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Extracorporeal membrane oxygenation (ECMO) is a type of circulatory life support for patients with severe lung failure. The use of ECMO has increased worldwide since the pandemic of H1N1 in 2009 and more recently SARS‐CoV‐2 in 2020 both of which caused severe respiratory failure. ECMO patients experience both increased risk of bleeding and thrombosis. This is due to the pathological insult that damages the lungs, the ECMO circuit, coagulopathy, inflammation and anticoagulation. ECMO presents unique demands on the coagulation laboratory both in tests required to manage the patients and result interpretation. This is a personal opinion of 20 years ECMO experience as a clinical scientist and a short current review of the literature. It will focus on the laboratory coagulation tests used to manage ECMO patients, including different anticoagulants used, testing frequency and interpretation of the results. [ABSTRACT FROM AUTHOR]

Background Rejected samples lead to prolonged turnaround time and delayed diagnosis and treatment of patients. This study was conducted to determine minimum acceptable sample volume in Sarstedt brand coagulation tubes to reduce high sample rejection rate. Methods Blood samples were drawn from 20 participants (10 healthy volunteers and 10 patients receiving oral anticoagulant) into coagulation tubes. Six samples were taken from each participant, with tube fill volumes of 100%, 90%, 80%, 70%, 60%, and 50%. Prothrombin time (PT), active partial thromboplastin time (aPTT), and fibrinogen tests were analyzed. Results According to quality performance specifications, the tube fill volume must be at least 70% for PT and aPTT and 50% for fibrinogen. There was no statistical difference in samples from healthy volunteers for PT, aPTT, and fibrinogen tests when the minimum tube fill volume was at least 80%, 90%, and 50%, respectively. These percentages were 50%, 70%, and 60%, respectively, in patients receiving oral anticoagulant. Conclusions Sarstedt tubes meet quality standard specifications at a 70% fill rate for PT and aPTT and a 50% fill rate for fibrinogen. Comprehensive studies with larger populations are needed to accept these values as sample acceptance criteria for the laboratory. [ABSTRACT FROM AUTHOR]

This article provides guidelines for assessing and managing bleeding risk before invasive procedures. It recommends individualized assessment and decision-making based on the specific procedure and patient characteristics. The article discusses the management of anticoagulant and antiplatelet therapy, the limitations of routine coagulation testing, and the potential use of global haemostatic and platelet function testing to predict bleeding risk. It also addresses the use of plasma products and platelet transfusions in the ICU, emphasizing the lack of evidence supporting their prophylactic use. The article highlights the importance of operator and procedural factors in reducing the risk of complications during procedures. [Extracted from the article]

Objectives: This study aimed to ascertain pediatric age-specific reference ranges for prothrombin time (PT), international normalized ratio (INR), and activated partial thromboplastin time (aPTT). Retrospective data were obtained from healthy children who had undergone preoperative tests and compared with those obtained from a group of adult patients. Methods: Reference individuals were determined by the indirect method. A total of 15,179 patients who presented to our hospital in 2022 and 2023 were retrospectively reviewed. Pediatric patients were divided into three age groups: 1-5 years (n=1949), 6--10 years (n=1563), and 11-17 years (n=508). The adult age group consisted of healthy individuals aged 18--50 years (n=11165). The tests were run in a coagulation autoanalyzer with the mechanical coagulometric measurement method. Reference ranges were analyzed using the non-parametric method statistically. Results: The mean PT, INR, and aPTT values were found to be 14.34±1.99 s, 1.07±0.16, and 31.43±3.47 s, respectively, in children aged 1-5 years; 14.48±1.40 s, 1.08±0.11, and 31.30±2.66 s, respectively, in those aged 6-10 years; and 14.73±1.12 s, 1.10±0.09, and 31.21±2.91 s, respectively, in those aged 11-17 years. Among the adults aged 18-50 years, the mean PT, INR, and aPTT values were 13.95±1.40 s, 1.04±0.11, and 30.21±2.86 s, respectively. The mean PT, INR, and aPTT values of children aged 1-5 years, 6-10 years, and 11-17 years were statistically significantly higher than those of adults aged 18-50 years (for each group p<0.01). Conclusion: It is important for laboratories to employ age-specific reference ranges for coagulation tests performed on children to ensure accurate diagnosis and avoid unnecessary further investigations. In this study, the reference ranges of the PT, INR, and aPTT parameters were determined for pediatric patients and found to be significantly higher than those of adults, which will be useful for clinical evaluation and diagnosis. [ABSTRACT FROM AUTHOR]

Introduction: Establish the referenceintervals (RIs) and analyze biological variability (BV) to introduce the thrombin generation test (TGT) into clinical practice. Methods: To determine the RIs parameters of TGT, we analyzed platelet‐poor plasma (PPP) (n = 123), rich (PRP) (n = 76), and microparticle‐mediated TGT (MP‐TGT) (n = 32) in healthy participants. For the BV study, we collected samples from five participants over 5 weeks. A nested analysis of variance (ANOVA) was performed to evaluate the BV results. Results: The between‐individual variation (CVG), within‐individual variation (CVI), analytical variation (CVA) for TGT on PPP for all parameters were from 5.5% to 17.3%, 5.4% to 17.7%, and 2.6% to 5.3%, respectively. For PRP, the CVG, CVI, and CVA were ranged from 3.0% to 23.7%, 8.4% to 23.0%, and 4.1% to 6.9%, respectively. The index of individuality (II) ranged from 0.3 to 3.1 for PPP and from 0.3 to 4.5 for PRP. The reference change value (RCV) for PPP was from 19.8% to 50.1%, while for PRP, it was 27.2% to 66.5%. We recommend using the RIs for the parameters ETP (nM/min): 1101.6–2332.1 and Peak (nM): 163.5–381.3 for PPP and ETP (nM/min): 1088.5–2634.9; Peak (nM): 72.6–210.7 for PRP. The resulting MP‐TGT are highly dependent on age require a larger sample. Conclusion: For TGT on PPP and PRP the RIs developed on our population for Peak and ETP parameters can be used. Time parameters: Lagtime and ttPeak, min with II < 0.6, require monitoring over time with RCV calculation. [ABSTRACT FROM AUTHOR]

Intrauterine growth restriction (IUGR) affects nearly 10 to 15% of pregnancies and is responsible for many short- and long-term adverse consequences, including hemostatic derangement. Both thrombotic and hemorrhagic events are described in the perinatal period in these neonates. The aim of this study was to systematically review the literature on the laboratory studies used to evaluate the hemostatic system of the IUGR small for gestational age neonate. We reviewed the current literature via PubMed and Scopus until September 2022. Following our inclusion/exclusion criteria, we finally included 60 studies in our review. Thrombocytopenia, characterized as hyporegenerative and a kinetic upshot of reduced platelet production due to in utero chronic hypoxia, was the main finding of most studies focusing on growth-restricted neonates, in most cases is mild and usually resolves spontaneously with the first 2 weeks of life. In regard to coagulation, growth-restricted newborns present with prolonged standard coagulation tests. Data regarding coagulation factors, fibrinolytic system, and anticoagulant proteins are scarce and conflicting, mainly due to confounding factors. As thromboelastography/rotational thromboelastometry (TEG/ROTEM) provides a more precise evaluation of the in vivo coagulation process compared with standard coagulation tests, its use in transfusion guidance is fundamental. Only one study regarding TEG/ROTEM was retrieved from this population, where no difference in ROTEM parameters compared with appropriate for gestational age neonates was found. Despite the laboratory aberrations, no correlation could be achieved with clinical manifestations of bleeding or thrombosis in the studies included. More studies are needed to assess hemostasis in IUGR neonates and guide targeted therapeutic interventions. [ABSTRACT FROM AUTHOR]

