Interpretation Of Laboratory Tests Research Articles

Dried blood spot reference intervals for 18 amino acids in a 1 to 6 years old pediatric cohort

ObjectivesReference intervals are indispensable for the accurate clinical interpretation of clinical laboratory tests. The reference intervals of amino acids in dried blood spots (DBS) from nonnewborn children are limited. In this study, we aim to establish the pediatric reference intervals for amino acids in DBS from healthy Chinese children aged from 1 to 6 years and to investigate the effect of sex and age. Design and MethodsIn 301 healthy subjects aged from 1 to 6 years old, eighteen DBS amino acids were determined using ultra-performance chromatography-tandem mass spectrometry method. Amino acid concentrations were examined in relation to sex and age. Reference intervals were established according to the CLSI C28-A3 guidelines. ResultsReference intervals of 18 amino acids bounded by the 2.5 and 97.5 percentiles were calculated in DBS specimen. No significant influence of age was observed for all the target amino acid concentrations in 1- to 6-year-olds. Sex differences were found in leucine and aspartic acid. ConclusionsThe RIs established in the present study added value for diagnosing and managing the amino acid-related diseases in the pediatric population.

An Improved Acid Fracturing Design through RoqSCAN Technology: A Case Study from Daniudi Gas Field in Ordos Basin, China

The concept of geological engineering-integrated fracturing is widely applied in the conventional and unconventional reservoirs, aiming to achieve efficient and economic development. There is no doubt that fine reservoir evaluation is the basis and core of geological engineering-integrated fracturing. Therefore, in this paper, we performed a series of investigations on the basis of formation fine evaluation by using RoqScan technology. Firstly, the physical parameters of the target well located in Daniudi Gas Field were evaluated by a laboratory test and logging interpretation. Next, the composition and function of the RoqSCAN tool were introduce in detail. Furthermore, the elements, minerals, and rock mechanical parameters of the target well were evaluated by the RoqSCAN tool. Finally, the fine reservoir model was established on the basis of fine formation evaluation. Moreover, we conducted a series of research on porosity and principal stress of the target formation to compare the difference between the fine model and the conventional model. Based on the fine reservoir model, the acid-fracturing design and numerical simulation were further investigated. The results of experiments and numerical simulation mainly achieved the following findings: 1. The porosity and permeability of the target formation indicated that it was a tight, low-permeability reservoir; 2. According to the comparison of the distribution for different parameters in the target well, the modeling with fine reservoir evaluation had higher accuracy than the traditional modeling; 3. Based on the fine evaluation results, acid fracturing is recommended as a stimulation method to enhance the productivity of the target formation. This study provides an essential method for the integrated fracturing design of geological engineering.

Pathomorphology of cutaneous mastocytosis

Introduction. Mastocytosis as a result of mast cell infiltration of the skin and other organs develops at any age. The relevance of this work is determined by the lack of systematic data on the pathomorphological features of the clinical forms and types of cutaneous mastocytosis, defined by the Consensus European-American Mastocytosis Group and the WHO classification in 2016. The variability of dermatological clinical manifestations in children and adults, the difficulties in interpreting laboratory tests create a problem for verifying the diagnosis and further treatment. The aim. To determine the main pathohistological features of clinical forms and types of cutaneous mastocytosis. Material and methods. The article includes data from patients who were treated and monitored at the Moscow Scientific and Practical Center of Dermatovenereology and Cosmetology in 2019–2022. Results. The literature and own data on the characteristic pathomorphological patterns that are important for the diagnosis of mastocytosis with skin lesions in children and adults are systematized. The pathological substrate of lesions in diffuse cutaneous mastocytosis and mastocytoma was a massive infiltrate of mast cells in the papillary and reticular layers of the dermis. The histological picture in the monomorphic type of maculopapular cutaneous mastocytosis (MPCM) in children was characterized by a relatively lower density of mast cell infiltration of the papillary dermis compared to other clinical forms of mastocytosis. Also, in children, the density of mast cells in the affected skin was significantly higher compared to adults. In addition, in adults with PPCM, the papillary dermis was less infiltrated with mast cells. This confirms the opinion that the monomorphic type of MPCM in children is phenotypically similar to MPCM in adults. Conclusions. Further prospective follow-up of patients may allow conclusions to be drawn about the prognostic value of pathological examination in mastocytosis in adults and children.

