CamGFR v2: A New Model for Estimating the Glomerular Filtration Rate from Standardized or Non-standardized Creatinine in Patients with Cancer.

PURPOSE: Management of patients with cancer, specifically carboplatin dosing, requires accurate knowledge of glomerular filtration rate (GFR). Direct measurement of GFR is resource limited. Available models for estimated GFR (eGFR) are optimized for patients without cancer and either isotope dilution mass spectrometry (IDMS)- or non-IDMS-standardized creatinine measurements. We present an eGFR model for patients with cancer compatible with both creatinine measurement methods. EXPERIMENTAL DESIGN: GFR measurements, biometrics, and IDMS- or non-IDMS-standardized creatinine values were collected for adult patients from three cancer centers. Using statistical modeling, an IDMS and non-IDMS creatinine-compatible eGFR model (CamGFR v2) was developed. Its performance was compared with that of the existing models Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), Modification of Diet in Renal Disease (MDRD), Full Age Spectrum (FAS), Lund-Malmö revised, and CamGFR v1, using statistics for bias, precision, accuracy, and clinical robustness. RESULTS: A total of 3,083 IDMS- and 4,612 non-IDMS-standardized creatinine measurements were obtained from 7,240 patients. IDMS-standardized creatinine values were lower than non-IDMS-standardized values in within-center comparisons (13.8% lower in Cambridge; P < 0.0001 and 19.3% lower in Manchester; P < 0.0001), and more consistent between centers. CamGFR v2 was the most accurate [root-mean-squared error for IDMS, 14.97 mL/minute (95% confidence interval, 13.84-16.13) and non-IDMS, 15.74 mL/minute (14.86-16.63)], most clinically robust [proportion with >20% error of calculated carboplatin dose for IDMS, 0.12 (0.09-0.14) and non-IDMS, 0.17 (0.15-0.2)], and least biased [median residual for IDMS, 0.73 mL/minute (-0.68 to 2.2) and non-IDMS, -0.43 mL/minute (-1.48 to 0.91)] eGFR model, particularly when eGFR was larger than 60 ml/minute. CONCLUSIONS: CamGFR v2 can utilize IDMS- and non-IDMS-standardized creatinine measurements and outperforms previous models. CamGFR v2 should be examined prospectively as a practice-changing standard of care for eGFR-based carboplatin dosing.

Impact of variability in estimated glomerular filtration rate on major clinical outcomes: A nationwide population-based study.

BACKGROUND: The estimated glomerular filtration rate (eGFR), commonly estimated using the serum creatinine value, often fluctuates throughout the serial measurement. The clinical significance of GFR variation among the general population with normal renal function has not yet been demonstrated. Thus, we explored the impact of GFR variability on adverse clinical outcomes. METHODS: A nationwide retrospective cohort study using the Korean National Health Insurance System database was performed. National health screening examinees who underwent creatinine measurement ≥3 times between 2012 and 2016 were considered. Those with eGFR under 60 mL/min/m2 were excluded. The fluctuation of eGFR was represented with variability independent of the mean (VIM) index; which was calculated by the standard deviation divided by the exponent of the regression coefficient of the mean. Then, the risks of myocardial infarction (MI), stroke and death were assessed according to the quartiles of the VIM. RESULTS: Of total 3,538,500 participants, 0.29% of myocardial infarction (MI), 0.14% of stroke, 0.36% of deaths were observed during the median follow up of 3.27 years. Participants with the highest VIM index, which represents the highest eGFR variability, were significantly associated with an increased risk of MI (hazard ratio [HR]; 1.10, 95% confidence interval [95% CI]; 1.04-1.16), stroke (HR: 1.16; 95% CI 1.09-1.23), and death (HR: 1.18; 95% CI 1.12-1.24). The elevated risk of adverse events was consistent after the multivariate adjustment with potential confounding factors, except the risk of MI (HR 1.06; 95% 1.00-1.06). CONCLUSIONS: Increased eGFR variability exhibited an association with major clinical outcomes, indicating that monitoring eGFR variability might be a useful parameter for predicting the adverse outcomes.

