Preanalytical Phase Of Laboratory Testing Research Articles

Analysis of Preanalytical Errors in Clinical Biochemistry Laboratory of a Tertiary Care Hospital: A Retrospective Study

Introduction: Pre-analytical phase of laboratory testing is the most susceptible phase, as errors in this phase leads to more than 50% of erroneous results and often breaches the trust of the stakeholders on the quality of the laboratory results. Many pre-analytical errors occur during the pre-analytical phase, encompassing sample collection, labelling and transportationfactors often beyond the laboratory’s direct control. Aim: To determine the type and frequency of pre-analytical errors leading to sample rejection in clinical biochemistry laboratory. Materials and Methods: Being a retrospective descriptive study, convenient sampling was used to analyse sample rejection due to pre-analytical errors in clinical biochemistry laboratory of a tertiary care teaching hospital- PSG Institute of Medical Sciences and Research, Coimbatore, Tamil Nadu, India for a period of six months from May 2023 to October 2023. All the cases/blood samples from Outpatient Department (OPD) and Inpatient Department (IPD), received and rejected during this period were included under study. The data collection and analysis was done over a period of five months using the sample rejection and resample description from Laboratory Information System (LIS). Using Statistical Package for the Social Sciences (SPSS) version 28.0, data were summarised using descriptive statistics such as numbers and percentages. Results: During the six months period out of the total of 667454 samples, 1505 (0.23%) samples were rejected due to pre-analytical errors. The majority of the samples which were rejected were from IPD than OPD. Among the pre-analytical errors, haemolysis accounted for 806 (53.6%), clotted samples 256 (17%), delta check 217 (14.4%), insufficient sample 129 (8.6%), contamination 74 (4.9%), identification error 14 (0.9%), sample without request form 3 (0.2%) while missing samples, billing error, inappropriate tube, delay in transport and wrong test selection accounted for <3 (0.1%). Conclusion: Haemolysis and clotted samples were the most common pre-analytical causes for sample rejection in the laboratory. The samples from IPD were rejected more often than OPD due to incorrect phlebotomy techniques. This accentuates the need for proper hands-on phlebotomy training sessions for novice nurses following their recruitment, as their competency will be instrumental in bringing down the errors in pre-analytical phase.

Measuring the operational performance of an artificial intelligence-based blood tube-labeling robot, NESLI.

Laboratory testing, crucial for medical diagnosis, has 3 phases: preanalytical, analytical, and postanalytical. This study set out to demonstrate whether automating tube labeling through artificial intelligence (AI) support enhances efficiency, reduces errors, and improves outpatient phlebotomy services. The NESLI tube-labeling robot (Labenko Informatics), which uses AI models for tube selection and handling, was used for the experiments. The study evaluated the NESLI robot's operational performance, including labelling time, technical problems, tube handling success, and critical stock alerts. The robot's label readability was also tested on various laboratory devices. This research will contribute to the field's understanding of the potential impact of automated tube-labeling systems on laboratory processes in the preanalytical phase. NESLI demonstrated high performance in labeling processes, achieving a success rate of 99.2% in labeling parameters and a success rate of 100% in other areas. For nonlabeling parameters, the average labeling time per tube was measured at 8.96 seconds, with a 100% success rate in tube handling and critical stock warnings. Technical issues were promptly resolved, affirming the NESLI robot's effectiveness and reliability in automating the tube-labeling processes. Robotic systems using AI, such as NESLI, have the potential to increase process efficiency and reduce errors in the preanalytical phase of laboratory testing. Integration of such systems into comprehensive information systems is crucial for optimizing phlebotomy services and ensuring timely and accurate diagnostics.