Background and Objectives: HIV disease is recognized to cause inconsistencies in coagulation via various pathways during infection. Some studies have indicated that HIV-infected patients are prone to developing thrombocytopenia, thrombosis, or autoantibodies that may cause difficulties in diagnosis. This study is intended to measure the trend of coagulation parameters in Sudanese patients with HIV. Materials and Methods: A cross-sectional study was carried out in patients with HIV admitted to the Sudan National AIDS Program (SNAP) from January 2018 to December 2019. Prothrombin time (PT), partial thromboplastin time (PTT), thrombin time (TT), D-dimer (DD), hemoglobin (HB), total lymphocyte count (TLC), platelet count (PLT), and a disintegrin and metalloproteinase with thrombospondin type 1 motif, member 13 (ADAMTS13), were evaluated among HIV Sudanese patients. Results: Out of the 44 HIV patients included, 6 (13.6%) were found to have thrombotic thrombocytopenic purpura-like events and 12 (27.2%) had antiphospholipid antibodies, of whom 8 (66.6%) showed anticardiolipin antibody (1gG (75%) and IgM (25%)) and 4 showed lupus anticoagulants. The HB, TLC, and PLT values were found to be significantly lower in HIV patients than in control (p = 0.000, 0.000, and 0.050, respectively). The PT and ADAMTS13 values showed no significant difference between HIV patients and control (p = 0.613 and 0.266, respectively). The PTT, TT, and DD values were found to be augmented in HIV patients versus the control (p = 0.000). Conclusions: Thrombotic thrombocytopenic purpura-like events among HIV Sudanese patients were explored. In addition, antiphospholipid antibodies were strikingly seen in these patients. Additional research is anticipated to confirm these diagnoses. [ABSTRACT FROM AUTHOR]

There are many preanalytical variables affecting routine coagulation tests. Increased hematocrit (Htc) levels are one of these variables. However, no study has been conducted to determine the effect of low Htc values on coagulation tests. Therefore, in this study, we aimed to evaluate whether low Htc values affect coagulation tests besides high Htc values.

Introduction: coagulation tests are no value to determine the risk of perioperative bleeding. Material and methods: an observational descriptive cross-sectional study was carried out in 2,114 patients in the anesthesiology consultation of the University Hospital «Dr. Celestino Hernández Robau». Results: the clotting and bleeding time was performed in 100% of cases, the platels count in 93.99%. While the prothrombin time and activated partial tromboplastin time were performed in 66.27 and 55.62% respectively. Of 8,834 tests carried out, 49 were found to be altered for 0.55%. Patients with altered tests were for 1.56%, patients at risk of bleeding from coagulation tests were 30 for 1.42% and patients at risk with no history of bleeding detected by coagulation tests were three for 0.14%. Perioperative bleeding was reported in 16 patients for 0.76%, seven patients with positive questioning and normal tests and nine patients with negative questioning and normal tests. Conclusions: the patient’s medical history and physical examination are the best tools to predict the risk of surgical bleeding and isolated coagulation tests do not constitute a good predictor of perioperative bleeding. [ABSTRACT FROM AUTHOR]

Background and objective: A hyperinflammatory environment is thought to be the distinctive characteristic of COVID-19 infection and an important mediator of morbidity. This study aimed to determine the effect of other immunological parameter levels, especially ferritin, as a predictor of COVID-19 mortality via decision-trees analysis. Material and method: This is a retrospective study evaluating a total of 2568 patients who died (n = 232) and recovered (n = 2336) from COVID-19 in August and December 2021. Immunological laboratory data were compared between two groups that died and recovered from patients with COVID-19. In addition, decision trees from machine learning models were used to evaluate the performance of immunological parameters in the mortality of the COVID-19 disease. Results: Non-surviving from COVID-19 had 1.75 times higher ferritin, 10.7 times higher CRP, 2.4 times higher D-dimer, 1.14 times higher international-normalized-ratio (INR), 1.1 times higher Fibrinogen, 22.9 times higher procalcitonin, 3.35 times higher troponin, 2.77 mm/h times higher erythrocyte-sedimentation-rate (ESR), 1.13sec times longer prothrombin time (PT) when compared surviving patients. In addition, our interpretable decision tree, which was constructed with only the cut-off values of ferritin, INR, and D-dimer, correctly predicted 99.7% of surviving patients and 92.7% of non-surviving patients. Conclusions: This study perfectly predicted the mortality of COVID-19 with our interpretable decision tree constructed with INR and D-dimer, especially ferritin. For this reason, we think that it may be important to include ferritin, INR, and D-dimer parameters and their cut-off values in the scoring systems to be planned for COVID-19 mortality.

• Clear evidence-based interpretative comments on laboratory reports may be a great aid for physicians. • Two plasma samples with increased APTT were distributed throughout Europe for coagulation result interpretation. • ICs were evaluated in terms of classification, interpretation, advice, clarity, length and answer to clinical question. • Although most comments contained useful information, up to 36 % of misleading advice was given to physicians. • Several confusing and misleading comments highlights the need for recommendations on elaboration of interpretative comments. Providing evidence-based interpretative comments (IC) is an integral task of clinical laboratory professionals. It may be of special relevance for coagulation testing, where pathological first-line tests could trigger more specialized tests. Our aim was to evaluate the quality of ICs provided to the physician in two samples with activated partial thromboplastin time (APTT) prolongation. Two lyophilized plasma samples and their respective fictional clinical cases (case 1: heparin contamination and case 2: factor VIII deficiency) were sent to European laboratories for APTT and APTT mixing test measurement, and elaboration of ICs based on their results. The quality of ICs was evaluated in terms of analytical classification, laboratory interpretation, advice to physician, clarity, length and whether the clinical question was answered. A total of 214 laboratories were included. Classification of the analytical result was stated in 57 % of comments. Laboratory interpretation was found in 91 % of comments for case 1 and 83.3 % for case 2, among which 9.3 % and 6.5 % were considered wrong, respectively. Advice for the requesting physician was provided in 65.8 % of comments for case 1 and 61.2 % for case 2, among which 36 % and 4.7 % were considered wrong, respectively. More than 70 % of comments for both cases were evaluated as clear and of an adequate length. A significant number of laboratories provide clear interpretations and helpful advice for the management of altered coagulation results. Nevertheless, the finding of several confusing and misleading comments highlights the need for recommendations on elaboration of interpretative comments. [ABSTRACT FROM AUTHOR]

