Fasting lipid profile results do not represent the actual average plasma lipid concentrations of a patient. Fasting would not be critical in the screening stage, but it may be relevant to establish an accurate diagnosis or initiate treatment. Regarding glycemia, if it is indicated in the routine control of the patient and there is no suspicion of alterations in carbohydrate metabolism, non-fasting glycemia can be requested, comparing it with adequate cut-off values. Different national and international guidelines recommend that the choice of metrics for the evaluation, control, and follow-up of patients with diabetes should be made according to the therapeutic objective. In the studies analyzed, we found that several biochemical parameters presented statistical differences, although the clinical differences were not relevant and remained within the reference range. The limiting factor in the evaluation of biochemical parameters without fasting is the lack of adequate reference values. There is sufficient evidence that the lipid profile, glycemia, and the remaining biochemical parameters of the clinical chemistry laboratory should be requested with the indication of a physiological fast of 2, 4, or 6 hours, always depending on the reason for consultation and/or the patient's age. It is essential to extend the evaluation to other analytes in the pediatric population, as well as to evaluate new cut-off points for biochemical parameters without fasting (AU)

EQA-based evaluation of metrological traceability of clinical chemistry test results in Argentina / EQA-based evaluation of metrological traceability of clinical chemistry test results in Argentina

Equivalence of results among laboratories is a major mission for medical laboratories. In the Netherlands, medical laboratories only use homogenous, commercial for general chemistry analytes, whereas in Argentina heterogenous, home brew test applications are common. The effect of this practice difference on test accuracy is studied using key features of the accuracy-based EQA program of the Netherlands. Six frozen, human-based, commutable poolsera, covering the (patho) physiological measuring range for 17 general chemistry analytes, were assayed by ~75 Argentinian labs and ~200 Dutch laboratories in 2014. After removal of outliers, harmonization status among laboratories was evaluated by calculating overall mean interlaboratory coefficients of variation (CVs, %) per analyte and per country for all 6 levels. Evenso, standardization status was evaluated after removal of outliers by calculating overall mean recoveries (%) as compared to the assigned target values per analyte per country for all 6 levels. Absolute median biases were compared to (minimal/desirable) biases derived from biological variation criteria. For serum enzymes interlaboratory CVs in the Argentinian laboratories ranged between 10 and 22%, as compared to 3-6% in the Netherlands. For serum uric acid, creatinine, glucose and total protein, interlaboratory CVs varied between 4.3 and 13.1% in Argentinian labs, as compared to <3.5% in the Netherlands. For serum electrolytes, interlaboratory CVs ranged between 1.8 and 3.8% for Na+; 2.9-5.8% for Cl-; 3.8-7.5% for K+; 9.4-10.4% for Ca2+ and 16.2-22.3% for Mg2+ as compared to ≤2% (Na+, K+, Cl-, Ca2+) and ≤3% (Mg2+) in the Netherlands. Mean recoveries in Argentinian laboratories for e.g. serum creatinine, glucose, CK, Ca2+ and Na+ were 95-119%; 95-104%; 98-102%; 98-102% and 96-100% respectively, whereas min-max recovery ranges were 65-155%; 58-126%; 47-132%; 66-132% and 85-115%. In the Netherlands, absolute mean recoveries were overall 98.9% with a SD of 2.0%. Median biases in Argentinian laboratories ranged from -2.9 to 18.2%; -3.1 - 2.6%; -3.3 - 0.5%; -1.1 - 3.8% and -4.3-0% for serum creatinine, glucose, CK, Ca2+ and Na+. In the Netherlands overall mean/median biases were 1.1% (SD=2.0%). Exchange of commutable, value- assigned EQA-materials was helpful for studying the harmonization and standardization status of medical tests in Argentina, and for revealing the future harmonization and standardization potential. The results clearly demonstrate that metrological traceability of test results in Argentina is on average in line with what is expected; yet, the spreading among laboratories is far too high and should be improved.

