Femoral blood gas analysis, another tool to assess hemorrhage severity following trauma: an exploratory prospective study

BACKGROUND

Veno-arterial carbon dioxide tension difference (ΔPCO2) and mixed venous oxygen saturation (SvO2) have been shown to be markers of the adequacy between cardiac output and metabolic needs in critical care patients. However, they have hardly been assessed in trauma patients. We hypothesized that femoral ΔPCO2 (ΔPCO2 fem) and SvO2 (SvO2 fem) could predict the need for red blood cell (RBC) transfusion following severe trauma.

METHODS

We conducted a prospective and observational study in a French level I trauma center. Patients admitted to the trauma room following severe trauma with an Injury Severity Score (ISS) > 15, who had arterial and venous femoral catheters inserted were included. ΔPCO2 fem, SvO2 fem and arterial blood lactate were measured over the first 24 h of admission. Their abilities to predict the transfusion of at least one pack of RBC (pRBCH6) or hemostatic procedure during the first six hours of admission were assessed using receiver operating characteristics curve.

RESULTS

59 trauma patients were included in the study. Median ISS was 26 (22-32). 28 patients (47%) received at least one pRBCH6 and 21 patients (35,6%) had a hemostatic procedure performed during the first six hours of admission. At admission, ΔPCO2 fem was 9.1 ± 6.0 mmHg, SvO2 fem 61.5 ± 21.6% and blood lactate was 2.7 ± 1.9 mmol/l. ΔPCO2 fem was significantly higher (11.6 ± 7.1 mmHg vs. 6.8 ± 3.7 mmHg, P = 0.003) and SvO2 fem was significantly lower (50 ± 23 mmHg vs. 71.8 ± 14.1 mmHg, P < 0.001) in patients who were transfused than in those who were not transfused. Best thresholds to predict pRBCH6 were 8.1 mmHg for ΔPCO2 fem and 63% for SvO2 fem. Best thresholds to predict the need for a hemostatic procedure were 5.9 mmHg for ΔPCO2 fem and 63% for SvO2 fem. Blood lactate was not predictive of pRBCH6 or the need for a hemostatic procedure.

CONCLUSION

In severe trauma patients, ΔPCO2 fem and SvO2 fem at admission were predictive for the need of RBC transfusion and hemostatic procedures during the first six hours of management while admission lactate was not. ΔPCO2 fem and SvO2 fem appear thus to be more sensitive to blood loss than blood lactate in trauma patients, which might be of importance to early assess the adequation of tissue blood flow with metabolic needs.

Aspirin Discontinuation at 24 to 28 Weeks' Gestation in Pregnancies at High Risk of Preterm Preeclampsia: A Randomized Clinical Trial

Importance

Aspirin reduces the incidence of preterm preeclampsia by 62% in pregnant individuals at high risk of preeclampsia. However, aspirin might be associated with an increased risk of peripartum bleeding, which could be mitigated by discontinuing aspirin before term (37 weeks of gestation) and by an accurate selection of individuals at higher risk of preeclampsia in the first trimester of pregnancy.

Objective

To determine whether aspirin discontinuation in pregnant individuals with normal soluble fms-like tyrosine kinase-1 to placental growth factor (sFlt-1:PlGF) ratio between 24 and 28 weeks of gestation was noninferior to aspirin continuation to prevent preterm preeclampsia.

Design, Setting, and Participants

Multicenter, open-label, randomized, phase 3, noninferiority trial conducted in 9 maternity hospitals across Spain. Pregnant individuals (n = 968) at high risk of preeclampsia during the first-trimester screening and an sFlt-1:PlGF ratio of 38 or less at 24 to 28 weeks of gestation were recruited between August 20, 2019, and September 15, 2021; of those, 936 were analyzed (intervention: n = 473; control: n = 463). Follow-up was until delivery for all participants.

Interventions

Enrolled patients were randomly assigned in a 1:1 ratio to aspirin discontinuation (intervention group) or aspirin continuation until 36 weeks of gestation (control group).

Main Outcomes and Measures

Noninferiority was met if the higher 95% CI for the difference in preterm preeclampsia incidences between groups was less than 1.9%.

Results

Among the 936 participants, the mean (SD) age was 32.4 (5.8) years; 3.4% were Black and 93% were White. The incidence of preterm preeclampsia was 1.48% (7/473) in the intervention group and 1.73% (8/463) in the control group (absolute difference, -0.25% [95% CI, -1.86% to 1.36%]), indicating noninferiority.

Conclusions and Relevance

Aspirin discontinuation at 24 to 28 weeks of gestation was noninferior to aspirin continuation for preventing preterm preeclampsia in pregnant individuals at high risk of preeclampsia and a normal sFlt-1:PlGF ratio.

Trial Registration

ClinicalTrials.gov Identifier: NCT03741179 and ClinicalTrialsRegister.eu Identifier: 2018-000811-26.

Enoxaparin titrated by anti-Xa levels reduces venous thromboembolism in trauma patients

BACKGROUND

Trauma is a major risk factor for the development of a venous thromboembolism (VTE). After observing higher than expected VTE rates within our center's Trauma Quality Improvement Program data, we instituted a change in our VTE prophylaxis protocol, moving to enoxaparin dosing titrated by anti-Xa levels. We hypothesized that this intervention would lower our symptomatic VTE rates.

METHODS

Adult trauma patients at a single institution meeting National Trauma Data Standard criteria from April 2015 to September 2019 were examined with regards to VTE chemoprophylaxis regimen and VTE incidence. Two groups of patients were identified based on VTE protocol-those who received enoxaparin 30 mg twice daily without routine anti-Xa levels ("pre") versus those who received enoxaparin 40 mg twice daily with dose titrated by serial anti-Xa levels ("post"). Univariate and multivariate analyses were performed to define statistically significant differences in VTE incidence between the two cohorts.

RESULTS

There were 1698 patients within the "pre" group and 1406 patients within the "post" group. The two groups were essentially the same in terms of demographics and risk factors for bleeding or thrombosis. There was a statistically significant reduction in VTE rate (p = 0.01) and deep vein thrombosis rate (p = 0.01) but no significant reduction in pulmonary embolism rate (p = 0.21) after implementation of the anti-Xa titration protocol. Risk-adjusted Trauma Quality Improvement Program data showed an improvement in rate of symptomatic pulmonary embolism from fifth decile to first decile.

CONCLUSION

A protocol titrating prophylactic enoxaparin dose based on anti-Xa levels reduced VTE rates. Implementation of this type of protocol requires diligence from the physician and pharmacist team. Further research will investigate the impact of protocol compliance and time to appropriate anti-Xa level on incidence of VTE.

LEVEL OF EVIDENCE

Therapeutic/care management, Level IV.

Rebalanced hemostasis in liver disease: a misunderstood coagulopathy

The combination of frequently abnormal hemostatic markers and catastrophic bleeding as seen with variceal hemorrhage has contributed to the longstanding misperception that chronic liver disease (CLD) constitutes a bleeding diathesis. Laboratory studies of hemostasis in liver disease consistently challenge this with global coagulation assays incorporating activation of the protein C pathway demonstrating rebalanced hemostasis. It is now recognized that bleeding in CLD is predominantly secondary to portal hypertension (rather than a coagulopathy) and additionally that these patients are at increased risk of venous thrombosis, particularly in the portal venous system. This narrative review describes the current understanding of hemostasis in liver disease, as well as the periprocedural management of hemostasis and anticoagulation for management of venous thromboembolism in patients with CLD.

Thromboelastography with platelet mapping: Limited predictive ability in detecting preinjury antiplatelet agent use

BACKGROUND

Preinjury antiplatelet agent (APA) use in trauma patients can increase traumatic hemorrhage and worsen outcomes. Thromboelastography with platelet mapping (TEGPM) has characterized platelet function via arachidonic acid (AA) and adenosine diphosphate (ADP) inhibition in nontrauma settings, but limited data exist in the acute trauma population.

METHODS

A prospective observational study of adult trauma patients with suspected preinjury APA use who received TEGPM testing from 2017 to 2020 was performed. Patients on anticoagulants were excluded. Patients were grouped according to preinjury APA regimen: 81 mg or 325 mg of aspirin daily, 81 mg of aspirin and 75 mg of clopidrogrel daily, 75 mg of clopidrogrel daily, or no antiplatelet. Ability of TEGPM to detect APA use was assessed using predictive statistics and area under receiver operating characteristic curves (AUROCs).

RESULTS

A total of 824 patients were included with most patients taking 81 mg of aspirin (n = 558). Patients on no antiplatelet were younger and had higher baseline platelet counts, while patients on 75 mg of clopidrogrel were more likely to be admitted after ground level fall. All other baseline characteristics were balanced. Admission TEG values were similar between groups. Median AA inhibition was higher in patients on aspirin containing regimens (p < 0.0001). Median ADP inhibition was higher in patients on clopidogrel containing regimens and those taking 325 mg of aspirin (p < 0.0001). Arachidonic acid inhibition accurately detected preinjury APA use and aspirin use (AUROC, 0.89 and 0.84, respectively); however, ADP inhibition performed poorly (AUROC, 0.58). Neither AA nor ADP inhibition was able to discern specific APA regimens or rule out APA use entirely.

CONCLUSION

High AA inhibition accurately detects preinjury APA use in trauma patients. High ADP inhibition after trauma is common, limiting its utility to accurately identify preinjury APA use. Further study is needed to identify assays that can reliably detect and further characterize preinjury APA use in trauma populations.

LEVEL OF EVIDENCE

Diagnostic test, level II.

