Preanalytical phase--a continuous challenge for laboratory professionals

Analysis of thicknesses of blood collection needle by scanning electron microscopy reveals wide heterogeneity

OBJECTIVES

The preanalytical phase in clinical laboratory diagnostics is currently receiving more and more attention. This term describes one part of actions and aspects of the "brain-to-brain cycle" of the medical laboratory diagnostic procedure that take place before the analytical phase. However, the preanalytical activities, the handling of unsuitable samples and the reporting procedures are neither fully standardized nor harmonized worldwide. The influence of the properties of the blood collection needle must be acknowledged. In this work, we focused on the investigation of the internal structure and size of standardized 21G blood collection needles.

METHODS

All parameters were measured with a scanning electron microscope using a Jeol model JSM-6000PLUS. Our.

RESULTS

The obtained data shows that the internal surfaces of the needles vary greatly from manufacturer to manufacturer (by around 35 %), and this may play an important role in influencing blood flow and even the risk of blood cell injury (especially hemolysis) during blood drawing.

CONCLUSIONS

The differential actual needle diameters can vary greatly between needle manufactures and this variety may have a significant impact on laboratory values and may also lead to specimen rejection.

Venous blood collection systems using evacuated tubes: a systematic review focusing on safety, efficacy and economic implications of integrated vs. combined systems

Venous blood collection systems (VBCSs) are combinations of in-vitro diagnostics and medical devices, usually available as integrated set. However, purchasing and using a combination of devices from different sets is considered by clinical laboratories as an option to achieve specific sampling tasks or reduce costs. This systematic review aimed to retrieve available evidence regarding safety, efficacy, and economic aspects of VBCSs, focusing on differences between integrated and combined systems. The literature review was carried out in PubMed. Cited documents and resources made available by scientific organisations were also screened. Extracted evidence was clustered according to Quality/Efficacy/Performance, Safety, and Costs/Procurement domains and discussed in the current European regulatory framework. Twenty documents published between 2010 and 2021 were included. There was no evidence to suggest equivalence between combined and integrated VBCSs in terms of safety and efficacy. Scientific society's consensus documents and product standards report that combined VBCS can impact operators' and patients' safety. Analytical performances and overall efficacy of combined VBCSs are not guaranteed without whole system validation and verification. EU regulatory framework clearly allocates responsibilities for the validation and verification of an integrated VBCS, but not for combined VBCSs, lacking information about the management of product nonconformities and post-market surveillance. Laboratory validation of combined VBCS demands risk-benefit and cost-benefit analyses, a non-negligible organisational and economic burden, and investment in knowledge acquisition. Implications in terms of laboratory responsibility and legal liability should be part of a comprehensive assessment of safety, efficacy, and cost carried out during device procurement.

The influence of various sample storage conditions and sample bacterial contamination on concentrations of routine biochemical parameters

Background

The pre-analytical (PA) phase is the most vulnerable phase of the laboratory testing procedure, with critical procedures-collection, handling, sample transport, and time and temperature of sample storage. This study aimed to examine the stability of basic biochemical parameters depending on the samples' storage conditions and the number of freeze-thaw cycles (FTCs). In parallel, the presence of sample bacterial contamination during routine laboratory work was examined.

Methods

Two plasma pools (ethylenediaminetetraacetic acid (EDTA), and sodium-fluoride/potassium oxalate plasma (NaF)) were stored at +4 ˚C/-20 ˚C. Total chole - sterol (TC), glucose, triglycerides (TG), urea, and albumin concentrations were measured using BioSystems reagents (cholesterol oxidase/peroxidase, glucose oxidase/per - oxidase, glycerol phosphate oxidase/peroxidase, urease/ salicylate, and bromcresol green method, respectively) on Ilab 300+. Sample bacterial contamination was determined by 16S rRNA sequence analysis. The expe - riment encompassed a 5 day-period: Day 1-fresh sample, Day 2-1st FTC, Day 3-2nd FTC, Day 4-3rd FTC, Day 5-4th FTC. The appearance of bacteria in two consecutive samples was the experiment's endpoint.

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

Background

The 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.

Objective

To 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 methods

A 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.

Results

The 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 %).

Conclusion

This 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.

Preanalytical Errors in Clinical Laboratory Testing at a Glance: Source and Control Measures

The accuracy of diagnostic results in clinical laboratory testing is paramount for informed healthcare decisions and effective patient care. While the focus has traditionally been on the analytical phase, attention has shifted towards optimizing the preanalytical phase due to its significant contribution to total laboratory errors. This review highlights preanalytical errors, their sources, and control measures to improve the quality of laboratory testing. Blood sample quality is a critical concern, with factors such as hemolysis, lipemia, and icterus leading to erroneous results. Sources of preanalytical errors encompass inappropriate test requests, patient preparation lapses, and errors during sample collection, handling, and transportation. Mitigating these errors includes harmonization efforts, education and training programs, automated methods for sample quality assessment, and quality monitoring. Collaboration between laboratory personnel and healthcare professionals is crucial for implementing and sustaining these measures to enhance the accuracy and reliability of diagnostic results, ultimately improving patient care.

Engineering, feasibility, and safety of force-controlled oropharyngeal swabs with a 3D-printed feedback system FCCSS (force controlled COVID-19 swab study) - a preliminary study

Errors in laboratory diagnostics of viral infections primarily occur during the preanalytical phase, which is especially observed in sample collection. Hitherto, no efforts have been made to optimize oropharyngeal smears. An accurate method to analyze the necessary conditions for a valid oropharyngeal smear test is required, especially to avoid false negative results, which can lead to promotion of the spread of viruses such as SARS-CoV-2. In this study, a maximum-force failure analysis was performed on a swab, and the highest tolerable force was then measured on 20 healthy volunteers to obtain the dimensions of the possible force to be applied on a swab. Subsequently, a device which can validate and reproducibly indicate this force during swab collection was developed. The study demonstrated that swabs generally fail at a maximum force of 5 N. Furthermore, an average force of 2.4±1.0 N was observed for the 20 volunteers. Lastly, this study described the development of a device which presents the selected force with a mean accuracy of 0.05 N (Force applied by Device 1: 0.46±0.05 N, Device 2: 1.55±0.11 N, Device 3: 2.57±0.18 N) and provides feedback via haptic and acoustic clicks as well as with a visual indicator. In the future, the swab will be analyzed for the presence of viral pathogens to determine its diagnostic performance corresponding to the force (German Clinical Trials Register Number 00024455).