Potentials and pitfalls of ChatGPT and natural-language artificial intelligence models for the understanding of laboratory medicine test results. An assessment by the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Working Group on Artificial Intelligence (WG-AI).

ChatGPT, a tool based on natural language processing (NLP), is on everyone's mind, and several potential applications in healthcare have been already proposed. However, since the ability of this tool to interpret laboratory test results has not yet been tested, the EFLM Working group on Artificial Intelligence (WG-AI) has set itself the task of closing this gap with a systematic approach. WG-AI members generated 10 simulated laboratory reports of common parameters, which were then passed to ChatGPT for interpretation, according to reference intervals (RI) and units, using an optimized prompt. The results were subsequently evaluated independently by all WG-AI members with respect to relevance, correctness, helpfulness and safety. ChatGPT recognized all laboratory tests, it could detect if they deviated from the RI and gave a test-by-test as well as an overall interpretation. The interpretations were rather superficial, not always correct, and, only in some cases, judged coherently. The magnitude of the deviation from the RI seldom plays a role in the interpretation of laboratory tests, and artificial intelligence (AI) did not make any meaningful suggestion regarding follow-up diagnostics or further procedures in general. ChatGPT in its current form, being not specifically trained on medical data or laboratory data in particular, may only be considered a tool capable of interpreting a laboratory report on a test-by-test basis at best, but not on the interpretation of an overall diagnostic picture. Future generations of similar AIs with medical ground truth training data might surely revolutionize current processes in healthcare, despite this implementation is not ready yet.

A journal as a mirror of continued progress in internal medicine. A century of <i>Polish Archives of Internal Medicine</i>

Internal medicine emerged as a new medical specialty in the second half of the 19th century. It was based on a novel diagnostic and therapeutic paradigm, and included pathophysiologic interpretation of physical examination, laboratory tests, and imaging techniques, in contrast with previous descriptive approach to clinical problems. Professor Edward J. Sas-Korczyński in 1891 proposed to organize Polish meetings on internal medicine. The proposal was implemented only in 1906 by Antoni W. Gluziński, a famous Polish internist. Despite obstacles set by the partitioning powers, the Society of Internists of the Polish Lands was founded. The name of the association was changed to the Polish Society of Internal Medicine during the congress held in Vilna (now Vilnius) in 1923, the first one organized in the independent Poland. The journal of the Society, Polish Archives of Internal Medicine, was founded and Antoni W. Gluziński was its first editor-in-chief. Later, the journal was edited by Władysław Janowski, Witold E. Orłowski, Andrzej Biernacki, Tadeusz Orłowski, Artur Czyżyk, and Anetta Undas. Witold E. Orłowski was a father of modern Polish internal medicine, and contributed to the development of its subspecialties and their societies. Most of them had roots in the specialist sections of the Polish Society of Internal Medicine. The journal supported the newly founded societies by publication of issues focused on selected subspecialties. Despite the development of subspecialties, the role of internal medicine as a holistic discipline covering the diagnosis and therapy of many organs does not decrease.

Review on Diagnosis and Management of Cauda Equina

Disorders of the cauda equina are etiologically and physically connected to the neuromuscular system in the spinal cord. A thorough history and neurological examination are necessary for clinical recognition of a cauda equina-affecting condition, and to make a rapid diagnosis, the selection and interpretation of relevant neuroimaging investigations, neurophysiologic testing, and laboratory tests are necessary. The diagnosis and treatment of Cauda Equina Syndrome (CES) are difficult. It could app

S3276 A Rare Case of Non-Small Cell Lung Cancer Causing False Positive Hepatitis B Surface Antigen