A pilot study of stored low titer group O whole blood + component therapy versus component therapy only for civilian trauma patients

BACKGROUND

This pilot assessed transfusion requirements during resuscitation with whole blood followed by standard component therapy (CT) versus CT alone, during a change in practice at a large urban Level I trauma center.

METHODS

This was a single-center prospective cohort pilot study. Male trauma patients received up to 4 units of cold-stored low anti-A, anti-B group O whole blood (LTOWB) as initial resuscitation followed by CT as needed (LTOWB + CT). A control group consisting of women and men who presented when LTOWB was unavailable, received CT only (CT group). Exclusion criteria included antiplatelet or anticoagulant medication and death within 24 hours. The primary outcome was total transfusion volume at 24 hours. Secondary outcomes were mortality, morbidity, and intensive care unit- and hospital-free days.

RESULTS

Thirty-eight patients received LTOWB, with a median of 2.0 (interquartile range [IQR] 1.0-3.0) units of LTOWB transfused. Thirty-two patients received CT only. At 24 hours after presentation, the LTOWB +CT group had received a median of 2,138 mL (IQR, 1,275-3,325 mL) of all blood products. The median for the CT group was 4,225 mL (IQR, 1,900-5,425 mL; p = 0.06) in unadjusted analysis. When adjusted for Injury Severity Score, sex, and positive Focused Assessment with Sonography for Trauma, LTOWB +CT group patients received 3307 mL of blood products, and CT group patients received 3,260 mL in the first 24 hours (p = 0.95). The adjusted median ratio of plasma to red cells transfused was higher in the LTOWB + CT group (0.85 vs. 0.63 at 24 hours after admission; p = 0.043. Adjusted mortality was 4.4% in the LTOWB + CT group, and 11.7% in the CT group (p = 0.19), with similar complications, intensive care unit-, and hospital-free days in both groups.

CONCLUSION

Beginning resuscitation with LTOWB results in equivalent outcomes compared with resuscitation with CT only.

LEVEL OF EVIDENCE

Therapeutic (Prospective study with 1 negative criterion, limited control of confounding factors), level III.

Levels of procoagulant microparticles expressing phosphatidylserine contribute to bleeding phenotype in patients with inherited thrombocytopenia

Inherited thrombocytopenia is a heterogeneous group of hereditary disorders with varying bleeding tendencies, not simply related to platelet count. Platelets transform into different subpopulations upon stimulation, including procoagulant platelets and platelet microparticles (PMPs), which are considered critical for haemostasis. We aimed to investigate whether abnormalities in PMP and procoagulant platelet function were associated with the bleeding phenotype of inherited thrombocytopenia patients. We enrolled 53 inherited thrombocytopenia patients. High-throughput sequencing of 36 inherited thrombocytopenia related genes was performed in all patients and enabled a molecular diagnosis in 57%. Bleeding phenotype was evaluated using the ISTH bleeding assessment tool, dividing patients into bleeding (n = 27) vs. nonbleeding (n = 26). Unstimulated and ADP, TRAP or collagen-stimulated PMP and procoagulant platelet functions were analysed by flow cytometry using antibodies against granulophysin (CD63), P-selectin (CD62P), activated GPIIb/IIIa (PAC-1) and a marker for phosphatidylserine expression (lactadherin). Procoagulant platelets were measured in response to collagen stimulation. An in-house healthy reference level was available. Overall, higher levels of activated platelets, PMPs and procoagulant platelets were found in nonbleeding patients compared with the reference level. Nonbleeding patients had higher proportions of phosphatidylserine and PMPs compared with bleeding patients and the reference level, in response to different stimulations. Interestingly, this finding of high proportions of phosphatidylserine and PMPs was limited to PMPs, and not present in procoagulant platelets or platelets. Our findings indicate that nonbleeding inherited thrombocytopenia patients have compensatory mechanisms for improved platelet subpopulation activation and function, and that generation of phosphatidylserine expressing PMPs could be a factor determining bleeding phenotype in inherited thrombocytopenia.

Significance and management of isolated distal deep vein thrombosis

PURPOSE OF REVIEW

Management of isolated distal deep vein thrombosis (IDDVT) remains controversial. We summarize recent studies regarding the natural history of IDDVT as well as pertinent therapeutic trials. We also provide our management approach.

RECENT FINDINGS

IDDVT is more commonly associated with transient risk factors and less often associated with permanent, unmodifiable risk factors than proximal DVT. IDDVT has a significantly lower risk of proximal extension and recurrence than proximal DVT. Cancer-associated IDDVT has a similar natural history to cancer-associated proximal DVT, with substantially less favourable outcomes than noncancer-associated IDDVT. Anticoagulant treatment reduces the risk of proximal extension and recurrence in IDDVT at the cost of increased bleeding risk. Intermediate dosing of anticoagulation may be effective for treating noncancer-associated IDDVT in patients without prior DVT.

SUMMARY

IDDVT with a transient risk factor can be treated for 6 weeks in patients without a prior DVT. Unprovoked IDDVT in patients without malignancy can be treated for 3 months. Outpatients without malignancy or a prior DVT can be left untreated and undergo surveillance compression ultrasound in one week to detect proximal extension, but few patients opt for this in practice. Cancer-associated IDDVT should be treated analogously to cancer-associated proximal DVT.

Prognostic Implications of Declining Hemoglobin Content in Patients Hospitalized With Acute Coronary Syndromes

BACKGROUND

Contemporary definitions of bleeding endpoints are restricted mostly to clinically overt events. Whether hemoglobin drop per se, with or without overt bleeding, adversely affects the prognosis of patients with acute coronary syndrome (ACS) remains unclear.

OBJECTIVES

The aim of this study was to examine in the MATRIX (Minimizing Adverse Haemorrhagic Events by Transradial Access Site and Systemic Implementation of Angiox) trial the incidence, predictors, and prognostic implications of in-hospital hemoglobin drop in patients with ACS managed invasively stratified by the presence of in-hospital bleeding.

METHODS

Patients were categorized by the presence and amount of in-hospital hemoglobin drop on the basis of baseline and nadir hemoglobin values and further stratified by the occurrence of adjudicated in-hospital bleeding. Hemoglobin drop was defined as minimal (<3 g/dl), minor (≥3 and <5 g/dl), or major (≥5 g/dl). Using multivariate Cox regression, we modeled the association between hemoglobin drop and mortality in patients with and without overt bleeding.

RESULTS

Among 7,781 patients alive 24 h after randomization with available hemoglobin data, 6,504 patients (83.6%) had hemoglobin drop, of whom 5,756 (88.5%) did not have overt bleeding and 748 (11.5%) had overt bleeding. Among patients without overt bleeding, minor (hazard ratio [HR]: 2.37; 95% confidence interval [CI]: 1.32 to 4.24; p = 0.004) and major (HR: 2.58; 95% CI: 0.98 to 6.78; p = 0.054) hemoglobin drop were independently associated with higher 1-year mortality. Among patients with overt bleeding, the association of minor and major hemoglobin drop with 1-year mortality was directionally similar but had wider CIs (minor: HR: 3.53 [95% CI: 1.06 to 11.79]; major: HR: 13.32 [95% CI: 3.01 to 58.98]).

CONCLUSIONS

Among patients with ACS managed invasively, in-hospital hemoglobin drop ≥3 g/dl, even in the absence of overt bleeding, is common and is independently associated with increased risk for 1-year mortality. (Minimizing Adverse Haemorrhagic Events by Transradial Access Site and Systemic Implementation of Angiox; NCT01433627).

Coagulation disorders in patients with severe hemophagocytic lymphohistiocytosis

Background

Coagulation disorders are common in patients with hemophagocytic lymphohistiocytosis (HLH), associated with an increased risk of bleeding and death. We aim to investigate coagulation disorders and their outcome implications in critically ill patients with HLH.

Methods

We prospectively evaluated 47 critically ill patients with HLH (median age of 54 years [42–67]) between April 2015 and December 2018. Coagulation assessments were performed at day 1. Abnormal standard coagulation was defined as prothrombin time (PT) <50% and/or fibrinogen <2g/L. HLH aetiology was mostly ascribed to haematological malignancies (74% of patients).

Results

Coagulation disorders and severe bleeding events were frequent, occurring in 30 (64%) and 11 (23%) patients respectively. At day 1, median fibrinogen level was 2∙65g/L [1.61–5.66]. Fibrinolytic activity was high as suggested by increased median levels of D-dimers, fibrin monomers, PAI-1 (plasminogen activator inhibitor) and tPA (tissue plasminogen activator). Forty-one (91%) patients had a decreased ADAMTS13 activity (A Disintegrin-like And Metalloproteinase with ThromboSpondin type 1 repeats, member 13). By multivariable analysis, the occurrence of a severe bleeding (OR 3.215 [1.194–8.653], p = 0∙021) and SOFA score (Sepsis-Related Organ Failure Assessment) at day 1 (OR 1.305 per point [1.146–1.485], p<0∙001) were independently associated with hospital mortality. No early biological marker was associated with severe bleeding.

Conclusions

Hyperfibrinolysis may be the primary mechanism responsible for hypofibrinogenemia and may also participate in ADAMTS13 degradation. Targeting the plasmin system appears as a promising approach in severe HLH-related coagulation disorders.

