Fluorination of PVC medical devices to prevent plasticizers migration.

Medical devices (MD) are often made of plasticized polyvinylchloride (PVC). However, plasticizers may leach out into infused solutions and expose the patients to a toxic risk. The aim of the present work is to fluorinate plasticized PVC tubular MDs to create a barrier layer on their internal surface, and to study the impact of such a chemical treatment on the migration of the plasticizers. Following fluorination by pure molecular fluorine, the physico-chemical characterization of these modified MDs was carried out using various spectroscopic and microscopic techniques or tensile tests, evidencing the formation of covalent C-F bonds on the surface of the treated samples without modification of their mechanical and optical properties. The migration of plasticizers from fluorinated MDs was assessed using gas chromatography coupled with mass spectrometry and was found considerably decreased in comparison with the pristine MDs. After 24 h, the amount of tri-octyltrimellitate plasticizer (TOTM) detected in migrates from fluorinated MDs was even lower than the limit of quantification. Complementary cytotoxicity assays were performed according to the ISO EN 10993-5 standard, showing that the new fluorinated material does not cause a cytotoxic effect on L929 cells.

Effect of tube filling on plasma freezing for coagulation testing.

Background: Storage of frozen plasma samples for hemostasis testing is a key step to obtain reliable results. Variables that can affect the quality of plasma during storage include the cryotube type and volume and the tube filling level that conditions the residual air volume. To date, there are only few data on which to base recommendations. Objectives: The aim of this study was to investigate the influence of the tube filling volume (20%, 40%, and 80%) of 2-mL microtubes on frozen plasma for a large panel of hemostasis assays. Methods: For this study, 85 subjects were included, and blood samples were collected from them by venipuncture. After double centrifugation, each sample was aliquoted in 3 2-mL microtubes with different volumes (0.4, 0.8, and 1.6 mL) and stored at -80 °C. At the end of the frozen storage period (3 months ± 1 week), all aliquots from the sample were tested in the same analytical series for a large panel of hemostasis analyses. Results: Compared with completely filled microtubes (1.6/2 mL), storing frozen plasma in smaller volumes (0.4/2 mL) significantly decreased prothrombin time and activated partial thromboplastin time. Conversely, factor II, V, VII, and X levels were increased. Antithrombin, Russell's viper venom time, and anti-Xa activity in patients treated with heparin were also increased. Conclusion: To store plasma at -80 °C for hemostasis analysis, samples should be frozen in small-volume microtubes (<2 mL) with screw caps that are filled to 80% of their volume.

Hypercoagulability in critically ill patients with COVID 19, an observational prospective study.

OBJECTIVE: COVID 19 is often associated with hypercoagulability and thromboembolic (TE) events. The aim of this study was to assess the characteristics of hypercoagulability and its relationship with new-onset TE events and the composite outcome of need for intubation and/or death in intensive care unit (ICU) patients admitted for COVID. DESIGN: Prospective observational study. SETTING: Monocentric, intensive care, University Hospital of Clermont Ferrand, France. PATIENTS: Patients admitted to intensive care from January 2020 to May 2021 for COVID-19 pneumonia. INTERVENTIONS: Standard hemostatic tests and rotational thromboelastometry (ROTEM) were performed on admission and on day 4. Hypercoagulability was defined by at least one of the following criteria: D-dimers > 3000 µg/dL, fibrinogen > 8 g/L, EXTEM CFT below the normal range, EXTEM A5, MCF, Li 60 above the normal range, and EXTEM G-score ((5000 x MCF) / (100-MCF)) ≥ 11 dyne/cm2. MEASUREMENTS AND MAIN RESULTS: Of the 133 patients included, 17 (12.7%) developed new-onset TE events, and 59 (44.3%) required intubation and/or died in the ICU. ROTEM was performed in 133 patients on day 1 and in 67 on day 4. Hypercoagulability was present on day 1 in 115 (86.4%) patients. None of the hypercoagulability indices were associated with subsequent new-onset TE events on days 1 and 4 nor with the need for intubation and/or ICU death. Hyperfibrinogenemia > 8g/dL, higher D-dimers and higher EXTEM Li 60 on day 4 were predictive of need for intubation and/or of ICU death. CONCLUSIONS: Our study confirmed that most COVID-19 ICU patients have hypercoagulability on admission and almost all on day 4. Hyperfibrinogenemia or fibrinolysis shutdown on day 4 were associated with unfavorable outcome.