Determining the rate and reasons for specimen rejection among specimens referred for HIV viral load determination through referral linkage to Debre Tabor Comprehensive Specialized Hospital, north-central, Ethiopia,2023: Retrospective study

BackgroundThe preanalytical phase encompasses the time between the clinician's test order to the sample being ready for analysis. Of all errors during the laboratory diagnostic process,70 % appeared in the pre-analytical phase. In clinical laboratories, it is crucial to ensure proper specimen collection and handling, which is essential to guarantee quality assessment, monitoring process standardization, improving performance, and ensuring patient safety. Despite this importance, no study has been conducted in the study area to investigate the rate and reasons for human immunodeficiency virus viral load sample rejection. ObjectiveTo determine the rate of human immunodeficiency virus viral load sample rejection (number of preanalytical errors) documented during the preanalytical phase and articulate possible causes for specimen rejection. Material and methodsA retrospective study was conducted at Debre Tabor Comprehensive Specialized Hospital from January 1st to January 31, 2023. During the study period, 5950 samples were extracted from the human immunodeficiency virus viral load laboratory sample tracking log books, which were sent to the hospital for viral load testing between August 2021 to November 2022. The collected data were cleaned and entered into EPI data version 4.6 before transferred it to STATA version 14.0 for analysis. Descriptive statistics such as frequencies, percentages, and cross-tabulations were used to summarize the findings. ResultsThe study found that improper sample handling was common during the preanalytical phase. According to the current study, 3.6 % of the sample was rejected at pre analytical stage. The most common reasons for specimen rejection were using inappropriate containers (64.0 %) uncentrifuged specimens (20.4 %); hemolyzed specimens (7.0 %); insufficient specimen volume (6.2 %); clotted specimens (1.9 %); and specimen labeling problems (0.5 %). ConclusionThis study found that the most common preanalytical error was using an inappropriate sample collection container, followed by uncentrifuged samples, Therefore, it is recommended that mentorship programs be developed to educate staff on the preanalytical phase of laboratory testing, specifically on sample collection, storage, and transportation for HIV viral load testing. Additionally, the quality management system of laboratory processes should be strengthened to ensure accuracy and minimize errors.

Development of a virtual classroom for pre-analytical phase of laboratory medicine for undergraduate medical students using the Delphi technique.

Amongst the pre-analytical, analytical, and post-analytical phase of laboratory testing, pre-analytical phase is the most error-prone. Knowledge gaps in understanding of pre-analytical factors are identified in the clinical years amongst undergraduate students due to lack of formal teaching modules on the pre-analytical phase. This study was conducted to seek experts' consensus in Clinical Chemistry on learning objectives and contents using the Delphi technique with an aim to develop an asynchronous virtual classroom for teaching pre-analytical factors of laboratory testing. A mixed method study was conducted at the Aga Khan University. A questionnaire comprising of 16 learning objectives and their associated triggers was developed on Google Docs for developing the case vignettes. A four-point Likert Scale, which included strongly agree, agree, disagree and strongly disagree, was utilized for the learning objectives. An open-ended question was included for experts to suggest new items for inclusion. A cut off of at least 75% agreement was set to establish consensus on each item. A total of 17 Chemical Pathology faculty from 13 institutions across Pakistan were invited to participate in the first round of Delphi. Similar method of response was used in round two to establish consensus on the newly identified items suggested by the faculty in round 1. Later, the agreed-upon objectives and triggers were used to develop interactive scenarios over Moodle to concurrently test and teach medical students in a nonchalant manner. A total of 17 responses were received in Round 1 of the Delphi process (response rate = 100%), while 12 responses were received in Round 2 (response rate = 71%). In round 1, all 16 learning objectives reached the required consensus (≥ 75%) with no additional learning objectives suggested by the experts. Out of 75 triggers in round 1, 61 (81.3%) reached the consensus to be included while 39 were additionally suggested. In 2nd round, 17 out of 39 newly suggested triggers met the desired consensus. 14 triggers did not reach the consensus after two rounds, and were therefore eliminated. The virtual classroom developed using the agreed-upon learning objectives and triggers consisted of 20 items with a total score of 31 marks. The questions included multiple choice questions, fill in the blanks, drag and drop sequences and read-and-answer comprehensions. Specific learning points were included after each item and graphs and pictures were included for a vibrant experience. We developed an effective and interactive virtual session with expert consensus on the pre-analytical phase of laboratory testing for undergraduate medical students which can be used for medical technologist, graduate students and fellows in Chemical Pathology.

