Reference intervals for 21 clinical chemistry analytes in arterial and venous umbilical cord blood

1993 ◽  
Vol 39 (6) ◽  
pp. 1041-1044 ◽  
Author(s):  
S L Perkins ◽  
J F Livesey ◽  
J Belcher
Keyword(s):  
Alkaline Phosphatase ◽  
Umbilical Cord ◽  
Clinical Chemistry ◽  
Venous Blood ◽  
Reference Interval ◽  
Reference Intervals ◽  
Nonparametric Analysis ◽  
Term Infants ◽  
Male And Female ◽  
Gamma Glutamyltransferase

Abstract Reference intervals were determined for 21 clinical chemistry analytes in umbilical cord arterial and venous blood from healthy term infants. Nonparametric analysis (rank number) was used to determine the central 95% reference interval. No significant differences were observed between male and female infants. Reference intervals for glucose, urea, creatinine, urate, phosphate, calcium, albumin, total protein, cholesterol, triglycerides, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, creatine kinase, lactate dehydrogenase, gamma-glutamyltransferase, and magnesium all were significantly different from adult values.

Reference intervals for venous blood gas measurement in adults

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Kirsty L. Ress ◽  
Gus Koerbin ◽  
Ling Li ◽  
Douglas Chesher ◽  
Phillip Bwititi ◽  
...  
Keyword(s):  
Partial Pressure ◽  
Meta Analysis ◽  
Venous Blood ◽  
Reference Interval ◽  
Reference Intervals ◽  
Published Data ◽  
Blood Gas ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Venous Blood Gas

AbstractObjectivesVenous blood gas (VBG) analysis is becoming a popular alternative to arterial blood gas (ABG) analysis due to reduced risk of complications at phlebotomy and ease of draw. In lack of published data, this study aimed to establish reference intervals (RI) for correct interpretation of VBG results.MethodsOne hundred and 51 adult volunteers (101 females, 50 males 18–70 y), were enrolled after completion of a health questionnaire. Venous blood was drawn into safePICO syringes and analysed on ABL827 blood gas analyser (Radiometer Pacific Pty. Ltd.). A non-parametric approach was used to directly establish the VBG RI which was compared to a calculated VBG RI based on a meta-analysis of differences between ABG and VBGResultsAfter exclusions, 134 results were used to derive VBG RI: pH 7.30–7.43, partial pressure of carbon dioxide (pCO2) 38–58 mmHg, partial pressure of oxygen (pO2) 19–65 mmHg, bicarbonate (HCO3−) 22–30 mmol/L, sodium 135–143 mmol/L, potassium 3.6–4.5 mmol/L, chloride 101–110 mmol/L, ionised calcium 1.14–1.29 mmol/L, lactate 0.4–2.2 mmol/L, base excess (BE) −1.9–4.5 mmol/L, saturated oxygen (sO2) 23–93%, carboxyhaemoglobin 0.4–1.4% and methaemoglobin 0.3–0.9%. The meta-analysis revealed differences between ABG and VBG for pH, HCO3−, pCO2 and pO2 of 0.032, −1.0 mmol/L, −4.2 and 39.9 mmHg, respectively. Using this data along with established ABG RI, calculated VBG RI of pH 7.32–7.42, HCO3− 23 – 27 mmol/L, pCO2 36–49 mmHg (Female), pCO2 39–52 mmHg (Male) and pO2 43–68 mmHg were formulated and compared to the VBG RI of this study.ConclusionsAn adult reference interval has been established to assist interpretation of VBG results.

scholarly journals Personalized Reference Intervals in Laboratory Medicine: A New Model Based on Within-Subject Biological Variation

2020 ◽  
Author(s):  
Abdurrahman Coşkun ◽  
Sverre Sandberg ◽  
Ibrahim Unsal ◽  
Coskun Cavusoglu ◽  
Mustafa Serteser ◽  
...  
Keyword(s):  
Steady State ◽  
Personalized Medicine ◽  
Clinical Chemistry ◽  
Reference Interval ◽  
Reference Intervals ◽  
Biological Variation ◽  
Test Results ◽  
Steady State Condition ◽  
Laboratory Test Results ◽  
Measurement Results