Prediction of Iron Deficiency Anemia in Third Trimester of Pregnancy Based on Data in the First Trimester: A Prospective Cohort Study in a High-Income Country.

Background: Systematic iron supplementation may be harmful in pregnant women with non-depleted iron. Our objectives were to estimate the prevalence of anemia at the third trimester of pregnancy (T3) and to identify the parameters at the first trimester (T1), which best predict anemia at T3. Methods: This prospective cohort study in France included pregnant women at T1 without non-iron deficiency anemia. Clinical and social characteristics, health-related quality of life, blood count, and a frozen blood sample were collected at T1 and/or T3. Secondly, a matched nested case−control study was built for women with anemia at T3 but not at T1. Multivariate analyses and ROC curves were used to identify the best predictive parameter(s) of anemia at T3. Results: The prevalence of anemia at T3 in the cohort (629 women) was 21.9% (95% CI 18.7−25.2%). In the matched nested case−control study (256 women), hemoglobin (Hb), serum ferritin (SF) and the SF/soluble transferrin receptor ratio at T1 were predictive of anemia at T3 (p < 0.001); however, clinical and social characteristics, as serum hepcidin were not. In multivariate analyses, Hb at T1 was the best predictive biomarker of anemia at T3 with a cut-off value of 120 g/L (specificity 87.5%). Conclusions: The prevalence of anemia at the end of pregnancy remained high in a High-Income Country. Clinical, social, and biochemical parameters did not seem useful to predict anemia at T3 and could not guide iron supplementation. We suggest systematically performing a simple blood count in the first trimester of pregnancy and offering oral iron supplementation for women with Hb < 120 g/L.

Stability of coagulation parameters in plasma samples at room temperature after one freeze/thaw cycle.

INTRODUCTION: Sample freezing is a part of routine laboratory tasks because some coagulation parameters are analysed in batches to optimize reagent consumption. The coagulation parameter stability in fresh and frozen samples has been described, but data are scarcer after thawing. This study objective was to determine the stability of the main coagulation parameters (from blood withdrawn on siliconized CTAD tubes and double-centrifuged) after one freeze/thaw cycle to generate procedures for appropriate handling, storage and testing. METHODS: Prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, D-dimers, clotting factors (F), protein C, protein S, antithrombin, lupus anticoagulant (LA)-sensitive aPTT and diluted-Russel's viper venom time (dRVVT) were assessed in 60 plasma samples (n=30, normal range and n=30, outside the normal range). Thirty samples from anticoagulated patients [unfractionated heparin (UFH), low-molecular weight heparin (LMWH), apixaban or rivaroxaban] were assessed using specific anticoagulant assays. Frozen samples were thawed, and assays were performed at 15 min, 2, 4 and 6 h after thawing. The coagulation parameter stability was assessed with the method of rejection limit. RESULTS: After thawing, aPTT, PT, fibrinogen, D-dimers, FII, FV, FX, FIX, FXI, FXII, PC and UFH anti-Xa activity remained stable for at least 6 h, FVII for 5 h, PS, AT, dRVVT screen assay and LMWH anti-Xa activity for 4 h, and LA-sensitive aPTT and apixaban-specific anti-Xa activity for 3 h. FVIII, dRVVT confirm assay and rivaroxaban specific anti-Xa activity were stable for 2 h. CONCLUSION: These results suggest that sample stability for some haemostasis assays is limited after thawing.

[Study of thrombin generation in healthy children]. / Étude de la génération de thrombine dans une population pédiatrique.