Myxomavirus serpin alters macrophage function and prevents diffuse alveolar hemorrhage in pristane-induced lupus

C57BL/6 mice with pristane-induced lupus develop macrophage-dependent diffuse alveolar hemorrhage (DAH), which is blocked by treatment with liver X receptor (LXR) agonists and is exacerbated by low IL-10 levels. Serp-1, a myxomavirus-encoded serpin that impairs macrophage activation and plasminogen activation, blocks DAH caused by MHV68 infection. We investigated whether Serp-1 also could block DAH in pristane-induced lupus. Pristane-induced DAH was prevented by treatment with recombinant Serp-1 and macrophages from Serp1-treated mice exhibited an anti-inflammatory M2-like phenotype. Therapy activated LXR, promoting M2 polarization and expression of Kruppel-like factor-4 (KLH4), which upregulates IL-10. In contrast, deficiency of tissue plasminogen activator or plasminogen activator inhibitor had little effect on DAH. We conclude that Serp-1 blocks pristane-induced lung hemorrhage by enhancing LXR-regulated M2 macrophage polarization and KLH4-regulated IL-10 production. In view of the similarities between DAH in pristane-treated mice and SLE patients, Serp-1 may represent a potential new therapy for this severe complication of SLE.

Prehospital evaluation and detection of induced coagulopathy in trauma: The PREDICT study

BACKGROUND

Hemorrhage with trauma-induced coagulopathy (TIC) and hyperfibrinolysis (HF) increases the mortality risk after severe trauma. While TIC at hospital admission is well studied, little is known about coagulopathy at the incident site. The aim of the study was to investigate coagulation disorders already present on scene.

METHODS

In a prospective single-center observational study, blood samples of trauma patients obtained before and at hospital admission were analyzed. Data on rotational thromboelastometry, blood gas analysis, prehospital treatment, injury severity, in-hospital blood transfusions, and mortality were investigated according to the presence of coagulation disorders at the incident site. The patients were divided into three groups according to the presence of coagulation disorders (no coagulopathy, TIC, TIC with HF). In a subgroup analysis, patients with a Trauma-Induced Coagulopathy Clinical Score (TICCS) of ≥10 were investigated.

RESULTS

Between August 2015 and February 2018, 148 patients were enrolled in the study. The mean Injury Severity Score was 22.1, and overall mortality was 7.4%. Trauma-induced coagulopathy and HF were already detectable at the incident site in 18.2% and 6.1%, respectively. Patients with HF had significantly altered circulation parameters with significant changes in pH, hemoglobin, lactate, and base excess at the incident site. In patients with TICCS of ≥10 (14.2%), TIC was detected in 47.6% of the cases and HF in 28.6%. Furthermore, in these patients, blood gas parameters significantly changed and the need for blood transfusion and mortality.

CONCLUSION

Trauma-induced coagulopathy and HF can be detected in severely injured patients even before medical treatment is started. Furthermore, in patients with HF and TICCS of ≥10, blood gas parameters were significantly changed at the incident site.

LEVEL OF EVIDENCE

Prognostic study, level III.

Coagulopathy, Bleeding Events, and Outcome According to Rotational Thromboelastometry in Patients With Acute Liver Injury/Failure

BACKGROUND AND AIMS

Patients with acute liver injury or failure (ALI/ALF) experience bleeding complications uncommonly despite an abnormal hemostatic profile. Rotational thromboelastometry (ROTEM), which assesses clot formation in whole blood, was used to determine the nature of abnormal hemostasis and whether it contributes to bleeding events, illness severity, or survival.

APPROACH AND RESULTS

A total of 200 patients were recruited from sites of the ALF Study Group. Blood collected daily for up to 5 days was analyzed using ROTEM delta devices. Consistent with standard laboratory evidence of hypocoagulability (median international normalized ratio = 2.9 and platelet count = 144 × 109 /L), patients frequently exhibited ROTEM parameters outside the normal range (73% and 62% had abnormalities in clot formation from extrinsic and intrinsic clotting cascades, respectively); however, measures of clot stability were generally normal. Eighteen patients (9%) experienced bleeding events, in whom clot initiation, assembly, and firmness were more severely deranged than patients without bleeding. Abnormal ROTEM parameters were more frequently observed in patients with non-acetaminophen ALI/ALF than those with acetaminophen ALI/ALF (clot initiation [P < 0.001], assembly [P = 0.02], firmness at 10 minutes [P = 0.05], and maximal firmness [P = 0.06]). Patients with more severe systemic complications (high-grade hepatic encephalopathy and need for renal replacement therapy) also had a higher incidence of abnormal ROTEM parameters. Finally, more hypocoagulable ROTEM parameters (clot initiation (P = 0.005), stiffness at 10 minutes (P = 0.05), and maximal stiffness by fibrin assembly (P = 0.004)) were observed in patients who died or underwent liver transplantation than those who survived with their native liver.

CONCLUSIONS

In patients with ALI/ALF, abnormal ROTEM parameters are frequent and proportional to disease severity. Whether the increased bleeding risk associated with abnormal ROTEM indicates hemostatic failure or is a proxy for disease severity requires additional study.

Bleeding frequency during physiotherapy in thrombocytopenic patients undergoing hematopoietic stem cell transplantation

BACKGROUND

During hematopoietic stem cell transplantation (HSCT) the patients perform activities of low and moderate intensity because have reduced hematological lineages, leaving them susceptible to hemorrhagic events. The objective of this study was to describe the frequency of bleeding events, severity, and possible association with physical exercise in thrombocytopenic patients.

METHODS

A retrospective study with seventy-seven HSCT patients hospitalised, that had a platelet count ≤ 50,000 /μL and received physical exercise during physiotherapy intervention.

RESULTS

Regarding bleeding events, only six were related to physical exercise, and bleeding events occurred more frequently at platelet levels ≤ 10,000 /μL. The most frequent bleeding event was epistaxis, considered of low severity, and with the moderate possibility of being related to physical exercise; followed by extremity hematoma, considered of medium severity and highly related to physical exercise. In this study, there was no occurrence of bleeding events considered of high severity.

CONCLUSION

Bleeding frequency in supervised physical exercise during physiotherapy in adults with thrombocytopenia undergoing HSCT is minor and relatively rare but occurs more frequently in patients with platelet count ≤10,000 /μL. These results encourage the maintenance of physical activity in this population who is at high risk of developing immobility-related complications.

Direct Oral Anticoagulants Plasma Levels in Patients with Atrial Fibrillation at the Time of Bleeding: A Pilot Prospective Study

ABSTRACT

Patients with atrial fibrillation (AF) on long-term direct oral anticoagulants (DOACs) may be at higher risk of bleeding because of higher anti-Xa or anti-IIa levels. However, there is no postmarketing study investigating these DOAC plasma levels at the time of bleeding. The aim of this study was to evaluate DOAC levels at the time of a bleeding emergency. We analyzed 5440 patients examined at our Emergency Department in from April 1, 2019, to September 30, 2019. During this period, we prospective identified 105 consecutive patients with bleeding while on long-term antithrombotic therapy; 49 patients had AF on DOACs. We compared DOAC levels in patients who bled against a control sample of 55 patients who tolerated long-term high dose DOAC therapy without any emergency. Samples of these patients were tested with drug-specific anti-Xa chromogenic analysis (rivaroxaban and apixaban) and with Hemoclot Thrombin Inhibitor assay (dabigatran). Dabigatran-treated patients who bled had significantly higher anti-IIa levels when compared with trough (261.4 ± 163.7 vs. 85.4 ± 57.2 ng/mL, P < 0.001) and peak samples of controls (261.4 ± 163.7 vs. 138.8 ± 78.7 ng/mL, P < 0.05). Similarly, there were significantly higher anti-Xa levels in rivaroxaban-treated and apixaban-treated patients with bleeding compared with trough control samples (rivaroxaban: 245.9 ± 150.2 vs. 52.5 ± 36.4 ng/mL, P <0.001 and apixaban: 311.8 ± 142.5 vs. 119.9 ± 81.7 ng/mL, P < 0.001), as well as in apixaban-treated patients when compared with peak control samples (311.8 ± 142.5 vs. 210.9 ± 88.7 ng/mL, P < 0.05). Finally, rivaroxaban anti-Xa levels in patients who bled tended to be higher compared with peak control samples (245.9 ± 150.2 vs. 177.6 ± 38.6 ng/mL, P = 0.13). This observational study showed a significant difference in anti-IIa and anti-Xa plasma levels in patients with AF with bleeding complications compared with those who tolerated long-term high-dose DOAC therapy without bleeding complications.

Novel variant fibrinogen γp.C352R produced hypodysfibrinogenemia leading to a bleeding episode and failure of infertility treatment

INTRODUCTION

We identified a patient with a novel heterozygous variant fibrinogen, γp.C352R (Niigata II; N-II), who had a bleeding episode and failed infertility treatment and was suspected to have hypodysfibrinogenemia based on low and discordant fibrinogen levels (functional assay 0.33 g/L, immunological assay 0.91 g/L). We analyzed the mechanism of this rare phenotype of a congenital fibrinogen disorder.

MATERIALS AND METHODS

Patient plasma fibrinogen was purified and protein characterization and thrombin-catalyzed fibrin polymerization performed. Recombinant fibrinogen-producing Chinese hamster ovary (CHO) cells were established and the assembly and secretion of variant fibrinogen analyzed by ELISA and western blotting.

RESULTS

Purified N-II plasma fibrinogen had a small lower molecular weight band below the normal γ-chain and slightly reduced fibrin polymerization. A limited proportion of p.C352R fibrinogen was secreted into the culture medium of established CHO cell lines, but the γ-chain of p.C352R was synthesized and variant fibrinogen was assembled inside the cells.

CONCLUSION

We demonstrated that fibrinogen N-II, γp.C352R was associated with markedly reduced secretion of variant fibrinogen from CHO cells, that fibrin polymerization of purified plasma fibrinogen was only slightly affected, and that fibrinogen N-II produces hypodysfibrinogenemia in plasma.