The distributions of hematologic and biochemical values in healthy high-school adolescents in Japan.

Laboratory tests of adolescents are often interpreted by using reference intervals derived from adults, even though these populations differ in their physical and physiologic characteristics and disease susceptibility. Therefore, to examine the distribution of laboratory values specific for adolescents, we analyzed hematologic and biochemical measurements obtained from 12,023 healthy Japanese adolescents (ages 15 through 18 years; male, 9165; female, 2858) during 2009 through 2018. Distributions were shown as medians with 95% (2.5th and 97.5th percentiles) of values and were compared with those from previous studies that examined similar Asian populations. There were some differences between hematologic parameters, serum creatinine and uric acid concentration, and lipid levels of Japanese adults and adolescents. In comparison with other Asian populations, the distributions of serum uric acid and high-density-lipoprotein cholesterol in the present study were slightly higher than those in the other studies. Although further research is need, the distributions of hematologic and biochemical tests in adolescents may have the potential to facilitate the early identification and management of disease in this population.

How well do Croatian laboratories adhere to national recommendations for laboratory diagnostics of chronic kidney disease (CKD)?

Background In 2014, the Joint Croatian Working Group (JCWG) for laboratory diagnostic of chronic kidney disease (CKD) conducted a survey across medical-biochemistry laboratories which demonstrated a large heterogeneity in this area of laboratory medicine. To ensure the tools for the standardization process, in 2017 the JCWG-CKD published the first Croatian recommendations for laboratory diagnostics of CKD. To assess the implementation process, we have repeated a survey to explore how well laboratories adhere to the recommendations. Methods An invitation to the survey was sent to all Croatian medical-biochemistry laboratories (n = 196). The questionnaire was designed in a form of 19 questions and statements, with possible multiple answers. Results The response rate was 98/196 (50.0%). The predominant method for serum creatinine measurement was the standardized compensated Jaffe method (79.2%). There was substantial decrease in the number of laboratories which measure creatinine with the non-standardized uncompensated Jaffe method, compared with the initial 2014 assessment; 7% vs. 40%, respectively. The number of the laboratories that did not report estimated glomerular filtration rate (eGFR) values decreased almost by half compared to the initial data (37.6% vs. 74.4%). However, compared to the 2014 initial assessment, a similar number of laboratories (54/98 vs. 58/80) did not measure urine albumin or protein. Conclusions The collected data showed a substantial improvement in the standardization of the serum creatinine measurement, as well as in the reporting of eGFR. However, albuminuria or proteinuria assessment is still not implemented nationwide, mainly in primary health care laboratories. This demonstrates the importance of promoting and monitoring implementation of guidelines after publication.

CALIPER paediatric reference intervals for the urea creatinine ratio in healthy children & adolescents.

BACKGROUND: The urea creatinine ratio (UCR) is important in the clinical assessment of several medical conditions, including acute kidney injury and gastrointestinal bleeding. However, accurate and robust paediatric reference intervals (RIs) for this ratio have not been well established. Here, we determined age- and sex-specific discrete and continuous RIs for UCR in the Canadian Laboratory Initiative on Paediatric Reference Intervals (CALIPER) cohort of healthy children and adolescents for the first time. METHODS: UCR was calculated for approximately 1030 CALIPER participants using retrospective urea and creatinine (both Jaffe and enzymatic methods) normative data. Partitions were determined using the Harris & Boyd statistical method. Discrete RIs were established in accordance with the Clinical and Laboratory Standards Institute (CLSI) guidelines. Continuous RIs were established using nonparametric quantile regression. RESULTS: Several age- and sex-specific partitions were necessary to capture dynamic physiological trends associated with this ratio throughout childhood and adolescence, highlighting the benefit of continuous RI establishment. Established UCR RIs also demonstrated marked differences between Jaffe and enzymatic assay methods. CONCLUSION: Our results clearly demonstrate the critical need for RI stratification by important covariates such as age, sex, and creatinine assay methodology for paediatric UCR test result interpretation. These data contribute to our understanding of normative UCR values in childhood and adolescence and can be expected to improve paediatric test result interpretation in clinical laboratories that report this ratio.

