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Recommended puncture sites (hatched areas A, B and C) of the foot of an infant. Courtesy of the Department of Clinical Chemistry, Central Hospital, Eskilstuna. Sweden.
Source publication
Reference values should be produced under standardized conditions. To enable comparison it is desirable to use the same procedure also in other clinical situations. A procedure for the collection of venous blood from children with special reference to production of reference values is recommended. It deals with five items: preparation of the child...
Contexts in source publication
Context 1
... Note. Collection of blood drop by drop increases the risk of haemolysis. 4.1.1.3 Sites A and B. Use the plantar side of the heel outside the lateral and medial surfaces of the calcaneous, indicated in Fig. 2 by one line drawn through the middle of the great toe parallel to the medial side of the foot, and another line drawn between the fourth and fifth toes parallel to the lateral side of the foot. The puncture is thus performed in one of the hatched areas in Fig. 2. 4.1.1.4 Site C. The puncture is performed in the medial part of the ...
Context 2
... of the heel outside the lateral and medial surfaces of the calcaneous, indicated in Fig. 2 by one line drawn through the middle of the great toe parallel to the medial side of the foot, and another line drawn between the fourth and fifth toes parallel to the lateral side of the foot. The puncture is thus performed in one of the hatched areas in Fig. 2. 4.1.1.4 Site C. The puncture is performed in the medial part of the plantar arch of the foot in front of the calcaneous bone, in the cross- hatched area in Fig. 2. 4.1.1.5 The person collecting the specimen grips the heel of the infant with hidher second and third fingers behing the ankle and with the thumb over the plantar arch of the ...
Context 3
... side of the foot, and another line drawn between the fourth and fifth toes parallel to the lateral side of the foot. The puncture is thus performed in one of the hatched areas in Fig. 2. 4.1.1.4 Site C. The puncture is performed in the medial part of the plantar arch of the foot in front of the calcaneous bone, in the cross- hatched area in Fig. 2. 4.1.1.5 The person collecting the specimen grips the heel of the infant with hidher second and third fingers behing the ankle and with the thumb over the plantar arch of the foot, so that the second finger and the thumb form a ring around the heel. The fourth and the fifth fingers are kept over the dorsal surface of the foot so that ...
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Citations
... It is convenient to classify the factors into those that can be influenced and those that cannot (28). All the factors mentioned together with the specimen collection procedure (use of tourniquet, needle, collection vessel etc.) can be classified as preanalytical factors, discussed in the IFCC recom-mendation Part 3 (8) and in many Scandinavian publications (12)(13)(14) 1) . Obviously, the location of an observed (patient) value in relation to the location or statistical distribution of the reference value(s) becomes indistinct or not observable if these variations are great. ...
... Specimens from paediatric patients often cannot be taken under similar conditions as from adults. Hence, special recommendations have been worked out regarding the collection of skin puncture and venous blood (12,13) and urine 1) . ...
This manuscript reviews the introduction of the concept of reference values, the corresponding philosophy, and subsequent recommendations reflecting the different subtopics of the field. The generally unrecognised phenomenon that laboratory results of the population tended to be lognormal instead of Gaussian attracted the attention of the author, who became sceptical of the concept of normal values because of its ambiguity. Together with N.-E. Saris a new concept of reference values was launched at a congress in 1969. Briefly, clinical measurements should be interpreted against values from proper control subjects. Subsequently international, regional and national societies established expert panels which produced recommendations covering the general principles and terminology of reference values, the concept of health, standardised specimen collection and preanalytical factors, statistical treatment of collected values, stratification of data, relating observed (patient) values to reference values, etc. The importance of using correct terminology, taking into consideration the aim of ordering the laboratory test and some neglected procedures (e.g., survival values) are emphasised. New developments such as reference changes are mentioned. The field has evolved largely as the result of constructive international teamwork.
This chapter describes the neonatal and pediatric biochemistry. Compared with adults, children as they grow are normally intensely anabolic. They become catabolic rapidly during intercurrent illness and they have an immature endocrine system as they lack gonadal steroids. Their immune system is immature and in early infancy, some of the body organs are also still developing, notably the kidneys, liver, and lungs. For these reasons, the biochemistry of children in health differs in many respects from that of adults, and the metabolic response to illness is often more acute and intense. In addition, a different spectrum of diseases occurs in childhood: infections predominate, often associated with metabolic or nutritional imbalance. Congenital and inherited disorders most often manifest in early life, and the types of cancers encountered are different. Degenerative disorders, such as atherosclerosis, are rare. Pediatric medicine, therefore, makes special demands of a hospital biochemistry service. In addition, the small size of many of the patients and their reluctance to cooperate tax the resourcefulness of the service to provide meaningful data on meager biological samples. The chapter describes the reference ranges and discusses some biochemical disorders of particular importance in children. It also discusses the unique problems of sick and preterm, newborn infants.
Biological variations of total butyrylcholinesterase activity (EC 3.1.1.8) in sera were determined in 993 healthy school children (age 8–19 years) and 2246 healthy adults (20–70 years) in a population from Zagreb, Croatia. Physiological variations corresponding to age and sex and genetically determined changes were studied as the important factors affecting biological variation in total butyrylcholinesterase activity. Based on biological variability, using a non-parametric statistical method, reference intervals for total butyrylcholinesterase activity were produced in order to provide medically reliable evaluation of laboratory results by pediatricians and clinicians in our country.
