The current status of viscoelastic testing in septic coagulopathy

Effect of hypofibrinolysis on clinical outcomes of patients with septic disseminated intravascular coagulation

BACKGROUND

This study investigated the utility of thromboelastometry (ROTEM) in assessing hypofibrinolysis among septic patients, specifically the association of hypofibrinolysis, as determined by ROTEM, with septic disseminated intravascular coagulation (DIC), organ dysfunction, and clinical outcomes.

METHODS

This single-center, retrospective analysis included adult septic patients admitted to Saga University Hospital from 2013 to 2017, with available ROTEM data. Hypofibrinolysis was assessed using the lysis index at 60 min (LI60) in extrinsic thromboelastometry (EXTEM). Based on their LI60 values, patients were classified into three groups: Hyper (LI60 ≤ 85), Normal (LI60 86-96), and Hypo (LI60 ≥ 97).

RESULTS

Among the 63 cases analyzed, the Hypo group showed significantly higher APACHEII and SOFA scores than the Normal group, indicating greater disease severity. Similarly, DIC and sepsis-induced coagulopathy (SIC) scores were notably higher in the Hypo group. The diagnostic performance of LI60 for ISTH-overt DIC showed an area under the curve (AUC) of 0.954, with an optimal cutoff value of 97 %, achieving 100 % sensitivity and 83.3 % specificity. The odds ratio for ISTH-overt DIC was 2.894, indicating a strong association between elevated LI60 and occurrence of DIC. Hypofibrinolysis predicted 28-day mortality and high SOFA scores (≥ 10) with high specificity and negative predictive value (NPV). A Kaplan-Meier curve revealed that the Hypo Group showed significantly worse clinical outcomes than the Normal and Hyper groups.

CONCLUSION

For septic patients, fibrinolysis suppression presenting as "hypofibrinolysis" (elevated LI60) is associated with poor prognosis and risk of higher organ dysfunction. Moreover, it is a significant predictor of adverse clinical outcomes in sepsis.

Viscoelastic testing of fibrinolytic capacity in acutely infected critically ill patients: Protocol for a scoping review

INTRODUCTION

Viscoelastic testing (VET) has been implemented in clinical care to diagnose and manage coagulation in patients with manifest or high risk of major bleeding. However, the breakdown of formed blood clots, that is, fibrinolysis, has been comparatively less studied. There is an increasing recognition that acute infections trigger a dysregulated immunothrombotic response, which has focused attention on viscoelastic testing to identify in particular fibrinolysis resistant states.

METHODS

This scoping review on fibrinolysis assessment using viscoelastic testing will be conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). Publications will be included in the review if they evaluate the fibrinolytic capacity of adult patients admitted to an intensive care unit (ICU) for acute infection (including SARS-CoV2) using VET assays that included a fibrinolytic agent. No date or language restrictions will be applied, and all study designs will be considered. A peer-reviewed search strategy will be employed in multiple electronic bibliographic databases and will also include the grey literature.

RESULTS

The included studies will be reported by descriptive analyses and tabulated results.

CONCLUSION

This scoping review aims to map the research describing viscoelastic testing (VET) to assess fibrinolysis in acutely infected critically ill patients, with the goal of identifying diagnostic capabilities, any associations with patient outcomes, and the potential to guide clinical management.

Variability in individual native fibrin fiber mechanics

Fibrin fibers are important structural elements in blood coagulation. They form a mesh network that acts as a scaffold and imparts mechanical strength to the clot. A review of published work measuring the mechanics of fibrin fibers reveals a range of values for fiber extensibility. This study investigates fibrinogen concentration as a variable responsible for variability in fibrin mechanics. It expands previous work to describe the modulus, strain hardening, extensibility, and the force required for fiber failure when fibers are formed with different fibrinogen concentrations using lateral force atomic force microscopy. Analysis of the mechanical properties showed fibers formed from 1 mg ml-1and 2 mg ml-1fibrinogen had significantly different mechanical properties. To help clarify our findings we developed two behavior profiles to describe individual fiber mechanics. The first describes a fiber with low initial modulus and high extensible, that undergoes significant strain hardening, and has moderate strength. Most fibers formed with 1 mg ml-1fibrinogen had this behavior profile. The second profile describes a fiber with a high initial modulus, minimal strain hardening, high strength, and low extensibility. Most fibrin fibers formed with 2 mg ml-1fibrinogen were described by this second profile. In conclusion, we see a range of behaviors from fibers formed from native fibrinogen molecules but various fibrinogen concentrations. Potential differences in fiber formation are investigated with SEM. It is likely this range of behaviors also occursin vivo. Understanding the variability in mechanical properties could contribute to a deeper understanding of pathophysiology of coagulative disorders.