Introduction: Hepatitis B surface antigen (HBsAg) is a protein on the surface of HBV which can be a distinctive serological marker of acute or chronic hepatitis B infection. We present a case of 74-year-old male with a false positive HBsAg test. Case Description/Methods: A 74-year-old African American male with medical comorbidities of stage IV non-small cell lung cancer (NSCLC) and HTN presented to the hospital for an acute kidney injury with proteinuria. Hepatitis B virus (HBV) panel was obtained and revealed positive HBsAg. HBsAg was previously negative two years prior. Patient had multiple risk factors for hepatitis B infection including prior use of IV cocaine and multiple sexual partners. The patient denied any recent vaccinations. Liver function tests were normal. Physical examination did not reveal chronic liver disease manifestations. HBs Antibody (HBsAb) was positive with a quantitative value of 0.53. Hepatitis B core immunoglobulin M (HBc IgM), HBcAb total, HBeAg, HBeAb were all negative with undetectable serum HBV DNA. The HBsAg was not confirmed as a true positive after repeat testing with an antibody neutralizing procedure involving a human antibody to HbsAg. Discussion: Accurate interpretation of laboratory tests is imperative in diagnosing hepatitis B. There was high suspicion that patient had false positive HBsAg. The patient’s serological profile did not fit acute or chronic hepatitis B. The patient had no evidence of acute hepatitis B with negative HBc IgM, HBV DNA and no evidence of chronic hepatitis B with HBcAb total being negative. Furthermore, a positive HBsAb is not seen in acute and chronic hepatitis B. Transient HBsAg has been seen in patients for up to 2 weeks after HBV vaccination, however, our patient had not been vaccinated recently. The most common cause is the presence of heterophile antibodies. These naturally occurring human antibodies can bind to a variety of chemical structures including animal antibodies seen in immunochemistry assays. They can be neutralized by specific inactivating binders. Other viral infections such as Epstein-Barr Virus (EBV), transfusions, or systemic disease can cause false positives. A likely suspect was the patient’s NSCLC causing a paraneoplastic syndrome which would be the first instance of such in the literature. There have been cases of parathyroid adenoma and basal cell carcinoma causing false positivity. Patients with false-positive HBsAg need further workup to prevent misdiagnosis and potentially harmful management.

Reference Value Evaluation of Urine Sediment in Indonesian Adult Population Using Automated Urine Analyzer

Locally established clinical laboratory reference value are required to interpret laboratory test results for screening, diagnosis, prognosis, determining retest criteria or as microscopic confirmation. The objective of this study is to establish urine sediments reference value by using automated urine flow cytometry, investigating erythrocyte, leukocyte, epithelial cells, types of epithelial cells, bacteria, casts, pathologic casts, crystals, yeast, sperm, and mucus in Indonesian population using Sysmex UF-4000. A cross sectional study was conducted in October 2018 – April 2019 at R. Said Sukanto National Police Hospital in Jakarta. The study involved 240 participants comprised of clinically healthy 120 males and 120 females aged 18-65, with normal urine chemistry, hematology, blood glucose, liver function (AST, ALT), and renal function (urea, creatinine). The reference value was reported in microliter (μL) or in High Performance Field (HPF) or Low Performance Field (LPF). Mann-Whitney test through MedCalc software was used to test significant differences with p value <0.05. This study observed significant differences between males and females in erythrocyte, epithelial cells, epithelial cell variety, bacteria, pathologic casts, and yeast”which are evidently higher in female patients. However, the mucus in LPF levels is found to be higher in male patients instead of the female, disparate than current reference value. Therefore, the reference value results were separated between the two groups in those aspects, whereas the results of other urine sediment characteristics studied were combined. As most reference value obtained are still within range of existing references, reference value established with Sysmex UF-4000 can be useful.

Laboratory-Reported Normal Value Ranges Should Not Be Used to Diagnose Periprosthetic Joint Infection.