Pre-analytical diagnostic differences despite high adherence to guidelines for gestational diabetes mellitus

Regional variations in the prevalence of gestational diabetes mellitus (GDM) have been found across Denmark. The objectives of this exploratory survey were to evaluate adherence to the national guideline for screening and diagnosing GDM and to identify variations in pre-analytical or analytical factors, which could potentially contribute to variations in GDM prevalence across regions. In a national interview-based survey, obstetric departments and laboratories throughout Denmark handling GDM screening or diagnostic testing were invited to participate. Survey questionnaires were completed through personal interviews. In total, 21 of 22 identified obstetric departments and 44 of 45 identified laboratories participated. Adherence to guideline among obstetric departments ranged 67-100% and uniformity in laboratory procedures was high. However, the gestational age at the time of late diagnostic testing with oral glucose tolerance test (OGTT) varied considerably, with 48% (10/21) of departments testing outside the recommended 24-28 weeks' gestation. Procedural heterogeneity was most pronounced for the parts not described in current guidelines, with choice of laboratory equipment being the most diverse factor ranging 3-39% nationally. In conclusion, the overall adherence to the national guidelines was high across regions, and obstetric departments and laboratories had high uniformity in the procedures for screening and diagnosing GDM. Uniformity was generally high for procedures included in the guideline and low if not included. However, a high proportion of GDM testing was performed outside the recommended gestational window in late pregnancy, which may be a pre-analytical contributor to regional differences in GDM prevalence.

Blood microsampling technologies: Innovations and applications in 2022

With the development of highly sensitive bioanalytical techniques, the volume of samples necessary for accurate analysis has reduced. Microsampling, the process of obtaining small amounts of blood, has thus gained popularity as it offers minimal-invasiveness, reduced logistical costs and biohazard risks while simultaneously showing increased sample stability and a potential for the decentralization of the approach and at-home self-sampling. Although the benefits of microsampling have been recognised, its adoption in clinical practice has been slow. Several microsampling technologies and devices are currently available and employed in research studies for various biomedical applications. This review provides an overview of the state-of-the-art in microsampling technology with a focus on the latest developments and advancements in the field of microsampling. Research published in the year 2022, including studies (i) developing strategies for the quantitation of analytes in microsamples and (ii) bridging and comparing the interchangeability between matrices and choice of technology for a given application, is reviewed to assess the advantages, challenges and limitations of the current state of microsampling. Successful implementation of microsampling in routine clinical care requires continued efforts for standardization and harmonization. Microsampling has been shown to facilitate data-rich studies and a patient-centric approach to healthcare and is foreseen to play a central role in the future digital revolution of healthcare through continuous monitoring to improve the quality of life.

Drug interference with biochemical laboratory tests

Clinical laboratory practice represents an essential part of clinical decision-making, as it influences 60-70% of medical decisions at all levels of health care. Results of biochemical laboratory tests (BLTs) have a key role in establishment of adequate diagnosis as well as in evaluation of treatment progress and outcome. The prevalence of drug-laboratory test interactions (DLTIs) is up to 43% of patients who had laboratory results influenced by drugs. Unrecognized DLTIs may lead to misinterpreted BLTs results, incorrect or delayed diagnosis, extra costs for unnecessary additional tests or inadequate therapy, as all may cause false clinical decisions. The significance of timely and adequate recognition of DLTIs is to prevent common clinical consequences such as incorrectly interpreted test results, delayed or non-treated condition due to erroneous diagnosis or unnecessary extra tests or therapy. Medical professionals should be educated that it is essential to obtain patient data about medications especially for the drugs used in the last 10 days before biological material collection. Our mini-review aims to provide a comprehensive overview of the current state in this important domain of medical biochemistry with detailed analysis of the effect of drugs on BLTs and to give detailed information to medical specialists.

Retrospective analysis of intra-patient laboratory variation demonstrates that the BD Vacutainer® Barricor™ blood collection tube reduces troponin variation

OBJECTIVE

The BD Vacutainer® Barricor™ plasma blood collection tube uses a mechanical separator during centrifugation to separate plasma from the cellular elements of blood. Compared to use of plasma separator tubes (PST™) with gel, Barricor™ produces a cleaner sample with less residual cellular content. We sought to determine if Barricor™ reduces pre-analytical error compared to PST™.

DESIGN & METHODS

We used a model previously published that utilizes serial differences between intra-patient measurements transformed into a Taylor series of variation vs time with the y-intercept equal to the sum of short-term analytic variation, preanalytic variation and biologic variation. The intra-patient variation of chloride, sodium, potassium, and troponin-T (hs-TnT) obtained from the Emergency Department of a large tertiary care center sampled with PST™ (May 2015-April 2018, n = 59,762 specimens) or Barricor™ (May 2018-May 2021, n = 61,512 specimens) was evaluated. All specimens were analyzed on either Roche Modular or Cobas® instruments. For each analyte, pairs of intra-patient results were tabulated and separated by 1 h intervals. The average between-pair variations were then regressed against time. We also determined the number of intra-patient outliers using the reference change value for each analyte.

RESULTS

The Barricor™ hs-TnT y-intercept (-0.0132) was significantly lower than the PST™ intercept (0.9109; p = 0.022). This was also true for chloride (y-intercept = 1.0067 in Barricor™ and 1.3431 in PST™, p = 0.037). The percentage of hs-TnT outliers was significantly lower in Barricor™ (8.32 %) vs PST™ (12.2 %; p < 0.001).

CONCLUSION

The analytical and biological variations are assumed to be steady over the study periods; we ascribe the difference in the y-intercept to the preanalytical effect of the Barricor™ tube reducing platelets and other cellular debris.

An Overview of Complete Blood Count Sample Rejection Rates in a Clinical Hematology Laboratory Due to Various Preanalytical Errors

Introduction The Chughtai Laboratory collects blood samples for complete blood counts from various hospitals, emergency departments, ICUs, and through home sampling services all across the country. The preanalytical phase is an integral component of laboratory medicine. A laboratory report has a key role in patient treatment and the clinician's decision in the management of the disease. Preanalytical errors are most frequently caused by the absence of a sample and/or inappropriate understanding of a test request, mislabeling, contamination from the sampling site, hemolyzed, clotted, insufficient samples, storage issues, and inappropriate blood to anticoagulant proportion or inappropriate choice of anticoagulant. Objective To identify the cause of rejection rates of the complete blood count samples and reduce the rejection rates by improving the accuracy of the results and lowering pre-analytical errors. Methods This cross-sectional study was done in the Hematology Department of Chughtai Laboratory's head office in Lahore between 19-06-2021 and 19-10-2021. Simple random sampling was applied to collect the data. About 3 ml of each blood sample was received in an ethylenediaminetetraacetic acid (EDTA) vial, inspected visually, run on Sysmex XN-9000 (Sysmex Corporation, Kobe, Hyogo, Japan), and was reviewed on peripheral smears. Results Out of 231,008 blood samples, 11,897 (5.15%) samples were rejected. The most common pre-analytical mistake was storage issues due to transportation delay (19.45%) followed by wrong medical records (19.16%), diluted samples (16.35%), incorrect tubes (16.01%), hemolyzed samples (15.13%), unlabeled samples (10.01%), and clotted sample (3.88%). Conclusion In the hematology department, the total rejection rate observed during the study period was 5.15%. Recognition of preanalytical errors and avoiding them will help us lower the sample rejection rate and raise the overall quality of laboratory management.