Hemostatic disorders in patients with infective endocarditis undergoing urgent surgical valve replacement - Rethinking current beliefs

BACKGROUND

Although infective endocarditis (IE) represents a unique model of thrombo-inflammatory disease, the most frequent early complications of surgical valve replacement (SVR) in IE population are coagulopathy and bleeding. The hemostatic capacity and procedure-related coagulation disorders of IE patients undergoing SVR are unknown. The aims of this study were to test periprocedural hemostasis in IE patients undergoing urgent SVR, and to assess the association between disorders of hemostasis and early bleeding as well as with thromboembolic events.

METHODS

A prospective, two-center, hypothesis generating, observational study was performed between Dec 2017 and Jan 2020. Periprocedural hemostasis of IE patients was assessed using Total Thrombus-formation Analysis System (T-TAS Plus) within 24 h before and 72 h post SVR.

RESULTS

Overall, 25 patients with active IE undergoing urgent SVR were tested. Hemostatic capacity of IE patients was significantly impaired pre-SVR as well as post-SVR compared to normal values, in most aspects of T-TAS assays under high and low shear forces, including prolonged activation of coagulation (T10), final clot formation (OT) and clot strength (AUC30). Post-SVR T-TAS results were significantly associated with early bleeding and with red blood cell, platelet, and fresh frozen plasma administration. No association with thrombo-embolic events was found.

CONCLUSIONS

Patients with active IE undergoing urgent SVR have significantly reduced hemostatic capacity before and after SVR. Hemostatic insufficiency post-SVR is related to bleeding and blood products transfusion. T-TAS may be helpful in assessment of periprocedural hemostasis in patients with IE undergoing SVR.

D-DI/PLT can be a prognostic indicator for sepsis

Aims

To investigate the indicators affecting the early outcome of patients with sepsis and to explore its prognostic efficacy for sepsis.

Methods

We collected clinical data from 201 patients with sepsis admitted to the emergency department of Xijing Hospital between June 2019 and June 2022. The patients were categorized into groups (survival or fatality) based on their 28-day prognosis. The clinical characteristics, biochemical indexes, organ function-related indicators, and disease scores of the patients were analyzed for both groups. Risk factor analysis was conducted for the indicators with significant differences.

Results

Among the indicators with significant differences between the deceased and survival groups, D-dimer (D-DI), Sequential Organ Failure Assessment (SOFA) score, platelet (PLT), international normalized ratio (INR), and D-DI/PLT were identified as independent risk factors affecting the prognosis of sepsis patients. Receiver operating characteristic (ROC) curves showed that D-DI/PLT (area under the curve (AUC) = 93.9), D-DI (AUC = 89.6), PLT (AUC = 81.3), and SOFA (AUC = 78.4) had good judgment efficacy. Further, Kaplan Meier (K-M) survival analysis indicated that the 28-day survival rates of sepsis patients were significantly decreased when they had high levels of D-DI/PLT, D-DI, and SOFA as well as low PLTs. The hazard ratio (HR) of D-DI/PLT between the two groups was the largest (HR = 16.19).

Conclusions

D-DI/PLT may be an independent risk factor for poor prognosis in sepsis as well as a clinical predictor of patient prognosis.

Sepsis Induced Coagulopathy: Bringing Science to the Bedside

How to cite this article: Samavedam S, Sepsis Induced Coagulopathy: Bringing Science to the Bedside. Indian J Crit Care Med 2023;27(9): 611-612.