Introduction: Clinical laboratories offer several multipurpose tests, such as the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), which are not intended to diagnose any specific disease but are used by clinicians in multiple fields. The results and laboratory interpretation (normal/abnormal) of these multipurpose tests are based on laboratory-reported normal thresholds, which vary across clinical laboratories. In 2018, the International Consensus Meeting on Musculoskeletal Infection (2018 ICM) provided a gold-standard definition to diagnose periprosthetic joint infection (PJI) which included many multipurpose laboratory tests, along with thresholds optimized to diagnose PJI. The discrepancy between laboratory-reported normal thresholds and 2018 ICM-recommended PJI-optimized test thresholds has never been studied. The purpose of this study was to assess the existing variation in laboratory-reported normal thresholds for tests commonly used to diagnose PJI and evaluate the potential diagnostic impact of using laboratory-reported normal thresholds instead of 2018 ICM-recommended PJI-optimized thresholds.Methods: Clinical laboratories (N=85) were surveyed to determine the laboratory-reported units of measure and normal thresholds for common multipurpose tests to diagnose PJI, including the ESR, CRP, D-dimer, synovial fluid white blood cells (SF-WBC), and polymorphonuclear cell percent (SF-PMN%). The variability of units of measure and normal thresholds for each test was then assessed among the 85 included clinical laboratories. A representative dataset from patients awaiting a revision arthroplasty was used to determine the clinical significance of the existing discrepancy between laboratory-reported normal test interpretations and 2018 ICM-recommended PJI-optimized test interpretations.Results: Two units of measure for the CRP and six units of measure for the D-dimer were observed, with only 59% of laboratories reporting the CRP in terms of mg/L and only 16% reporting the D-dimer in ng/ml, as needed to utilize the 2018 ICM definition of PJI. Across clinical laboratories surveyed, the mean laboratory-reported normal thresholds for the ESR (20 mm/h), CRP (7.69 mg/L), D-dimer (500 ng/mL), SF-WBC (5 cells/uL), and SF-PMN% (25%) were substantially lower than the 2018 ICM-recommended PJI-optimized thresholds of 30 mm/h, 10 mg/L, 860 ng/mL, 3,000 cells/uL, and 70%, respectively. Interpretation of test results from a representative PJI dataset using each laboratory’s normal test thresholds yielded mean false-positive rates of 14% (ESR), 18% (CRP), 42% (D-dimer), 93% (SF-WBC), and 36% (SF-PMN%) versus the ICM-recommended PJI-optimized thresholds.Conclusion: When reporting the results for multipurpose laboratory tests, such as the ESR, CRP, D-dimer, SF-WBC, and SF-PMN%, clinical laboratories utilize laboratory-reported units of measure and normal thresholds that are not intended to diagnose PJI, and therefore may not match the 2018 ICM recommendations. Our findings reveal that laboratory-reported normal thresholds for these multipurpose tests are well below the 2018 ICM recommendations to diagnose PJI. Clinical reliance on laboratory-reported results and interpretations, instead of strict use of the 2018 ICM-recommended units and PJI-optimized thresholds, may lead to false-positive interpretation of multipurpose laboratory tests.

Investigative algorithms for disorders affecting plasma chloride: a narrative review

Background and Objective: The following article is part of a special series to aid the reader in diagnosing the cause of various electrolyte imbalances. A focussed literature review will, by the end of this article, enable the reader to correctly order and interpret laboratory tests to investigate derangements in plasma chloride.

The role of diffusion induced electro-osmosis in the coupling between hydraulic and ionic fluxes through semipermeable clay soils

Most of the experimental research conducted to date has provided evidence on the semipermeable membrane behaviour of smectite-rich clay soils, the extent of which is typically quantified through the reflection coefficient, when the permeant (electrolyte) solution contains a single monovalent or divalent salt. Under such conditions, the osmotic flow of solution is controlled to a great extent by the different accessibility of ions and water molecules to the soil porosity, which is referred to as the chemico-osmotic effect. However, theoretical simulations of coupled solute and solvent transport suggest that, when two or more cations that diffuse in water at different rates are present simultaneously in the permeant solution, the electro-osmotic effect, which stems from the condition of null electric current density through the porous medium, can be enhanced compared to the case of a single salt to such an extent that it becomes comparable to or even greater than the chemico-osmotic effect. An original closed-form analytical solution to the problem of calculating the diffusion potential, which in turn controls the magnitude of the electro-osmotic effect, is here illustrated, and the relative importance of the aforementioned contributions to multi-electrolyte systems is examined through the interpretation of laboratory test results from the literature pertaining to a bentonite amended clay soil in equilibrium with aqueous mixtures of potassium chloride (KCl) and hydrochloric acid (HCl). The proposed mechanistic model is shown to be able to quantitatively capture the impact of both chemico-osmosis and electro-osmosis on the measured reflection coefficient of smectite clays, thereby breaking new ground in the experimental and theoretical research on the osmotic properties of engineered clay barriers in contact with mixed aqueous electrolyte solutions.