Abstract Background The concept of personalized medicine has received widespread attention in the last decade. However, personalized medicine depends on correct diagnosis and monitoring of patients, for which personalized reference intervals for laboratory tests may be beneficial. In this study, we propose a simple model to generate personalized reference intervals based on historical, previously analyzed results, and data on analytical and within-subject biological variation. Methods A model using estimates of analytical and within-subject biological variation and previous test results was developed. We modeled the effect of adding an increasing number of measurement results on the estimation of the personal reference interval. We then used laboratory test results from 784 adult patients (>18 years) considered to be in a steady-state condition to calculate personalized reference intervals for 27 commonly requested clinical chemistry and hematology measurands. Results Increasing the number of measurements had little impact on the total variation around the true homeostatic set point and using ≥3 previous measurement results delivered robust personalized reference intervals. The personalized reference intervals of the study participants were different from one another and, as expected, located within the common reference interval. However, in general they made up only a small proportion of the population-based reference interval. Conclusions Our study shows that, if using results from patients in steady state, only a few previous test results and reliable estimates of within-subject biological variation are required to calculate personalized reference intervals. This may be highly valuable for diagnosing patients as well as for follow-up and treatment.

Normal limits of urinary excretion of eleven enzymes.

1976 ◽  
Vol 22 (10) ◽  
pp. 1567-1574 ◽  
Author(s):  
D Maruhn ◽  
I Fuchs ◽  
G Mues ◽  
K D Bock
Keyword(s):  
Alkaline Phosphatase ◽  
Lactate Dehydrogenase ◽  
Urinary Excretion ◽  
Gel Filtration ◽  
Reference Intervals ◽  
Creatinine Concentration ◽  
Urinary Creatinine ◽  
Gamma Glutamyltransferase ◽  
Normal Limits ◽  
Alpha Glucosidase

Abstract Urinary excretion of lactate dehydrogenase, hydroxybutyrate dehydrogenase, gamma-glutamyltransferase, alkaline phosphatase, arylsulphatase A, alpha-glucosidase, beta-galactosidase, trehalase, N-acetyl-beta-glucosaminidase, beta-glucuronidase, and leucinearylamidase was studies in a carefully selected group of 100 healthy subjects, 50 women and 50 men. Enzyme activities were assayed in 3-h morning samples after gel filtration of the urine. Activities were related to time volume, and to urinary creatinine concentration. Several transforming functions had to be applied to enzyme output data to obtain an approximation to gaussian frequency distribution. Men showed a significantly higher excretion of gamma-glutamyltransferase, alpha-glucosidase, trehalase, N-acetyl-beta-glucosaminidase,beta-glucuronidase, and leucine arylamidase activity than did women if enzyme activity was related to urinary time volume. Women excreted more lactate dehydrogenase, hydroxybutyrate dehydrogenase, gamma-glutamyltransferase, alkaline phosphatase, alpha-glucosidase, trehalase, and N-acetyl-beta-glucosaminidase activity than did men, if urinary creatinine was used as the basis of reference. Reference intervals were calculated as 2.5 and 97.5 percentiles for both sexes.

scholarly journals Indirect methods for reference interval determination – review and recommendations

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Graham R.D. Jones ◽  
Rainer Haeckel ◽  
Tze Ping Loh ◽  
Ken Sikaris ◽  
Thomas Streichert ◽  
...  
Keyword(s):  
Clinical Chemistry ◽  
Direct Methods ◽  
Analytical Techniques ◽  
Reference Interval ◽  
Reference Population ◽  
Reference Intervals ◽  
Statistical Techniques ◽  
Indirect Methods ◽  
Indirect Approach ◽  
Patient Health

Abstract Reference intervals are a vital part of the information supplied by clinical laboratories to support interpretation of numerical pathology results such as are produced in clinical chemistry and hematology laboratories. The traditional method for establishing reference intervals, known as the direct approach, is based on collecting samples from members of a preselected reference population, making the measurements and then determining the intervals. An alternative approach is to perform analysis of results generated as part of routine pathology testing and using appropriate statistical techniques to determine reference intervals. This is known as the indirect approach. This paper from a working group of the International Federation of Clinical Chemistry (IFCC) Committee on Reference Intervals and Decision Limits (C-RIDL) aims to summarize current thinking on indirect approaches to reference intervals. The indirect approach has some major potential advantages compared with direct methods. The processes are faster, cheaper and do not involve patient inconvenience, discomfort or the risks associated with generating new patient health information. Indirect methods also use the same preanalytical and analytical techniques used for patient management and can provide very large numbers for assessment. Limitations to the indirect methods include possible effects of diseased subpopulations on the derived interval. The IFCC C-RIDL aims to encourage the use of indirect methods to establish and verify reference intervals, to promote publication of such intervals with clear explanation of the process used and also to support the development of improved statistical techniques for these studies.