Lower creatinine concentration values and lower inter-laboratory variation among Swedish hospital laboratories in 2014 compared to 1996: results from the Equalis external quality assessment program.

Background Creatinine measurement for estimation of glomerular filtration rate (GFR) is a frequently used laboratory test. Differences in analytic creatinine methods have caused large inter-laboratory variation. International and national standardization efforts have been made in the last decade. Methods This study describes the results of the standardization efforts in Sweden by summarizing data for creatinine concentration in blood plasma in the Equalis quality assessment program during 1996-2014. Results Non-compensated Jaffe methods dominated in 1996-2001 (91 of 103 laboratories; 90%) and were then gradually replaced by either compensated Jaffe methods or enzymatic creatinine methods. In 2014 a majority of Swedish hospital laboratories (139 of 159; 87%) used enzymatic methods. The reported mean creatinine value by the Swedish laboratories was about 10 µmol/L higher than the isotope dilution mass spectrometry (IDMS) assured reference value in 2003, but consistent with the reference value from 2009 to 2014. The inter-laboratory CV was 7%-9% for creatinine values until 2007, and thereafter gradually decreased to about 4%-5% in 2014. Conclusions The introduction of enzymatic methods in Swedish laboratories has contributed to achieving a low inter-laboratory variation. Also, the reported values are lower for enzymatic methods compared to Jaffe methods, and the values obtained with enzymatic methods were consistent with IDMS certified values established at reference laboratories. Thus, many Swedish hospital laboratories reported 10 µmol/L lower, and more true, creatinine concentrations in 2012 than in 2003, which may cause bias in longitudinal studies.

Uso de la fórmula de Cockcroft-Gault para el ajuste de dosis de los fármacos en insuficiencia renal: ¿hasta cuándo? / How long should we continue to use the Cockcroft-Gault formula for dose-adjustment of drugs in renal failure?

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Algorithm on age partitioning for estimation of reference intervals using clinical laboratory database exemplified with plasma creatinine.

BACKGROUND: We describe an algorithm to determine age-partitioned reference intervals (RIs) exemplified for creatinine using data collection from the clinical laboratory database. METHODS: The data were acquired from the test results of creatinine of 164,710 outpatients aged <18 years in Beijing Children's Hospital laboratories' databases between January 2016 and December 2016. The tendency of serum creatinine with age was examined visually using box plot by gender first. The age subgroup was divided automatically by the decision tree method. Subsequently, the statistical tests of the difference between subgroups were performed by Harris-Boyd and Lahti methods. RESULTS: A total of 136,546 samples after data cleaning were analyzed to explore the partition of age group for serum creatinine from birth to 17 years old. The suggested age partitioning of RIs for creatinine by the decision tree method were for eight subgroups. The difference between age subgroups was demonstrated to be statistically significant by Harris-Boyd and Lahti methods. In addition, the results of age partitioning for RIs estimation were similar to the suggested age partitioning by the Canadian Laboratory Initiative in Pediatric Reference Intervals study. Lastly, a suggested algorithm was developed to provide potential methodological considerations on age partitioning for RIs estimation. CONCLUSIONS: Appropriate age partitioning is very important for establishing more accurate RIs. The procedure to explore the age partitioning using clinical laboratory data was developed and evaluated in this study, and will provide more opinions for designing research on establishment of RIs.

Comparison of Three Methods Estimating Baseline Creatinine For Acute Kidney Injury in Hospitalized Patients: a Multicentre Survey in Third-Level Urban Hospitals of China.