Restart TICrH: An Adaptive Randomized Trial of Time Intervals to Restart Direct Oral Anticoagulants after Traumatic Intracranial Hemorrhage

Anticoagulants prevent thrombosis and death in patients with atrial fibrillation and venous thromboembolism (VTE) but also increase bleeding risk. The benefit/risk ratio favors anticoagulation in most of these patients. However, some will have a bleeding complication, such as the common trip-and-fall brain injury in elderly patients that results in traumatic intracranial hemorrhage. Clinicians must then make the difficult decision about when to restart the anticoagulant. Restarting too early risks making the bleeding worse. Restarting too late risks thrombotic events such as ischemic stroke and VTE, the indications for anticoagulation in the first place. There are more data on restarting patients with spontaneous intracranial hemorrhage, which is very different than traumatic intracranial hemorrhage. Spontaneous intracranial hemorrhage increases the risk of rebleeding because intrinsic vascular changes are widespread and irreversible. In contrast, traumatic cases are caused by a blow to the head, usually an isolated event portending less future risk. Clinicians generally agree that anticoagulation should be restarted but disagree about when. This uncertainty leads to long restart delays causing a large, potentially preventable burden of strokes and VTE, which has been unaddressed because of the absence of high quality evidence. Restart Traumatic Intracranial Hemorrhage (the "r" distinguished intracranial from intracerebral) (TICrH) is a prospective randomized open label blinded end-point response-adaptive clinical trial that will evaluate the impact of delays to restarting direct oral anticoagulation (1, 2, or 4 weeks) on the composite of thrombotic events and bleeding in patients presenting after traumatic intracranial hemorrhage.

Tissue factor-bearing microparticles are a link between acute promyelocytic leukemia cells and coagulation activation: a human subject study

Acute promyelocytic leukemia (APL) cells constitutively express a large amount of tissue factor (TF) antigen, most of which is present in the cytoplasm. Coagulopathy may persist after induction therapy. We evaluated the overall role of circulating microparticles (MPs) in coagulation activation in APL-associated coagulopathy before and during induction therapy. Eleven adult patients with ≥ World Health Organization's (WHO) grade 2 bleeding events and 11 sex- and age-matched healthy controls were selected. All patients received arsenic trioxide alone as induction therapy. MP-associated TF (MP-TF) activity and MP procoagulant activity (MP-PCA) and 12 coagulation- and anticoagulation-associated indexes were measured before, during, and after induction therapy. Correlation between MP-associated indexes and the other 12 indexes was analyzed in patients. The MP-TF activity was negligible in controls, whereas it markedly increased in patients, dropped rapidly after treatment, and returned to normal at the end of induction therapy. The MP-PCA was similar between patients and controls. The correlation analysis revealed that TF-bearing MPs in patients mainly originated from APL cells. Partially differentiated APL cells could also release TF-bearing MPs, and the higher the degree of APL cell differentiation, the lower the ability of APL cells to release TF-bearing MPs. MP-TF was the main source of active TF in plasma and an important contributor for the coagulation activation in APL-associated coagulopathy. It was MPs released by APL cells/partially differentiated APL cells that served as the vehicle to transfer the large amount of TF to plasma to activate coagulation.

The fibrinogen levels on admission is a predictive marker of the contrast extravasation on enhanced computed tomography in sacral fracture

Sacral fracture is the most frequent posterior injury among unstable pelvic ring fractures and is prone to massive hemorrhage and hemodynamic instability. Contrast extravasation (CE) on computed tomography (CT) is widely used as an indicator of significant arterial bleeding. However, while CE is effective to detect significant arterial bleeding but negative result cannot completely rule out massive bleeding. Therefore, additional factors help to compensate CE for the prediction of early hemodynamically unstable condition.We evaluated the risk factors that predict CE on enhanced computed CT in patients with sacral fractures. Patients were classified into 2 groups: CE positive on enhanced CT of the pelvis [CE(+)] and CE negative [CE(-)]. We compared age, sex, injury severity score (ISS), systolic blood pressure (sBP), type of sacral fracture based on Denis classification, platelet (PLT), base excess, lactate, prothrombin time-international normalized ratio, hemoglobin (Hb), activated partial thromboplastin time, D-dimer, and fibrinogen between the 2 groups.A total of 82 patients were treated for sacral fracture, of whom 69 patients were enrolled. There were 17 patients (10 men and 7 women) in CE(+) and 52 patients (28 men and 24 women) in CE(-). Age, ISS, and blood transfusion within 24 hours were significantly higher in the CE(+) group than in the CE(-) group (P = .023, P < .001, P < .001). sBP, Hb, PLT, fibrinogen were significantly lower in the CE(+) group than in the CE(-) group (P < .001, P < .001, P < .001, P < .001). D-dimer and lactate were higher in the CE(+) group than in the CE(-) group (P = .036, P < .001) with significant differences. On multivariate analysis, the level of fibrinogen was an independent predictor of CE(+). The area under the curve value for fibrinogen was 0.88, and the optimal cut-off value for prediction was 199 mg/dL.The fibrinogen levels on admission can predict contrast extravasation on enhanced CT in patients with sacral fractures. The optimal cut-off value of fibrinogen for CE(+) prediction in sacral fracture was 199 mg/dL. The use of fibrinogen to predict CE(+) could lead to prompt and effective treatment of active arterial hemorrhage in sacral fracture.

The swine as a vehicle for research in trauma-induced coagulopathy: Introducing principal component analysis for viscoelastic coagulation tests

BACKGROUND

Uncontrolled bleeding is the leading cause of potentially preventable deaths among trauma patients. Tissue injury and shock result in trauma-induced coagulopathy (TIC). There are still uncertainties regarding detection methods and best practice management for TIC, and a deeper understanding of the pathophysiology requires robust animal models. The applicability of swine in coagulation studies, particularly after trauma has not been sufficiently elucidated. We, therefore, evaluated the swine as a vehicle for TIC research in a selection of trauma modalities.

METHODS

Twenty-six landrace swine (3 females/23 males) (mean weight, 60.0 kg) were anesthetized and randomized to negative controls, receiving no manipulation (n = 5), positive controls by hemodilution (n = 5), pulmonary contusion without hemorrhage (n = 5), pulmonary contusion with hemorrhage (n = 5), and blast polytrauma with hypothermia, hypoperfusion, hypoventilation, and systemic inflammation (n = 6). A comprehensive coagulation panel was analyzed at baseline, 20 minutes and 120 minutes after trauma.

RESULTS

PT(INR), aPTT, thrombocytes, and fibrinogen did not change after trauma. D-dimer increased (p < 0.0001), prothrombin decreased (p < 0.05) and aPC decreased (p < 0.01) after polytrauma. PAI-1 decreased after pulmonary contusion with hemorrhage (p < 0.05). Positive controls displayed changes in PT(INR), thrombocytes, fibrinogen, prothrombin, aPC (p < 0.05). Principal Component Analysis of rotational thromboelastometry presented pathologic coagulation profiles in both polytrauma and positive control groups with vectors extending outside the 95% confidence interval, which were not detected in negative controls.

CONCLUSION

Coagulopathy was induced after severe porcine blast polytrauma, specifically detected in rotational thromboelastometry. A novel method for principal component analysis of viscoelastic tests was introduced which may increase the detection sensitivity and differentiation of TIC phenotypes and should be further investigated in trauma populations.

Association of myocardial hemorrhage and persistent microvascular obstruction with circulating inflammatory biomarkers in STEMI patients

INTRODUCTION

Myocardial hemorrhage (IMH) and persistent microvascular obstruction (MVO) are associated with impaired myocardial recovery and adverse clinical outcomes in STEMI patients. However, their relationship with circulating inflammatory biomarkers is unclear in human patients.

METHODS AND RESULTS

Twenty consecutive patients referred for primary percutaneous coronary intervention of first STEMI were included in a prospective study. Blood sampling was performed at admission, 4, 12, 24, 48 hours, 7 and 30 days after reperfusion for inflammatory biomarker (C reactive protein, fibrinogen, interleukin-6 (IL-6) and neutrophils count) assessment. At seven days, cardiovascular magnetic resonance (CMR) was performed for infarct size, MVO and IMH assessment. Median infarct size was 24.6% Interquartile range (IQR) [12.0-43.5] of LV mass and edema was 13.2% IQR [7.7-36.1] of LV mass. IL-6 reached a peak at H24 (5.6 pg/mL interquartile range (IQR) [2.5-17.5]), CRP at H48 (11.7 mg/L IQR [7.1-69.2]), fibrinogen one week after admission (4.4 g/L IQR [3.8-6.7]) and neutrophils at H12 (9.0 G/L IQR [6.5-12.7]). MVO was present in 11 patients (55% of the study population) and hemorrhage in 7 patients (35%). Patients with IMH had significantly higher IL-6, CRP, fibrinogen, and neutrophils levels compared to patients without IMH. Patients with persistent MVO had significantly higher CRP, fibrinogen and neutrophils level compared to patients without MVO, but identical IL-6 kinetics.

CONCLUSION

In human patients with acute myocardial infarction, intramyocardial hemorrhage appears to have a stronger relationship with inflammatory biomarker release compared to persistent MVO. Attenuating myocardial hemorrhage may be a novel target in future adjunctive STEMI treatments.

The usefulness of the percentage of immature granulocytes in predicting in-hospital mortality in patients with upper gastrointestinal bleeding

BACKGROUND

Upper gastrointestinal bleeding (UGIB) is an important health problem with a potentially life threatening course. Measurement of immature granulocytes percentage (IG %), reflecting the fraction of circulating immature granulocyte (IG), is associated with increased mortality in patients with systemic inflammation, or distress. The aim of this study was to evaluate whether the IG% is an effective predictive marker for estimating the in-hospital mortality for patients with UGIB admitting to the emergency department (ED).