• Mixing tests are helpful for the work-up of unexpected APTT prolongations. • Two lyophilized plasma samples were distributed throughout Europe for APTT analysis. • Most laboratories obtained acceptable results for APTT and correctly performed mixing studies. • Only 15% of respondents selected the right cause of APTT prolongation for sample 1 (unfractionated heparin contamination), with 88% for sample 2 (factor VIII deficiency). • More training on coagulation testing is recommended to harmonize protocols and for ensure proper result classifications. Unexpected prolongation of first-line coagulation tests, including activated partial thromboplastin time (APTT), should trigger further work-up by performing mixing tests to elucidate the underlying cause, direct further specific testing and clarify their possible clinical impact. The aim of our study was to assess whether methodological diversity has any impact on the APTT mixing test results and their interpretation. Two lyophilized plasma samples (case 1: heparin contamination [0.5 IU/mL]; case 2: factor VIII deficiency [0.13 IU/mL]) and their respective fictional clinical cases were sent to European laboratories for APTT measurement and performance of mixing tests. Participants were surveyed about the methodology (reagents, analytical platform, reference ranges), APTT results, mixing test conditions, their classification (normal, equivocal, prolonged) and categorization of the sample (factor deficiency, presence of inhibitor, anticoagulant, unknown). A total of 269 responses were included. For case 1, all participants reported a prolonged APTT, and 91% obtained no correction in the mixing test, without differences among reagents or analytical platforms. Only 15% of them selected the presence of an anticoagulant as the single cause for the prolongation. For case 2, 99% of participants reported a prolonged APTT, while some heterogeneity in the mixing test results was found. Eighty-six percent of participants selected factor deficiency as the cause for APTT prolongation. Most European laboratories obtained valid results for APTT and the subsequent mixing tests, despite using different methodologies. However, their classification could be improved. Therefore, more training and periodic evaluations are recommended to harmonize protocols and ensure proper result classification and categorization. [ABSTRACT FROM AUTHOR]

Current guidelines recommend monitoring the anticoagulant effect of unfractionated heparin (UFH) by measuring anti-Xa activity rather than activated partial thromboplastin time (aPTT) in intensive care unit (ICU) patients. The primary objective of this study was to evaluate the correlation of aPTT, anti-Xa activity, and thrombin generation in UFH-treated ICU patients. A prospective observational pilot study was conducted in adult surgical ICU patients treated with UFH. aPTT and anti-Xa activity were monitored daily. The therapeutic target was aPTT between 50 s and 84 s, and/or anti-Xa between 0.3 and 0.7 U/mL. Correlation among aPTT, anti-Xa activity, and thrombin generation was determined by measuring endogenous thrombin potential (ETP), with the inflammatory response evaluated. C-reactive protein (CRP) was used as a marker of inflammatory response. The plasma of 107 samples from 30 ICU patients was analyzed. The correlation between aPTT and anti-Xa activity was 0.66, CI95% [0.54;0.76] (p < 0.0001). Although thrombin generation, aPTT, and anti-Xa were correlated with inflammatory responses, the correlation was higher with thrombin generation and anti-Xa activity compared to aPTT. When aPTT was in a therapeutic range, a low thrombin generation was observed but was 50% inhibited when anti-Xa was in a therapeutic range. Coagulation testing with aPTT, anti-Xa correlated with thrombin generation. A 50% decrease in thrombin generation was observed when anti-Xa was within a therapeutic range. Further work is needed to evaluate coagulation biomarker responses and clinical outcomes in specific ICU populations. [ABSTRACT FROM AUTHOR]

Accurate diagnosis of von Willebrand disease (VWD) depends on the quality, precision, and variability of the laboratory assays. The North American Specialized Coagulation Laboratory Association (NASCOLA) is a provider of external quality assessment (EQA) for approximately 60 specialized coagulation laboratories in North America. In this report, NASCOLA EQA data from 2010 to 2021 are reviewed for trends in methodology and precision among various assays. In particular, recent ASH ISTH NHF WFH (American Society of Hematology, International Society on Thrombosis and Haemostasis, National Hemophilia Foundation, and World Hemophilia Federation) guidelines for diagnosis of VWD are reviewed in light of EQA data. In contrast to other geographic regions, laboratories in North America predominantly use three-assay screening panels (antigen, platelet-binding activity, and factor VIII [FVIII] activity) rather than four-assay panels (antigen, platelet-binding activity, FVIII activity, and collagen-binding activity). They also use latex immunoassays rather than chemiluminescence immunoassays, and the classic ristocetin cofactor (VWF:RCo) assay and monoclonal antibody (VWF:Ab) assay to assess VWF platelet-binding activity over newer recommended assays (VWF:GPIbM and VWF:GPIbR). Factors that may be influencing these North American practice patterns include lack of Food and Drug Administration approval of the VWF:GPIbM, VWF:GPIbR, collagen binding assays, and chemiluminescence methodologies, and the influence of the 2008 National Heart, Lung, and Blood Institute guidelines on laboratory practice. Lastly, systems-based solutions are urgently needed to improve the overall accuracy of laboratory testing for VWD by minimizing preanalytical variables and adopting assay standardization. [ABSTRACT FROM AUTHOR]

Background: Rejected samples lead to prolonged turnaround time and delayed diagnosis and treatment of patients. This study was conducted to determine minimum acceptable sample volume in Sarstedt brand coagulation tubes to reduce high sample rejection rate., Methods: Blood samples were drawn from 20 participants (10 healthy volunteers and 10 patients receiving oral anticoagulant) into coagulation tubes. Six samples were taken from each participant, with tube fill volumes of 100%, 90%, 80%, 70%, 60%, and 50%. Prothrombin time (PT), active partial thromboplastin time (aPTT), and fibrinogen tests were analyzed., Results: According to quality performance specifications, the tube fill volume must be at least 70% for PT and aPTT and 50% for fibrinogen. There was no statistical difference in samples from healthy volunteers for PT, aPTT, and fibrinogen tests when the minimum tube fill volume was at least 80%, 90%, and 50%, respectively. These percentages were 50%, 70%, and 60%, respectively, in patients receiving oral anticoagulant., Conclusions: Sarstedt tubes meet quality standard specifications at a 70% fill rate for PT and aPTT and a 50% fill rate for fibrinogen. Comprehensive studies with larger populations are needed to accept these values as sample acceptance criteria for the laboratory., (© The Author(s) 2023. Published by Oxford University Press on behalf of American Society for Clinical Pathology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Introduction: Several automated coagulation analyzers are available for laboratory use. In a university hospital central laboratory, we compared four different instruments. The results for global coagulation assays are presented here. Methods: ACL TOP 750 CTS (Instrumentation Laboratory), Atellica COAG 360 (COAG 360), BCS XP (both Siemens Healthineers), and cobas t 711 (Roche Diagnostics) were compared. For inter‐instrument comparison, five basic coagulation parameters were analyzed in 476 patient plasma samples. Additional assessments included precision testing using commercial control samples and plasma pools, analysis time for a defined set of samples, sample capacity testing, minimum required sample volumes, and detection quality for hemolytic, icteric, or lipemic (HIL) interferences. Results: Good concordance between different instruments was evident from Bland–Altman plots and comparison of data from each instrument with the overall median (τ≥0.8). Shortest analysis times were found for BCS XP and COAG 360, COAG 360 revealed highest sample capacity. Observed required sample volumes were broadly in line with manufacturer specifications and varied according to instrument configurations. HIL detection differed between instruments and was best with ACL TOP 750 CTS. Conclusion: The four analyzers showed similarly high levels of concordance, although some variations were apparent. The most significant differences between the instruments were found in analysis times and sample capacity. Analyzer capabilities must be considered when selecting laboratory equipment and defining algorithms for clinical practice. [ABSTRACT FROM AUTHOR]