Influence of exogenous and endogenous factors on the quality of the preanalytical stage of laboratory tests (review of literature).

A literature review in the article presents an analysis of the influence of endogenous and exogenous factors on quality of preanalytical phase of laboratory testing. The review shows significance of external and internal factors influencing blood samples at preanalytical phase of laboratory testing. Among the exogenous factors considered: phlebotomy, test tubes for samples, transportation and storage. A number of factors exist at this phase that significantly affect test results. We examined these aspects of phlebotomy process: staff training, disinfectant contamination, needle diameter, needle material contamination. The review considers possible contamination with tube components and the importance of choosing the right anticoagulants and excipients. Transportation and storage of biological samples can be a source of errors at the preanalytical phase of laboratory testing. We analyzed the problem of determining the stability of analytes during storage and aspects of transportation samples by modern means. Among the endogenous factors considered: hemolysis, lipemia, icterricity, cell metabolism.. Hemolysis is one of the most frequent consequences of errors at the preanalytical phase. We analyzed importance of choosing a method for identifying hemolized tubes and the heterogeneity of bias results on different analytical systems. The review shows contribution of various classes of lipoproteins to turbidity of sample, possible preanalytical errors and impact on analytical tests. We examined possible effects of high bilirubin concentrations on analyte measurements. In the review, we also examined metabolism of some cells and its effect on samples.

Questionnaire-based Study to Assess Knowledge of Preanalytical Phase of Laboratory Testing Among Trainee Doctors in a Tertiary Care Hospital Medical College.

Objective To determine the knowledge base of common laboratory practices related to preanalytical phase of laboratory testing among medical interns and first-year postgraduate residents in a tertiary care hospital medical college. Materials and methods Questionnaire-based survey on preanalytical phase of laboratory testing was conducted among 208 participants, who volunteered and were MBBS interns and first-year postgraduate residents in a medical college, over the period from June 2018 to December 2019. A total of 15-item, multiple-choice questions (MCQs) were included, of which four were opinion-based and not considered for analysis. Responses were further categorized based on percentages with correct response, so we could identify specific knowledge points which need training. Statistical analysis Results were analyzed using Microsoft Excel functions and a simple calculator. Results A total of 208 participants were included in the study, which consisted of an equal number of interns (104) and first-year postgraduate residents (104). The term “preanalytical error” was known to 62.5% of participants. Only 9.62% participants took formal training in phlebotomy. Topics related to questions like coagulation testing, ideal fasting duration, mixing of blood, and order of draw received less than 40% correct response which meant that it requires more training. Conclusions In this era of evidence-based medicine, central laboratory plays a pivotal role in patient management, and quality of laboratory results are of paramount importance. Over a period of time, automation technology has reduced analytical phase errors to the minimum. Most errors reported are part of the preanalytical phase, and it has been found that a majority of them are committed due to a lack of knowledge and skills. In order to improve the preanalytical phase and make it as error-free as possible, the staff (technicians, nurses, and trainee doctors) should be constantly motivated and trained.

Impact of specific preclinical variables on coagulation biomarkers in cancer-associated thrombosis

Coagulation biomarkers are being actively studied for their diagnostic and prognostic value in patients with venous thromboembolism and cancer, as well as in the study of pathogenic mechanisms between cancer and thrombosis. For the results of such studies to be accurate and reproducible, attention must be paid to minimize sources of error in all phases of testing. The pre-analytical phase of laboratory testing is known to be fraught with the majority of errors. Coagulation testing is particularly susceptible to conditions during collection, processing, transport and storage of specimens which can lead to clinically significant errors in results. In addition, changes in pre-analytical conditions can impact different biomarkers differently. Therefore, research studies investigating coagulation biomarkers must carefully standardize not just the analytical phase, but also the pre-analytical phase of testing to ensure accuracy and reliability. We briefly review the impact of pre-analytical conditions on coagulation testing in general, and on specific biomarkers in cancer and thrombosis. In addition, we provide recommendations to reduce pre-analytical errors by developing and sharing standard operating procedures that specifically target standardization of methodologies for collecting specimens and measuring current and emerging coagulation biomarkers in cancer studies.