METHOD

This retrospective study included patients with UGIB who admitted to the ED, between 01.01.2019 and 31.12.2019. The patients were divided into two groups as discharged and dead. The IG% and other parameters were recorded. The primary end point of the study was in-hospital mortality. Logistic regression model was used to determine the factors affecting mortality.

RESULTS

This study included 149 patients, 94 of whom were men. The mean age of the patients was 64.5 ± 14.2. Twenty patients died during hospitalization and 129 were discharged. IG% was significantly higher in patients who died compared with patients who discharged. In the receiver operating characteristic (ROC) curves analysis to determine the in-hospital mortality, the cut-off value (>1%) for IG% level was found specificity (93.8%), sensitivity (100%), positive predictive value (PPV = 71.43%), negative predictive value (NPV = 100.00%) and area under curve (AUC = 0.98). Univariate logistic regression analysis showed that IG% was predicting in-hospital mortality (odds ratio, OR = 65.6, confidence interval, CI = 2.00-2152.6). CONCLUSıONS: High IG% levels may be used as a predictor of in-hospital mortality in patients with UGIB.

"TEG talk": expanding clinical roles for thromboelastography and rotational thromboelastometry

Viscoelastic assays (VEAs) that include thromboelastography and rotational thromboelastometry add value to the investigation of coagulopathies and goal-directed management of bleeding by providing a complete picture of clot formation, strength, and lysis in whole blood that includes the contribution of platelets, fibrinogen, and coagulation factors. Conventional coagulation assays have several limitations, such as their lack of correlation with bleeding and hypercoagulability; their inability to reflect the contribution of platelets, factor XIII, and plasmin during clot formation and lysis; and their slow turnaround times. VEA-guided transfusion algorithms may reduce allogeneic blood exposure during and after cardiac surgery and in the emergency management of trauma-induced coagulopathy and hemorrhage. However, the popularity of VEAs for other indications is driven largely by extrapolation of evidence from cardiac surgery, by the drawbacks of conventional coagulation assays, and by institution-specific preferences. Robust diagnostic studies validating and standardizing diagnostic cutoffs for VEA parameters and randomized trials comparing VEA-guided algorithms with standard care on clinical outcomes are urgently needed. Lack of such studies represents the biggest barrier to defining the role and impact of VEA in clinical care.

Women and bleeding disorders: diagnostic challenges

Women with bleeding disorders suffer from multiple bleeding symptoms, including easy bruising, epistaxis, bleeding from minor wounds and the oral cavity, and bleeding after dental work or surgery. However, women with bleeding disorders especially suffer from gynecologic and obstetrical bleeding. These symptoms often are not recognized as abnormal, and many women are left undiagnosed and without access to appropriate medical care. Additional challenges to diagnosing women with bleeding disorders include lack of access to appropriate laboratory testing and issues around disease classification and nomenclature. Efforts have been undertaken to address these challenges, including the development and validation of bleeding assessment tools and strategies to clarify diagnostic thresholds and algorithms for von Willebrand disease (VWD) and platelet function disorders. Efforts to improve communication with the nomenclature used for hemophilia carriers are also underway.

Characterization of the cortisol response to traumatic hemorrhage and intra-abdominal contamination models in Cynomologus Macaques

INTRODUCTION

Trauma, hemorrhage, and peritonitis have widely varying impacts on endocrine response in the injured patient. We sought to examine cortisol response in established non-human primate models of traumatic hemorrhage and intra-abdominal contamination.

METHODS

Cynomologus Macaques were separated into two experimental groups, the polytrauma and hemorrhage model, involving a laparoscopic liver resection with uncontrolled hemorrhage, cecal perforation, and soft tissue excision; and the traumatic hemorrhage model, involving only liver resection and uncontrolled hemorrhage. Cortisol levels were measured pre-operatively, at the time of injury, and at regular intervals until post-operative day 1.

RESULTS

Cortisol levels increased 600% from the pre-operative value in the polytrauma and hemorrhage model, with minimal changes (20%) in the hemorrhage only model.

CONCLUSION

Cortisol levels increase dramatically in response to polytrauma and intra-abdominal contamination as compared to hemorrhage only. The lack of response in the hemorrhage only group may be due to relative adrenal insufficiency caused by the shock state or lack of enticing stimuli from fecal peritonitis.

An audit of fluid resuscitation practice in trauma patients with mmajor haemorrhage at Christchurch Hospital

AIMS

Damage control resuscitation with limited crystalloids and early use of blood products is now considered standard care in major trauma. The purpose of this study was to audit resuscitation practice in trauma patients where a massive transfusion protocol (MTP) had been activated, to determine whether crystalloid administration and adherence to the MTP had improved since an audit and education sessions in July 2017.

METHODS

We conducted a retrospective study looking at trauma patients presenting to Christchurch Hospital who had a MTP activated form the 1 May 2016 to 1 March 2019. Patients were identified by cross-referencing the trauma call database with the electronic transfusion registry.

RESULTS

Thirty-four patients were included in the audit. There was no significant difference in mean crystalloid administration before and after July 2017 (5.74 litres and 4.86 litres respectively). Patients presenting before July 2017 received a significantly lower mean fresh frozen plasma to red blood cells (FFP:RBC) compared to patients after July 2017.

CONCLUSIONS

Trauma patients with major haemorrhage at Christchurch Hospital are still receiving excess crystalloids; however, our audit suggests that compliance with the MTP has improved. Further education involving the entire trauma team is required to improve fluid resuscitation practice.

Clinical and pathophysiologic aspects of ECMO-associated hemorrhagic complications

Extracorporeal membrane oxygenation (ECMO) is increasingly used to treat severe cases of acute respiratory or cardiac failure. Hemorrhagic complications represent one of the most common complications during ECMO, and can be life threatening. The purpose of this study was to elucidate pathophysiological mechanisms of ECMO-associated hemorrhagic complications and their impact on standard and viscoelastic coagulation tests. The study cohort included 27 patients treated with VV-ECMO or VA-ECMO. Hemostasis was evaluated using standard coagulation tests and viscoelastic parameters investigated with rotational thromboelastometry. Anticoagulation and hemorrhagic complications were analyzed for up to seven days depending on ECMO duration. Hemorrhagic complications developed in 16 (59%) patients. There were 102 discrete hemorrhagic episodes among 116 24-hour-intervals, of which 27% were considered to be clinically significant. The highest number of ECMO-associated hemorrhages occurred on the 2^nd and 3^rd day of treatment. Respiratory tract bleeding was the most common hemorrhagic complication, occurring in 62% of the 24-hour intervals. All 24-hours-intervals were divided into two groups: “with bleeding” and “without bleeding”. The probability of hemorrhage was significantly associated with abnormalities of four parameters: increased international normalized ratio (INR, sensitivity 71%, specificity 94%), increased prothrombin time (PT, sensitivity 90%, specificity 72%), decreased intrinsic pathway maximal clot firmness (MCFin, sensitivity 76%, specificity 89%), and increased extrinsic pathway clot formation time (CFTex, sensitivity 77%, specificity 87%). In conclusions, early ECMO-associated hemorrhagic complications are related to one traditional and two novel viscoelastic coagulation abnormalities: PT/INR elevation, reduced maximum clot firmness due to intrinsic pathway dysfunction (MCFin), and prolonged clot formation time due to extrinsic pathway dysfunction (CFTex). When managing hemostasis during ECMO, derangements in PT/INR, MCFin and CFT_ex should be focused on.

The Progression of Hemophilic Arthropathy: The Role of Biomarkers

BACKGROUND

Hemophilia A and B are X-linked congenital bleeding disorders characterized by recurrent hemarthroses leading to specific changes in the synovium and cartilage, which finally result in the destruction of the joint: this process is called hemophilic arthropathy (HA). This review highlights the most prominent molecular biomarkers found in the literature to discuss their potential use in the clinical practice to monitor bleeding, to assess the progression of the HA and the effectiveness of treatments.

METHODS

A review of the literature was performed on PubMed and Embase, from 3 to 7 August 2020. Study selection and data extraction were achieved independently by two authors and the following inclusion criteria were determined a priori: English language, available full text and articles published in peer-reviewed journal. In addition, further articles were identified by checking the bibliography of relevant articles and searching for the studies cited in all the articles examined.

RESULTS

Eligible studies obtained at the end of the search and screen process were seventy-three (73).

CONCLUSIONS

Despite the surge of interest in the clinical use of biomarkers, current literature underlines the lack of their standardization and their potential use in the clinical practice preserving the role of physical examination and imaging in early diagnosis.

Immune complement and coagulation dysfunction in adverse outcomes of SARS-CoV-2 infection

Understanding the pathophysiology of SARS-CoV-2 infection is critical for therapeutic and public health strategies. Viral-host interactions can guide discovery of disease regulators, and protein structure function analysis points to several immune pathways, including complement and coagulation, as targets of coronaviruses. To determine whether conditions associated with dysregulated complement or coagulation systems impact disease, we performed a retrospective observational study and found that history of macular degeneration (a proxy for complement-activation disorders) and history of coagulation disorders (thrombocytopenia, thrombosis and hemorrhage) are risk factors for SARS-CoV-2-associated morbidity and mortality-effects that are independent of age, sex or history of smoking. Transcriptional profiling of nasopharyngeal swabs demonstrated that in addition to type-I interferon and interleukin-6-dependent inflammatory responses, infection results in robust engagement of the complement and coagulation pathways. Finally, in a candidate-driven genetic association study of severe SARS-CoV-2 disease, we identified putative complement and coagulation-associated loci including missense, eQTL and sQTL variants of critical complement and coagulation regulators. In addition to providing evidence that complement function modulates SARS-CoV-2 infection outcome, the data point to putative transcriptional genetic markers of susceptibility. The results highlight the value of using a multimodal analytical approach to reveal determinants and predictors of immunity, susceptibility and clinical outcome associated with infection.