Determination of Reference Intervals for Platelet Parameters using Sysmex XN-1000 among South Indian Population

Introduction: Reference intervals are important for interpretation of clinical laboratory tests. The platelet parameters are recently reported newer haematological parameters and serve as clinically valuable biomarkers. It provides further information on platelet morphology and proliferation kinetics. The lack of information from manufacturers about the geographical reference ranges for the Complete Blood Count (CBC) parameters highlights the need for laboratories to establish reference intervals. Aim: To determine the reference interval for platelet parameters using Sysmex XN-1000 haematology analyser in South Indian population. Materials and Methods: The present retrospective recordbased study was carried out during July 2021 to September 2021 and the data was retrieved from a continuous 12-month period (November 2018-October 2019) in the haematology laboratory at a tertiary care dental hospital, Chennai, Tamil Nadu, India. The data of CBC parameters were retrieved from the Sysmex XN-1000 analyser and a total of 1,883 reports labelled as negative/ unflagged were included in the study. The reference intervals for platelet parameters which include Mean Platelet Volume (MPV), Platelet Distribution Width (PDW), Platelet Large Cell Ratio (P-LCR) and Plateletcrit (PCT) for male and female subjects were compared using the Mann-Whitney U-test. Kruskal-Wallis test was used to compare between the different age groups using Statistical Package for the Social Sciences (SPSS) version 24.0 software. Results: The data for the platelet parameters are shown as median, with statistically significant difference in the reference interval for all the parameters (p<0.001). There was no significant difference in age divided reference intervals, except for PCT (p=0.04) PDW was found to be 9-16.4 fL for males and 9.1-16.6 fL for females (p<0.001). Similarly, MPV was 9-12.3 fL for males and 9-12.6 fL for females (p<0.001); P-LCR was 16-42.1% for males and 16.6-43% for females (p<0.001); and PCT was 0.15- 0.36% for males and 0.14-0.41% for females (p<0.001). Conclusion: The study has determined the reference interval for platelet parameters with respect to age and gender in area specific population and these results can be utilised for other laboratories using the same analyser system for south Indian population.

Post-Vasectomy Semen Analysis: Optimizing Laboratory Procedures and Test Interpretation through a Clinical Audit and Global Survey of Practices.

PurposeThe success of vasectomy is determined by the outcome of a post-vasectomy semen analysis (PVSA). This article describes a step-by-step procedure to perform PVSA accurately, report data from patients who underwent post vasectomy semen analysis between 2015 and 2021 experience, along with results from an international online survey on clinical practice.Materials and MethodsWe present a detailed step-by-step protocol for performing and interpretating PVSA testing, along with recommendations for proficiency testing, competency assessment for performing PVSA, and clinical and laboratory scenarios. Moreover, we conducted an analysis of 1,114 PVSA performed at the Cleveland Clinic’s Andrology Laboratory and an online survey to understand clinician responses to the PVSA results in various countries.ResultsResults from our clinical experience showed that 92.1% of patients passed PVSA, with 7.9% being further tested. A total of 78 experts from 19 countries participated in the survey, and the majority reported to use time from vasectomy rather than the number of ejaculations as criterion to request PVSA. A high percentage of responders reported permitting unprotected intercourse only if PVSA samples show azoospermia while, in the presence of few non-motile sperm, the majority of responders suggested using alternative contraception, followed by another PVSA. In the presence of motile sperm, the majority of participants asked for further PVSA testing. Repeat vasectomy was mainly recommended if motile sperm were observed after multiple PVSA’s. A large percentage reported to recommend a second PVSA due to the possibility of legal actions.ConclusionsOur results highlighted varying clinical practices around the globe, with controversy over the significance of non-motile sperm in the PVSA sample. Our data suggest that less stringent AUA guidelines would help improve test compliance. A large longitudinal multi-center study would clarify various doubts related to timing and interpretation of PVSA and would also help us to understand, and perhaps predict, recanalization and the potential for future failure of a vasectomy.