PAPP-A as a screening tool for assessment of gestational age before medication abortion in an intended-use population

Introduction: Prior studies indicate that PAPP-A could serve as a marker of gestational age (GA) with the potential to determine eligibility for medication abortion. The authors validated the relationship between PAPP-A and GA in an actual-use population. Materials & methods: The authors collected blood samples, medical histories and ultrasound-determined GA from patients presenting for abortion services. They measured PAPP-A using two immunoassays and assessed diagnostic accuracy for predicting GA ≥71 days. Results: The Ansh Labs and R&D Systems immunoassays produced an area under the ROC curve of 0.982 (95% CI: 0.958-0.994) and 0.986 (95% CI: 0.963-0.996), respectively, for predicting GA ≥71 days. Conclusion: This validation study in an intended-use population confirmed that PAPP-A has a strong ability to distinguish pregnancies above and below 71 days' gestation. Clinical trial registration: NCT04232189 (ClinicalTrials.gov).

Results of using Luer-Lok access device for clinics, intensive care units, and emergency services with high pre-analytical errors: analysis of 491.850 samples

Objectives

The effectiveness of the Luer-Lok™ Access Device (LL) with the intravenous catheter (IVC) on sample rejections, which is used to prevent primarily hemolysis in the emergency department (ED), clinics, and intensive care units (ICU), was examined.

Methods

A total of 491.850 samples of eight months from Amasya University Sabuncuoğlu Şerefeddin Training and Research Hospital were investigated retrospectively. Inpatient, intensive care unit and emergency department samples were included in the study. Pre- (BLL) and post-Luer Lok (ALL) rejection of the samples analyzed. In the BLL period, 3,463 rejection samples out of 253,818 (1.36%) in the September-December period of 2020; in the ALL period, 1819 rejected samples from 238,032 (0.76%) in January-April 2021 were analyzed for all reasons.

Results

It was determined that the use of LL significantly reduced all-cause sample rejections. In addition, a significant decrease was observed in the rates of hemolysis and clot-related rejection thanks to LL.

Conclusions

According to our study data, in patients with IVC with the LL device, the pressure brought by the syringe is mainly avoided, and reliable blood collection is achieved, similar to the routine vacutainer blood collection apparatus, and hemolysis- and clot-related sample rejections are largely prevented.

Factors associated with anxiety symptoms among medical laboratory professionals in Khobar: Single institution study

Background

A clinical professional has a challenging role during the coronavirus disease (COVID-19) pandemic in providing timely and accurate results with limited resources and a rapid increase in the number of samples to be tested. However, during the ongoing pandemic, the anxiety level of Medical Laboratory Professionals (MLT) has not been studied in Saudi Arabia within the hospital environment.

Aim

To determine the associated factors related with anxiety level of MLT at King Fahd Hospital of the University (KFHU) during the COVID-19 pandemic.

Methods

The study design was a cross-sectional quantitative study. Data were collected by administering a paper-based questionnaire that was distributed among MLT at KFHU. The questionnaire consisted of three sections. The first two sections were prepared by the researchers and included participant demographics and questions related to COVID-19. The third section used the Hamilton Anxiety Scale to assess anxiety levels.

Result

The study revealed that 70.4% of MLT showed no signs of anxiety, while 19.2% showed mild/moderate anxiety levels, and approximately 10.4% showed severe to extreme anxiety levels. In addition, a significant association between the anxiety level and difficulty breathing among MLT wearing personal protective equipment was observed. Moreover, a significant association between sex and anxiety level was identified. Females MLT had higher percentages of severe anxiety (12.8% vs. 5.1%) and mild/moderate anxiety (24.4 vs. 7.7%) than males.

Conclusions

Protecting the mental health status of MLT is an essential part of public health measures to fight the COVID-19 pandemic.

Assessing the Impacts of Preanalytical Field Sampling Challenges on the Reliability of Serum Aflatoxin B1-Lysine Measurements by Use of LC-MS/MS

Aflatoxin exposure is endemic in developing countries with warm, humid climates that promote toxigenic mold growth on crops and foodstuffs. Estimating human aflatoxin exposure is key to identifying and abating contamination sources. Serum aflatoxin B1 bound to albumin lysine (AFB1-lys) is a preferred exposure biomarker, but field sample collection, processing, transportation, and storage logistics are challenging. We validated an improved LC-MS/MS method for serum AFB1-lys and applied it to three field sampling challenges: transportation/storage (elevated temperature); collection/processing (hemolysis); and sample type substitution (heparinized plasma). Our new LC-MS/MS method had a LOD of 0.03 ng/mL, accuracy (mean spike recovery) of 112%, total imprecision (replicate pool measurements) ≤5% at ≥0.2 ng/mL, and results that were 95.1% similar (mean percentage similarity) to an established method. AFB1-lys in human serum spiked with serum from aflatoxin-dosed rats was stable for 14 days at both ambient (22.5 °C) and elevated (38 °C) temperatures. Simulated hemolysis (adding 0.25–3 mg hemoglobin) did not affect AFB1-lys accuracy at ≥0.5 ng/mL but caused 10–25% signal suppression. Heparinized plasma AFB1-lys was 99.0% similar to serum but interfered with albumin measurements (bromocresol green) causing spurious low bias. Further investigation is warranted, but our findings suggest that AFB1-lys is pre-analytically robust.

Compliance with the clinical laboratory quality protocol in public primary healthcare centres

The clinical and economic relevance of the clinical laboratories procedures in Andalusia (Spain) have led the Regional Department of Health to focus attention on their improvement. A unified laboratory protocol was implemented that consisted of the unification of criteria in the handling and processing of samples, and report of results. The objective of this study is to describe the degree of compliance with the clinical laboratory protocol in the preanalytical phase, which includes the analytical request and up to the delivery in the laboratory, as well as the influencing factors. Cross-sectional descriptive study with a sample of 214 healthcare professionals involved in the preanalytical phase of laboratory procedures in primary care. A self-reported questionnaire with 11 items was used for data collection. Each item was assessed separately with a scale from 0 to 10. A 5 points score was considered as the cutoff point. Descriptive analysis was conducted and Mann-Whitney U test was used to determine differences between subgroups. Internal consistency of the questionnaire was considered. The best rated item was verifying the correspondence between the request form and identity of the patient. Each item scored from 3 to 10, and the mean for each item ranged from 6.40 (standard deviation = 3.06) to 8.57 (standard deviation = 2.00). Values above or equal to 8 were obtained, for 63.6% of them. Statistically significant differences between accredited and nonaccredited centres were found. Differences were not noteworthy regarding centres with a teaching activity or those without it. All the items were measured separately. The compliance with the protocol was adequate among primary healthcare professionals, who have a strategic position in the sample collection and its transport during the preanalytical phase. Being so, standardisation should be a priority to reduce errors and improve clinical safety and results.