Are Iranian patients with von Willebrand disease type 2N properly differentiated from hemophilia A and do they receive appropriate treatment?

: The defect function of the von Willebrand factor (VWF) in carrying factor VIII (FVIII) leads to von Willebrand disease type 2N (VWD 2N) which could be easily misdiagnosed as hemophilia A. Differentiating of VWD 2N from hemophilia A is crucial for patient treatment and genetic counseling. As a retrospective study, we aimed to evaluate the current diagnostic work-up of Iranian patients with mild/moderate deficiency of FVIII levels and the possibility of misdiagnosis of VWD 2N as hemophilia A. All patients who referred to the reference coagulation laboratory at the Iranian Blood Transfusion Organization in a 10-months period for bleeding diathesis work-up with the request of FVIII activity level were included. Clinical and laboratory phenotypes including International Society on Thrombosis and Hemostasis - Bleeding Assessment Tool, FVIII activity, VWF antigen, VWF ristocetin cofactor, and FVIII binding capacity of VWF were assessed on suspected cases for VWD 2N. In total, the results of 896 patients for investigation of VWD 2N were evaluated and five new patients were identified within unrelated families with abnormal VWF:FVIIIB levels. Four were heterozygous for VWD 2N and one homozygous whom all were misdiagnosed as hemophilia A and underwent inappropriate treatments. The median bleeding score of the VWD 2N population was nine (4-13). In Iran, probably a significant number of VWD 2N patients are misdiagnosed as hemophilia A due to insufficient test panel for subtyping of von Willebrand disease. This study also emphasized the need for inclusion of the VWF:FVIIIB in suspected hemophilia A to achieve an optimal treatment strategy.

Prospective Analysis of Hemorrhagic Cystitis and BK Viremia in Allogeneic Hematopoietic Stem Cell Transplantation

Objective

BK virus (BKV) infection has been shown to be related to hemorrhagic cystitis (HC) in allogeneic hematopoietic stem cell transplantation (allo-HSCT). There are conflicting data regarding the association between BKV titers in plasma and clinical disease as well as the risk factors for BKV-related HC. Our aim is to study the risk factors and relationship with plasma BK viral load for development of HC in a prospective analysis.

Materials and Methods

We prospectively evaluated 59 patients who received allo-HSCT between 2014 and 2016 by quantitative BK virus polymerase chain reaction (PCR) (Altona Diagnostics, Germany) from blood samples at days 0, 30, 60, and 90 after allo-HSCT. The patients were monitored for signs and symptoms of HC.

Results

HC was diagnosed in 22 patients (37%) at a mean of 100 days (range: 0-367 days). In multivariate analysis, the usage of cyclophosphamide (sub-distribution hazard ratio [sdHR]: 7.82, confidence interval [CI]: 1.375-39.645, p=0.02), reactivated CMV (sdHR: 6.105, CI: 1.614-23.094, p=0.008), and positive BKV viremia (sdHR: 2.15, CI: 1.456-22.065, p=0.01) significantly increased the risk of developing HC. Patients with higher viral loads at day 30 and day 60 were diagnosed with more severe HC (p<0.001). Median BK viral loads of >101.5 copies/mL at day 0 (sensitivity 0.727, specificity 0.875), >98.5 copies/mL at day 30 (sensitivity 0.909, specificity 0.875), and >90.0 copies/mL at day 60 (sensitivity 0.909, specificity 0.875) were indicative of HC.

Conclusion

Our study showed that administration of cyclophosphamide, CMV reactivation, and BK virus positivity were associated with HC. Plasma BK virus PCR titers at days 0, 30, and 60 after transplant were sensitive tools for predicting clinically proven HC.

Differential coagulotoxicity of metalloprotease isoforms from Bothrops neuwiedi snake venom and consequent variations in antivenom efficacy

Bothrops (lance-head pit vipers) venoms are rich in weaponised metalloprotease enzymes (SVMP). These toxic enzymes are structurally diverse and functionally versatile. Potent coagulotoxicity is particularly important for prey capture (via stroke-induction) and relevant to human clinical cases (due to consumption of clotting factors including the critical depletion of fibrinogen). In this study, three distinct isoforms of P-III class SVMPs (IC, IIB and IIC), isolated from Bothrops neuwiedi venom, were evaluated for their differential capacities to affect hemostasis of prey and human plasma. Furthermore, we tested the relative antivenom neutralisation of effects upon human plasma. The toxic enzymes displayed differential procoagulant potency between plasma types, and clinically relevant antivenom efficacy variations were observed. Of particular importance was the confirmation the antivenom performed better against prothrombin activating toxins than Factor X activating toxins, which is likely due to the greater prevalence of the former in the immunising venoms used for antivenom production. This is clinically relevant as the enzymes displayed differential potency in this regard, with one (IC) in particular being extremely potent in activating Factor X and thus was correspondingly poorly neutralised. This study broadens the current understanding about the adaptive role of the SVMPs, as well as highlights how the functional diversity of SVMP isoforms can influence clinical outcomes. Key Contribution: Our findings shed light upon the hemorrhagic and coagulotoxic effects of three SVMPs of the P-III class, as well as the coagulotoxic effects of SVMPs on human, avian and amphibian plasmas. Antivenom neutralised prothrombin-activating isoforms better than Factor X activating isoforms.

Plasma Exchange as an Initial Treatment for Severe Bleeding Induced by Acquired Factor V Deficiency: A Case Report and Mini Literature Review

Acquired factor V deficiency (AFVD) is a rare autoimmune bleeding disorder. Unlike acquired hemophilia, bypass therapies with recombinant activated factor VII and activated prothrombin complex concentrates are ineffective for severe bleeding due to AFVD. Although several treatment strategies have been attempted, a standard of care for severe hemorrhage induced by AFVD is lacking. Herein, we report a case of AFVD with severe bleeding that responded to plasma exchange (PE) combined with immunosuppression. We also reviewed previously reported AFVD cases with severe hemorrhage and suggest that PE may be an effective initial treatment for AFVD-induced severe hemorrhage.

Computational model of tranexamic acid on urokinase mediated fibrinolysis

Understanding the coagulation process is critical to developing treatments for trauma and coagulopathies. Clinical studies on tranexamic acid (TXA) have resulted in mixed reports on its efficacy in improving outcomes in trauma patients. The largest study, CRASH-2, reported that TXA improved outcomes in patients who received treatment prior to 3 hours after the injury, but worsened outcomes in patients who received treatment after 3 hours. No consensus has been reached about the mechanism behind the duality of these results. In this paper we use a computational model for coagulation and fibrinolysis to propose that deficiencies or depletions of key anti-fibrinolytic proteins, specifically antiplasmin, a1-antitrypsin and a2-macroglobulin, can lead to worsened outcomes through urokinase-mediated hyperfibrinolysis.

Cost-effectiveness evaluation of the PROPPR trial transfusion protocols

BACKGROUND

There have been no prior investigations of the cost effectiveness of transfusion strategies for trauma resuscitation. The Pragmatic, Randomized, Optimal Platelet and Plasma Ratios (PROPPR) study was a Phase III multisite, randomized trial in 680 subjects comparing the efficacy of 1:1:1 transfusion ratios of plasma and platelets to red blood cells with the 1:1:2 ratio. We hypothesized that 1:1:1 transfusion results in an acceptable incremental cost-effectiveness ratio, when estimated using patients' age-specific life expectancy and cost of care during the 30-day PROPPR trial period.

STUDY DESIGN AND METHODS

International Classification of Diseases, Ninth Revision codes were prospectively collected, and subjects were matched 1:2 to subjects in the Healthcare Utilization Program State Inpatient Data to estimate cost weights. We used a decision tree analysis, combined with standard costs and estimated years of expected survival to determine the cost effectiveness of the two treatments.

RESULTS

The 1:1:1 group had higher overall costs for the blood products but were more likely to achieve hemostasis and decreased hemorrhagic death by 24 hours (p = 0.006). For every 100 patients treated in the 1:1:1 group, eight more achieved hemostasis than in the 1:1:2 group. At 30 days, the total hospital cost per 100 patients was $5.6 million in the 1:1:1 group compared with $5.0 million in the 1:1:2 group. For each 100 patients, the 1:1:1 group had 218.5 more years of life expectancy. This was at a cost of $2994 per year gained.

CONCLUSION

The 1:1:1 transfusion ratio in severely injured hemorrhaging trauma patients is a very cost-effective strategy for increasing hemostasis and decreasing trauma deaths.

Heterogeneity of Integrin αIIbβ3 Function in Pediatric Immune Thrombocytopenia Revealed by Continuous Flow Cytometry Analysis

Immune thrombocytopenia (ITP) is an autoimmune condition primarily induced by the loss of immune tolerance to the platelet glycoproteins. Here we develop a novel flow cytometry approach to analyze integrin α_IIbβ₃ functioning in ITP in comparison with Glanzmann thrombasthenia (GT) (negative control) and healthy pediatric donors (positive control). Continuous flow cytometry of Fura-Red-loaded platelets from whole hirudinated blood was used for the characterization of platelet responses to conventional activators. Calcium levels and fibrinogen binding were normalized to ionomycin-induced responses. Ex vivo thrombus formation on collagen was observed in parallel-plate flow chambers. Platelets from all ITP patients had significantly higher cytosolic calcium concentration in the quiescent state compared to healthy donors (15 ± 5 nM vs. 8 ± 5 nM), but calcium increases in response to all activators were normal. Clustering analysis revealed two subpopulations of ITP patients: the subgroup with high fibrinogen binding (HFB), and the subgroup with low fibrinogen binding (LFB) (8% ± 5% for LFB vs. 16% ± 3% for healthy donors in response to ADP). GT platelets had calcium mobilization (81 ± 23 nM), fibrinogen binding (5.1% ± 0.3%) and thrombus growth comparable to the LFB subgroup. Computational modeling suggested phospholipase C-dependent platelet pre-activation for the HFB subgroup and lower levels of functional integrin molecules for the LFB group.