BACKGROUND/AIMS: A lack of baseline serum creatinine (SCr) data leads to underestimation of the burden caused by acute kidney injury (AKI) in developing countries. The goal of this study was to investigate the effects of various baseline SCr analysis methods on the current diagnosis of AKI in hospitalized patients. METHODS: Patients with at least one SCr value during their hospital stay between January 1, 2011 and December 31, 2012 were retrospectively included in the study. The baseline SCr was determined either by the minimum SCr (SCrMIN) or the estimated SCr using the MDRD formula (SCrGFR-75). We also used the dynamic baseline SCr (SCrdynamic) in accordance with the 7 day/48 hour time window. AKI was defined based on the KDIGO SCr criteria. RESULTS: Of 562,733 hospitalized patients, 350,458 (62.3%) had at least one SCr determination, and 146,185 (26.0%) had repeat SCr tests. AKI was diagnosed in 13,883 (2.5%) patients using the SCrMIN, 21,281 (3.8%) using the SCrGFR-75 and 9,288 (1.7%) using the SCrdynamic. Compared with the non-AKI patients, AKI patients had a higher in-hospital mortality rate regardless of the baseline SCr analysis method. CONCLUSIONS: Because of the scarcity of SCr data, imputation of the baseline SCr is necessary to remedy the missing data. The detection rate of AKI varies depending on the different imputation methods. SCrGFR-75 can identify more AKI cases than the other two methods.

GFR estimation based on standardized creatinine and cystatin C: a European multicenter analysis in older adults.

BACKGROUND: Although recommended by the Kidney Disease Improving Global Outcomes, the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPICR) creatinine equation was not targeted to estimate glomerular filtration rate (eGFR) among older adults. The Berlin Initiative Study (BIS1CR) equation was specifically developed in older adults, and the Lund-Malmö revised (LMRCR) and the Full Age Spectrum (FASCR) equations have shown promising results in older adults. Our aim was to validate these four creatinine equations, including addition of cystatin C in a large multicenter cohort of Europeans ≥70 years. METHODS: A total of 3226 individuals (2638 with cystatin C) underwent GFR measurement (mGFR; median, 44 mL/min/1.73 m2) using plasma iohexol clearance. Bias, precision (interquartile range [IQR]), accuracy (percent of estimates ±30% of mGFR, P30), eGFR accuracy diagrams and probability diagrams to classify mGFR<45 mL/min/1.73 m2 were compared. RESULTS: The overall results of BIS1CR/CKD-EPICR/FASCR/LMRCR were as follows: median bias, 1.7/3.6/0.6/-0.7 mL/min/1.73 m2; IQR, 11.6/12.3/11.1/10.5 mL/min/1.73 m2; and P30, 77.5%/76.4%/80.9%/83.5% (significantly higher for LMR, p<0.001). Substandard P30 (<75%) was noted for all equations at mGFR<30 mL/min/1.73 m2, and at body mass index values <20 and ≥35 kg/m2. LMRCR had the most stable performance across mGFR subgroups. Only LMRCR and FASCR had a relatively constant small bias across eGFR levels. Probability diagrams exhibited wide eGFR intervals for all equations where mGFR<45 could not be confidently ruled in or out. Adding cystatin C improved P30 accuracy to 85.7/86.8/85.7/88.7 for BIS2CR+CYS/CKD-EPICR+CYS/FASCR+CYS/MEANLMR+CAPA. CONCLUSIONS: LMRCR and FASCR seem to be attractive alternatives to CKD-EPICR in estimating GFR by creatinine-based equations in older Europeans. Addition of cystatin C leads to important improvement in estimation performance.

A validated LC-MS/MS method for the quantitative measurement of creatinine as an endogenous biomarker in human plasma.

BACKGROUND: Creatinine is an endogenous compound generated from creatine by normal muscular metabolism. It is an important indicator of renal function and the serum level is routinely monitored in clinical labs. Results & methodology: Surrogate analyte (d3-creatinine) was used for calibration standard and quality control preparation and the relative instrument response ratio between creatinine and d3-creatinine was used to calculate the endogenous creatinine concentrations. CONCLUSION: A fit-for-purpose strategy of using a surrogate analyte and authentic matrix was adopted for this validation. The assay was the first human plasma assay using such strategy and was successfully applied to a clinical study to confirm a transient elevation of creatinine observed using an existing clinical assay.

How to define a significant deviation from the expected internal quality control result.