Impact of Pneumatic Transport System on Preanalytical Phase Affecting Clinical Biochemistry Results

Introduction PTS (pneumatic transport system) is extensively being used in modern hospitals for rapid transportation of blood samples and other specimens. However, it has a potential impact on blood components, which should be investigated and nullified accordingly. This study was part of a correction program aimed at reducing hemolysis. It was done by comparing paired samples transported manually and by PTS.

Materials and Methods This study was initiated to monitor the impact of PTS on hemolysis of clinical biochemistry blood samples. It was performed in two phases—before and after the corrective action taken. Phase I: done after PTS installation but before the corrective action was taken. Duplicate samples from 100 healthy individuals were collected, one set transported by PTS and the other by human carriers. Both sets were assessed for 25 biochemistry analytes, hemolysis index (HI), and acceleration profiles using a data logger. Corrective measures were then taken, followed by phase II of the study. In phase II, the sample size and study design remained the same as phase I. All the test results of PTS and hand-carried samples were statistically analyzed for any significant difference.

Result In phase I, all the hemolysis-manifesting parameters, LDH (lactate dehydrogenase), potassium, AST (aspartate transaminase), and phosphorus, were raised in PTS samples as compared with the manual samples. Their differences were significant as the p-values were 0.001, 0.000, 0.025, and 0.047, respectively. The differences for LDH and potassium were clinically significant as well. HI (9%) and peak acceleration (15.7 g) were high in PTS samples.

In phase II, no statistically significant difference between paired samples was found for all biochemistry parameters except for a few which were clinically nonsignificant. For PTS samples, HI was 2.5% and the peak acceleration was 11.2 g, whereas for manual samples, HI was 2%.

Conclusion Evidence of hemolysis was found in PTS samples as compared with handheld samples, which was resolved after several corrective actions were taken. Thereafter, PTS became reliable for sample delivery in a routine biochemistry laboratory. Hence, each hospital should scrutinize their PTS for its effects on sample integrity to get rid of PTS-induced preanalytical errors.

Detection of preanalytical errors in arterial blood gas analysis

Introduction

Blood gas analysis (BGA) is an essential test used for years to provide vital information in critically ill patients. However, the instability of the blood gases is a problem. We aimed to evaluate time and temperature effects on blood gas stability.

Materials and methods

Arterial blood was collected from 20 patients into syringes. Following BGA for baseline, syringes were divided into groups to stand at 4°C and 22°C for 30, 60, 90, 120 minutes. All were tested for pH, partial pressure of carbon dioxide (pCO₂), partial pressure of oxygen (pO₂), oxygen saturation (sO₂), oxyhemoglobin (O₂Hb), sodium, potassium, glucose, lactate, oxygen tension at 50% hemoglobin saturation (p50), and bicarbonate. A subgroup analysis was performed to detect the effect of air on results during storage. Percentage deviations were calculated and compared against the preset quality specifications for allowable total error.

Results

At 4°C, pO₂ was the least stable parameter. At 22°C, pO₂ remained stable for 120 min, pH and glucose for 90 min, lactate and pCO₂ for 60 min. Glucose and lactate were stable when chilled. Air bubbles interfered pO₂ regardless of temperatures, whereas pCO₂ increased significantly at 22°C after 30 min, and pH decreased after 90 min. Bicarbonate, sO₂, O₂Hb, sodium, and potassium were the unaffected parameters.

Conclusions

Correct BGA results are essential, and arterial sample is precious. Therefore, if immediate analysis cannot be performed, up to one hour, syringes stored at room temperature will give reliable results when care is taken to minimize air within the blood gas specimen.

Preanalytical DNA assessment for downstream applications: How to optimize the management of human biospecimens to support molecular diagnosis-An experimental study

Background

The development of next‐generation sequencing approaches has accelerated the diagnostic process, although at present, there is a lack of a clear consensus on efficient management of human samples for downstream applications. This study aims to investigate timeframe (in terms of short preservation), temperature, and additional preservation procedures (i.e., freeze and thaw cycles) for human biospecimens to implement the reliability and reproducibility of molecular investigations.

Methods

Overall, 45 whole peripheral bloods, 22 peripheral blood mononuclear cells samples, 15 saliva, and 15 buccal swab biospecimens (through the extracted DNA) were investigated, assessing yield, integrity, amplifiability, and sizing accuracy via the most common molecular techniques.

Results

Based on the overall evaluation criteria, the results indicate that DNA extracted from all samples, shortly preserved, have suitable quality and reliable reproducibility to be used in diagnostic activities and biomedical research, even if DNA from peripheral blood mononuclear cells is more affected by the experimental conditions.

Conclusion

Our findings confirm the reliability of peripheral blood samples in almost all the experimental conditions. Saliva and buccal swabs are efficient almost as well, while peripheral blood mononuclear cells, albeit remain a primary source of DNA for molecular screenings, represent a less efficient source.

The impact of laboratory staff training workshops on coagulation specimen rejection rates

Background

Pre-analytical variables can have a significant adverse impact on the quality and credibility of coagulation test results. Therefore, correct and consistent identification of pre-analytical variables that compromise coagulation specimen quality is of paramount importance. Lack of standardization and heterogeneity among laboratory staff when assessing coagulation specimens can lead to inconsistent identification of these variables. Failure to recognize such pre-analytical variables results in the analysis of poor quality specimens and the authorization of spurious test results.

Objectives

To determine the impact of a laboratory staff training workshop on coagulation specimen rejection rates and to ascertain the level of knowledge of laboratory personnel concerning coagulation specimen rejection criteria before and after the workshop.

Methods

A retrospective three-month audit was performed with rejection data of incorrect blood to additive ratio, clotted, aged and haemolysed specimens collected. Training workshops and evaluation sessions were subsequently presented. A revised standard operating procedure delineating coagulation specimen rejection criteria was implemented and a repeat three-month audit was conducted.

Results

In total, 13 162 coagulation specimens were received during the initial audit with 1 104 specimens (8.39%) rejected. Following the workshops, the rejection rate increased by 3.49% to 11.88% with 12 743 coagulation specimens received and 1 514 specimens rejected. Evaluation sessions performed before and after the workshops revealed that 95.2% of attendees attained improved knowledge.

Conclusion

This study demonstrated the pivotal importance of regular laboratory staff training. The increase in specimen rejection following the workshops signifies their success in educating laboratory personnel regarding the correct identification of pre-analytical variables. Since most pre-analytical variables occur outside the laboratory, educational workshops need to be extended to non-laboratory personnel responsible for specimen collection and transport.

Factors affecting the accuracy and reliability of the measurement of anti-Müllerian hormone concentration in the clinic

OBJECTIVE

We aimed to identify the factors that influence serum anti-Müllerian hormone (AMH) concentration measurements.

METHODS

We collected serum samples between May and September 2018 and compared the effect on AMH concentration measured by ELISA of conditions including venepuncture, storage time, storage temperature, locations of the reaction microplate, and the use of the oral contraceptive pill and gonadotrophin-releasing hormone (GnRH).