La equivalencia de resultados entre laboratorios es una mision importante para los laboratorios medicos. En los Paises Bajos, los laboratorios medicos solo usan aplicaciones comerciales homogeneas, regulatoriamente aprobadas (CE-IVD) para analitos quimicos, mientras que en la Argentina son comunes las aplicaciones heterogeneas caseras. El efecto de esta diferencia practica en la precision de la prueba se estudia utilizando caracteristicas clave del programa EQA, basado en la precision, de los Paises Bajos. Se ensayaron seis pools de sueros, congelados, de origen humano, conmutables, que cubrian el rango de medidas (pato)fisiologicas para 17 analitos de quimica clinica. Estos analitos de quimica clinica fueron analizados por ~75 laboratorios argentinos y ~200 laboratorios holandeses en 2014. Despues de eliminar los valores atipicos, el estado de armonizacion entre los laboratorios fue evaluado calculando los coeficientes de variacion interlaboratorios medios globales (CV%) por analito y por pais para los 6 niveles. No obstante, el estado de estandarizacion se evaluo despues de la eliminacion de valores atipicos mediante el calculo de recuperaciones medias generales (%) en comparacion con los valores asignados por analito por pais para los 6 niveles. Los sesgos medios absolutos se compararon con los sesgos (minimos / deseables) derivados de los criterios de variacion biologica. Para enzimas sericas los CV interlaboratorio en los laboratorios argentinos oscilaron entre 10 y 22%, en comparacion con 3-6% en los Paises Bajos. Para el acido urico serico, creatinina, glucosa y proteinas totales, los CV entre laboratorios variaron entre 4,3 y 13,1% en los laboratorios argentinos, en comparacion con <3,5% en los Paises Bajos. Para los electrolitos sericos, los CV interlaboratorios oscilaron entre 1,8 y 3,8% para Na+; 2,9-5,8% para Cl-; 3,8-7,5% para K+; 9,4-10,4% para Ca2+ y 16,2-22,3% para Mg2+ en comparacion a ≤2% (Na+, K+, Cl-, Ca2+) y ≤3% (Mg2+) en los Paises Bajos. Las recuperaciones medias en laboratorios argentinos para, p.ej. la creatinina serica, glucosa, CK, Ca2+ y Na+ fueron 95-119%; 95-104%; 98-102%; 98-102% y 96-100% respectivamente, mientras que los rangos de recuperacion min-max fueron 65-155%; 58-126%; 47-132%; 66-132% y 85-115%. En los Paises Bajos, las recuperaciones medias absolutas fueron en general del 98,9% con una desviacion estandar (DE) del 2,0%. La mediana de los sesgos medios de los laboratorios argentinos oscilo entre -2,9 y 18,2%; -3,1 - 2,6%; -3,3 - 0,5%; -1,1 - 3,8% y -4,3-0% para creatinina serica, glucosa, CK, Ca2+ y Na+. En los Paises Bajos, las medias / medianas en general fueron de 1,1% (DE=2,0%). El intercambio de los valores asignados a los materiales EQA, conmutables fue de gran ayuda para la armonizacion y estandarizacion de los ensayos medicos en la Argentina y para revelar el potencial futuro de armonizacion y estandarizacion. Estos resultados claramente demuestran que la trazabilidad metrologica de los resultados de las pruebas en la Argentina esta, en promedio, de acuerdo con lo esperable; sin embargo, la dispersion entre laboratorios es muy grande y deberia ser mejorada.