Exploring coagulation in newborns and children is a challenge due to the low levels of both procoagulant factors and inhibitors. Conventional coagulation tests might be inadequate to explore all of these changes. The aim of the study is to evaluate the thrombin generation assay, a global test to explore coagulation, in a pediatric population (n=586) compared to an adult population (n=166). The thrombin generation assays were performed using Calibrated Automated Thrombography with two different tissue factor concentrations (1 and 5 pM), with and without thrombomodulin (TM). In the absence of TM, the endogenous thrombin potential (ETP) is significantly lower in the pediatric population, reflecting the decrease in procoagulant factors. In the presence of TM, ETP values in pediatric subjects are within the reference range of adult values. The thrombin generation assay demonstrates that coagulation balance is maintained in the pediatric population.

[Evaluation of the coagulometer STA R Max® (Stago) for routine coagulation parameters]. / Évaluation des performances de l'automate STA R Max® (Stago) pour les paramètres d'hémostase de routine.

The STA R Max® is a fully automated multiparameter coagulometer using clotting (viscosity-based detection system), chromogenic and immunologic assays. STA R Max® is equipped with an innovative software (STA Coag Expert®) designed to assist laboratory in accreditation. The aim of this study was to evaluate its performances for the certification according to ISO 15189 quality standard in the haemostasis unit of our university hospital. The following tests were evaluated: prothrombin time (PT), activated partial thromboplastin time (aPTT), kaolin cephalin clotting time (KCCT), fibrinogen, anti-Xa assay and D-dimers. In normal and pathological range, the intra-assay coefficients of variation (CV) for PT, aPTT, KCCT and fibrinogen were below 4.0%. Intra-assay CV was of 4.0% for the anti-Xa assay and intra-assay CV was of 7.9% for D-dimers. Inter-assay CV were below 5.0% for PT, aPPT, KCCT and fibrinogen, 14.9% for anti-Xa assay and 8.6% for D-dimers. The interlaboratory comparisons were below 8.7% for PT, aPPT and KCCT, 5.0% for fibrinogen and 15.5% for anti-Xa assay. All results were acceptable according to suitable CV established by GFHT and the provider. The concordance between all coagulometers was excellent, with correlation coefficient close to 1 (0.99 for all parameters except for aPPT which was 0.98) calculated thanks to an intra-class correlation study. In conclusion, the STA R Max® analyser is suitable for haemostasis laboratories and facilitates certification of a laboratory.

Contribution to diagnosis and treatment of bone marrow aspirate results in critically ill patients undergoing bone marrow aspiration: a retrospective study of 193 consecutive patients.

BACKGROUND: The purpose of the work was to assess the contribution to diagnosis and/or treatment (CDT) of bone marrow aspiration (BMA) in the critically ill patient. METHODS: The retrospective study included 193 patients. On the basis of BMA findings, contribution to diagnosis was defined by one of four previously unestablished diagnoses (maturation arrest of granulocyte precursors, hemophagocytic lymphohistiocytosis, hematological malignancy, marrow infiltration with cancer cells) and to treatment as the initiation or withdrawal of a specific treatment including the decision to forgo life-sustaining treatment (DFLST). RESULTS: A CDT of BMA was observed in 40/193 patients (20.7%). BMA contributed to diagnosis in 37 cases (granulocyte precursor maturation arrest, N = 10; hemophagocytic lymphohistiocytosis, N = 12; hematological malignancy, N = 15) and to treatment in 14, including three DFLSTs. In multivariate analysis, the factors associated with a CDT were hematological malignancy, cancer or non-malignant hematological abnormality known on admission, indication for BMA excluding isolated thrombocytopenia, higher pre-BMA HScore (calculated prior to BMA), and higher SOFA score with or without platelet-count SOFA subscore. In the 160 patients without hematological malignancy or cancer known on admission, non-malignant hematological abnormality known on admission, indication for BMA excluding isolated thrombocytopenia, higher pre-BMA HScore, and higher SOFA score calculated with or without platelet-count SOFA subscore were independently associated with a CDT of BMA. CONCLUSION: BMA can have a significant CDT in ICU patients with or without a known hematological malignancy or cancer on admission. An HScore calculated before BMA can be a valuable tool for predicting a CDT of BMA.