REQUISITION FORMS AND REPORTS-'GARBAGE IN GARBAGE OUT' – SIGNIFICANCE OF CLINICAL DATA IN MICROBIAL CULTURE & ANTIBIOTIC SUSCEPTIBILITY TESTING OF SURGICAL SAMPLES

OBJECTIVES: The pre-analytical phase of laboratory testing is an important component of testing process. Laboratory requisition forms(LRF) for microbial culture and antibiotic susceptibility testing for pus, exudate, aspirate, tissue and swabs were analysed in our study following a noncompliance identied during a National Accreditation Board for Testing and Calibration Laboratories(NABL) Surveillance Audit. METHODS: LRFs were analyzed between June-August 2019 for various components in this prospective study. RESULTS: Of the 424 LRFs, 35 % were from outpatients and 65% from in-patients. 100% of the forms had patient identiers of patient name, age, unique hospital identication number. 97.6 % of the LRFs had sample type mentioned. 95.5 % did not mention who collected the sample. 95.7 % did not mention the time of collection. 79.2 % had clinical ndings mentioned but 22.4 % did not mention the site of infection. Only 8 % had history of antibiotics mentioned and 1.4 % had previous culture reports mentioned. 5.6% had no name of the requesting physician mentioned and 3.5 % were illegible abbreviations. 6.1% did not have signature of the requesting doctors, 0.4 % had illegible signatures. 4.2 % had no date on LRFs. CONCLUSION: Our root cause analysis helped us in identifying the factors for incomplete LRFs based on which we recommend proper categorization of samples with test codes on requisition forms, use of information & technology to integrate electronic data entry to reduce transcription errors, periodic training of doctors on pre-analytical phase of testing, stringent sample rejection and acceptance criteria and regular audits of LRFs.

Quality laboratory issues in bleeding disorders.

Selected quality issues pertinent to the determination of accurate results in the haemostasis laboratory are discussed. Specifically, the implementation of a successful external quality-assessment scheme is described, including its impact on result accuracy as well as the programme's unique challenges and opportunities. Errors in the preanalytical phase of laboratory testing represent the greatest source for reporting incorrect test results. Some of the most common preanalytical errors are described including those that necessitate sample rejection. Analytical means to identify potential sources of error and analytical means to overcome particular interferences are described. Representing the most important clinical complication in the treatment of patients with haemophilia, quality issues related to determination of the presence of inhibitory antibodies against factor VIII (FVIII) are reviewed. Heat treatment of patient plasma prior to testing, particularly in patients receiving replacement FVIII concentrate or during induction of immune tolerance to achieve more accurate results is recommended, while screening activated partial thromboplastin time-based mixing tests to rule out inhibitor presence is discouraged. The initiatives presented in this review can be implemented in robust and resource restricted settings to improve the quality of laboratory testing in patients with bleeding disorders.

The knowledge and understanding of preanalytical phase among biomedicine students at the University of Zagreb.