Comparison of a viscoelastic point-of-care coagulation monitor with thromboelastography in sick dogs with hemostatic abnormalities

BACKGROUND

Viscoelastic coagulation monitor (VCM-Vet) is a point-of-care device that has been used to characterize hemostatic abnormalities in sick pets but has not been validated in veterinary patients.

OBJECTIVES

We aimed to compare VCM-Vet and thromboelastography (TEG) in sick dogs with suspected disorders of hemostasis.

METHODS

Duplicate VCM-Vet tests using untreated native blood performed concurrently on two VCM-Vet machines, and simultaneous TEG tests were performed (one citrated native (CN), and one activated with tissue factor (TF) at a 1:3600 dilution). Each VCM-Vet result was compared with both TF-activated and CN TEG.

RESULTS

Fifty-three dogs were enrolled. Eleven cases displayed apparent hyperfibrinolysis. Spearman correlation coefficients for individual VCM-Vet devices and CN and TF TEG were obtained between R and CT values and ranged from 0.21 to 0.27, CFT and K (r = 0.60-0.67), angles (r = 0.51-0.62), and MCF and MA (r = 0.85-0.87). Comparison of the two VCM-Vet devices displayed positive correlations for all clot formation parameters with Lin's concordance correlation coefficients of 0.75-0.95. Variable lysis parameter agreement existed between the VCM-Vet devices and VCM-Vet and TEG. When samples were classified as hypercoagulable or coagulopathic, VCM-Vet had a low positive predictive value (17-33%) for the detection of hypercoagulable states and a moderate negative predictive value (64-74%) for the detection of coagulopathy as defined by TEG.

CONCLUSIONS

VCM-Vet and TEG had variable correlations in clot formation values and a strong correlation for final clot strength. More information is needed to make conclusions about the lysis parameters. Artifact in the fibrinolysis portion of the test can confound the interpretation of VCM-Vet results.

Sepsis-Induced Coagulopathy: An Update on Pathophysiology, Biomarkers, and Current Guidelines

Significant cross talk occurs between inflammation and coagulation. Thus, coagulopathy is common in sepsis, potentially aggravating the prognosis. Initially, septic patients tend to exhibit a prothrombotic state through extrinsic pathway activation, cytokine-induced coagulation amplification, anticoagulant pathways suppression, and fibrinolysis impairment. In late sepsis stages, with the establishment of disseminated intravascular coagulation (DIC), hypocoagulability ensues. Traditional laboratory findings of sepsis, including thrombocytopenia, increased prothrombin time (PT) and fibrin degradation products (FDPs), and decreased fibrinogen, only present late in the course of sepsis. A recently introduced definition of sepsis-induced coagulopathy (SIC) aims to identify patients at an earlier stage when changes to coagulation status are still reversible. Nonconventional assays, such as the measurement of anticoagulant proteins and nuclear material levels, and viscoelastic studies, have shown promising sensitivity and specificity in detecting patients at risk for DIC, allowing for timely therapeutic interventions. This review outlines current insights into the pathophysiological mechanisms and diagnostic options of SIC.

Comparison of assessment of coagulation in healthy dogs by the TEG 6s and TEG 5000 viscoelastic analyzers

The TEG 6s (Haemonetics) point-of-care viscoelastic analyzer is portable, compact, simple to use, and has the potential for rapid viscoelastic analysis that can guide the treatment of veterinary patients at the site of care. Although approved for use in people, the TEG 6s has yet to be evaluated for hemostatic analysis in veterinary medicine. Citrated whole blood (CWB) was collected from 27 healthy dogs. An aliquot of CWB from each dog was diluted by 33% with an isotonic crystalloid, representing an in vitro model of hemodilution. Unaltered and diluted CWB samples were analyzed using 2 TEG 6s and 6 TEG 5000 (Haemonetics) analyzers. The 6 TEG 5000 analyzers ran duplicate analyses of either unaltered or diluted samples using 1 of 3 reagents (Haemonetics): Kaolin TEG, RapidTEG, or TEG Functional Fibrinogen. Duplicate TEG 5000 analyses were averaged and compared with a single TEG 6s analysis. Lin concordance correlation coefficient and Bland-Altman plots were used to evaluate agreement of reaction time, kinetic time, alpha angle, maximum amplitude (MA), and G value (G) for samples activated with Kaolin TEG, and agreement of MA for samples activated with RapidTEG between the 2 machines. Overall, agreement between the TEG 6s and TEG 5000 analyzers was poor. Viscoelastic measurements by the TEG 6s and TEG 5000 in healthy dogs were not all interchangeable. Agreement was satisfactory only for MA and G measurements of diluted blood samples activated with Kaolin TEG, and MA measurements for both unaltered and diluted blood samples activated with RapidTEG.