RESULTS

AMH concentration was not affected by food intake but was affected by haemolysis. It was also much higher in samples on the edge of the ELISA microtitre plate. AMH concentration increased after incubation at room temperature for 1 day, 4°C for 3 days, -20°C for 1 month and -40°C for 4 months, but no change occurred during storage at -80°C for 9 months. AMH concentration was high in patients following GnRH agonist treatment but was not affected by oral contraceptives.

CONCLUSIONS

No fasting is required prior to AMH measurement. Placement of serum samples on the edge of microtitre plates affects the results of the AMH ELISA. If serum samples cannot be assayed immediately, it is best to store them at -80°C. Basal AMH concentration cannot be used as a measure of ovarian reserve after GnRH agonist treatment.

Quality Control of Breast Cancer Surgery Samples: Introducing Time Stamp Checking

Background: Analytical information obtained from clinical tissue samples has recently become more important due to recent advancements in the clinical practice of medicine, for example, gene panel testing. However, acquiring and managing the sample quality, which greatly influences the analyses, are not sufficient and hence requires immediate attention. We introduced time stamp (TS) recording and documentation using the Standard PREanalytical Code (SPREC) for breast cancer surgery samples to monitor and control their quality. Materials and Methods: The TS recording used SPREC for quality control of each sample by recording seven factors: type of sample, type of collection, warm ischemia time (WIT), cold ischemia time (CIT), fixation type, fixation time (FT), and long-term storage. The responsibilities to record each factor were assigned among group members (breast surgeons, anesthesiologists, pathologists, operating room nurses, and medical technologists in pathology). Results: Records based on SPREC were recorded for 393 surgical cases of first-time breast cancer patients performed at the Kanagawa Cancer Center from May 2018 to April 2019. The vascular clamp time was defined as when skin flap formation was completed, regardless of the surgical procedure. An anesthesiologist recorded the vascular clamp time and sample collection time, and the pathologist recorded the fixation start time and fixation end time. WIT was 23 (3-116) minutes (breast-conserving surgery, 11 [3-38] minutes; mastectomy, 26 [5-116] minutes; and nipple-sparing mastectomy, 39 [31-43] minutes), CIT was 37 (3-1052) minutes, and FT was 43 (17-115) hours. The median CIT and FT were significantly shortened after introducing the TS system, and the variabilities were reduced. Conclusion: A TS system for quality control of breast cancer surgical sample functions well due to the establishment of highly versatile WIT and a working group consisting of multiple members of different occupations who shared roles.

Reducing Surgical Specimen Errors Through Multidisciplinary Quality Improvement

BACKGROUND

Each year, our institution performs more than 34,000 surgical cases and obtains close to 10,000 surgical specimens. Within those procedures, we averaged 10 errors for every 1,000 surgical specimens. Any level of preventable harm is unacceptable, as it could lead to risks of treatment delay, improper therapy selection, or missed diagnoses. This quality improvement (QI) effort aimed to decrease errors in surgical specimens from 10 errors per 1,000 surgical specimens to 0 errors each month.

METHODS

Using the Institute for Healthcare Improvement Model for Improvement QI methodology, we determined the root causes of error, identified key drivers, and tested change interventions. We implemented changes in surgical specimen labeling, standardized specimen time-out and reconciliation processes, and optimized a method of communication between consultants, surgeons, operating room staff, and laboratory staff with the implementation of a Specimen Request Form.

RESULTS

Over 46 months, we identified 234 specimen errors in 33,962 surgical pathology specimens. The error rate was reduced from 10 to 2.31 errors per 1,000 specimens. The mean rate of order errors decreased from 3.66 to 0.13 per month, and the mean rate of labeling-related errors decreased from 1.5 to 0.5 per month.

CONCLUSIONS

A multidisciplinary project team implemented changes to specimen test requesting and intraoperative specimen handling with an associated reduction in errors to reduce potential patient harm involving surgical specimen errors. This article demonstrates how applying these methods and interventions can be associated with a reduction in surgical specimen errors.

How to meet ISO15189:2012 pre-analytical requirements in clinical laboratories? A consensus document by the EFLM WG-PRE

The International Organization for Standardization (ISO) 15189:2012 standard aims to improve quality in medical laboratories through standardization of all key elements in the total testing process, including the pre-analytical phase. It is hence essential that accreditation bodies, assessing laboratories against ISO15189:2012, pay sufficient attention to auditing pre-analytical activities. However, there are significant differences in how technical auditors interpret the pre-analytical requirements described in ISO15189:2012. In this consensus document, the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Working Group for Pre-analytical Phase (WG-PRE) sets out to review pre-analytical requirements contained in ISO15189:2012 and provide guidance for laboratories on how to meet these requirements. The target audience for this consensus document is laboratory professionals who wish to improve the quality of the pre-analytical phase in their laboratory. For each of the ISO requirements described in ISO15189:2012, members of EFLM WG-PRE agreed by consensus on minimal recommendations and best-in-class solutions. The minimal consensus recommendation was defined as the minimal specification which laboratories should implement in their quality management system to adequately address the pre-analytical requirement described in ISO15189:2012. The best-in-class solution describes the current state-of-the-art in fulfilling a particular pre-analytical requirement in ISO15189:2012. We fully acknowledge that not every laboratory has the means to implement these best-in-class solutions, but we hope to challenge laboratories in critically evaluating and improving their current procedures by providing this expanded guidance.

Case report of spuriously low sodium and calcium in a 36-year-old male in primary care

An unseparated serum specimen for a 36-year-old male was received from primary care. The specimen arrived in the laboratory at Cork University Hospital one day after collection, as documented on the paper request card, and was promptly centrifuged. Analysis was delayed for three days due to operational constraints and serum indices were run at the same time as the biochemical analyses. Results showed a moderately haemolysed specimen with remarkably low concentrations of both sodium (119 mmol/L) and total calcium (1.15 mmol/L), with all other parameters within their appropriate reference intervals (RIs). The complete report was released electronically and both sodium and calcium results were phoned to, and acknowledged by, the requesting general practitioner (GP). Discussion between the medical scientists and clinical biochemist on duty raised the possibility that the specimen was significantly older than initially thought. Further discussion of results with the GP clarified that the documented time of collection corresponded with specimen receipt by the courier, rather than the time of phlebotomy. Thus, the specimen was 7 days old when received in the laboratory and 10 days old when analysed. This case illustrates the dangers of multiple convergent preanalytical errors. Laboratories should be mindful of the stability of analytes in unseparated blood and unusual patterns of results which might suggest a specimen is "old", and that this may coexist with erroneous request information. Any potential adverse effects on patient care were prevented in this case by laboratory vigilance.

Challenges in Preanalytical Phase of Laboratory Medicine: Rate of Blood Sample Nonconformity in a Tertiary Care Hospital

OBJECTIVE

To evaluate the major causes of preanalytical errors in medical laboratory of a tertiary care hospital.