IntroductionThe educational program for health care personnel is important for reducing preanalytical errors and improving quality of laboratory test results. The aim of our study was to assess the level of knowledge on preanalytical phase in population of biomedicine students through a cross-sectional survey.Materials and methodsA survey was sent to students on penultimate and final year of Faculty of Pharmacy and Biochemistry – study of medical biochemistry (FPB), Faculty of Veterinary Medicine (FVM) and School of Medicine (SM), University of Zagreb, Croatia, using the web tool SurveyMonkey. Survey was composed of demographics and 14 statements regarding the preanalytical phase of laboratory testing. Comparison of frequencies and proportions of correct answers was done with Fisher’s exact test and test of comparison of proportions, respectively.ResultsStudy included 135 participants, median age 24 (23-40) years. Students from FPB had higher proportion of correct answers (86%) compared to students from other biomedical faculties 62%, P < 0.001. Students from FPB were more conscious of the importance of specimen mixing (P = 0.027), prevalence of preanalytical errors (P = 0.001), impact of hemolysis (P = 0.032) and lipemia interferences (P = 0.010), proper choice of anticoagulants (P = 0.001), transport conditions for ammonia sample (P < 0.001) and order of draw during blood specimen collection (P < 0.001), in comparison with students from SM and FVM.ConclusionsStudents from FPB are more conscious of the importance of preanalytical phase of testing in comparison with their colleagues from other biomedical faculties. No difference in knowledge between penultimate and final year of the same faculty was found.

A study of pre-analytical errors in a hospital based clinical biochemistry laboratory and formulation of measures for correction

A prospective observational study was done in the Central Clinical Laboratory of Gauhati Medical College & Hospital for a period of 2 months from 1 st March to 30 th April 2014. The objective of the study was to evaluate the pre-analytical phase of laboratory testing in a Clinical Biochemistry Laboratory to detect the different errors which occurred in the preanalytical phase and calculate their percentage and to determine in which step the error occurred so that corrective measures can be formulated to avoid such errors. All the samples and their accompanying laboratory request forms were screened for pre-analytical errors and the daily errors and their types recorded in Problem Notification Logbook. The data collected was analyzed and the entire process of sample collection and transport was evaluated to formulate corrective measures to prevent these errors from occurring. The total number of samples received in 2 months was 23,680. Out of this OPD samples were 11,414 and Indoor samples were 12,266.Of the 12,266 laboratory request forms which were screened 12,106, forms were incomplete i.e. only 160 forms carried all the required information. Out of the total 23,680 sample tubes screened preanalytical errors were observed in 6.61% of Indoor samples and 3.69% of OPD samples. Hemolysed sample was the most commonly observed preanalytical error both in OPD and Indoor samples. Hemolysis was observed in 4.25% of Indoor samples and in 3.55% of OPD samples. Insufficient sample volume was observed in 1.74% of Indoor and .026% of OPD samples. Preanalytical error was observed in 5.20% of samples during the study period. Of this 3.91% of samples received were hemolysed and were rejected .Corrective measures have to be taken to reduce the percentage of rejected samples.

Influence of method of venous blood collection on the blood cell count determination result

Introduction: The preanalytical phase of laboratory testing, including collecting of the material, is one of the most important factors affecting the quality of the results of analyzes. Aim of the research: To evaluate the influence of the method of collecting venous blood on the result of blood cell count determination. Material and methods: Venous blood of 20 healthy people was collected into tubes with K 2 EDTA using two types of blood collection system: an open blood collection system (consisting of a syringe and needle) and a vacuum blood collection system (consisting of a vacuum tube for blood collection and matching needle). Results: Statistical analysis of the results showed that the method of blood venous collection influenced the result of some parameters of blood cell count determination, such as red blood cell count, white blood cell count, hemoglobin, hematocrit and platelet count, but did not influence mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration. These differences are clinically relevant because they do not exceed 5% of the value. Conclusions: Results of blood morphology appears to depend on the method of sample collection. The observed differences are not clinically significant, because they do not exceed 5%.

Is Phlebotomy Part of the Dark Side in the Clinical Laboratory Struggle for Quality?