BACKGROUND: Internal quality control (IQC) is an everyday practice described in several documents. Its planning requires the definition of quality goals and a documentation system able to provide alarms as soon as the goals are not reached. We propose the use of the uncertainty approach to develop an effective alarm system. METHODS: The use of the uncertainty information to verify the conformity to specifications is described. A top-down approach to the definition of the uncertainty of the method is described. Once the uncertainty is calculated, the complete measurement result (result ± expanded uncertainty) is compared with the maximum permissible error (quality goal). An alternative and more immediate presentation is obtained defining an "acceptance zone" derived from the maximum permissible error reduced on either sides by expanded uncertainty. This approach is applied to two analytes: glucose and creatinine. RESULTS: The relationship between quality goal and expanded uncertainty defines the width of the acceptance zone; if uncertainty is equal or larger than the quality goal, the goal is not attainable. CONCLUSIONS: The proposed approach uses an information, expanded uncertainty, that each laboratory seeking ISO 15189 accreditation should already have. The data presentation is immediate and easy to interpret allowing a direct comparison between the performance of the method and the quality goals.

Bioanalytical comparison between dried urine spots and liquid urine bioassays used for the quantitative analysis of urinary creatinine concentrations.

BACKGROUND: quantitative bioassays for determination of urinary creatinine concentrations using liquid urine and dried urine on paper disks (DUPD) specimens were developed and validated. The bioassays were cross-validated by means of measurement of the urinary creatinine concentrations applying DUPD (3 and 5 mm) and liquid urine specimens. RESULTS: LLOQ and LOD for all bioassays were 0.88 and 0.27 mmol/l creatinine, respectively. All bioassays were cross-validated by the analysis of urine samples from healthy voluntary individuals and bioassays performed were statistically not significantly different. Mean observed urinary creatinine concentrations ranged between 0.44 and 25.6, 0.24 and 23.9, 0.13 and 31.26 mmol/l for liquid, DUPD-5mm and DUPD-3mm bioassays, respectively. CONCLUSION: the advantage of the DUPD bioassays was the relatively small amounts of urine necessary, making these microsampling techniques attractive when limited amounts of urine specimens of, for example, rodents from drug development studies are available.

A reference system for urinary albumin: current status.

BACKGROUND: Increased urinary excretion of albumin reflects kidney damage and is a recognized risk factor for progression of renal and cardiovascular disease. Considerable inter-method differences have been reported for both albumin and creatinine measurement results, and therefore the albumin-to-creatinine ratio. Measurement accuracy is unknown and there are no independent reference measurement procedures for albumin and no reference materials for either measurand in urine. METHODS: The National Kidney Disease Education Program (NKDEP) Laboratory Working Group and the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) have initiated joint projects to facilitate standardization of urinary albumin and creatinine measurement. RESULTS: A candidate LC-MS/MS reference measurement procedure for urinary albumin and candidate reference materials for urinary albumin and creatinine has been developed. The status of validations of these reference system components is reported. CONCLUSIONS: The development of certified reference materials and reference measurement procedures for urinary albumin will enable standardization of this important measurand.

The changing definition of contrast-induced nephropathy and its clinical implications: insights from the Blue Cross Blue Shield of Michigan Cardiovascular Consortium (BMC2).

BACKGROUND: The traditional definition of contrast-induced nephropathy (CIN) has been an absolute rise of serum creatinine (Cr) of ≥0.5 mg/dL, although most recent clinical trials have included a ≥25% increase from baseline Cr. The clinical implication of this definition change remains unknown. METHODS AND RESULTS: We compared the association of the two definitions with risk of death or need for dialysis among 58,957 patients undergoing percutaneous coronary intervention in 2007 to 2008 in a large collaborative registry. Patients with a preexisting history of renal failure requiring dialysis were excluded. Contrast-induced nephropathy as defined by a rise in Cr ≥0.5 mg/dL (CIN(Traditional)) developed in 1,601, whereas CIN defined either as Cr ≥0.5 mg/dL or ≥25% increase in baseline Cr (CIN(New)) developed in 4,308 patients. Patients meeting the definition of CIN(New) but not CIN(Traditional) were classified as CIN(Incremental) (n = 2,707). Compared with CIN(New), CIN(Traditional) was more commonly seen in patients with abnormal renal function, which was more likely to develop in patients with normal renal function at baseline. Compared with CIN(Incremental), patients meeting the definition of CIN(Traditional) were more likely to die (16.7% vs 1.7%) and require in-hospital dialysis (9.8% vs 0%). CONCLUSIONS: Our data suggest that the traditional definition of CIN (a rise in Cr of ≥0.5 mg/dL) in patients undergoing PCI is superior to ≥25% increase in Cr at identifying patients at greater risk for adverse renal and cardiac events.