Abstract Background Determination of anticoagulant therapy is of pronounced interest in emergency situations. However, routine tests do not provide sufficient insight. This study was performed to investigate the impact of anticoagulants on the results of viscoelastometric assays using the ClotPro device. Methods This prospective, observational study was conducted in patients receiving dabigatran, factor Xa (FXa)-inhibitors, phenprocoumon, low molecular weight heparin (LMWH) or unfractionated heparin (UFH) (local ethics committee approval number: 17–525-4). Healthy volunteers served as controls. Viscoelastometric assays were performed, including the extrinsic test (EX-test), intrinsic test (IN-test) Russel’s viper venom test (RVV-test), ecarin test (ECA-test), and the tissue plasminogen activator test (TPA-test). Results 70 patients and 10 healthy volunteers were recruited. Clotting time in the EX-test (CTEX-test) was significantly prolonged versus controls by dabigatran, FXa inhibitors and phenprocoumon. CTIN-test was prolonged by dabigatran, FXa inhibitors and UFH. Dabigatran, FXa inhibitors and UFH significantly prolonged CTRVV-test in comparison with controls (median 200, 207 and 289 vs 63 s, respectively; all p

Background & Objectives: Coagulation test results in clinical laboratories are released after manual verification, which increases the laboratory turnaround time (TAT). The purpose of this study was to establish auto-verification rules for routine coagulation tests that can reduce the laboratory TAT as well as ensure the accuracy of results. Methods: Auto-verification rules were established for six routine coagulation tests, i.e., prothrombin time, activated partial thromboplastin time, thrombin time, fibrinogen (FIB), fibrin/fibrinogen degradation product, and D-Dimer. Data were collected from nine centers and the auto-verification rules were designed with reference to CLSI Auto 10A guidelines, which included quality control (QC) status check, consistency check (checking whether sample test assays match the medical order or if results are in correct numerical form), sample quality check, alarm check, critical value check, delta check, limit range check, and logical rules check. The auto-verification rules were then assessed based on passing rate, true-positive rate, true-negative rate, false-positive rate, and false-negative rate. The efficiency of the auto-verification rules was evaluated by TAT. Results: From January 2020 to March 2020, 22,072 coagulation results were collected from nine hospitals for establishing auto-verification rules. The preliminary evaluation of the rules was a simulation validation with data from the rule-generating group, and the passing rate was 69.5% with no false-negative cases. In phase I evaluation, a total of 32,743 results were randomly collected from four hospitals. The overall auto-verification rate was 66.7% (true-positive rate 100.0%; true-negative rate 82.5%; false-positive rate 17.6%; false-negative rate 0%). The phase II evaluation was based on validation of results of actual samples. Auto-verification rules were configured in a middleware (HemoHub) and 14,642 samples results were verified by the auto-verification rules. The overall passing rate was 69.5%. Auto-verification significantly decreased the mean laboratory TAT from 90.8 min to 71.8 min (P = 0.006). Conclusion: This study established auto-verification rules for routine coagulation tests based on Werfen coagulation instrument. Use of auto-verification rules significantly improved the laboratory TAT and workflow. This study provides insights and methods for establishing auto-verification rules.

Abstract Objective The value of pre-operative coagulation testing for adenotonsillar surgery is controversial. The purpose of this study was to evaluate the role of routine coagulation tests and a standardized questionnaire in children before tonsillectomy and/or adenoidectomy. Results A total of 143 children were prospectively enrolled in the study between 2013 and 2017, 81 males (56.6%) and 62 females (43.4%), age range 1 to 18 years (median age 5 years). Eighteen bleeding events were documented, three of them required treatment in the operating room. Abnormal coagulation tests were not associated with higher odds of bleeding after surgery. Higher risk of bleeding (p = 0.01) was associated with an abnormal standardized medical questionnaire.

Liver resection poses many challenges for the anesthesiologist, including intraoperative hemodynamic instability, postoperative pain, and risk of coagulopathy. We report a case of epidural hematoma after epidural catheter removal, following a minor liver single metastasectomy. The main purpose of this case report is to bring to light the false security provided by traditional coagulation parameters and whether further investigation should be considered in selected cases, before handling neuraxial catheters. Alterations in coagulation after a partial hepatectomy remain poorly understood; thus, we believe that additional hemostatic values such as viscoelastic testing might be considered to better assess these patients., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Pereira et al.)

Objectives: To determine the influence of prolonged exposure to radiation based on dosimeter readings on hematological parameters among radiologic technologists (RTs) in Saudi Arabia. Methods: The study was specifically conducted on selected RTs with experience of more than 10 years and the highest thermoluminescent dosimeter (TLD) readings among all RTs in the Radiological Department, Sabya General Hospital, Ministry of Health, Saudi Arabia from August to October 2020. The RTs group was compared with a control group of non-irradiated participants. Blood samples were collected for hematological and coagulation profile evaluation. Results: The acquired radiation dose analysis revealed that the average accumulated dose in 10 years is 7.6 mSv. The medians of prothrombin time (PT) and activated partial thromboplastin time (APTT) of the RTs group were significantly lower when compared to the control group. In addition, RTs group exhibited a significant reduction in neutrophil count and an elevation in lymphocyte count. Conclusion: Chronic exposure to radiation revealed a significant change in blood tests and may reflect an effect on RTs tissues, leading to serious health problems. However, further investigation in a large cohort to study the association between alteration in hematological parameters and chronic radiation exposure is required. [ABSTRACT FROM AUTHOR]

Background: Laparoscopic cholecystectomy, one of the most common elective surgical procedures, is a minimally invasive surgical procedure for patients with gallbladder diseases. Objectives: This study aimed to evaluate the effect of laparoscopic cholecystectomy on coagulation tests among patients undergoing the surgery in Ali Ibn Abi Taleb Hospital in Zahedan. Methods: Following a quasi-experimental design, 21 cases scheduled for laparoscopic cholecystectomy for whatever reasons at Ali Ibn Abi Taleb Hospital in Zahedan (Iran) were selected. To study the serum levels of blood factors, blood samples were collected at three stages, i.e., before the surgery (time point 1), 30 minutes after pumping the carbon dioxide gas into the abdomen (time point 2), and 30 minutes after removing the last port from the abdomen (time point 3). Data were analyzed using repeated measures. Results: According to the findings, laparoscopic cholecystectomy surgery only had a significant effect on the PT coagulation factor at the 99% confidence level. Also, PTwas increased and significantly differed at time points 2 (30 minutes after pumping) and 3 (30 minutes after removing the port) compared to time point 1 (30 minutes before the surgery). Conclusions: Generally, it can be argued that despite observing some variations in the PT coagulation factor during the laparoscopic surgery, the INR level did not change. Hence, it can be considered as a safe surgical intervention for renal and liver functions. [ABSTRACT FROM AUTHOR]

Current guidelines recommend monitoring the anticoagulant effect of unfractionated heparin (UFH) by measuring anti-Xa activity rather than activated partial thromboplastin time (aPTT) in intensive care unit (ICU) patients. The primary objective of this study was to evaluate the correlation of aPTT, anti-Xa activity, and thrombin generation in UFH-treated ICU patients. A prospective observational pilot study was conducted in adult surgical ICU patients treated with UFH. aPTT and anti-Xa activity were monitored daily. The therapeutic target was aPTT between 50 s and 84 s, and/or anti-Xa between 0.3 and 0.7 U/mL. Correlation among aPTT, anti-Xa activity, and thrombin generation was determined by measuring endogenous thrombin potential (ETP), with the inflammatory response evaluated. C-reactive protein (CRP) was used as a marker of inflammatory response. The plasma of 107 samples from 30 ICU patients was analyzed. The correlation between aPTT and anti-Xa activity was 0.66, CI95% [0.54;0.76] (p < 0.0001). Although thrombin generation, aPTT, and anti-Xa were correlated with inflammatory responses, the correlation was higher with thrombin generation and anti-Xa activity compared to aPTT. When aPTT was in a therapeutic range, a low thrombin generation was observed but was 50% inhibited when anti-Xa was in a therapeutic range. Coagulation testing with aPTT, anti-Xa correlated with thrombin generation. A 50% decrease in thrombin generation was observed when anti-Xa was within a therapeutic range. Further work is needed to evaluate coagulation biomarker responses and clinical outcomes in specific ICU populations.