[Low sensibility to the action of thrombomodulin in cirrhotic patients. Interest of thrombinography]. / Faible sensibilité à l'action de la thrombomoduline chez le patient cirrhotique. Intérêt de la thrombinographie.

Cirrhosis is associated with complex hemostatic modifications. Most coagulation factors, either procoagulants or anticoagulants, are reduced. Conventional coagulation tests (prothrombin time, activated partial thromboplastin time) don't allow to precisely identify the thrombotic risk as they are not sensible to coagulation inhibitors deficiencies. The aim of this study was to evaluate the coagulation in a population of cirrhotic patients using thrombinography. We analyzed the plasma samples from 30 cirrhotic patients (10 Child A, 10 Child B, Child C 10) compared to 10 healthy controls using thrombinography with and without thrombomodulin to sensiblise this test at the activated protein C pathway. The results of endogenous thrombin potential, the main parameter, expressed as a ratio (thrombinography with/without thrombomodulin) were significantly higher in cirrhotic patients (0.69 ± 0.16) than in controls (0.49 ± 0.10) which reflects a low sensibility to the action of thrombomodulin. This resistance increases with the severity of the disease assessed by the Child-Pugh score, demonstrating a potential hypercoagulable state. The results of the thrombinography challenge the dogma that cirrhotic patients are naturally "anticoagulated." These results highlight the potential interest of the thrombinography in the detection and monitoring of hypercoagulability in cirrhotic patient. Increasing hypercoagulability with the severity of the disease seems to be correlated with clinical observations since the occurrence of thrombosis is more common when cirrhosis is at an advanced stage.

Repeated early hemofiltration filters clotting and heparin-induced thrombocytopenia in ICU.

Repeated early hemofiltration filter clotting are real thrombotic events. Diagnosis of heparin-induced thrombocytopenia (HIT) in this setting in ICU remains difficult. We describe two cases of repeated early hemofiltration filters clotting in ICU and to evaluate their impact on the probability test 4T's score and diagnosis of HIT. Two patients undergoing at least three repeated early hemofiltration clotting filters in <6 h revealing HIT in ICU had a low probability score for HIT. Despite a 4T's score of three for the two patients and persistent early hemofiltration clotting filters, functional tests for HIT antibodies (heparin induced platelet activation assay and serotonin release assay) were positive, permitting the diagnosis of HIT in both patients. We suggest that the occurrence of repeated, rapid (within 6 h) hemofiltration filter clotting should score as two points for "Thrombosis" in the 4T's scoring system, thereby increasing the pretest probability for HIT in this clinical situation.

Low Molecular Weight Heparin Induced Skin Necrosis without Platelet Fall Revealing Immunoallergic Heparin Induced Thrombocytopenia.

Low molecular weight heparins (LMWH) are commonly used in the ICU setting for thromboprophylaxis as well as curative decoagulation as required during renal replacement therapy (RRT). A rare adverse event revealing immunoallergic LMWH induced thrombopenia (HIT) is skin necrosis at injection sites. We report the case of a patient presenting with skin necrosis witnessing an HIT after RRT, without thrombocytopenia. The mechanism remains unclear. Anti-PF4/heparin antibodies, functional tests (HIPA and/or SRA), and skin biopsy are of great help to evaluate differential diagnosis with a low pretest probability 4T's score.

Epidemiology and outcome of thrombocytopenic patients in the intensive care unit: results of a prospective multicenter study.