A equivalencia de resultados entre laboratorios e uma missao importante para os laboratorios medicos. Nos Paises Baixos, os laboratorios medicos so utilizam aplicacoes comerciais homogeneas, aprovadas por regulacoes (CE-IVD) para analitos quimicos, ao passo que na Argentina sao comuns as aplicacoes heterogeneas caseiras. O efeito desta diferenca pratica na exatidao do teste e estudado utilizando caracteristicas essenciais do programa EQA, dos Paises Baixos, baseado na exatidao. Foram ensaiados seis pools de soros, congelados, de origem humana, comutaveis, que abrangiam a faixa de medidas (pato)fisiologicas para 17 analitos quimicos gerais. Esses analitos quimicos foram analisados por ~75 laboratorios argentinos e ~200 laboratorios holandeses em 2014. Apos eliminar os valores atipicos, o estado de harmonizacao entre os laboratorios foi avaliado atraves do calculo dos coeficientes de variacao interlaboratorio meios globais (CV%) por analito e por pais para os 6 niveis. Nao obstante, o estado de padronizacao foi avaliado depois da eliminacao de valores atipicos pelo calculo de recuperacoes medias gerais (%) se comparados com os valores atribuidos por analito por pais para os 6 niveis. Os vieses medios absolutos foram comparados com os vieses (minimos / desejaveis) decorrentes dos criterios de variacao biologica. Para enzimas sericas, os CV interlaboratorio nos laboratorios argentinos oscilaram entre 10 e 22%, em comparacao com 3-6% nos Paises Baixos. Para o acido urico serico, creatinina, glicose e proteinas totais, os CV entre laboratorios variaram entre 4,3 e 13,1% nos laboratorios argentinos, em comparacao com <3,5% nos Paises Baixos para os eletrolitos sericos, os CV interlaboratorios oscilaram entre 1,8 e 3,8% para Na+; 2,9-5,8% para Cl-; 3,8-7,5% para K+; 9,4-10,4% para Ca2+ e 16,2-22,3% para Mg2+ em comparacao com ≤2% (Na+, K+, Cl-, Ca2+) e ≤3% (Mg2+) nos Paises Baixos. As recuperacoes medias em laboratorios argentinos para, p.ex. a creatinina serica, glicose, CK, Ca2+ e Na+ foram 95-119%; 95-104%; 98-102%; 98-102% e 96-100% respectivamente, enquanto que os intervalos de recuperacao min-max. foram 65-155%; 58-126%; 47-132%; 66-132% e 85-115%. Nos Paises Baixos, as recuperacoes medias absolutas foram em geral de 98,9% com um desvio padrao (DE) de 2,0%. A mediana dos vieses medios dos laboratorios argentinos oscilou entre -2,9 e 18,2%; -3,1 - 2,6%; -3,3 - 0,5%; -1,1 - 3,8% e -4,3-0% para creatinina serica, glicose, CK, Ca2+ e Na+. Nos Paises Baixos, as medias / medianas em geral foram de 1,1% (DE=2,0%). O intercambio dos valores atribuidos aos materiais EQA, comutaveis, foi de grande ajuda para a harmonizacao e padronizacao dos ensaios medicos na Argentina e para revelar o potencial futuro de harmonizacao e padronizacao. Esses resultados demonstram as claras que a rastreabilidade metrologica dos resultados dos testes na Argentina esta de acordo com o esperavel; a dispersao entre laboratorios ainda e muito grande e deveria ser melhorada.

Stability indicating RP-LC-PDA method for the quantitative analysis of saxagliptin in pharmaceutical dosage form / Estabilidade indicando o método de RP-LC-PDA para a análise quantitativa de saxagliptina em forma de dosagem farmacêutica

Saxagliptin is a potent and selective inhibitor of the enzyme dipeptidyl peptidase 4. It is effective in the treatment of type 2 diabetes mellitus because it stimulates the pancreas to produce insulin. In the present study, a liquid chromatography method was developed and validated to quantify the drug in tablets. This method was based on the isocratic elution of saxagliptin, using a mobile phase consisting of 0.1% phosphoric acid at pH 3.0 - methanol (70: 30, v/v) at a flow rate of 1 mL.min^-1 with UV detection at 225 nm. The chromatographic separation was achieved in 8 minutes on a Waters XBridge C18 column (250 mm x 4.6 mm, 5µm) maintained at ambient temperature. The proposed method proved to be specific and robust for the quality control of saxagliptin in pharmaceutical dosage forms, showing good linearity in the range of 15.0 - 100.0 µg.mL^-1 (r>0.999), precision (RSD<1.49%) and accuracy values between 99.42 and 101.59%. The method was found to be stability indicating and was successfully applied for the analysis of saxagliptin in tablets in a routine quality control laboratory...