Objective: To evaluate the prognostic value of routine coagulation tests for patients with heat stroke.Methods: This was a multi-center retrospective study. Patients who arrived at the hospital <24 h after the onset of Heat Stroke (HS) were included. The routine coagulation variables were detected within 24 h after the onset, including the lowest platelet count (PLC).Results: 60-day mortality rate was 20.9%. The median Prothrombin Time-International Normalized Ratio (PT-INR) of the non-surviving patients was significantly higher than that of the survivors (P < 0.01). The median Activated Partial Thromboplastin Time (APTT) in non-surviving patients was significantly higher than in the surviving patients (P < 0.01). A Cox regression analysis revealed that 60-day mortality was associated with PT-INR (P = 0.032) and APTT (P = 0.004). The optimal PT-INR point for predicting 60-day mortality rate was 1.7. The optimal APTT point for predicting 60-day mortality was 51.45. Patients with increased PT-INR (≥1.7) levels had, overall, a significantly reduced survival time (P < 0.01). Patients with elevated APTT (≥51.45) also had a decrease in survival time (P < 0.01). The prognostic scoring, with increased PT-INR (≥1.7) and prolonged APTT (≥51.45) at one point each, was also demonstrated to be useful in predicting 60-day mortality. Patients whose temperature fell to 38.9 °C within 30 min had significantly lower levels of PT-INR and APTT within 24 h than those who took longer to cool down.Conclusions: A prolonged APTT and elevated PT-INR within 24 h are independent prognostic factors of 60-day mortality in HS. [ABSTRACT FROM AUTHOR]

The assessment of hemostatic disorders in neonates is crucial, but remains challenging for clinicians. Although the concept of developmental hemostasis is widely accepted among hemostasis specialists globally, it is probably under-recognized by clinicians and laboratory practitioners. In parallel with age-dependent hemostatic status maturation, comprehension of the differences between normal values is crucial for the accurate diagnosis of potential hemorrhagic and thrombotic disorders of the vulnerable neonatal population. This review outlines the basics of developmental hemostasis and the features of the available coagulation testing methods, with a focus on novel tools for evaluating the neonatal hemostatic profile. Common errors, issues, and pitfalls during the assessment of neonatal hemostasis are discussed, along with their impact on patient management. Current knowledge gaps and research areas are addressed. Further studying to improve our understanding of developmental hemostasis and its reflection on everyday clinical practice is warranted. [ABSTRACT FROM AUTHOR]

Background: Determination of anticoagulant therapy is of pronounced interest in emergency situations. However, routine tests do not provide sufficient insight. This study was performed to investigate the impact of anticoagulants on the results of viscoelastometric assays using the ClotPro device. Methods: This prospective, observational study was conducted in patients receiving dabigatran, factor Xa (FXa)-inhibitors, phenprocoumon, low molecular weight heparin (LMWH) or unfractionated heparin (UFH) (local ethics committee approval number: 17–525-4). Healthy volunteers served as controls. Viscoelastometric assays were performed, including the extrinsic test (EX-test), intrinsic test (IN-test) Russel's viper venom test (RVV-test), ecarin test (ECA-test), and the tissue plasminogen activator test (TPA-test). Results: 70 patients and 10 healthy volunteers were recruited. Clotting time in the EX-test (CTEX-test) was significantly prolonged versus controls by dabigatran, FXa inhibitors and phenprocoumon. CTIN-test was prolonged by dabigatran, FXa inhibitors and UFH. Dabigatran, FXa inhibitors and UFH significantly prolonged CTRVV-test in comparison with controls (median 200, 207 and 289 vs 63 s, respectively; all p < 0.0005). Only dabigatran elicited a significant increase in CTECA-test compared to controls (median 307 vs 73 s; p < 0.0001). CTECA-test correlated strongly with dabigatran plasma concentration (measured by anti-IIa activity; r = 0.9970; p < 0.0001) and provided 100% sensitivity and 100% specificity for detecting dabigatran. Plasma concentrations (anti-XA activity) of FXa inhibitors correlated with CTRVV-test (r = 0.7998; p < 0.0001), and CTRVV-test provided 83% sensitivity and 64% specificity for detecting FXa inhibitors. Conclusions: In emergency situations, ClotPro viscoelastometric assessment of whole-blood samples may help towards determining the presence and type of anticoagulant class that a patient is taking. Trial registration: German clinical trials database ID: DRKS00015302. [ABSTRACT FROM AUTHOR]

Objectives: Preanalytical phase quality, which begins with a request for testing and continues with patient preparation, sample collection, transport, processing and storage, is essential for coagulation tests. The Turkish Biochemical Society Preanalytical Phase Working Group created a survey to evaluate the preanalytical phase practices for coagulation laboratories in our country. Methods: The survey consisted of a total of 26 questions and included almost all steps of the preanalytical phase. Results: Fifty-four laboratory specialists have participated in the study. The survey results showed that participants have different practices for most stages of the preanalytical phase for coagulation tests. Conclusion: According to the survey results, a national guideline may help standardisation of the preanalytical phase for coagulation tests in our country and increasing training in this respect would contribute to achieving accurate test results. [ABSTRACT FROM AUTHOR]

Objective: Coagulation tests are sensitive to pre-analytical variables. The aim of our study is to identify the effect of transportation and freeze-thaw status on for Factor VIII, Factor IX, Anti-thrombin III, Protein S, Protein C, Prothrombin time (PT) and Activated partial thromboplastin time (aPTT). Materials and methods: The study was performed on 102 plasma samples obtained from 34 healthy volunteers. The samples were divided into three groups. Group A was analyzed whereas group B, C were frozen at −20°C. After 24 h, group B and C were transported for 2 h. Following the transfer, group B was analyzed and C was frozen at −20°C. After 24 h, group C was analyzed. Analyses of samples were performed in Thrombolyzer-XRM for PT, aPTT, Factor VIII, Factor IX, Anti-thrombin III, Protein C and Protein S. Results: There were significant variations for PT, aPTT, Protein S, Factor VIII and Factor IX for group A&B and A&C comparisons in different stability criteria approaches. In significant change limit and percentage change calculations Protein S, Factor VIII and IX showed significant differences. For acceptable change limit approach, aPTT and Factor IX showed significant changes. Conclusion: Laboratories should take precautions for transportation and freeze-thaw cycles to prevent inaccurate results. [ABSTRACT FROM AUTHOR]

Abstract Background Coagulopathy is commonly observed after traumatic brain injury (TBI). However, it is not known whether using the standard independent predictors in conjunction with coagulation tests would improve their prognostic value. We determined the incidence of TBI-associated coagulopathy in patients with isolated TBI (iTBI), evaluated the prognostic value of coagulation tests for in-hospital mortality, and tested their predictive power for in-hospital mortality in patients with iTBI. Methods We conducted a retrospective, observational database study on 2319 consecutive patients with iTBI who attended the Huashan Hospital Department of the Neurosurgery Neurotrauma Center at Fudan University in China between December 2004 and June 2015. Two models based on the admission characteristics were developed: model A included predictors such as age, Glasgow Coma Scale (GCS) score, pupil reactivity, type of injury, and hemoglobin and glucose levels, while model B included the predictors from model A as well as coagulation test results. A total of 1643 patients enrolled between December 2004 and December 2011 were used to derive the prognostic models, and 676 patients enrolled between January 2012 and June 2015 were used to validate the models. Results Overall, 18.6% (n = 432) of the patients developed coagulopathy after iTBI. The prevalence of acute traumatic coagulopathy is associated with the severity of brain injury. The percentage of platelet count 1.25, the prothrombin time (PT) > 14 s, activated partial thromboplastin time (APTT) > 36 s, D-dimer >5 mg/L and fibrinogen (FIB) 1.25, and APTT >36 s exhibited strong prognostic effects in model B. Discrimination and calibration were good for the development group in both prediction models. However, the external validation test showed that calibration was better in model B than in model A for patients from the validation population (Hosmer–Lemeshow test, p = 0.152 vs. p = 0.046, respectively). Conclusions Coagulation tests can improve the predictive power of the standard model for in-hospital mortality after TBI.