Personalized reference intervals – statistical approaches and considerations

Abstract For many measurands, physicians depend on population-based reference intervals (popRI), when assessing laboratory test results. The availability of personalized reference intervals (prRI) may provide a means to improve the interpretation of laboratory test results for an individual. prRI can be calculated using estimates of biological and analytical variation and previous test results obtained in a steady-state situation. In this study, we aim to outline statistical approaches and considerations required when establishing and implementing prRI in clinical practice. Data quality assessment, including analysis for outliers and trends, is required prior to using previous test results to estimate the homeostatic set point. To calculate the prRI limits, two different statistical models based on ‘prediction intervals’ can be applied. The first model utilizes estimates of ‘within-person biological variation’ which are based on an individual’s own data. This model requires a minimum of five previous test results to generate the prRI. The second model is based on estimates of ‘within-subject biological variation’, which represents an average estimate for a population and can be found, for most measurands, in the EFLM Biological Variation Database. This model can be applied also when there are lower numbers of previous test results available. The prRI offers physicians the opportunity to improve interpretation of individuals’ test results, though studies are required to demonstrate if using prRI leads to better clinical outcomes. We recommend that both popRIs and prRIs are included in laboratory reports to aid in evaluating laboratory test results in the follow-up of patients.

Therapeutic Plasma Exchange for Apixaban Removal in the Setting of Delayed Clearance and Life-Threatening Bleeding

Introduction:The management of bleeding associated with direct oral anticoagulants (DOACs) is challenging and associated with high risk of morbidity/mortality despite the use of various reversal agents (Gomez-Outes et al. 2021). Routine tests cannot determine the level of DOAC anticoagulation and reversal agents carry potential prothrombotic complications (Garcia & Crowther 2021). We present an unusual case of a patient requiring emergent surgery with significant post-op bleeding due to profoundly delayed apixaban elimination.Case Description:A 63-year-old female presented to the emergency department (ED) with a 10-day history of worsening abdominal pain, distension, nausea and constipation. Her past medical history was notable for right sided heart failure, COVID-19 pneumonia requiring intubation, tissue mitral valve replacement, and post-op atrial fibrillation for which she was prescribed apixaban 5 mg BID. Her last dose of apixaban had been the night prior to ED presentation.In the ED, a CT of the abdomen revealed a 6 cm partially obstructing lesion involving the mid-sigmoid colon. Findings were consistent with evolving peritonitis and the patient underwent an emergent exploratory laparotomy, sigmoid resection, and end colostomy. Pre-op labs revealed WBC 12.4 x10 9/L, hemoglobin (hgb) 9.2 g/dL, and platelets 318 x10 9/L. Coagulation studies revealed a PT of 28 sec and INR of 2.5. The patient was given prothrombin complex concentrate (PCC) 25 units/kg and 1 mg of vitamin K prior to surgery. Postoperatively, the INR remained elevated, 2.0, and her hgb downtrended from 8.8 g/dL to 7.8 g/dL. On post-op day 1 the patient became hypotensive, with increased abdominal pain/distension, she also started bleeding from her ostomy. The INR was 2.4 and her hgb dropped to 6.0 g/dL. Red blood cells were given along with FFP, vitamin K and a 2 nd dose of PCC. The patient continued to decline, was transferred to the ICU where she was intubated and placed on CRRT. Hematology was consulted for the persistently prolonged PT/INR in the setting of bleeding despite multiple interventions to correct the INR.The patient's last dose of apixaban was ~48 h prior to ICU admission. A rapid heparin anti-Xa assay was performed and upon comparison with an in-house nomogram the result, 1.78 IU/mL, correlated to an apixaban dose between 180-200 ng/ml (average peak levels 2-4 h after administration are 171 ng/mL). This result was confirmed the following day by an apixaban anti-Xa assay, 190 ng/mL. A repeat test performed 11 h later showed a minimal decrease in apixaban indicating impaired clearance.Therapeutic plasma exchange (TPE) was considered for rapid removal of apixaban. We performed a 1.0 plasma volume exchange, using plasma as the replacement fluid, to remove apixaban. Pre and post TPE drug levels were 172 and 108 ng/mL, respectively. Due to an elevated apixaban level the next day, a second TPE was performed which dropped the level to 87 ng/mL. The patient began to improve clinically, with hgb stabilization ~10 g/dL. She was extubated and transferred to a medical floor for further management. Apixaban levels were still measurable, 16 ng/mL, on post op day 8, 11 days after her last dose.Discussion:Apixaban is a highly protein-bound drug (~90%) that is rapidly absorbed in the small intestine with a large Vd (21 L) and a t1/2 of ~12 h. Elimination primarily occurs through the fecal route (Byon et al. 2019). The factors impairing the elimination of the drug in this patient were the following: 1. Pre-op constipation resulting in 10 days without a bowel movement; 2. Minimal bowel function post-op; and 3. Renal failure requiring CRRT after admission to the ICU.This case illustrates the profound effect intestinal obstruction/dysfunction can have on apixaban clearance. It also highlights the importance of laboratory test interpretation when managing coagulopathic patients. TPE is an effective way to remove drugs with high protein binding affinity (Mahmoud et al. 2021). TPE significantly reduced apixaban levels in our patient allowing for hemostasis and clinical improvement. To our knowledge, there are only two case reports regarding the effect of TPE on DOACs, one for apixaban, the other rivaroxaban (Hodulik et al. 2019).Conclusion:TPE can be considered as an option for rapid clearance of apixaban, or other highly protein bound anti-Xa inhibitors, in the setting of delayed elimination or when specific reversal agents are not safe/available. DisclosuresNo relevant conflicts of interest to declare.