A saxagliptina é uma inibidora potente e seletiva da enzima dipeptidil peptidase 4. É efetiva no tratamento do Diabete mellitus tipo 2, pois estimula a produção de insulina pelo pâncreas. No presente estudo, desenvolveu-se e validou-se método por cromatografia líquida de alta eficiência para quantificar o fármaco em comprimidos. O método foi baseado em eluição isocrática, utilizando fase móvel constituída por ácido fosfórico 0,1% pH 3,0-metanol (70 : 30, v/v), fluxo de 1,0 mL.min^-1, com detecção UV em 225 nm. A separação cromatográfica foi alcançada em 8 minutos em coluna Waters XBridge C18 (250 mm x 4,6 mm, 5 µm) mantida à temperatura ambiente. O método proposto mostrou-se específico e robusto para o controle de qualidade de saxagliptina em comprimidos, sendo linear na faixa de concentração de 15,0-100,0 µg.mL^-1 (r>0,999), preciso (RSD<1,49%) e exato, com resultados entre 99,42 e 101,59%. O método mostrou-se indicativo de estabilidade e foi aplicado com sucesso no controle de qualidade de saxagliptina em comprimidos...

Pharmacokinetic-pharmacodynamic correlation of imipenem in pediatric burn patients using a bioanalytical liquid chromatographic method / Correlação farmacocinética-farmacodinâmica de imipenem em pacientes queimados pediátricos utilizando um método bioanalítico de cromatografia líquida

A bioanalytical method was developed and applied to quantify the free imipenem concentrations for pharmacokinetics and PK/PD correlation studies of the dose adjustments required to maintain antimicrobial effectiveness in pediatric burn patients. A reverse-phase Supelcosil LC18 column (250 x 4.6 mm 5 micra), binary mobile phase consisting of 0.01 M, pH 7.0 phosphate buffer and acetonitrile (99:1, v/v), flow rate of 0.8 mL/min, was applied. The method showed good absolute recovery (above 90%), good linearity (0.25-100.0 µg/mL, r²=0.999), good sensitivity (LLOQ: 0.25 µg/mL; LLOD: 0.12 µg/mL) and acceptable stability. Inter/intraday precision values were 7.3/5.9%, and mean accuracy was 92.9%. A bioanalytical method was applied to quantify free drug concentrations in children with burns. Six pediatric burn patients (median 7.0 years old, 27.5 kg), normal renal function, and 33% total burn surface area were prospectively investigated; inhalation injuries were present in 4/6 (67%) of the patients. Plasma monitoring and PK assessments were performed using a serial blood sample collection for each set, totaling 10 sets. The PK/PD target attained (40%T>MIC) for each minimum inhibitory concentration (MIC: 0.5, 1.0, 2.0, 4.0 mg/L) occurred at a percentage higher than 80% of the sets investigated and 100% after dose adjustment. In conclusion, the purification of plasma samples using an ultrafiltration technique followed by quantification of imipenem plasma measurements using the LC method is quite simple, useful, and requires small volumes for blood sampling. In addition, a small amount of plasma (0.25 mL) is needed to guarantee drug effectiveness in pediatric burn patients. There is also a low risk of neurotoxicity, which is important because pharmacokinetics are unpredictable in these critical patients with severe hospital infection. Finally, the PK/PD target was attained for imipenem in the control of sepsis in pediatric patients...