Blood collection is a critical part of the preanalytical phase of laboratory testing. Only a few procedures are evaluable for detecting errors in this non-automatic activity. Information about potential sources of error is frequently absent from quality-control procedures and training materials. To evaluate the performance of phlebotomists and to identify the major sources of errors during diagnostic blood collection. We evaluated the performance of 3 phlebotomists each from 10 laboratories regarding tourniquet time, request for fist clenching, excessive friction during skin cleaning, sequence of vacuum-tube usage, and mixing of tube contents after specimen collection. The total number of these laboratories represented an equal number of private (ie, owned by private parties) and public (ie, administration by government organizations) settings. An error rate of greater than 60% was observed in the performance of procedures we examined, and the error rate was not significantly different between public and private settings other than more adequate mixing of the contents of primary collection tubes in private facilities. Most facilities did not achieve adequate quality standards in phlebotomy. In procedural manuals, training materials and practices for phlebotomists, greater emphasis should be placed on presenting information on possible sources of error and on the correct implementation of procedures that ensure the quality of diagnostic blood specimens collected for laboratory analysis.

Incident reporting practices in the preanalytical phase: Low reported frequencies in the primary health care setting

Objective: Incident reporting is commonly used to improve patient safety. The preanalytical phase of laboratory testing contains several manual error-prone tasks where mistakes can affect patient outcomes. However, the practical use of incident reports in this area has not been previously investigated in the primary health care setting, where the majority of the patients come in contact with health care. Material and methods: All staff responsible for venous blood sampling in 70 primary health care centres and in two hospital clinical laboratories (317 respondents, response rate 94%) completed a questionnaire. Results: Of the primary health care staff, 69% reported that they had never filed an incident report regarding venous blood sampling. Barriers for not filing incident reports often/always included lack of time (44%) and a complicated reporting procedure (27%). A higher proportion of staff with re-education (43%) had filed at least one incident report as compared to those without re-education (20%, p < 0.001). No differences in incident reporting practices were found between primary health care and hospital clinical laboratory staff. Conclusions: The investigated incident reporting system is likely to underreport incidents in the preanalytical phase. Therefore, the ability to discover preventable system vulnerabilities needs refinement.

“Pre-pre” and “post-post” analytical error: high-incidence patient safety hazards involving the clinical laboratory

Data from recent studies suggest that the highest incidence of laboratory-related errors occurs in the pre-analytical phase of laboratory testing. However, few studies have examined the frequency of errors in laboratory test selection and interpretation. A survey of physicians who use our clinical laboratory demonstrated that the largest number of test ordering errors appear to involve physicians simply ordering the wrong test. Diagnostic algorithms providing guidance for test selection in specific disorders are also used as the basis for the establishment of reflex protocols in the clinical laboratory. The provision of an expert-driven interpretation by laboratory professionals resulted in improvements both in the time to and the accuracy of diagnosis. A survey of our physician staff has shown that in the absence of such an interpretation, for patients being assessed for a coagulation disorder, approximately 75% of the cases would have involved some level of test result misinterpretation.

Risk management in the preanalytical phase of laboratory testing

The clinical laboratory is no longer its own limited ecosystem, as it is increasingly integrated with patient care, assisting diagnosis, monitoring therapies and predicting clinical outcomes. Although efforts and resources are continuously focused to achieve a satisfactory degree of analytical quality, there is clear evidence that the preanalytical phase is much more vulnerable to uncertainties and accidents, which can substantially influence patient care. Most errors within the preanalytical phase result from system flaws and insufficient audit of the operators involved in specimen collection and handling responsibilities, leading to an unacceptable number of unsuitable specimens due to in vitro hemolysis, clotting, insufficient volume, wrong container, contamination and misidentification. A reliable approach to overcome this problem entails prediction of accidental events (exhaustive process analysis, reassessment and rearrangement of quality requirements, dissemination of operating guidelines and best-practice recommendations, reduction of complexity and error-prone activities, introduction of error-tracking systems and continuous monitoring of performances), an increase in and diversification of defenses (application of multiple and heterogeneous systems to identify non-conformities), and a decrease in vulnerability (implementation of reliable and objective detection systems and causal relation charts, education and training). This policy, which requires integration between requirements and design, full commitment and interdepartmental cooperation, should make laboratory activity more compliant to the inalienable paradigm of total quality in the testing process.