scholarly journals A robust approach to reference interval estimation and evaluation

1998 ◽  
Vol 44 (3) ◽  
pp. 622-631 ◽  
Author(s):  
Paul S Horn ◽  
Amadeo J Pesce ◽  
Bradley E Copeland
Keyword(s):  
Prediction Interval ◽  
Clinical Chemistry ◽  
Real Data ◽  
Reference Interval ◽  
Reference Intervals ◽  
Small Sample ◽  
The Other ◽  
Robust Estimator ◽  
Sample Sizes ◽  
Robust Approach

Abstract We propose a new methodology for the estimation of reference intervals for data sets with small numbers of observations or for those with substantial numbers of outliers. We propose a prediction interval that uses robust estimates of location and scale. The SAS software can be readily modified to do these calculations. We compared four reference interval procedures (nonparametric, transformed, robust with a nonparametric lower limit, and transformed robust) for sample sizes of 20, 40, 60, 80, 100, and 120 from χ2 distributions of 1, 4, 7, and 10 df. χ2 distributions were chosen because they simulate the skewness of distributions often found in clinical chemistry populations. We used the root mean square error as the measure of performance and used computer simulation to calculate this measure. The robust estimator showed the best performance for small sample sizes. As the sample size increased, the performance values converged. The robust method for calculating upper reference interval values yields reasonable results. In two examples using real data for haptoglobin and glucose, the robust estimator provides slightly smaller upper reference limits than the other procedures. Lastly, the robust estimator was compared with the other procedures in a population where 5% of the values were multiplied by a factor of 5. The reference intervals were calculated with and without outlier detection. In this case, the robust approach consistently yielded upper reference interval values that were closer to those of the true underlying distributions. We propose that robust statistical analysis can be of great use for determinations of reference intervals from limited or possibly unreliable data.

Establishment of Reference Intervals for Alkaline Phosphatase in Pakistani Children Using a Data Mining Approach

2019 ◽  
Vol 51 (5) ◽  
pp. 484-490 ◽  
Author(s):  
Sibtain Ahmed ◽  
Jakob Zierk ◽  
Aysha Habib Khan
Keyword(s):  
Data Mining ◽  
Alkaline Phosphatase ◽  
Clinical Decision Making ◽  
Clinical Chemistry ◽  
Age Groups ◽  
Clinical Decision ◽  
German Society ◽  
Reference Intervals ◽  
Photometric Method ◽  
Data Mining Approach

Abstract Objective To establish reference intervals (RIs) for alkaline phosphatase (ALP) levels in Pakistani children using an indirect data mining approach. Methods ALP levels analyzed on a Siemens Advia 1800 analyzer using the International Federation of Clinical Chemistry’s photometric method for both inpatients and outpatients aged 1 to 17 years between January 2013 and December 2017, including patients from intensive care units and specialty units, were retrieved. RIs were calculated using a previously validated indirect algorithm developed by the German Society of Clinical Chemistry and Laboratory Medicine’s Working Group on Guide Limits. Results From a total of 108,845 results, after the exclusion of patients with multiple specimens, RIs were calculated for 24,628 males and 18,083 females with stratification into fine-grained age groups. These RIs demonstrate the complex age- and sex-related ALP dynamics occurring during physiological development. Conclusion The population-specific RIs serve to allow an accurate understanding of the fluctuations in analyte activity with increasing age and to support clinical decision making.

scholarly journals Variability in the measurement of C-reactive protein in healthy subjects: implications for reference intervals and epidemiological applications

1997 ◽  
Vol 43 (1) ◽  
pp. 52-58 ◽  
Author(s):  
Elizabeth M Macy ◽  
Timothy E Hayes ◽  
Russell P Tracy
Keyword(s):  
Clinical Chemistry ◽  
Reference Interval ◽  
Reference Intervals ◽  
C Reactive Protein ◽  
Reactive Protein ◽  
Analytical Variability ◽  
Subject Variability ◽  
Donor Population ◽  
Index Of Individuality ◽  
Small Index