Desenvolveu-se e aplicou-se método bioanalítico para quantificar concentrações de imipenem livre para estudos de farmacocinética (PK) e de correlação PK/PD dos ajustes de dose requeridos para manter a efetividade antimicrobiana em pacientes pediátricos queimados. Utilizou-se coluna Supelcosil LC18 (250 x 4,6 mm 5 micra), fase móvel binária, consistindo de tampão fosfato 0,01M pH 7,0 e acetonitrila (99:1, v/v) e fluxo de 0,8 mL/min. O método mostrou boa recuperação absoluta (acima de 90%), boa linearidade (0,25-100,0 µg/mL, r²=0.999), boa sensibilidade (LLOQ: 0,25 µg/mL; LLOD: 0,12 µg/mL) e estabilidade aceitável. Os valores de precisão inter/intradia foram 7,3/5,9% e a exatidão média foi de 92,9%. O método bioanalítico foi aplicado para quantificar concentrações de fármaco livre em crianças com queimaduras, Seis pacientes pediátricos queimados (idade média de 7,0 anos, 27,5 kg), com função renal normal e 33% da superfície total queimada foram investigados prospectivamente. Lesões por inalação estavam presentes em 4/6 (67%) dos pacientes. O monitoramento plasmático e a as avaliações de PK foram efetuadas utilizando coleção de amostras seriais de sangue para cada série, totalizando 10 conjuntos. O alvo PK/PD alcançado (40%T>MIC) para cada concentração inibitória mínima (MIC: 0,5, 1,0, 2,0, 4,0 mg/L) ocorreu em porcentagem maior do que 80% dos conjuntos investigados e 100% após o ajuste de dose. Em conclusão, a purificação das amostras do plasma usando técnica de ultrafiltração seguida de quantificação das medidas do imipenem no plasma usando método de cromatografia líquida é bastante simples, útil e necessita de pequenos volumes para as amostras de sangue. Além disso, pequena quantidade de plasma (0,25 mL) é necessário para garantir a efetividade do fármaco nos pacientes pediátricos queimados. Há, ainda, baixo risco de neurotoxicidade, o que é importante, visto que as farmacocinéticas são imprevisíveis nesses pacientes...

Differential pulse voltammetric determination of diclofenac in pharmaceutical preparations and human serum / Pulso diferencial determinação voltamétrica de diclofenaco em preparações farmacêuticas e em soro humano

This article describes a differential pulse voltammetric (DPV) method for the determination of diclofenac in pharmaceutical preparations and human serum. The proposed method was based on electro-oxidation of diclofenac at platinum electrode in 0.1 M TBAClO₄/acetonitrile solution. The well-defined two oxidation peaks were observed at 0.87 and 1.27 V, respectively. Calibration curves that obtained by using current values measured for second peak were linear over the concentration range of 1.5-17.5 μg mL^-1and 2-20 μg mL^-1 in supporting electrolyte and serum, respectively. Precision and accuracy were also checked in all media. Intra- and inter-day precision values for diclofenac were less than 3.87, and accuracy (relative error) was better than 4.12%. The method developed in this study is accurate, precise and can be easily applied to Diclomec, Dicloflam and Voltaren tablets as pharmaceutical preparation. In addition, the proposed technique was successfully applied to spiked human serum samples. No electro-active interferences from the endogenous substances were found in human serum...

Este artigo descreve um método de voltametria de pulso diferencial (VPD) para a determinação de diclofenaco em preparações farmacêuticas e em soro humano. O método proposto foi baseado em eletroxidação de diclofenaco no eléctrodo de platina em solução 0,1 M TBAClO₄/acetonitrila. Dois picos de oxidação bem definidos foram observados em 0,87 e 1,27 V, respectivamente. As curvas de calibração obtidas utilizando-se valores de corrente medidos por segundo pico foram lineares no intervalo de concentração de 1,5-17,5 μg mL^-1e 2-20 μg mL^-1em eletrólito suporte e soro, respectivamente. Precisão e exatidão também foram verificadas em todos os meios. Valores de precisão intra- e inter-dia para o diclofenaco foram inferiores a 3.87 e a precisão (erro relativo) foi melhor do que 4,12%. O método desenvolvido neste estudo é exato, preciso e pode ser facilmente aplicado a Diclomec, Dicloflam e comprimidos Voltaren, como preparação farmacêutica. Além disso, a técnica proposta foi aplicada com sucesso em amostras de soro humano. Não se observaram interferências das substâncias endógenas no soro humano...