Background: It is well known that low platelet count on admission to intensive care units (ICU) is associated with increased mortality. However, it is unknown whether prothrombin time (PT-INR) and activated partial thromboplastin time (APTT) on admission correlate with mortality and organ failure. Therefore, the aim of this study was to investigate whether PT-INR and APTT at admission can predict outcome in the critically ill patient after adjusting for severity of illness measured with Simplified Acute Physiology Score 3 (SAPS 3).Materials and Methods: Data were retrospectively collected. APTT and PT-INR taken on admission and SAPS 3 score were independent variables in all regression analyses. Survival analysis was done with Cox regression. Organ failure was reported as days alive and free (DAF) of vasopressors and invasive ventilation, need of continuous renal replacement therapy (CRRT) and Acute Kidney Injury Network creatinine score (AKIN-crea).Results: A total of 3585 ICU patients were included. Prolonged APTT correlated with mortality with 95% confidence interval (CI) of hazard ratio 1.001-1.010. Prolonged APTT also correlated with DAF vasopressor, CRRT and AKIN-crea with 95% CI of odds ratio (OR) 1.009-1.034, 1.016-1.037 and 1.009-1.028, respectively. Increased PT-INR correlated with DAF vasopressor and DAF ventilator with 95% CI of OR 1.112-2.014 and 1.135-1.847, respectively.Conclusions: Activated partial thromboplastin time prolongation was associated with mortality and all morbidity outcomes except the DAF ventilator. PT-INR increase at admission was associated with DAF vasopressor and DAF ventilator. APTT and PT-INR at admission correlate with morbidity, which is not accounted for in the SAPS 3 model. [ABSTRACT FROM AUTHOR]

Hemostasis is stopping bleeding in a controlled manner whereas coagulation is a series criterion and to diagnose disorders caused by coagulation in an early period is to determine the coagulation time. These phases are controlled with various tests. In this study, the aim is to determine some coagulation parameters in Sivas Kangal dogs by taking the age and sex into consideration. Coagulation is vitally important in many physiological and pathological cases. The most important tests, complete blood count with peripheral blood smear, prothrombin time (PT), activated partial thromboplastin time (aPTT), and D-dimer fibrin degradation product assay were applied to all subjects, respectively. It was found that thrombocyte counts in Sivas Kangal dogs were affected by the age factor in automatic and manual counting, whereas they were not affected by sex. In the same way, while PT times showed a meaningful change among groups depending on age, aPTT times were not affected by sex or age. The D-dimer assay results, which show the existence of fibrin degradation product, change depending on age and sex. [ABSTRACT FROM AUTHOR]

Changes in the coagulation profile in children with liver disease and extrahepatic portal vein obstruction or shunt result in both bleeding and thrombosis. Routine coagulation tests do not accurately predict bleeding risk, as they are not sensitive to changes in anticoagulant factors. The thrombin generation assay could be suitable for describing the overall balance of coagulation in children with liver disease. This study aims to characterise the mechanism of thrombin generation in this population, focusing on prothrombin conversion and thrombin inhibition. Patients were categorised as: severe (paediatric end stage liver disease score > 15) and mild disease, or portal vein obstruction or shunt. Age and gender matched healthy controls were used. The thrombin generation assay was performed in plasma samples from patients and controls with and without exogenous thrombomodulin and the results were further analysed with the computational thrombin dynamics method. A total of 42 patients (severe, n = 5; mild, n = 29, obstruction/shunt, n = 8) and 20 controls were included in this study. The total prothrombin conversion, thrombin-antithrombin formation and the thrombin decay capacity, in the presence and absence of thrombomodulin were reduced in children with severe liver disease. The rate of prothrombin conversion was increased and thrombin decay capacity was decreased in patients with portal vein obstruction or shunt compared to controls. This study demonstrates changes in the mechanism in thrombin generation seen in severe chronic liver disease. The changes vary in parenchymal versus non parenchymal liver disease and further study assessing the clinical significance of these variations in mechanism is required. • The thrombin generation assay represents an alternative to traditional coagulation tests in paediatric chronic liver disease. • Children with liver disease have a reduction in both the rate of prothrombin conversion and thrombin decay capacity. • In extrahepatic portal vein obstruction or shunt the balance of haemostatic changes tend towards a pro-thrombotic state. [ABSTRACT FROM AUTHOR]

Objective: The value of pre-operative coagulation testing for adenotonsillar surgery is controversial. The purpose of this study was to evaluate the role of routine coagulation tests and a standardized questionnaire in children before tonsillectomy and/or adenoidectomy. Results: A total of 143 children were prospectively enrolled in the study between 2013 and 2017, 81 males (56.6%) and 62 females (43.4%), age range 1 to 18 years (median age 5 years). Eighteen bleeding events were documented, three of them required treatment in the operating room. Abnormal coagulation tests were not associated with higher odds of bleeding after surgery. Higher risk of bleeding (p = 0.01) was associated with an abnormal standardized medical questionnaire. [ABSTRACT FROM AUTHOR]

Depending on test assays and the time of last DOAC intake, direct thrombin inhibitors (DTI) and direct FXa inhibitors (DXI) may or may not affect prothrombin time (PT), international normalized ratio (INR) or activated thromboplastin time (aPTT) but the clinical impact is unknown. Using data from the Dresden NOAC Registry, we evaluated the impact of DOAC on first PT, INR or aPTT tests during emergency hospitalizations of DTI/DXI patients and the assay performance across 50 coagulation laboratories. In 724 emergency admissions (77 DTI; 647 DXI), 490 cases (67.7%) had a reported last DOAC intake within 12 h before blood sampling. INR and PT were elevated above the upper limit of normal (ULN) in >65% of all cases and aPTT was elevated in 45%. On the other hand, >30% of all cases had normal values of INR, PR and aPTT despite a DOAC intake within the last 12 h. Assay performance for detecting or ruling out therapeutic DOAC levels was highly variable and, overall, insufficient to guide clinical decisions. DOAC specific testing was performed in <10% of all cases. Many DOAC recipients present with elevated PT, INR or aPTT during emergency admissions but false negative values within 12 h of last intake as well as elevated values beyond 24 h after last DOAC intake are common. Both scenarios may result in clinical misinterpretation and, potentially, in patient harm, also because DOAC specific testing is rarely performed in emergency settings. • The effect of DOAC on prothrombin time or activated thromboplastin time is variable. • In 724 emergency admissions, PT or aPTT poorly indicated DOAC intake <12 h. • PT and aPTT assay performance was very variable across 50 coagulation laboratories. • DOAC specific testing was performed in <10% of all cases. [ABSTRACT FROM AUTHOR]