Direct oral anticoagulant plus antiplatelet therapy: prescribing practices and bleeding outcomes

Concurrent antiplatelet therapy (APT) is common during warfarin therapy but is less well-documented during direct oral anticoagulant (DOAC) therapy. Combined anticoagulant and APT use has been associated with increased bleeding risk without providing additional protection against thrombosis. This study aimed to describe single-center prescribing rates of DOAC + APT as well as compare bleeding rates between DOAC monotherapy and DOAC + APT cohorts. Patients receiving DOAC therapy were evaluated for APT use at the time of hospital discharge. Patients were categorized into DOAC monotherapy and DOAC + APT cohorts. Primary outcomes included DOAC + APT prescribing rate as well as rates of major bleeding and clinically relevant non-major bleeding (CRNMB) within six months after hospital discharge. Secondary outcomes included rates of thromboembolism and all-cause mortality. Of 407 patients receiving DOAC therapy, 78 (19.2%) also received APT at hospital discharge. Common indications for APT included secondary cardiovascular event prevention (57.7%) and primary cardiovascular event prevention (29.5%). The indication for APT could not be determined in 12.8% of patients. The major bleeding rate was 1.3% for DOAC + APT and 1.2% for DOAC monotherapy (p = 0.95). The CRNMB rate was 10.2% for DOAC + APT and 6.4% for DOAC monotherapy (p = 0.23). Thromboembolism and mortality were infrequent in both cohorts. DOAC + APT was documented in approximately 1 of 5 patients. Adding APT to DOAC therapy did not significantly increase the major bleeding or CRNMB rates compared to DOAC monotherapy but the sample size limits drawing conclusions about the safety of these regimens. Targeting primary prevention or unclear indications for APT could be a focus of future interventions.

Serum insulin levels are associated with vulnerable plaque components in the carotid artery: the Rotterdam Study

BACKGROUND

To investigate the association between fasting serum insulin and glucose levels with atherosclerotic plaque composition in the carotid artery. Impaired insulin and glucose levels are implicated in the etiology of cardiovascular disease; however, their influence on the formation and composition of atherosclerotic plaque remains unclear.

METHODS

In 1740 participants (mean age 72.9 years, 46% women, 14.4% diabetes mellitus) from the population-based Rotterdam Study, we performed carotid MRI to evaluate the presence of calcification, lipid core, and intraplaque hemorrhage in carotid atherosclerosis. All participants also underwent blood sampling to obtain information on serum insulin and glucose levels. Using logistic regression models, we assessed the association of serum insulin and glucose levels (per s.d. and in tertiles) with the different plaque components, while adjusting for sex, age, intima-media thickness, and cardiovascular risk factors.

RESULTS

Serum insulin levels were associated with the presence of intraplaque hemorrhage (adjusted odds ratio (OR): 1.42 (95% CI: 1.12-1.7)) We found no association with the presence of calcification or lipid core. Sensitivity analyses restricted to individuals without diabetes mellitus yielded similar results. No associations were found between serum glucose levels and any of the plaque components.

CONCLUSIONS

Serum insulin levels are associated with the presence of vulnerable components of carotid plaque, specifically with intraplaque hemorrhage. These findings suggest a complex role for serum insulin in the pathophysiology of carotid atherosclerosis and in plaque vulnerability.

The Monocyte-to-Lymphocyte Ratio at Hospital Admission Is a Novel Predictor for Acute Traumatic Intraparenchymal Hemorrhage Expansion after Cerebral Contusion

PURPOSE

To explore the potential of monocyte-to-lymphocyte ratio (MLR) at hospital admission for predicting acute traumatic intraparenchymal hematoma (tICH) expansion in patients with cerebral contusion. Patients and Methods. This multicenter, observational study included patients with available at-hospital admission (baseline) and follow-up computed tomography for volumetric analysis (retrospective development cohort: 1146 patients; prospective validation cohort: 207 patients). Semiautomated software assessed tICH expansion (defined as ≥33% or 5 mL absolute growth). MLR was acquired from routine blood tests upon admission. We constructed two predictive models: basic combined model of clinical and imaging variables and MLR combined model of both MLR and other variables in the basic model. Receiver operating characteristic (ROC) analysis and decision curve analysis (DCA) were used to estimate the performance of MLR for predicting acute tICH expansion.

RESULTS

MLR was significantly larger in patients with acute tICH expansion compared to those without acute tICH expansion (mean [SD], 1.08 [1.05] vs. 0.59 [0.37], P < 0.001). A nonlinear positive relationship between MLR and the incidence of acute tICH expansion was observed. Multivariate logistic regression indicated MLR as an independent risk factor for acute tICH expansion (odds ratio (OR), 5.88; 95% confidence interval (CI), 4.02-8.61). The power of the multivariate model for predicting acute tICH expansion was substantially improved with the inclusion of MLR (AUC 0.86 vs. AUC 0.74, P < 0.001), as was also observed in an external validation cohort (AUC 0.83 vs. AUC 0.71, P < 0.001). The net benefit of MLR model was higher between threshold probabilities of 20-100% in DCA. For clinical application, a nomogram derived from the multivariate model with MLR was introduced. In addition, MLR was positively associated with 6-month unfavorable outcome.

CONCLUSION

MLR is a novel predictor for traumatic parenchymatous hematoma expansion. A nomogram derived from the MLR model may provide an easy-to-use tool for predicting acute tICH expansion and promoting the individualized treatment of patients with hemorrhagic cerebral contusion. MLR is associated with long-term outcome after cerebral contusion.

Varying effects of tyrosine kinase inhibitors on platelet function-A need for individualized CML treatment to minimize the risk for hemostatic and thrombotic complications?

Since their introduction, tyrosine kinase inhibitors (TKIs, eg, imatinib, nilotinib, dasatinib, bosutinib, ponatinib) have revolutionized the treatment of chronic myeloid leukemia (CML). However, long-term treatment with TKIs is associated with serious adverse events including both bleeding and thromboembolism. Experimental studies have shown that TKIs can cause platelet dysfunction. Herein, we present the first side-by-side investigation comparing the effects of currently used TKIs on platelet function and thrombin generation when used in clinically relevant concentrations. A flow cytometry multiparameter protocol was used to study a range of significant platelet activation events (fibrinogen receptor activation, alpha granule, and lysosomal exocytosis, procoagulant membrane exposure, and mitochondrial permeability changes). In addition, thrombin generation was measured in the presence of TKIs to assess the effects on global hemostasis. Results show that dasatinib generally inhibited platelet function, while bosutinib, nilotinib, and ponatinib showed less consistent effects. In addition to these general trends for each TKI, we observed a large degree of interindividual variability in the effects of the different TKIs. Interindividual variation was also observed when blood from CML patients was studied ex vivo with whole blood platelet aggregometry, free oscillation rheometry (FOR), and flow cytometry. Based on the donor responses in the side-by-side TKI study, a TKI sensitivity map was developed. We propose that such a sensitivity map could potentially become a valuable tool to help in decision-making regarding the choice of suitable TKIs for a CML patient with a history of bleeding or atherothrombotic disease.

Coagulant Effects and Mechanism of Schefflera heptaphylla (L.) Frodin

Schefflera heptaphylla (L.) Frodin, are commonly used in anti-inflammatory, analgesic, traumatic bleeding and hemostasisas. In this paper, the coagulation effect of the ethanol extract (Set), ethyl acetate phase (Sea) and n-butanol phase (Sbu) was evaluated by prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT) and fibrinogen content (FIB) assays in vitro. Then, Three main lupanine triterpenes (compounds A-C) were isolated and identified from Sea and Sbu by a bioassay-guided method and their structure were identified as 3α-Hydroxy-lup-20(29)-ene-23, 28-dioic acid, betulinic acid 3-O-sulfate and 3α-Hydroxy-lup-20(29)-ene-23, 28-dioic acid 28-O-(α-l-rhamnopyranosyl(1→4)-O-β-d-glucopyranosyl(1→6))-β-d-glucopyranoside) by spectroscopic data analysis. Among of them, compound B was confirmed to have significant coagulant effect in vitro. Furthermore, the pro-coagulation mechanism of S. heptaphylla extracts and compound B were investigated by measuring whole blood viscosity (WBV), plasma viscosity (PV), erythrocyte sedimentetion rate (ESR), pack cell volume (PCV), APTT, PT, TT, and FIB in vivo. Meanwhile, the levels of thromboxane B2 (TXB2), 6-keto prostaglandin F1α (6-keto-PGF1α), endothelial nitric oxide synthase (eNOS) and (endothelin-1) ET-1 were detected. The bleeding time (BT) was tested by tail bleeding method, which proved the traumatic bleeding and hemostasis activities of S. heptaphylla. The pharmacology experiments showed that the Set, Sea, Sbu and compound B has significant pro-coagulation effect. In addition, compound B might be the main constituent of pro-coagulation in S. heptaphylla These results could support the fact that S. heptaphylla could be used traditionally to cure traumatic bleeding, and the pro-coagulation effects were associated with the regulation of vascular endothelium active substance and hemorheology parameters.