METHODS

It was a retrospective study in which we analyzed the sample rejection data of hematology and chemical pathology sections from January to December 2018. Number of rejected samples, reason for rejection and type of test ordered on monthly basis were recorded on a platform.

RESULTS

A total of 113,817 samples were received during the study period. Preanalytical errors were found in 1,688 samples, which constitute approximately 1.48% of the total number of samples received.

CONCLUSION

Our study highlights the magnitude of preanalytical errors in our setup. Preanalytical errors can lead to loss of patient trust in diagnostic services, can dent the laboratory's reputation, and lead to an increase in the overall operating expenses, both for laboratories as well as the hospitals. Compliance with good laboratory practices can significantly reduce the frequency of pre analytical errors.

Sample Management: Stability of Plasma and Serum on Different Storage Conditions

BACKGROUND AND OBJECTIVE

The analytes stability on serum and plasma are critical for clinical laboratory, especially if there is a delay in their processing or if they need to be stored for future research. The objective of this research was to determine the stability of K3EDTA-plasma and serum on different storage conditions.

MATERIALS AND METHODS

A total of thirty healthy adults were studied. The serum/plasma samples were centrifuged at 2000g for 10 minutes. Immediately after centrifugation, the serum/plasma analytes were assayed in primary tubes using a Cobas c501 analyzer (T0); the residual serum/plasma was stored at either 2-8°C or -20°C for 15 (T15) and 30 days (T30).Mean concentrations changes in respect of initial concentrations (T0) and the reference change values were calculated. For assessing statistical difference between samples, the Wilcoxon ranked-pairs test was applied.

RESULTS

We evidenced instability for total bilirubin, uric acid, creatinine and glucose at T15 and T30 and stored at -20°C (p<0.05). However, potential clinical impact significance were observed only for total bilirrubin T30 at -20°C, and creatinine T30 at 2-8°C.

CONCLUSIONS

Our results had shown that storage samples at -20°C is a better way to preserve glucose, creatinine, and uric acid. Therefore, laboratories should freeze their samples as soon as possible to guarantee proper stability when there is need to repeat analysis, verify a result, or add a laboratory testing.

Sampling and processing blood samples within the South American Youth/Child cARdiovascular and Environmental (SAYCARE) Study

Obesity and overweight in children and adolescents is increasing rapidly worldwide; however, scarce data have been reported from South America countries. With the purpose of assessing hyperlipidemia, insulin resistance and chronic inflammation, the evaluation of blood biomarkers such as glucose, lipoproteins and chronic inflammation proteins is required. In the context of the SAYCARE study, in children and adolescents (3 to 18 years) from seven South American cities, our aim was to assess the impact of pre analytical conditions on different biomarkers evaluated in 474 fresh serum samples, in different country centers. We also evaluated the stability according to time and frozen storage within this study across the concordance of the results obtained from the 49 blood samples measured in three different centers. Significant correlations as well as concordance were observed in TG, Total-C, HDL-C and glucose between Buenos Aires and São Paulo. The samples evaluated in Teresina and São Paulo presented similar results, with exception of total cholesterol. We observed acceptable concordance between Buenos Aires vs São Paulo and Teresina vs São Paulo, suggesting that samples could be processed in each of these centers. This concordance is a consequence of the strict pre analytical conditions previously established in the SAYCARE study.

PREDICT: a checklist for preventing preanalytical diagnostic errors in clinical trials

Although the importance of guaranteeing a high level of preanalytical quality in routine diagnostic testing has already been largely acknowledged over the past decades, minor emphasis is currently being placed on the fact that accurate performance and standardization of many preanalytical activities are also necessary prerogatives of clinical trials. Reliable evidence exists that clear indications on how to manage the different preanalytical steps are currently lacking in many clinical trials protocols, nor have detailed authoritative documents been published or endorsed on this matter to the best of our knowledge. To fill this gap, the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Working Group for Preanalytical Phase (WG-PRE) will provide here a specific checklist for preventing preanalytical diagnostic errors in clinical trials (PREDICT), especially focused on covering the most important preanalytical aspects of blood sample management in clinical studies, and thus encompassing test selection, patient preparation, sample collection, management and storage, sample transportation, as well as specimen retrieval before testing. The WG-PRE members sincerely hope that these recommendations will provide a useful contribution for increasing the success rate in clinical trials.

Managing hemolyzed samples in clinical laboratories

Hemolysis is conventionally defined as membrane disruption of red blood cells and other blood cells that is accompanied by subsequent release of intracellular components into the serum or plasma. It accounts for over 60% of blood sample rejections in the laboratory and is the most common preanalytical error in laboratory medicine. Hemolysis can occur both in vivo and in vitro. Intravascular hemolysis (in vivo) is always associated with an underlying pathological condition or disease, and thus careful steps should always be taken by the laboratory to exclude in vivo hemolysis with confidence. In vitro hemolysis, on the other hand, is highly preventable. It may occur at all stages of the preanalytical phase (i.e. sample collection, transport, handling and storage), and may lead to clinically relevant, yet spurious, changes in patient results by interfering with laboratory measurements. Hemolysis interference is exerted through several mechanisms: (1) spectrophotometric interference, (2) release of intracellular components, (3) sample dilution and (4) chemical interference. The degree of interference observed depends on the level of hemolysis and also on the assay methodology. Recent evidence shows that preanalytical practices related to detection and management of hemolyzed samples are highly heterogeneous and need to be standardized. The Working Group for Preanalytical Phase (WG-PRE) of the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) has published many recommendations for facilitating standardization and improvement of this important preanalytical issue. Some key EFLM WG-PRE publications related to hemolysis involve: (i) a call for more transparency and some practical recommendations for improving the harmonization of the automatic assessment of serum indices and their clinical usefulness, specifically the hemolysis index (H-index), (ii) recommendations on how to manage local quality assurance of serum or plasma hemolysis/icterus/lipemia-indices (HIL-indices) and (iii) recommendations on how to detect and manage hemolyzed samples in clinical chemistry testing. In this review we provide a comprehensive overview of hemolysis, including its causes and effects on clinical laboratory assays. Furthermore, we list and discuss the most recent recommendations aimed at managing hemolyzed samples in everyday practice. Given the high prevalence of hemolyzed blood samples, the associated costs, the great heterogeneity in how hemolysis is handled across healthcare settings, countries and continents, and increasing patient cross-border mobility, standardization and quality improvement processes aimed at combatting this important preanalytical problem are clearly warranted.

Flushing of an intravenous catheter: a cause for unreliable laboratory results

Introduction

Phlebotomy is an error-prone process in which mistakes are difficult to reveal. This case report describes the effect on laboratory results originating from a blood sample collected in close proximity to an intravenous catheter.

Materials and methods

A 69-year-old male patient was referred to the Emergency department where pneumonia was suspected. Phlebotomy was performed to collect blood samples to assess electrolytes, renal function, liver function, infection and haematological parameters.