Electronic tools in clinical laboratory diagnostics: key examples, limitations, and value in laboratory medicine

Abstract Electronic tools in clinical laboratory diagnostics can assist laboratory professionals, clinicians, and patients in medical diagnostic management and laboratory test interpretation. With increasing implementation of electronic health records (EHRs) and laboratory information systems worldwide, there is increasing demand for well-designed and evidence-based electronic resources. Both complex data-driven and simple interpretative electronic healthcare tools are currently available to improve the integration of clinical and laboratory information towards a more patient-centered approach to medicine. Several studies have reported positive clinical impact of electronic healthcare tool implementation in clinical laboratory diagnostics, including in the management of neonatal bilirubinemia, cardiac disease, and nutritional status. As patients have increasing access to their medical laboratory data, it is essential that accessible electronic healthcare tools are evidence-based and user-friendly for individuals of varying digital and medical literacy. Indeed, studies suggest electronic healthcare tool development processes significantly lack the involvement of relevant healthcare professionals and often present misinformation, including erroneous calculation algorithms or inappropriate interpretative recommendations. The current review provides an overview of the utility of available electronic healthcare tools in clinical laboratory diagnostics and critically reviews potential limitations and benefits of their clinical implementation. The Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER) online database is also detailed as an example of a pediatric diagnostic tool with widespread global impact.

1555 Comparison of Face-To-Face Versus Online Delivery of a Preparatory Course for First Year Clinical Students

AimThe coronavirus pandemic has had a huge impact on medical education, with increasing reliance on online delivery of teaching. Sound awareness of investigations available to clinicians is an essential skill, the foundations of which are built from the first clinical year. Our aim is to evaluate whether online teaching has the same efficacy as face-to-face teaching in the context of clinical investigations teaching.MethodWe designed a case-based course using active learning methods (by means of audience participation tools) to prepare first year clinical students in interpreting key investigations (bedside, laboratory and imaging tests) with focus on surgical conditions. This course was delivered face-to-face in November 2019 and subsequently re-delivered via an online platform in November 2020. We utilised a pre- (PR) and post- (PS) confidence questionnaire and a 13-part mock single best answer examination.Results32 students attended the face-to-face course; 27 (84.3%) completed the PR and 21 (65.6%) completed the PS. There was a significant improvement in examination scores (56.9% to 71.7%, P < 0.01) and a significant improvement in one of the 6 confidence domains tested (interpreting abdominal radiographs, P < 0.001). 80 students attended the online course; 46 (57.5%) completed the PR and 40 (50%) completed the PS. There was a significant improvement in examination scores (58.8% to 73.2%, P < 0.001) and a significant improvement in two of the 6 confidence domains (interpreting laboratory tests and abdominal radiographs, P < 0.001 for both).ConclusionsOnline teaching is as effective as face-to-face teaching in improving knowledge and confidence in clinical investigations for first clinical year students.

