Creatinina plasmática medida por método enzimático y estimulación del filtrado glomerular con la fórmula Full-Age-Spectrum, en una población pediátrica ambulatoria de la Argentina / Plasma creatinine measured by enzymatic method and estimation of glomerular filtration rate using the Full-Age-Spectrum equation in a pediatric outpatient population in Argentina

Introducción: el método recomendado para la medición de creatinina plasmática (Cr) es el enzimático, que permite obtener la tasa de filtrado glomerular estimado (TFGe) con la fórmula Full-Age-Spectrum (FAS) para todas las edades, al normalizar la TFGe con valores poblacionales de Cr. Objetivos: obtener valores poblacionales de Cr medida con un método enzimático y evaluar la fórmula FAS, en una población pediátrica ambulatoria de la Argentina, puesto que no existen publicaciones al respecto en nuestro país. Material y métodos: estudio descriptivo, retrospectivo, transversal, por muestreo consecutivo. Se consideró la población pediátrica ambulatoria de 2 a 17 años que concurrió una sola vez, entre 07/2018 y 11/2021 al laboratorio del Hospital Municipal (Bahía Blanca, Argentina) con petición médica de Cr. Se evaluó la distribución poblacional de Cr. Se comparó FAS original (FAS-Belga) con FAS normalizada con valores locales de Cr (FAS-Local). Resultados: se estudiaron 2793 individuos. Los varones tuvieron un valor de Cr superior al de las mujeres a los 16 y 17 años. La TFGe fue menor con FAS-Local que con FAS-Belga [mediana (RI) mL/min/1,73 m2 : 107,3 (22,9) vs. 117,0 (26,5); p=0,0001; rbis=0,87 (tamaño del efecto grande)]. Del análisis del gráfico de Bland-Altman y el índice de concordancia Kappa se obtuvo que FAS-Local no fue comparable con FAS-Belga. Conclusiones: los valores poblacionales de Cr, medida con un método enzimático, son los primeros en obtenerse en una población pediátrica ambulatoria argentina. Dichos valores son necesarios para aplicar FAS en la Argentina (AU)

Introduction: the recommended test for the measurement of plasma creatinine (Cr) is the enzymatic method, which allows calculating the estimated glomerular filtration rate (eGFR) with the Full-Age-Spectrum (FAS) equation for all ages, by normalizing the eGFR with population Cr values. Objectives: to obtain population Cr values measured with an enzymatic method and to evaluate the FAS equation in an pediatric outpatient population in Argentina, since there are no reports on this subject in our country. Material and methods: A descriptive, retrospective, cross-sectional, consecutive sampling study. The pediatric outpatient population aged 2 to 17 years who attended only once to the laboratory of the Municipal Hospital (Bahía Blanca, Argentina) between 07/2018 and 11/2021 with medical request for Cr measurement. The population distribution of Cr was evaluated. The original FAS (FAS-Belgian) was compared to FAS normalized with local Cr values (FAS-Local). Results: 2793 individuals were studied. Males had a higher Cr value than females at 16 and 17 years of age. The eGFR was lower with FAS-Local than with FAS-Belgian [median (IQR) mL/min/1.73 m2: 107.3 (22.9) vs. 117.0 (26.5); p=0.0001; rbis=0.87 (large effect size)]. Analysis of the Bland-Altman plot and the Kappa concordance index showed that FAS-Local was not comparable to FAS-Belgian. Conclusions: population Cr values, measured with an enzymatic method, are the first to be obtained in an Argentine pediatric outpatient population. These values are necessary to apply the FAS in Argentina (AU)

Preanalytical phase: Effects of water ingestion during fasting on routine hematological parameters in a small cohort of young women.

BACKGROUND: We analyze the effects of water ingestion before blood extraction on routine hematological parameters. METHODS: Twenty female volunteers -mean 24 y- were included. Blood was collected after a 12 h fast period (T0) and 1 h after the ingestion of 300 ml water (T1). These parameters were analyzed: white blood cell (WBC) count; WBC differential count including lymphocytes (LYM), monocytes (MONO), neutrophils, eosinophils (EOS), and basophils; red blood cell (RBC) count; hematocrit (HCT); hemoglobin (HGB); mean cell volume; mean cell hemoglobin; RBC distribution width; and platelet count (PLT). Statistical significance: P < 0.05. Mean difference % (MD%) was calculated for each parameter and was compared with reference change value (RCV). A change was considered clinically significant when MD% exceeded the RCV. RESULTS: Significant differences were observed in (medians, T0 vs T1, P): WBC ×109/l (6.51 vs 6.12, 0.002); LYM ×109/l (2.90 vs 2.19, 0.000); MONO ×109/l (0.50 vs 0.48, 0.031); EOS ×109/l (0.17 vs 0.16, 0.003); RBC ×1012/l (4.46 vs 4.40, 0.024); HCT l/l (0.38 vs 0.37, 0.036); HGB g/l (129 vs 129, 0.009). All MDs% were lower than their respective RCV. CONCLUSION: Ingestion of 300 ml water 1 h before blood extraction does not alter the hematological parameters studied.