Results

The laboratory analysis showed reduced potassium and calcium concentrations. To prevent life-threatening cardiac failure the clinician decided to correct those electrolytes. Remarkably, the electrocardiogram showed no abnormalities corresponding to hypokalaemia and hypocalcaemia. This observation, in combination with an overall increase in laboratory parameters with the exception of sodium and chloride, led to the suspicion of a preanalytical error. Retrospectively, an intravenous catheter was inserted in close proximity of the puncture place but no continuous infusion was started prior to phlebotomy. However, the intravenous catheter was flushed with sodium chloride. Since potential other causes were excluded, the flushing of the intravenous catheter with sodium chloride prior to phlebotomy was the most probable cause for the deviating laboratory results and subsequently for the unnecessary potassium and calcium suppletion.

Conclusion

This case underlines the importance of caution in the interpretation of laboratory results obtained from specimens that are collected in the proximity of an intravenous catheter, even in the absence of continuous infusion.

Reduction of pre-analytical errors in the clinical laboratory at the University Hospital of Korea through quality improvement activities

BACKGROUND

The clinical laboratory is responsible for reporting accurate and expeditious results. However, the pre-analytical phase is directly related to the procedure of specimen collection and is mostly out of the direct control of the laboratory; further, most pre-analytical errors are related to human factors. Therefore, education and training programs for the phlebotomy teams are considered the most significant and necessary measures to reduce these errors.

METHODS

A cross-sectional study was conducted to investigate the types and frequencies of pre-analytical errors in the hospital laboratory. Pre-analytical errors were categorized into four main categories: rejected sample, error related to test ordering, misidentification, and others. Several activities were performed for quality improvement in order to reduce the rates of these errors. The data were analyzed by comparing the pre-intervention and post-intervention results along with the results of questionnaires to assess knowledge to investigate the effects of the activities.

RESULTS

The rates of pre-analytical errors decreased from 0.42% in the pre-intervention period to 0.32% in the post-intervention period. The rejected sample category accounted for the highest rates in the pre- and post-intervention periods. In the questionnaires, the overall average score after the intervention was 71.5, which was a significant increase from 46.0 in the pre-intervention period.

CONCLUSIONS

Each clinical laboratory has various types of pre-analytical errors due to the complexity of the healthcare environment. Therefore, targeted intervention including a quality improvement program and its continuous maintenance should be conducted to reduce pre-analytical errors and to improve patient safety.

Gentamicin and Vancomycin Interference on Results of Clinical Chemistry Parameters on Abbott Architect c8000

CONTEXT.—

Gentamicin and vancomycin are nephrotoxic antibiotics. Little is known about the influence of drug concentrations on results of clinical chemistry tests.

OBJECTIVE.—

To investigate gentamicin and vancomycin interference on results of 33 commonly measured biochemistry tests.

DESIGN.—

The study was carried out in the University Department of Chemistry, Medical School University Hospital Sestre Milosrdnice (Zagreb, Croatia). For each drug, 10 aliquots of pooled serum were prepared. In order to cover toxic concentrations, pool serum samples were spiked with drugs to obtain 0 to 50 μg/mL of gentamicin and 0 to 200 μg/mL of vancomycin. Biochemistry tests were measured in duplicate on the Architect c8000 analyzer, and drug concentrations were measured on Architect i2000 SR (both Abbott Laboratories, Abbott Park, Illinois). For each tested concentration, bias was calculated against the initial measurement. Acceptance criteria were defined as measurement uncertainty of the commercial control with the value close to the measured range of the pool sample.

RESULTS.—

For gentamicin, all bias values were below established criteria. For vancomycin, significant changes were observed for potassium, direct bilirubin, and immunoglobulin A. Significant bias was already detected at low vancomycin concentration (2.98 μg/mL) for direct bilirubin (bias = 9.7%; acceptable = 8%). Potassium bias at the highest vancomycin concentration (204.4 μg/mL) exceeded acceptance criteria (bias = 4.5%; acceptable = 4%). For immunoglobulin A, no apparent trend was observed, and bias is attributed to increased method imprecision.

CONCLUSIONS.—

Gentamicin did not interfere with the results of clinical chemistry tests. Direct bilirubin concentration is falsely increased in the presence of vancomycin, and potassium is affected at high concentrations.

Case report: An index of suspicion in hyponatraemia

Serum indices can give valuable information and should be interpreted as a result. Lipaemia can influence results through different mechanisms, an important one being the electrolyte exclusion effect. A case of pseudohyponatraemia due to this is reported. A 15-year-old female with type 2 diabetes was seen for follow-up. Her biochemistry results revealed severe hyponatraemia of 118 mmol/L. Her capillary glucose concentration was 13.7 mmol/L with a corrected sodium of 122 mmol/L. A lipaemic index of 3+ (absolute value 1320) was noted, which was not flagged by the laboratory information system, as it was below the critical lipaemia limit for sodium determination. Repeated analysis of the same sample using a direct ion selective electrode method, the serum sodium concentration was 134 mmol/L (sodium corrected for glucose = 138 mmol/L). A triglyceride concentration was requested, which was severely raised (100.1 mmol/L). The electrolyte exclusion effect is an analytical phenomenon that causes falsely low electrolyte concentrations in the presence of severe lipaemia or hyperproteinaemia when using indirect analytical methods. These methods are used on many modern-day automated chemistry analysers and should be considered in a patient with asymptomatic hyponatraemia.

Antibody validation: a view from the mountains

Validation of antibodies and other protein binders is a subject of pressing concern for the research community and one which is uppermost in the minds of all who use antibodies as research and diagnostic reagents. Assessing an antibody's fitness for purpose includes accurate ascertainment of its target specificity and suitability for the envisaged task. Moreover, standardised procedures are essential to guarantee sample quality in testing procedures. The problem of defining precise standards for antibody validation has engendered much debate in recent publications and meetings, but gradually a consensus is emerging. At the 8th Alpbach Affinity Proteomics workshop (March 2017), a panel of leaders in the antibody field discussed suggestions which could bring this complex but essential issue a step nearer to a resolution. 'Alpbach recommendations' for best practice include tailoring binder validation processes according to the intended applications and promoting greater transparency in publications and in the information available from commercial antibody developers/providers. A single approach will not fit all applications and end users must ensure that the reported validation holds for their specific requirements, highlighting the need for adequate training in the fundamentals of antibody characterisation and validation across the user community.

Errors in the Extra-Analytical Phases of Clinical Chemistry Laboratory Testing

The total testing process consists of various phases from the pre-preanalytical to the post-postanalytical phase, the so-called brain-to-brain loop. With improvements in analytical techniques and efficient quality control programmes, most laboratory errors now occur in the extra-analytical phases. There has been recent interest in these errors with numerous publications highlighting their effect on service delivery, patient care and cost. This interest has led to the formation of various working groups whose mission is to develop standardized quality indicators which can be used to measure the performance of service of these phases. This will eventually lead to the development of external quality assessment schemes to monitor these phases in agreement with ISO15189:2012 recommendations. This review focuses on potential errors in the extra-analytical phases of clinical chemistry laboratory testing, some of the studies performed to assess the severity and impact of these errors and processes that are in place to address these errors. The aim of this review is to highlight the importance of these errors for the requesting clinician.