Caracterización clínica, antropométrica y de laboratorio, de mujeres con diabetes mellitus tipo 2 / Clinical, anthropometric and laboratory characterization of women with type 2 diabetes mellitus

Introducción: la diabetes mellitus es un problema de salud pública cuya mejor comprensión ayudaría a reducir sus complicaciones. Objetivo: caracterizar las pacientes con diabetes mellitus tipo 2 a partir de variables clínicas, antropométricas y de laboratorio. Métodos: estudio transversal descriptivo en el municipio Holguín a una muestra probabilística por conglomerados de 134 mujeres con factores de riesgo. Se aplicó el ANOVA, la prueba de Mann-Whitney y X2 con α = 0,05 en SPSS. Resultados: la frecuencia de diabetes mellitus fue del 43,2 por ciento. Las diabéticas presentaron valores superiores de la edad, circunferencia abdominal, del índice cintura/cadera, de la presión arterial, de la glucemia y los triglicéridos que el grupo sin diabetes mellitus (n = 74), lo contrario ocurrió con la circunferencia de cadera. Se encontró una asociación significativa entre la diabetes mellitus y la presencia del síndrome metabólico (X2 = 41,570; p = 0,000). La diabetes se relacionó con el exceso de peso corporal (X2 = 7,506; p = 0,023), la cardiopatía isquémica (X2 = 6,778; p = 0,009) y la hipertensión arterial (X2 = 5,245, p = 0,022), aunque no se asoció con el hábito de fumar (X2 = 0,233, p = 0,629). Conclusiones: es importante la caracterización de la diabetes mellitus por la elevada frecuencia de comorbilidad como el síndrome metabólico, la cardiopatía isquémica, la hipertensión arterial, la obesidad, las dislipidemias aterógenas, y se recomienda la intervención de estas pacientes con cambios en el estilo de vida, la incorporación de nuevas variables y la extensión de la investigación a la provincia Holguín.

Introduction: The diabetes mellitus is a public health problem and its understanding would help to reduce complications. Objective: Characterizing the patients with type 2 diabetes mellitus based on clinical, anthropometric, and laboratory variables. Methods: Cross-sectional study in the municipality of Holguin to a prospective sample per groups of 134 women with risk factors. We applied the ANOVA, the Mann-Whitney test and X2 with α = 0,05, in SPSS. Results: The diabetes mellitus frequency was 43,2 per cent. Diabetic women had higher values of age, waist circumference, waist/hip ratio, blood pressure, blood glucose and triglycerides than patients without diabetes mellitus (n = 74); the opposite occurred with the hip circumference. It was found a significant association between the diabetes mellitus and the presence of the metabolic syndrome ( X2 = 41,570; p = 0,000). The diabetes was associated with the body weight excess ( X2 = 7,506; p = 0,023), the ischemic heart disease ( X2 = 6,778; p = 0,009), and the arterial hypertension ( X2 = 5,245, p = 0,022), although it was not associated with smoking ( X2 = 0,233, p = 0,629). Conclusions: It is important the characterization of the diabetes mellitus because of the high frequency of co-morbidities such as the metabolic syndrome, the ischemic heart disease, the arterial hypertension, the obesity, the atherogenic dyslipidemia. We recommend the intervention of these patients with changes in their lifestyle, incorporating new variables and extending the research to the province of Holguin.

New Decision Criteria for Selecting Delta Check Methods Based on the Ratio of the Delta Difference to the Width of the Reference Range Can Be Generally Applicable for Each Clinical Chemistry Test Item

BACKGROUND: Many laboratories use 4 delta check methods: delta difference, delta percent change, rate difference, and rate percent change. However, guidelines regarding decision criteria for selecting delta check methods have not yet been provided. We present new decision criteria for selecting delta check methods for each clinical chemistry test item. METHODS: We collected 811,920 and 669,750 paired (present and previous) test results for 27 clinical chemistry test items from inpatients and outpatients, respectively. We devised new decision criteria for the selection of delta check methods based on the ratio of the delta difference to the width of the reference range (DD/RR). Delta check methods based on these criteria were compared with those based on the CV% of the absolute delta difference (ADD) as well as those reported in 2 previous studies. RESULTS: The delta check methods suggested by new decision criteria based on the DD/RR ratio corresponded well with those based on the CV% of the ADD except for only 2 items each in inpatients and outpatients. Delta check methods based on the DD/RR ratio also corresponded with those suggested in the 2 previous studies, except for 1 and 7 items in inpatients and outpatients, respectively. CONCLUSIONS: The DD/RR method appears to yield more feasible and intuitive selection criteria and can easily explain changes in the results by reflecting both the biological variation of the test item and the clinical characteristics of patients in each laboratory. We suggest this as a measure to determine delta check methods.