An international assessment of the metrological equivalence of higher-order measurement services for creatinine in serum.

The Consultative committee for amount of substance-metrology in chemistry (CCQM)-K80 Key Comparison directly assessed the equivalence of many of the world's higher-order value-assigned materials (HOVAMs) for creatinine in human serum. This 2009 international study compared the certified values and uncertainties of the materials using measurements made under repeatability conditions. The study evaluated 17 materials submitted by 6 national metrology institutes (NMIs). The creatinine quantity in these materials ranged from 3 mg/kg to 57 mg/kg (about 0.3 mg/dL to 6 mg/dL or 30 nmol/L to 500 nmol/L). All materials were stored and prepared according the specifications provided by the participating NMIs. Samples were processed and analyzed under repeatability conditions by one analyst using isotope-dilution liquid chromatography-mass spectrometry in two measurement campaigns. The certified values and repeatability measurements were compared using uncertainty-weighted generalized distance regression. The instrumental repeatability relative standard deviation was 1.2%. The measurement design required assessment of within-unit and between-campaign variability in addition to measurement repeatability. At a 95% level of confidence, the certified values for all 17 materials agreed to within their assigned uncertainties. CCQM-K80 demonstrated the metrological equivalence of the currently available HOVAMs for creatinine in human serum and of the creatinine measurement services provided by the participating NMIs.

Intervalos de referencia de determinaciones bioquímicas en el laboratorio central del Hospital de Trelew / Reference intervals of biochemical determinations in the central laboratory in Trelew Hospital / Intervalos de referencia de determinagóes bioquímicas no laboratorio central do Hospital de Trelew

El objetivo del presente trabajo fue establecer los intervalos de referencia de las determinaciones: glucosa, urea, colesterol, proteínas totales, albúmina, ácido úrico, creatinina, hematocrito y hemoglobina en el Laboratorio Central del Hospital Zonal de Trelew. La población bajo estudio fueron pacientes mayores de 18 años atendidos por consultorio externo entre diciembre de 2008 y marzo de 2009. El estudio fue completado entre marzo y abril de 2011. Las determinaciones se realizaron con un autoanalizador de química clínica Metrolab 2300 plus y un contador hematológico Sysmex 2100. Se comprobó que los valores de las determinaciones se ajustaran a una distribución normal y se realizó el cálculo de los fractiles 0,025 y 0,975 para la obtención del intervalo de referencia (IR) del 95%. En un caso se utilizó transformación logarítmica de los datos y para dos categorías se aplicó el método no paramétrico. Para los valores de referencia inferior y superior se establecieron los intervalos con un 90% de confianza (IC). Los valores de referencia obtenidos fueron: glucosa de 0,74 a 1,07 g/L, urea de 0,19 a 0,51 g/L, colesterol de 1,21 a 2,43 g/L, proteínas totales de 6,45 a 7,99 g/dL, albúmina de 3,62 a 4,61 g/dL, creatinina de 0,57 a 1,10 mg/dL, ácido úrico para el sexo femenino de 18,69 a 51,93 mg/L y para el sexo masculino de 30,50 a 62,92 mg/L, hematocrito para sexo femenino de 37 a 45% y para el sexo masculino de 40 a 50%, hemoglobina para el sexo femenino de 11,70 a 15,17 g/dL y para el sexo masculino de 13,09 a 17,19 g/dL. Los valores de ácido úrico, hematocrito y hemoglobina se separaron por sexo para dar continuidad a la política del laboratorio y de los fabricantes de CAICYTtivos, que consiste en considerar las diferencias existentes entre ambos sexos. Dentro del rango dado por el fabricante se obtuvieron los resultados para glucosa, albúmina y hemoglobina; sobre el mismo, para urea, colesterol, proteínas y ácido úrico y por debajo del mismo para creatinina.

