Objective: A variety of influences reduce the validity of the measured oxygen partial pressure (paO(2)). Most errors occur when obtaining the blood sample and preparing it for analysis. Unfortunately, there is great controversy concerning the relevance and extent of these pre-analytic errors. Apart from this, the exact estimation of influencing factors under hyperoxic conditions has been neglected. Therefore, the objective of this study was to assess pre-analytic measuring errors for paO(2) under the condition of hyperoxia as completely as possible and to work out solutions to eliminate these errors.
Methods: paO(2) analysis was performed on more than 2000 blood samples. Errors analyzed were the technique of sample taking (direct puncture or from an indwelling catheter), aspirated air bubbles (0.05-0.35 ml), time and temperature of sample storage, and the material, size and manufacturer of the analyzing syringe.
Results: The paO(2) was on average 41 mmHg lower in samples taken from the indwelling catheter than by direct puncture. An air bubble size of 0.1-0.25 ml caused a decrease of 17-41 mmHg. Storage time of 2 min accounted for an paO(2) reduction of 6-67 mmHg depending on the type of syringe used. Glass syringes turned out to be more accurate than plastic syringes. The best results were obtained not from commercial "blood gas syringes" but from a simple plastic injection syringe. For all pre-analytic errors correction factors were established.
Conclusion: All pre-analytic errors investigated caused a significant paO(2) decrease. Even an ideal procedure (almost no air bubble, short storage on ice) contributes a significant error. Only the appropriate correction factors as calculated from this study for routine use lead to the correct results. If they are not taken into account the paO(2) values will be falsely low, potentially leading to misinterpretation and misjudgement of a patient's condition.
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http://dx.doi.org/10.1007/s001010050744 | DOI Listing |
Mol Genet Metab Rep
September 2024
Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA.
Treatment of phenylketonuria (PKU) has evolved since the initial introduction of a phenylalanine (Phe) restricted diet. The most recent option for adults affected with PKU is treatment with an alternate enzyme, phenylalanine ammonia lyase (PAL), that metabolizes excess Phe. Proper management of all patients with PKU relies on accurate measurement of Phe levels in blood, to comply with guidance intended to minimize the neurological symptoms.
View Article and Find Full Text PDFDiagn Pathol
February 2024
Institute of Pathology, Tel-Aviv Sourasky Medical Center, 6 Weizmann Street, 6423906, Tel Aviv, Israel.
Background: Differences in the preparation, staining and scanning of digital pathology slides create significant pre-analytic variability. Algorithm-assisted tools must be able to contend with this variability in order to be applicable in clinical practice. In a previous study, a decision support algorithm was developed to assist in the diagnosis of Hirschsprung's disease.
View Article and Find Full Text PDFVirchows Arch
May 2024
Division of Anatomic Pathology, Department of Laboratory Medicine and Molecular Diagnostics, Sunnybrook Health Science Center, Toronto, ON, M4N 3M5, Canada.
Pre-analytical deficiencies (PADs) are a major source of errors in anatomical pathology, accounting for about 70% of laboratory deficiencies. These can lead to incorrect diagnoses, delayed treatments, and increased healthcare costs. As part of a quality improvement initiative, we retrospectively identified and characterized 237 PADs documented over a 1-year period in a tertiary care academic center.
View Article and Find Full Text PDFBiosensors (Basel)
December 2022
Institute of Biomedical Engineering, University of Luebeck, 23562 Luebeck, Germany.
Objective: The main objective of this investigation is to provide data about the accuracy of total hemoglobin concentration measurements with respect to clinical settings, and to devices within the categories of point-of-care and reference systems. In particular, tolerance of hemoglobin concentrations below 9 g/dL that have become common in clinical practice today determines the need to demonstrate the limits of measurement accuracy in patient care.
Methods: Samples extracted from six units of heparinized human blood with total hemoglobin concentrations ranging from 3 to 18 g/dL were assigned to the test devices in a random order.
Introduction: The errors in the pre-analytic phase are at the origin of 60 to 85% of the errors in the results proceeded from laboratory.
Aim: To evaluate the impact of the pre-analytical phase on the received bacteriology samples received at the medical bacteriology laboratory of Ibn Sina UH in Rabat Morocco in order to propose corrective actions.
Methods: A descriptive and quantitative study of the non-conformities of the pre-analytical phase identified in the central laboratory of medical bacteriology of the Ibn Sina hospital in Rabat over a period of 6 months (from January 01 to July 01, 2020).
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