New Decision Criteria for Selecting Delta Check Methods Based on the Ratio of the Delta Difference to the Width of the Reference Range Can Be Generally Applicable for Each Clinical Chemistry Test Item

BACKGROUND: Many laboratories use 4 delta check methods: delta difference, delta percent change, rate difference, and rate percent change. However, guidelines regarding decision criteria for selecting delta check methods have not yet been provided. We present new decision criteria for selecting delta check methods for each clinical chemistry test item. METHODS: We collected 811,920 and 669,750 paired (present and previous) test results for 27 clinical chemistry test items from inpatients and outpatients, respectively. We devised new decision criteria for the selection of delta check methods based on the ratio of the delta difference to the width of the reference range (DD/RR). Delta check methods based on these criteria were compared with those based on the CV% of the absolute delta difference (ADD) as well as those reported in 2 previous studies. RESULTS: The delta check methods suggested by new decision criteria based on the DD/RR ratio corresponded well with those based on the CV% of the ADD except for only 2 items each in inpatients and outpatients. Delta check methods based on the DD/RR ratio also corresponded with those suggested in the 2 previous studies, except for 1 and 7 items in inpatients and outpatients, respectively. CONCLUSIONS: The DD/RR method appears to yield more feasible and intuitive selection criteria and can easily explain changes in the results by reflecting both the biological variation of the test item and the clinical characteristics of patients in each laboratory. We suggest this as a measure to determine delta check methods.

Two Evaluation Budgets for the Measurement Uncertainty of Glucose in Clinical Chemistry / 대한진단검사의학회지

BACKGROUND: Measurement uncertainty characterizes the dispersion of the quantity values attributed to a measurand. Although this concept was introduced to medical laboratories some years ago, not all medical researchers are familiar with it. Therefore, the evaluation and expression of measurement uncertainty must be highlighted using a practical example. METHODS: In accordance with the procedure for evaluating and expressing uncertainty, provided by the Joint Committee for Guides in Metrology (JCGM), we used plasma glucose (Glu) as an example and defined it as the measurand. We then analyzed the main sources of uncertainty, evaluated each component of uncertainty, and calculated the combined uncertainty and expanded uncertainty with 2 budgets for single measurements and continuous monitoring, respectively. RESULTS: During the measurement of Glu, the main sources of uncertainty included imprecision, within-subject biological variance (BVw), calibrator uncertainty, and systematic bias. We evaluated the uncertainty of each component to be 1.26%, 1.91%, 5.70%, 0.42%, and -2.87% for within-run imprecision, between-day imprecision, BVw, calibrator uncertainty, and systematic bias, respectively. For a single specimen, the expanded uncertainty was 7.38% or 6.1+/-0.45 mmol/L (kappa=2); in continuous monitoring of Glu, the expanded uncertainty was 13.58% or 6.1+/-0.83 mmol/L (kappa=2). CONCLUSIONS: We have demonstrated the overall procedure for evaluating and reporting uncertainty with 2 different budgets. The uncertainty is not only related to the medical laboratory in which the measurement is undertaken, but is also associated with the calibrator uncertainty and the biological variation of the subject. Therefore, it is helpful in explaining the accuracy of test results.

Two Evaluation Budgets for the Measurement Uncertainty of Glucose in Clinical Chemistry / 대한진단검사의학회지