PURPOSE: To assess the epidemiology of intensive care unit (ICU) patients with thrombocytopenia (TP). METHODS: All consecutive ICU-admitted patients with TP either on admission or acquired during ICU stay were included. TP was defined as either absolute (platelet count <100 × 10(9)/L) or relative (decrease in the platelet count >30 %). Extensive diagnostic workup of TP including bone marrow aspiration was performed. RESULTS: Absolute TP was diagnosed in 208 patients and relative TP in 93. In six patients (2 %), no cause of TP was identified. The median number of TP etiologies per patient was two, with sepsis being the leading cause. Bone marrow aspirates were analyzed in 238 patients. They showed a normal megakaryocyte number in 221 (93 %) and provided novel information for diagnosis in 52 (22 %). Results were susceptible to having an impact on patient management in 22 cases (11 %). The frequency of bone marrow aspiration with results susceptible to having an impact on management did not differ between patients with and without disseminated intravascular coagulation (P = 0.22) and with and without sepsis/septic shock (P = 0.7) but was significantly lower in patients with relative TP than in those with absolute TP (P < 0.01). A serious bleeding event was observed in 30 patients (14.9 %) and a nadir platelet count below 50 × 10(9)/L was an independent risk factor (P < 0.05). CONCLUSIONS: In thrombocytopenic patients, sepsis is the leading cause of TP. Bone marrow aspirates may yield significant information on TP mechanisms and contribute to the subsequent management of patients, especially those with absolute TP.

[Factor V inhibitor: case report and literature review]. / Anticoagulant acquis anti-facteur V : à propos d'un cas et revue de la littérature.

Acquired inhibitors to factor V are considered rare events and the cause is often unknown. Diagnostic haemostasis assays to correctly assess this phenomenon are not always perfect and reproducible. Various treatments have been attempted but a standardised management of patients is still lacking. We report the case of a patient who developed a factor V inhibitor and we take the opportunity to make an inventory of the latest data.

Proposal of a score combining red blood cell indices for early differentiation of beta-thalassemia minor from iron deficiency anemia.

This study evaluates the diagnostic reliability of 11 red blood cells indices, together with our new index, referred to as '11T', in differentiation of beta-thalassemia minor (BTm) from iron deficiency anemia (IDA). A total of 129 patients with microcytic anemia were involved in a retrospective study, 80 with IDA and 49 with BTm. Using an automatic program, we calculated 11 discrimination indices and a new score, 11T, based on the results of these 11 tests. To confirm the interest of 11T, we performed a prospective study with 53 patients. 11T was most effective in differentiating BTm from IDA: 11T had the highest Youden's index (83%) and the best percentage of correctly identified patients (93%) and gave optimal performance in our prospective study. We proposed a score, 11T, which is able to discriminate between IDA and BTm with high specificity and high sensitivity in order to conduct the appropriate confirmatory examination.

Increase in proinflammatory cytokines in peripheral blood without haemostatic changes after LPS inhalation.

INTRODUCTION: Bronchoalveolar fibrin deposition is a characteristic of various lung disorders including acute lung injury, acute respiratory distress syndrome and sepsis. It is secondary to the activation of coagulation and inhibition of fibrinolysis in the alveolar space, and can be stimulated by lipopolysaccharide (LPS) inhalation. The aim of this study was to determine the relation between compartmental stress in the lung and systemic response after LPS inhalation by measuring haemostatic parameters. PATIENTS AND METHODS: 12 healthy subjects underwent a bronchial challenge test with LPS; sequential dosages were performed for 5 biological markers (Interleukin-6 (IL-6), C-Reactive Protein (CRP), Prothrombin Fragments 1 and 2 (F 1+2), cortisol and Plasminogen Activator Inhibitor 1 (PAI-1) before endotoxin inhalation and 2, 4, 6, 8 and 24 hours afterwards. RESULTS: IL-6 and CRP levels in the peripheral blood were higher after LPS inhalation; there was no activation of coagulation and no increase in PAI-1 level. CONCLUSION: This study confirms that despite systemic release of proinflammatory cytokines, LPS inhalation does not induce systemic haemostatic response to LPS challenge.