Preanalytics of urine sediment examination: effect of relative centrifugal force, tube type, volume of sample and supernatant removal

INTRODUCTION

Laboratories often modify procedures recommended by the European Urinalysis Guidelines for urine sediment analysis. The aim of this study was to compare the recommended protocol with our routine laboratory procedure and to evaluate the possible impact of modifications in the relative centrifugal force, type of tube, method of supernatant aspiration and urine volume on patient's results.

MATERIAL AND METHODS

Firstly, relative centrifugal force was investigated using 20 pairs of samples examined after centrifugation at 400xg and 1358xg. In phase two, 110 samples were examined, paired as: round bottom vs conical tube (N = 46), decanting vs suction of supernatant (N = 100) and 10 mL vs 5 mL of urine sample (N = 101).

RESULTS

The number of erythrocytes, leukocytes and squamous epithelial cells was significantly lower after centrifugation at 400xg (P = 0.001, 0.002 and 0.004, respectively). The number of leukocytes was significantly lower in conical tubes (P = 0.010), after the suction of supernatant (P = 0.045) and in 5 mL urine (P < 0.001). The number of squamous epithelial cells was significantly lower after the suction of supernatant (P < 0.001) and in 5 mL urine (P < 0.001). The number of erythrocytes (P < 0.001), total non-hyaline casts (P < 0.001) and the frequency of granular casts (P = 0.039) was significantly lower in 5 mL urine.

CONCLUSION

Lower results of leukocytes, erythrocytes, squamous cells and non-hyaline casts were recorded in recommended procedures (centrifugation at 400xg, suction of supernatant, conical tube, 5 mL of sample) than in routine procedure (centrifugation at 1358xg, decanting of supernatant, round bottom tube, 10 mL) used in our laboratory.

Pseudohyperkalemia - Potassium released from cells due to clotting and centrifugation - a case report

Hyperkalemia is a potentially lethal condition. Pseudohyperkalemia should be always excluded before implementing treatment to prevent inappropriate cause of hypokalemia – equally a potentially lethal condition. Here we present a case report of a 62 year female with chronic myeloproliferative disorder, i.e. essential thrombocythemia. The laboratory test results for potassium concentration were 6.3 mmol/L, for platelet count 1305 x10⁹/L and for leukocyte count 39.8 x10⁹/L. This was due to a temporary drug withdrawal after a surgical intervention for gastric bleeding. Potassium concentration in lithium heparin plasma collected in a vacuum tube without gel separator and in whole blood syringe were 4.6 mmol/L and 3.4 mmol/L, respectively. It means that mechanical stress such as centrifugation can contribute to spurious hyperkalemia.
Prior to reporting unexpected hyperkalemia result, pseudohyperkalemia should always be considered by the laboratory. Such potassium results require investigation in case it is pseudohyperkalemia, which may be due to thrombocytosis and leukocytosis. In cases where thrombocytosis or leukocytosis exists, an interpretative comment indicating these conditions inserted with the results of the potassium concentration can increase awareness for more accurate patient care decisions.

Impact of Educational Activities in Reducing Pre-Analytical Laboratory Errors: A quality initiative

OBJECTIVES

Pre-analytic errors during diagnostic laboratory investigations can lead to increased patient morbidity and mortality. This study aimed to ascertain the effect of educational nursing activities on the incidence of pre-analytical errors resulting in non-conforming blood samples.

METHODS

This study was conducted between January 2008 and December 2015. All specimens received at the Haematology Laboratory of the Sultan Qaboos University Hospital, Muscat, Oman, during this period were prospectively collected and analysed. Similar data from 2007 were collected retrospectively and used as a baseline for comparison. Non-conforming samples were defined as either clotted samples, haemolysed samples, use of the wrong anticoagulant, insufficient quantities of blood collected, incorrect/lack of labelling on a sample or lack of delivery of a sample in spite of a sample request. From 2008 onwards, multiple educational training activities directed at the hospital nursing staff and nursing students primarily responsible for blood collection were implemented on a regular basis.

RESULTS

After initiating corrective measures in 2008, a progressive reduction in the percentage of non-conforming samples was observed from 2009 onwards. Despite a 127.84% increase in the total number of specimens received, there was a significant reduction in non-conforming samples from 0.29% in 2007 to 0.07% in 2015, resulting in an improvement of 75.86% (P <0.050). In particular, specimen identification errors decreased by 0.056%, with a 96.55% improvement.

CONCLUSION

Targeted educational activities directed primarily towards hospital nursing staff had a positive impact on the quality of laboratory specimens by significantly reducing pre-analytical errors.

Novel Opportunities for Improving the Quality of Preanalytical Phase. A Glimpse to the Future?

The preanalytical phase is crucial for assuring the quality of in vitro diagnostics. The leading aspects which contribute to enhance the vulnerability of this part of the total testing process include the lack of standardization of different practices for collecting, managing, transporting and processing biological specimens, the insufficient compliance with available guidelines and the still considerable number of preventable human errors. As in heavy industry, road traffic and aeronautics, technological advancement holds great promise for decreasing the risk of medical and diagnostic errors, thus including those occurring in the extra-analytical phases of the total testing process. The aim of this article is to discuss some potentially useful technological advances, which are not yet routine practice, but may be especially suited for improving the quality of the preanalytical phase in the future. These are mainly represented by introduction of needlewielding robotic phlebotomy devices, active blood tubes, drones for biological samples transportation, innovative approaches for detecting spurious hemolysis and preanalytical errors recording software products.

Acutely developing, spurious anaemia without actual blood loss. A paradigmatic case report

We describe the case of a 55-year old women admitted at night to the emergency department (ED), complaining for acute abdominal pain lasting for nearly 5 hours. A first blood testing, performed immediately after admission, revealed mild anaemia. A second blood sample, drawn two hours after admission, revealed a considerable decrease of haemoglobin, haematocrit, total white blood cell and platelet counts (between 10-15% reduction). Abdominal ultrasonography was normal and the patient had no signs or symptoms of internal or external haemorrhage. Pre-analytical and analytical errors were accurately excluded. No infusion therapy was administered. After thoughtful discussing the sequence of events, it was ascertained that the first set of blood samples was drawn with the patient in seated position, immediately after ED admission (i.e., approximately 1 min passed from standing to seated position before venipuncture), whereas the second set of blood samples was drawn with the patient lying for two hours in supine position. This case report highlights the importance of standardizing patient position before venous blood collection, along with the crucial role played by cooperation and communication between laboratory and clinical wards for identifying and troubleshooting potential causes of spurious results of in vitro diagnostic testing.