Establishment of Hematological Reference intervals for healthy Children in Elobied City, Sudan

Hemogram Reference intervals are established since a healthy population is critical to accurately interpret laboratory tests, which include Hemoglobin estimation, Red blood cells count and indices, White blood cells count and differential in addition to Platelets count. This study aims to establish the reference interval of the complete hemogram amongst healthy Sudanese children in Elobied city, Sudan. A descriptive cross-sectional study included 354 healthy children, aged between 3 to 17 years, who were categorized into three groups according to age. A questionnaire was fulfilled, EDTA anti-coagulated venous blood sample was collected from each child then the complete hemogram was performed automated hematological analyzer (Sysmex Xp 300), Finally, Data was analyzed by a software program (SPSS version 21). The hematological reference intervals for healthy children [Hb g/dl, HCT%, RBCs count x106μL, MCV/fL ,MCH /pg., MCHC g/dl ,WBCs count x10³/μL, Neutrophil count%, Eosinophil count %, Basophile count %, lymphocyte count ,Monocytes count%, RDW CV and PLTs count×10³/μL] are [(12.4±1.2),(37±4),(5.0 ±0.4), (82±5.0), (26±3.0), (32±3.0) ,(7.0±2.0) (47±10), (1±0.1) ,(0±0),(45± 10),(7 ± 4), (13±1.8) &amp;(227±91)] respectively. The hematological RI for healthy children in Elobied was established in this study to be representative of this population, there was a significant gender-based difference in all the evaluated hematological parameters, they were found to be higher in males than in females except for basophil (%). Finally, the results of this study would shed a light on the importance of establishing RI for the children population in Elobied.

Identifying Content Themes in Primary Care Physician and Rheumatologist Communications Within Electronic Consultations: A Qualitative Study.

ObjectiveElectronic consultation (eConsult) communications between primary care physicians (PCPs) and rheumatologists may reveal common knowledge gaps and educational opportunities. The aim of our study was to identify content themes in PCP questions and rheumatology recommendations through analysis of eConsult and the need for rheumatology appointments and facilitated urgent visits post‐eConsult.MethodsA descriptive cross‐sectional study involving qualitative and quantitative analysis of rheumatology eConsults in a single center was performed from May 1, 2019, to January 9, 2020. Conventional content analysis was used to derive content themes in PCP questions and rheumatology recommendations. We evaluated the proportion of eConsults, which included a need for rheumatology appointments and expedited visits through frequency counts.ResultsAmong 120 rheumatology eConsults, six PCP questions and five rheumatology recommendation content themes were identified. The most common PCP question themes were the following: 1) joint pain, 2) suspected rheumatic disease differential, and 3) abnormal laboratory tests. The most common rheumatology recommendation or teaching themes were the following: 1) education on differential diagnoses of rheumatic diseases, 2) education on the specific rheumatic disease, and 3) laboratory test interpretation. The majority of eConsults (82%) recommended a subsequent rheumatology appointment, and 27% facilitated an expedited appointment.ConclusionIn this analysis of eConsults, we identified common knowledge gaps in PCPs and rheumatology educational topics, including differentiating inflammatory from noninflammatory arthritis, using caution in interpreting abnormal laboratory tests without clinical manifestations, managing chronic gout, evaluating elevated creatine phosphokinase levels, and differentiating C‐reactive protein (CRP) from high‐sensitivity CRP. Timely feedback through eConsult recommendations may allow for focused educational opportunities.

RefineR: A Novel Algorithm for Reference Interval Estimation from Real-World Data

Reference intervals are essential for the interpretation of laboratory test results in medicine. We propose a novel indirect approach to estimate reference intervals from real-world data as an alternative to direct methods, which require samples from healthy individuals. The presented refineR algorithm separates the non-pathological distribution from the pathological distribution of observed test results using an inverse approach and identifies the model that best explains the non-pathological distribution. To evaluate its performance, we simulated test results from six common laboratory analytes with a varying location and fraction of pathological test results. Estimated reference intervals were compared to the ground truth, an alternative indirect method (kosmic), and the direct method (N = 120 and N = 400 samples). Overall, refineR achieved the lowest mean percentage error of all methods (2.77%). Analyzing the amount of reference intervals within ± 1 total error deviation from the ground truth, refineR (82.5%) was inferior to the direct method with N = 400 samples (90.1%), but outperformed kosmic (70.8%) and the direct method with N = 120 (67.4%). Additionally, reference intervals estimated from pediatric data were comparable to published direct method studies. In conclusion, the refineR algorithm enables precise estimation of reference intervals from real-world data and represents a viable complement to the direct method.