Abstract We developed a reproducible ELISA for C-reactive protein (CRP), calibrated with WHO Reference Material, for which intra- and interassay CVs were 3.0% and 6.0%, respectively. Analytical recovery was 97.9%. The distribution of CRP in a healthy blood donor population (n = 143) was nongaussian, with 2.5th, 50th, and 97.5th percentile values of 0.08, 0.64, and 3.11 mg/L, respectively. There was no sex-related difference, and the association with age was weak. In a study of variability [by the method of Fraser and Harris (Crit Rev Clin Lab Sci 1989;27:409–37)], the analytical variability was 5.2%; the within-subject variability, CVI, was 42.2%; and the between-subject variability, CVG, was 92.5%. The critical difference for sequential values significant at P ≤0.05 (i.e., the smallest percentage change unlikely to be due to analytical variability or CVI) was calculated as 118%, and the index of individuality, CVI/CVG, was 0.46. This suggests that CRP, like many clinical chemistry analytes, has limited usefulness in detecting early disease-associated changes when used in conjunction with a healthy reference interval. From a molecular epidemiological standpoint, the usefulness of CRP in longitudinal studies is suggested by the small index of individuality and by observations that (a) short-term fluctuations were infrequent, (b) all data stayed within the reference interval, and (c) relative rankings of the subjects over 6 months only moderately deteriorated.

scholarly journals Hematological Indices Reference Intervals for Healthy Arab Population in Qatar: Effect of Age, Gender, Geographic Location and ABO Blood Group

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 22-23
Author(s):  
Mohamed A Yassin ◽  
Ashraf Tawfiq Soliman ◽  
Feryal Abbas ◽  
Abdulqadir Jeprel Nashwan ◽  
Mahmood B Aldapt ◽  
...  
Keyword(s):  
Blood Cell ◽  
Venous Blood ◽  
Geographical Location ◽  
Geographic Location ◽  
Reference Interval ◽  
Reference Intervals ◽  
Specific Reference ◽  
Abo Blood Group ◽  
Arab Population ◽  
Young Males

Introduction: The majority of physicians' medical judgments are based on clinical information supported by laboratory reports . The availability of a reference interval for different lab values facilitates the process of interpretation . Complete blood count (CBC), testing is one of the most frequently performed hematology test in any clinical setting. Analysis of CBC by hematology analyzers is an indispensable means in the evaluation of many acute and chronic disorders including traumatic, infectious, immunological, and hematological diseases. Establishment of a normal reference interval is essential for accurate clarification of the disease diagnosis as well as for follow up. CBC techniques have improved significantly, and the accurate automated methods have now substituted manual methods. In addition, various novel blood cell parameters have been developed alongside to aid in diagnosis and management of several blood disorders . However significant differences exist in the reference intervals based on age, gender, ethnicity, genetic differences, environmental factors, and geographical location.. Dietary habits and occupational exposures are factors that have been shown to affect reference interval . Therefore, there is a requirement for each country to establish its own reference intervals. Country-specific reference intervals for CBC of adult peripheral blood have been established in many countries around the world; however, there have been no specific comprehensive studies in Arab population in Qatar based on age, gender, geographic location and ABO blood groups. To the best of our knowledge, this is the first study in Qatar that investigated CBC reference intervals in relation to age, gender, and blood grouping which can now be used as a reference when evaluating patient samples in Qatar. Methods: Venous blood specimens were collected from 720 healthy randomly selected individuals aged 18 to 69 years from 2018 to 2019 and analyzed by Sysmex NX-10 and NX -20 automated hematology analyzers. Results were statistically analyzed and compared by gender, age, and ABO blood group. Arab adults were divided into African Arabs (Egypt, Libya, Tunisia, Morocco) and Asian Arabs (Syria, Lebanon, Jordon, Palestine, Qatar). The lower and upper reference limits of the hematology reference intervals were established at the -2 SD and +2SD respectively. Results: Reference intervals were calculated for all the hematology parameters which included red blood cell, white blood cell and differential count, and platelet parameters. Arab males had significantly higher Hb, Hct, RDW, ANC, lymphocytes and monocyte counts compared to adult females. Asian-Arab males had significantly higher Hb concentration and higher WBC, lymphocytes and eosinophil counts compared to African- Arab males. Asian Arab young males had significantly higher Hb level and lymphocyte count and lower monocytes counts compared old males. African Arab young males had significantly higher lymphocyte and lower monocytes counts compared to old males. Asian- Arab young females had higher WBC, ANC counts compared to old Asian Arab females. No statistical difference in the studied hematological parameters was detected among the three groups with different ABO subgroups Conclusions: Data from this study established specific reference intervals which could be considered for general use in the Arab world. The differences in hematology reference intervals in respect to age, sex and geographical location highlights the necessity to establish reference intervals for venous blood parameters among the healthy population in each country or at least in each region. Disclosures No relevant conflicts of interest to declare.

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