BACKGROUND: Measurement uncertainty characterizes the dispersion of the quantity values attributed to a measurand. Although this concept was introduced to medical laboratories some years ago, not all medical researchers are familiar with it. Therefore, the evaluation and expression of measurement uncertainty must be highlighted using a practical example. METHODS: In accordance with the procedure for evaluating and expressing uncertainty, provided by the Joint Committee for Guides in Metrology (JCGM), we used plasma glucose (Glu) as an example and defined it as the measurand. We then analyzed the main sources of uncertainty, evaluated each component of uncertainty, and calculated the combined uncertainty and expanded uncertainty with 2 budgets for single measurements and continuous monitoring, respectively. RESULTS: During the measurement of Glu, the main sources of uncertainty included imprecision, within-subject biological variance (BVw), calibrator uncertainty, and systematic bias. We evaluated the uncertainty of each component to be 1.26%, 1.91%, 5.70%, 0.42%, and -2.87% for within-run imprecision, between-day imprecision, BVw, calibrator uncertainty, and systematic bias, respectively. For a single specimen, the expanded uncertainty was 7.38% or 6.1+/-0.45 mmol/L (kappa=2); in continuous monitoring of Glu, the expanded uncertainty was 13.58% or 6.1+/-0.83 mmol/L (kappa=2). CONCLUSIONS: We have demonstrated the overall procedure for evaluating and reporting uncertainty with 2 different budgets. The uncertainty is not only related to the medical laboratory in which the measurement is undertaken, but is also associated with the calibrator uncertainty and the biological variation of the subject. Therefore, it is helpful in explaining the accuracy of test results.

Definições, conceitos e aspectos operacionais utilizados em farmacovigilância / Definitions, concepts and operational aspects utilized in drug surveillance

O artigo expõe definições e conceitos utilizados na área de farmacovigilância, métodos de pesquisa para a identificação de reações adversas a medicamentos, notificação e organização de sistemas de farmacovigilância. De modo geral, as ações de farmacovigilância assumem dois aspectos diversos conforme o objetivo a ser atingido: (i) ações dos profissionais de saúde, que mantêm contato direto com o paciente e (ii) organização de sistemas de coleta, análise, processamento de informaçao e disseminação dos resultados, que incluem os sistemas nacionais de farmacovigilância e o Centro Colaborativo de Monitorização Internacional de Medicamentos da Organização Mundial da Saúde. Para se estabelecer a verdadeira...

Marcadores biologicos do alcoolismo / Biological markers on alcoholism

O diagnostico do alcoolismo e fundamentado na informacao verbal do paciente ao seu medico. Inumeros marcadores biologicos do alcoolismo vem sendo pesquisados nas ultimas decadas. Sao parametros laboratoriais que podem fornecer informacoes a respeito do consumo e abstinencia...

Vantagens e limitacoes do uso da urina como amostra biologica na dosagem alcoolica / Advantages and limitations in the use of urine as biological sample in the alcoholic dosage

Tendo em vista o grande interesse do uso da urina nos programas de controle e prevencao do uso de alcool e drogas no ambiente de trabalho e nas clinicas de reabilitacao, surge a necessidade de estudos mais detalhados sobre o fator de conversao utilizado para tranformar os valores de concentracao urinaria e sanguinea e sua validade...

C-Reactive protein: re-evaluation of a diagnostic laboratory test

C-reactive protein has been a measure of acute phase reactions to inflammatory for 40 years. Recently improved quantitative assays in serum and cerebrospinal fluid (CSF) have allowed a re-evaluation of its potential as a diagnostic laboratory test. The main advances in the newer methods have been that they can provide rapid (hours) information on the hepatocyte synthesis of this molecule during immune response. We have tested its value in patients with presumed bacterial meningitis. Based on our experience, newer standardized, quantitative assessments of C-reactive protein can be very useful in distinguishing between bacterial and other forms of meningeal irritation during during the first few days of hospitalization. Other investigators have indicated that by serial measurement important information on the resolution or continuation of inflammatory processes can be obtained. We recommend improved standardization of this test, and recalculation of its usefulness as a diagnostic laboratory test.

Prediction of total cholesterol: high-density-lipoprotein-cholesterol ratio in young adults.

Abnormal cholesterol fraction is an essential risk factor for atherosclerosis of large cerebral arteries in young Asians. In order to reduce the medical cost and social resource for cholesterol electrophoresis, especially in undeveloped and developing Asian countries, we evaluated the validity of Nanji's GUT score for predicting TC: HDLC ratio in this population. Results showed that GUT score only predicted 71% of them. We also tested the predictive power of CUT index, and predicting rate was 81%. Therefore, Nanji's GUT score is not an ideal surrogate for cholesterol electrophoresis. We recommend CUT index to screen for high-risk subjects till a new method can satisfy the economic pattern in Asian countries.