The aim of the present work was to establish the reference intervals of the following determinations, glucose, urea, cholesterol, total proteins, albumin, uric acid, creatinine, hematocrite and hemoglobin in the Central Laboratory of Trelew Zonal Hospital. The population under study was defined as 18-year-old or older patients that came to the laboratory from the ambulatory consulting room since December 2008 to March 2009, and then between March and April 2011. Blood samples were processed with a Metrolab 2300 plus clinical chemistry autoanalyser and a Sysmex 2100 hematological counter. After checking if the result distribution applied to a normal distribution, fractiles 0.025 and 0.975 were calculated to obtain a 95% Reference Interval (RI). In one case, a logarithmic transformation of the results was needed and for two categories a non-parametric method was used. For the upper and lower reference values, the intervals were calculated at 90% confidence (CI) The reference values obtained were; 0.74-1.07 g/L glucose, 0.19-0.51 g/L urea, 1.21-2.43 g/L cholesterol, 6.45-7.99g/dL total proteins, 3.62-4.61 g/dL albumin and 0.57-1.10 mg/dL creatinine, 18.69 - 51.93 mg/L uric acid in women, and 30.50 - 69.92 mg/L in men; 37 - 45% hematocrite in women and 40 - 50% in men; 11.70 - 15.17 g/dL hemoglobin in women and 13.09 - 17.19 g/dL hemoglobin in men. Uric acid, hematocrite and hemoglobin values were calculated according to sex in order to offer concordance with commercial kit and the laboratory policies which consist in considering the significant differences between both sexes. The results obtained for glucose, albumin and hemoglobin were within the reference interval given by the commercial kits; urea, cholesterol, total protein and uric acid were above it; and creatinine reference interval was lower than the reference interval from the commercial kits.

O objetivo do presente trabalho foi estabelecer os intervalos de referencia das determinagóes: glicose, ureia, colesterol, proteínas totais, albumina, ácido úrico, creatinina, hematocrito e hemoglobina no Laboratorio Central do Hospital Zonal de Trelew. A populagao sob estudo foram pacientes de mais de 18 anos atendidos através de consultorio externo entre dezembro do ano 2008 e margo de 2009. O estudo foi completado entre margo e abril de 2011. As determinagóes foram realizadas com um auto-analisador de química clínica Metrolab 2300 plus e um contador hematológico Sysmex 2100. Comprovouse que os valores das determinagóes se ajustaram a uma distribuigao normal e se realizou o cálculo dos quantis 0,025 e 0,975 para a obtengao do intervalo de referencia (IR) de 95%. Num caso foi utilizada transformagao logarítmica dos dados e para duas categorias se aplicou o método nao paramétrico. Para os valores de referencia inferior e superior foram estabelecidos os intervalos com 90% de confianga (IC). Os valores de referencia obtidos foram: glicose de 0,74 a 1,07 gr/L, ureia de 0,19 a 0,51 gr/L, colesterol de 1,21 a 2,43 g/L, proteínas totais de 6,45 a 7,99 gr/dL, albumina de 3,62 a 4,61 gr/dL, creatinina de 0,57 a 1,10 mg/dL, ácido úrico para o sexo feminino de 18,69 a 51,93 mg/L e para o sexo masculino de 30,50 a 62,92 mg/l, hematocrito para sexo feminino de 37 a 45% e para o sexo masculino de 40 a 50%, hemoglobina para o sexo feminino de 11,70 a 15,17 g/dL e para o sexo masculino de 13,09 a 17,19 g/dL. Os valores de ácido úrico, hematocrito e hemoglobina foram separados por sexo para dar continuidade a política do laboratorio e dos fabricantes de reagentes, que consiste em considerar as diferengas existentes entre ambos os sexos. Dentro do intervalo dado pelo fabricante foram obtidos os resultados para glicose, albumina e hemoglobina; superior ao mesmo para ureia, colesterol, proteínas e ácido úrico e inferior ao mesmo para creatinina.