Background: Correct handling and storage of blood samples for coagulation tests are important to assure correct diagnosis and monitoring. The aim of this study was to assess the pre-analytical practices for routine coagulation testing in European laboratories. Methods: In 2013–2014, European laboratories were invited to fill in a questionnaire addressing pre-analytical requirements regarding tube fill volume, citrate concentration, sample stability, centrifugation and storage conditions for routine coagulation testing (activated partial thromboplastin time [APTT], prothrombin time in seconds [PT-sec] and as international normalised ratio [PT-INR] and fibrinogen). Results: A total of 662 laboratories from 28 different countries responded. The recommended 3.2% (105–109 mmol/L) citrate tubes are used by 74% of the laboratories. Tube fill volumes ≥90% were required by 73%–76% of the laboratories, depending upon the coagulation test and tube size. The variation in centrifugation force and duration was large (median 2500 g [10- and 90-percentiles 1500 and 4000] and 10 min [5 and 15], respectively). Large variations were also seen in the accepted storage time for different tests and sample materials, for example, for citrated blood at room temperature the accepted storage time ranged from 0.5–72 h and 0.5–189 h for PT-INR and fibrinogen, respectively. If the storage time or the tube fill requirements are not fulfilled, 72% and 84% of the respondents, respectively, would reject the samples. Conclusions: There was a large variation in pre-analytical practices for routine coagulation testing in European laboratories, especially for centrifugation conditions and storage time requirements. [ABSTRACT FROM AUTHOR]

The patients infected with SARS-CoV-2 have a prothrombotic state. The incidence of thromboembolic complications in patients with severe disease is much higher than in those with non-severe disease. Coagulation parameters, D-dimers, fibrinogen and platelet count are important for the identification and intervention of thromboinflammation, as early as possible. Lowmolecular-weight heparin and unfractionated heparin are the anticoagulants of choice in the prevention of thrombotic complications. [ABSTRACT FROM AUTHOR]

Both thrombelastography (TEG) and rotational thromboelastometry (ROTEM) have been investigated for diagnosis of coagulopathy and guidance of resuscitation in trauma and surgery. Given similarities between the two systems, it is important to determine whether one is superior to the other and how comparable they are to conventional coagulation tests (CCTs). Therefore, we conducted a comparative study of functional fibrinogen and coagulation assays using TEG and ROTEM and CCTs to determine their capability to monitor coagulation profiles, diagnose coagulopathy and predict blood transfusion requirements in trauma patients. Blood samples were collected from 45 patients at admission and during 48-h hospitalization as part of a randomized control trial on early fibrinogen replacement in trauma. Functional fibrinogen (FF) TEG, ROTEM FIBTEM and EXTEM, and CCTs were performed and compared. We found significant differences between the placebo and fibrinogen groups over hospitalization time in FF TEG MA, ROTEM CT, MCF and LI30. FF TEG MA and ROTEM FIBTEM MCF mirrored plasma fibrinogen profiles, reached a maximum difference between the two groups 1–3 h after fibrinogen administration. In comparison, CCTs detected minimal hemostatic changes by fibrinogen treatment. TEG and ROTEM showed various degrees of correlations with CCTs. TEG MA and ROTEM MCF provided better predictions for plasma and RBC transfusions than CCTs, but poor accuracy for cryoprecipitate transfusion. Both TEG and ROTEM well predicted hypofibrinogenemia (fibrinogen concentration < 1 g/L), but poorly detected coagulopathy (INR ≥ 1.2). TEG and ROTEM detected increases in clot strength following early use of fibrinogen. ROTEM also detected changes in coagulation time and clot lysis. Both were better than CCTs for monitoring coagulation profiles and predicting transfusion requirements. • TEG and ROTEM play an important role in monitoring and guiding transfusion decisions in trauma. • TEG and ROTEM fibrinogen assays were compared with conventional coagulation tests (CCTs) in trauma patients. • TEG and ROTEM were superior to INR and PTT to detect the effects of fibrinogen replacement on hemostasis. • ROTEM FIBTEM detected more changes in parameters than functional fibrinogen TEG. • TEG and ROTEM fibrinogen assays provided better predictions for RBC and plasma transfusions than CCTs. [ABSTRACT FROM AUTHOR]

Objective: Free flap surgeries constitute the basis of reconstruction surgery in patients with major defects. Prediction of complications that cause flap loss in such patients is important in terms of reducing the length of hospital stay and expenses. We aimed to retrospectively investigate the effect of co-morbidities and the coagulation status on flap loss and complications in patients with reconstructed free flap. Methods: Demographic data, smoking, alcohol habits, co-morbidities, coagulation tests and thromboelastogram results from preoperative, intraoperative and postoperative anaesthesia and surgical records of patients undergoing free flap surgeries between January 2015 and June 2017 were retrospectively screened. Results: Flap success rate was found to be 96.1% in total 77 patients with free flap. Coagulation related complication rate, such as thrombosis, haematoma and partial necrosis, were 22.1%. There was a significant relationship between age, chronic obstructive pulmonary disease and hypercholesterolaemia and flap loss (p=0.006, p=0.025 ve p=0.025, respectively). Flap complications were more frequent in patients with chronic obstructive pulmonary disease and hypertension. Laboratory test results revealed no statistical correlation between flap complications and flap loss with preoperative and postoperative TEG. Conclusion: Advanced age, co-morbidities such as hypertension and chronic obstructive pulmonary disease are associated with complications and flap loss in free flap surgery. However, there were no clinically significant association of complications and flap loss with laboratory tests showing coagulation. We believe that standardised protocols should be established in terms of preparation, intraoperative management and postoperative follow-ups because the time between taking the coagulation tests and postoperative anticoagulant administration should be standardised in such surgeries. [ABSTRACT FROM AUTHOR]

Dabigatran is an oral anticoagulant used for atrial fibrillation and venous thromboembolism. While an effective antibody reversal agent is available, its cost precludes routine use and the mainstay of preoperative management is timely dabigatran interruption. Unlike warfarin, there are no universally accepted protocols for interruption of dabigatran in the preoperative period and there is uncertainty around the interpretation of standard coagulation tests in the presence of dabigatran. We performed a prospective, observational pilot study in patients presenting for elective surgery to examine: 1) the preoperative plasma dabigatran concentrations on day of surgery associated with the local dabigatran interruption protocol, 2) the potential utility of dabigatran concentrations on day of surgery, and 3) the utility of standard coagulation tests in determining whether dabigatran concentrations were below a 'safe' threshold for surgery. We recruited patients presenting to pre-admission clinics for elective surgery. Dabigatran concentrations below 30 µg/L were considered adequate for proceeding with surgery. Data were obtained and analysed from 21 patients with a median (range) age of 70 (20-86) years. Median (range) dabigatran concentrations on the day of surgery were 5 (0-59) µg/L. Two patients had day of surgery concentrations exceeding 30 µg/L. Of the standard coagulation tests examined, only the thrombin clotting time (TCT) was abnormal for these two patients. Our interruption protocol was associated with safe dabigatran concentrations in most patients on the day of surgery. A minority of patients had dabigatran concentrations above the safe threshold, which were detectable by abnormal TCT results. [ABSTRACT FROM AUTHOR]