New advances in the diagnosis of von Willebrand disease

von Willebrand disease (VWD) is the most common autosomal inherited bleeding disorder, with an estimated prevalence of 1 in 1000 individuals. VWD is classified into quantitative and qualitative forms. Diagnosis of VWD is complex and requires (1) a personal history of bleeding symptoms, (2) family history of bleeding or VWD, and (3) confirmatory laboratory testing. There are certain bleeding assessment tools to objectively measure bleeding symptoms in patients that have been shown to correlate with the diagnosis as well as the severity of VWD. Laboratory diagnosis requires at least initially a measurement of von Willebrand factor (VWF) antigen levels, VWF platelet binding activity (VWF:RCo, VWF:GPIbM, and VWF:GPIbR), and factor VIII (FVIII) activity. Additional testing to confirm the specific subtype may include VWF collagen binding activity, low-dose ristocetin VWF-platelet binding, FVIII-VWF binding, VWF multimer analysis, and VWF propeptide antigen. Recent advances have been made regarding some of these assays. Molecular testing in VWD is not found to be useful in "low VWF" or most type 1 VWD cases but may be informative in patients with severe type 1 VWD, type 1C VWD, type 2 VWD, or type 3 VWD for accurate diagnosis, genetic counseling, and appropriate treatment. The diagnostic algorithm for VWD is complex, but advances continue to be made in improving VWF functional assays and diagnostic pathways.

Tranexamic Acid for Acute Hemorrhage: A Narrative Review of Landmark Studies and a Critical Reappraisal of Its Use Over the Last Decade

The publication of the Clinical Randomization of an Antifibrinolytic in Significant Hemorrhage-2 (CRASH-2) study and its intense dissemination prompted a renaissance for the use of the antifibrinolytic agent tranexamic acid (TXA) in acute trauma hemorrhage. Subsequent studies led to its widespread use as a therapeutic as well as prophylactic agent across different clinical scenarios involving bleeding, such as trauma, postpartum, and orthopedic surgery. However, results from the existing studies are confounded by methodological and statistical ambiguities and are open to varied interpretations. Substantial knowledge gaps remain on dosing, pharmacokinetics, mechanism of action, and clinical applications for TXA. The risk for potential thromboembolic complications with the use of TXA must be balanced against its clinical benefits. The present article aims to provide a critical reappraisal of TXA use over the last decade and a "thought exercise" in the potential downsides of TXA. A more selective and individualized use of TXA, guided by extended and functional coagulation assays, is advocated in the context of the evolving concept of precision medicine.

Factor VIII replacement is still the standard of care in haemophilia A

Prophylactic factor VIII (FVIII) has dramatically improved haemophilia A treatment, preventing joint bleeding and halting the deterioration of joint status. FVIII products with an extended plasma half-life further improve patients' quality of life and increase therapeutic adherence. New licensed classes of non-replacement products include prophylactic emicizumab, which is administered subcutaneously up to every 4 weeks. However, this drug is not suitable for acute bleeding episodes or management of major surgery, and long-term data on the impact of emicizumab on joint health, FVIII inhibitor development and thrombotic risk are awaited. Prophylaxis with FVIII replacement remains the standard of care in haemophilia A, with the aim of achieving a level of haemostasis control that allows patients to meet their lifestyle goals.

D-dimer levels enhance the discriminatory capacity of bleeding risk scores for predicting in-hospital bleeding events in acute pulmonary embolism

INTRODUCTION

Bleeding is a major complication of anticoagulation in acute pulmonary embolism (APE) while estimating individual bleeding risk remains challenging. Elevated D-dimer levels (DD) have been shown to predict bleeding events.

OBJECTIVES

(1) direct comparison of the capacity of bleeding risk prediction scores (VTE-BLEED, RIETE, HAS-BLED, HEMORR₂HAGES) to prognosticate in-hospital bleeding events in the acute phase of APE in a real-life population of APE patients;(2) augmentation of the discriminative capacity of fore mentioned scores with DD.

MATERIALS

Post-hoc analysis of a prospective observational study. DD levels were measured using the VIDAS D-dimer Exclusion test. Receiver operating characteristic curves, areas under the curve (AUC) for bleeding prediction were calculated for scores and DD. Bleeding scores+DD were compared using an established index quantifying the reclassification of patients (net reclassification index, NRI).

RESULTS

310 APE patients were included. 35(11.3%) bleeding events occurred (hematomas, GI, urinary tract, retroperitoneal, uterine, CNS, respiratory tract): 17 major (MB) and 18 clinically-relevant non-major bleedings (CRNMB), none were fatal. All scores had satisfactory AUCs (0.754-0.767), except HAS-BLED (AUC = 0.512; 0.455-0.569). DD were higher in patients with bleeding events (29,911 ng/ml vs. 4805 ng/ml, p = .031), AUC 0.621(0.520-0.721), p = .02. DD = 5750 ng/ml was characterized by OR = 2.3(95%CI 1.05-5.0) for all bleeding events. Adding DD improved the discriminatory capacity of tested scores in the non-high risk of bleeding category, NRI 0.07-03.

CONCLUSIONS

Of the tested scores RIETE, HEMORR₂HAGES, VTE-BLEED performed best at identifying APE patients at risk of in-hospital bleeding complications. DD levels may predict in-hospital bleeding events and may improve identifying patients classified as non-high risk who experience bleeding complications.

The risk of major bleeding in patients with suspected heparin-induced thrombocytopenia

BACKGROUND

The presence of a hypercoagulable disorder such as heparin-induced thrombocytopenia (HIT) may protect against anticoagulant-associated bleeding.

OBJECTIVES

To determine the incidence of major bleeding in patients with suspected HIT.

METHODS

We performed a retrospective analysis of 310 patients suspected of having HIT from the Hospital of the University of Pennsylvania and an affiliated community hospital. We compared the cumulative incidence of major bleeding following suspicion for HIT by ultimate HIT status (HIT+ or HIT-) and exposure to an alternative anticoagulant (Tx+ or Tx-). Secondary outcomes included the incidence of new/progressive thrombosis and 30-day mortality.

RESULTS

The incidence of major bleeding was high in the HIT+Tx+, HIT- Tx+, and HIT-Tx- groups (35.7%, 44.0%, and 37.3%, respectively). The time to first major bleeding event did not differ between groups (P = .24). Factors associated with increased risk of major bleeding included intensive care unit admission (HR 2.24, 95% CI 1.44-3.47), platelet count < 25 × 109 /L (HR 2.13, 1.10-4.12), and renal dysfunction (HR 1.56, 1.06-2.27); 35.7% of HIT+Tx+, 13.8% HIT-Tx+, and 9.3% of HIT-Tx- patients experienced new or progressive thrombosis. Mortality was similar among the three groups (26.2% HIT+Tx+, 34.5% HIT-Tx+, and 26.7% of HIT-Tx- [P = .34]).

CONCLUSIONS

Among patients with suspected HIT, major bleeding was common regardless of HIT status. Contrary to our hypothesis, HIT+ patients were not protected from major bleeding. A better understanding of bleeding risk is needed to inform management decisions in patients with suspected HIT.

Effect of tranexamic acid administration on acute traumatic coagulopathy in rats with polytrauma and hemorrhage

Trauma and hemorrhagic shock can lead to acute traumatic coagulopathy (ATC) that is not fully reversed by prehospital resuscitation as simulated with a limited volume of fresh whole blood (FWB) in a rat model. Tranexamic Acid (TXA) is used as an anti-fibrinolytic agent to reduce surgical bleeding if administered prior to or during surgery, and to improve survival in trauma if given early after trauma. It is not clear from the existing clinical literature whether TXA has the same mechanism of action in both settings. This study sought to explore the molecular mechanisms of TXA activity in trauma and determine whether administration of TXA as a supplement to FWB resuscitation could attenuate the established ATC in a rat model simulating prehospital resuscitation of polytrauma and hemorrhagic shock. In a parallel in-vitro study, the effects on clotting assays of adding plasmin at varying doses along with either simultaneous addition of TXA or pre-incubation with TXA were measured, and the results suggested that maximum anti-fibrinolytic effect of TXA on plasmin-induced fibrinolysis required pre-incubation of TXA and plasmin prior to clot initiation. In the rat model, ATC was induced by polytrauma followed by 40% hemorrhage. One hour after trauma, the rats were resuscitated with FWB collected from donor rats. Vehicle or TXA (10mg/kg) was given as bolus either before trauma (TXA-BT), or 45min after trauma prior to resuscitation (TXA-AT). The TXA-BT group was included to contrast the coagulation effects of TXA when used as it is in elective surgery vs. what is actually feasible in real trauma patients (TXA-AT group). A single dose of TXA prior to trauma significantly delayed the onset of ATC from 30min to 120min after trauma as measured by a rise in prothrombin time (PT). The plasma d-dimer as well as plasminogen/fibrinogen ratio in traumatized liver of TXA-BT were significantly lower as compared to vehicle and TXA-AT. Wet/dry weight ratio and leukocytes infiltration of lungs were significantly decreased only if TXA was administrated later, prior to resuscitation (TXA-AT). In conclusion: Limited prehospital trauma resuscitation that includes FWB and TXA may not correct established systemic ATC, but rather may improve overall outcomes of resuscitation by attenuation of acute lung injury. By contrast, TXA given prior to trauma reduced levels of fibrinolysis at the site of tissue injury and circulatory d-dimer, and delayed development of coagulopathy independent of reduction of fibrinogen levels following trauma. These findings highlight the importance of early administration of TXA in trauma, and suggest that further optimization of dosing protocols in trauma to exploit TXA’s various sites and modes of action may further improve patient outcomes.