A direct 17α-hydroxyprogesterone (17-OHP) radioimmunoassay kit was used for the assay of samples from 219 infants and children. The kit was used according to the manufacturer's protocol on unextracted serum or plasma and also on reconstituted material extracted from the serum with propanol-heptane. The extraction protocol recovers approximately 88% of 17-OHP. Patients were grouped as infants 3–90 days (96 subjects) or older children, adolescents and young adults 91 days-20 years (123 subjects). 17-OHP results by the direct and extraction protocols correlated but the slopes of the regression lines (0.43 and 0.63) differed in the two groups, indicating that only about 49% of the immunoreactive material measured by the kit in the infants was 17-OHP whereas the corresponding percentage was 72% in the older children. Despite this nonspecificity, the present antibody is much more specific for 17-OHP in the presence of neonatal plasma steroids than that used previously. Reference values were obtained for the two groups using the method with and without an extraction step. 17-OHP values on four untreated patients with CAH were clearly elevated at the time of diagnosis. It is recommended that when the kit is used with neonatal and infant samples, an extraction step should be incorporated to enhance specificity.
The concentrations of blood components are influenced by a number of pre-analytical factors, the importance of which varies [1]. Therefore it is necessary to standardize the specimen collection, as was done by the Committee on Reference Values of the Scandinavian Society for Clinical Chemistry and Clinical Physiology, which in 1975 published its recommendation on the production of reference values in clinical chemistry [2]. It was the very first recommendation of its kind. Since then, new information has accumulated, and it has become necessary to revise the part concerning the preparation of subjects for blood collection, the collection procedure itself, and the subsequent handling of the specimen. Also, The International Federation of Clinical Chemistry (Expert Panel on Theory of Reference Values) has produced its own recommendation [3]. The recommendation described below replaces pp. 39-44 of the former Scandinavian recommendation [2]. The procedure described below is designed for the collection of specimens for the measurement of the majority of components in blood and specimen collection from the cubital vein is described. It can be easily adapted for the collection of blood from other vessels [4]. Certain laboratory investigations require a special protocol. In that case, the preparation of the subject prior to and during specimen collection as well as the procedure itself should be described in sufficient detail to permit reproduction by adequately trained personnel. In any project designed to produce reference values the same protocol for the preparation of individuals and specimen collection should be used throughout the project. The protocol should be described in detail. Thus, it is not satisfactory to state only that the present recommendation was followed. Each section of the recommendation is followed by a check list for points which should be taken into account.
A review describing the fallacies of the concept of normal values and the reasons for its substitution with reference values. The "reference value philosophy", its terminology and recommended practical procedures are presented and it is warned not to use incorrect terms such as "normal reference range". The concepts of health and disease are discussed from the point of view of the laboratory. Reference values are not always derived from "healthy" persons. In order to be comparable, reference values and observed (i.e. patient) values should be produced in the same way, using the same analytical procedure, quality control, etc. The influence of preanalytical factors such as food intake, posture, use of tourniquet and freezing and storing samples is great and necessitates standardisation of specimen collection. Strategies for the selection of reference individuals are presented and the reasons and methods for subdivision of the data are described. Descriptions are also given of the individual reference values and the statistical treatment of collected data including multivariate analysis. Finally, the reporting of observed values in relation to reference values is discussed. There is a trend to avoid the use of the reference interval because of the temptation to regard the values falling outside it as pathological.
A supplement to a bibliography (Scand J Clin Lab Invest 1987;47 suppl. 187:1-96) dealing with quality assurance in the clinical laboratory is presented. The increasing role of national and international standardizing bodies is stressed as well as implementation of rules of "good laboratory practice". Objectively established quality goals for all services is highly needed in order to provide a rationale for the efforts dedicated to quality improvements. Quality goals for many clinical chemistry and haematology investigations are now available.
The concentrations of blood components are influenced by a number of preanalytical factors, the importance of which varies [1]. Therefore it is necessary to standardize the specimen collection, as was done by the Committee on Reference Values of the Scandinavian Society for Clinical Chemistry and Clinical Physiology, which in 1975 published its recommendation on the production of reference values in clinical chemistry [2]. It was the very first recommendation of its kind. Since then, new information has accumulated, and it has become necessary to revise the part concerning the preparation of subjects for blood collection, the collection procedure itself, and the subsequent handling of the specimen. Also, The International Federation of Clinical Chemistry (Expert Panel on Theory of Reference Values) has produced its own recommendation [3]. The recommendation described below replaces pp. 39-44 of the former Scandinavian recommendation [2]. The procedure described below is designed for the collection of specimens for the measurement of the majority of components in blood and specimen collection from the cubital vein is described. It can be easily adapted for the collection of blood from other vessels [4]. Certain laboratory investigations require a special protocol. In that case, the preparation of the subject prior to and during specimen collection as well as the procedure itself should be described in sufficient detail to permit reproduction by adequately trained personnel. In any project designed to produce reference values the same protocol for the preparation of individuals and specimen collection should be used throughout the project. The protocol should be described in detail. Thus, it is not satisfactory to state only that the present recommendation was followed. Each section of the recommendation is followed by a check list for points which should be taken into account.