Clot waveforms are generated by coagulation analyzers, such as the ACL-TOP, that utilize photo-optical turbidimetric methods to measure prothrombin time (PT) and activated partial thromboplastin time (aPTT), which are standard clotting tests (SCTs). Additional quantitative clot waveform analysis (CWA) parameters include maximum velocity of the PT curve (PT1d), maximum acceleration of the aPTT curve (aPTT2d), and their change in optical density (ODdelta). We explored the potential for CWA to contribute unique information compared to SCTs and quantitative fibrinogen assay (QFA) in dogs with clinical indications for laboratory evaluation of coagulation. We retrospectively evaluated the frequency and agreement between normal, high, and low values of CWA and SCTs for 203 dogs relative to reference intervals (RIs). Most dogs had SCTs within RIs, but most CWA values were high regardless of whether SCT values were within, below, or above the RI. Agreement between SCTs and CWA was slight (kappa <30%). Clinically significant bleeding was noted in 28 of 203 (14%) dogs. SCTs were not different between bleeders and non-bleeders. Median QFA, PT1d, aPTTdelta, and aPTT2d values were statistically significantly higher than RIs in non-bleeders compared to bleeders, whose median values were not below RI. Compared with SCTs, CWA identified differences between the 2 groups. However, wide overlap between the 2 groups limits the use of CWA to clinically discriminate between bleeders and non-bleeders in a heterogeneous population of dogs. Further studies on the diagnostic utility of CWA in coagulopathic dogs are needed. [ABSTRACT FROM AUTHOR]

Objectives: To determine the agreement, sensitivity, specificity and accuracy of prothrombin (PT) and activated partial thromboplastin time (aPTT) using the point‐of‐care analyser SCA2000™ with IDEXX Coag Dx™ cartridges against a reference laboratory (STAGO Start 4®) in canine blood. Methods: Citrated blood samples from 47 dogs were submitted for PT and aPTT measurements. The STAGO was taken as the gold standard and sensitivity, specificity and accuracy were calculated. Agreement between the IDEXX and STAGO test results was compared using Bland‐Altman analysis and Passing‐Bablok regression. Results: The IDEXX cartridges had a sensitivity of 92% (95% confidence interval (CI) 62–100%) and specificity of 98% (95% CI 87–100%; n = 54 samples). aPTT sensitivity was 100% (95% CI 63–100%) and specificity was 47% (95% CI 30–65%, n = 42 samples). The accuracy of IDEXX cartridges compared with the STAGO Start 4 was 96% (95% CI 91–100%) for PT and 57% (95% CI 42–72%) for aPTT. Agreement was moderate–good for PT measurements within the reference range (RR). Agreement was poor for PT measurements outside of the RR and for aPTT measurements within and outside the RR. The bias between measurements from the two machines was inconsistent. Conclusions: PT results from the point‐of‐care IDEXX were generally reliable for diagnosing or excluding a coagulopathy. The aPTT IDEXX sensitivity was excellent but the specificity was poor. Bland‐Altman analysis and Passing‐Bablok regression indicated an inconsistent bias between the two measurements and one measurement cannot be reliably converted to the other. [ABSTRACT FROM AUTHOR]

The Choosing Wisely campaign has stimulated clinicians to think about the appropriateness of various tests and procedures, compelling physicians to make smarter, safer and more effective choices for high quality patient care and to reduce healthcare cost. The American Society for Apheresis (ASFA) strives to advance apheresis medicine through education, evidence‐based practice, research and advocacy. To complement these shared missions, ASFA created a working group, consisting of representatives from the various ASFA committees, to produce recommendations for apheresis medicine that reflect the Choosing Wisely guiding principles. A diverse group of ASFA physician and allied health members reviewed, rated and ranked 9 original draft proposals. Additional revisions and refinements were made prior to external review and adoption of five final recommendations by the ASFA Board of Directors. The ASFA Choosing Wisely recommendations encourage apheresis practitioners, patients and donors to discuss and prioritize best clinical practices that avoid harm and waste while optimizing clinical benefit. [ABSTRACT FROM AUTHOR]

Background: In 2-4% of all patients requiring adenoidectomy, tonsillectomy or adenotonsillectomy, pre-operative screening tests for coagulation disorders are indicated to detect surgical bleeding complications. However, because of cost effect on the patients, the usefulness of these tests is being challenged. We therefore highlight our experience in paediatric patients undergoing adenoidectomy, tonsillectomy or both in our centre. Patients and Methods: This is a 3½-year analysis of the data of 165 paediatric patients who had adenoidectomy, tonsillectomy or both over the study period. The data collected included age, sex, procedure done and detailed clinical bleeding history. Results: A total of 165 children had either adenoidectomy or tonsillectomy, or both. There were 76 males and 89 females giving a male to female ratio of 1:1.2. Their ages ranged from 10 months to 18 years. Eighty-five (51.5%) patients had adenotonsillectomy, 48 (29.1%) and 32 (19.4%) had only tonsillectomies and adenoidectomies, respectively. Only 11 (6.7%) families volunteered the history of either prolonged bleeding with minor injury on the skin or occasional slight nose bleeding. Six (3.6%) patients including 3 of the children with positive family history had posttonsillectomy bleed, out of which 4 (66.7%) were moderate whereas the remaining 2 (33.3%) were severe bleeding, which was not statistically significant (P = 0.041). The two cases of severe bleeding had fresh whole blood transfused whereas the rest that had no bleeding issues were discharged home 48 h postoperatively. Conclusion: Our experience in this study suggests that detailed bleeding history is necessary as well as pre-operative haemostatic assessment, if available and affordable for paediatric patients undergoing adenotonsillectomy.

Introduction: Inadvertent inappropriate coagulation tests results are reported frequently inspite of using automated instruments and quality assurance measures, mostly due to pre analytical errors associated with sample collection and processing. Aim: This study was undertaken to evaluate pre-analytical variables in coagulation tests by inducing variables through simple experiments. The study also aimed to evolve rejection/ sample acceptability criteria for coagulation tests to minimise rejection of sample at the level of pre analytical phase. Materials and Methods: This cross sectional and observational study was carried out in the Pathology department of a tertiary care hospital from January 2014 to December 2014. Results obtained from reported blood samples with normal Prothrombin Time (PT) and Activated Partial Thromboplastin Time (APTT) values were used to induce processing variables. Coagulation tests results were collected by running samples in ideal conditions. Same samples were rerun with introducing variation in parameters and coagulation test measurements were taken. Differences between first and second coagulation measurements were noted and compared by applying t-test using IBM SPSS software version 25. For observational study, data were based on results of samples received and rejected in Clinical Pathology laboratory. Results: PT value was not significantly affected by haemolysis unlike aPTT which was altered due to haemolysis. By altering ratio of blood and anticoagulant, PT results were affected significantly when citrate concentration was increased by 0.4ml and aPTT results were affected more significantly when citrate concentration was increased by 0.1 ml. Centrifugation of samples for 10 minute at 1500xg or 3000xg did not alter the tests’ results significantly. PT values were not significantly affected upto 24 hours at room temperature. But aPTT values were significantly affected when sample was stored for more than 12 hours even on freezing temperature. In observational study, the major reason for rejection in the pre-analytical phase was clotted samples, followed by samples rejected due to underfilling. Conclusion: Samples should be properly identified and labeled. PT of haemolyzed samples giving results in normal range can be reported. A 67% of the optimum filled volume for PT and 86% for aPTT should be acceptable. A 10 minute centrifuge time at 1500xg might be suitable. Samples can be run for PT within 24 hours at room temperature and 48 hours in freezing condition and for aPTT within 12 hours.