Predictive ability of viscoelastic testing using ClotPro® for short-term outcome in patients with severe Covid-19 ARDS with or without ECMO therapy: a retrospective study

BACKGROUND

SARS-CoV-2 infections are suspected to trigger the coagulation system through various pathways leading to a high incidence of thromboembolic complications, hypercoagulation and impaired fibrinolytic capacity were previously identified as potentially mechanisms. A reliable diagnostic tool for detecting both is still under discussion. This retrospective study is aimed to examine the prognostic relevance of early viscoelastic testing compared to conventional laboratory tests in COVID-19 patients with acute respiratory distress syndrome (ARDS).

METHODS

All mechanically ventilated patients with COVID-19 related ARDS treated in our intensive care unit (ICU) between January and March 2021 were included in this study. Viscoelastic testing (VET) was performed using the ClotPro® system after admission to our ICU. Prevalence of thromboembolic events was observed by standardized screening for venous and pulmonary thromboembolism using complete compression ultrasound and thoracic computed tomography pulmonary angiography at ICU admission, respectively. We examined associations between the severity of ARDS at admission to our ICU, in-hospital mortality and the incidence of thromboembolic events comparing conventional laboratory analysis and VET. ECMO related coagulopathy was investigated in a subgroup analysis. The data were analyzed using the Mann-Whitney U test.

RESULTS

Of 55 patients enrolled in this study, 22 patients required treatment with ECMO. Thromboembolic complications occurred in 51% of all patients. Overall hospital mortality was 55%. In patients with thromboembolic complications, signs of reduced fibrinolytic capacity could be detected in the TPA assay with prolonged lysis time, median 460 s (IQR 350-560) vs 359 s (IQR 287-521, p = 0.073). Patients with moderate to severe ARDS at admission to our ICU showed increased maximum clot firmness as a sign of hypercoagulation in the EX-test (70 vs 67 mm, p < 0.05), FIB-test (35 vs 24 mm, p < 0.05) and TPA-test (52 vs 36 mm, p < 0.05) as well as higher values of inflammatory markers (CRP, PCT and IL6). ECMO patients suffered more frequently from bleeding complications (32% vs 15%).

CONCLUSION

Although, the predictive value for thromboembolic complications or mortality seems limited, point-of-care viscoelastic coagulation testing might be useful in detecting hypercoagulable states and impaired fibrinolysis in critically ill COVID-19 ARDS patients and could be helpful in identifying patients with a potentially very severe course of the disease.

Enhancing Anticoagulation Monitoring and Therapy in Patients Undergoing Microvascular Reconstruction in Maxillofacial Surgery: A Prospective Observational Trial

Background: In reconstructive surgery, loss of a microvascular free flap due to perfusion disorders, especially thrombosis, is a serious complication. In recent years, viscoelastic testing (VET) has become increasingly important in point-of-care (POC) anticoagulation monitoring. This paper describes a protocol for enhanced anticoagulation monitoring during maxillofacial flap surgery. Objective: The aim of the study will be to evaluate, in a controlled setting, the predictive value of POC devices for the type of flap perfusion disorders due to thrombosis or bleeding. VET, Platelet monitoring (PM) and standard laboratory tests (SLT) are comparatively examined. Methods/Design: This study is an investigator-initiated prospective trial in 100 patients undergoing maxillofacial surgery. Patients who undergo reconstructive surgery using microvascular-free flaps will be consecutively enrolled in the study. All patients provide blood samples for VET, PM and SLT at defined time points. The primary outcome is defined as free flap loss during the hospital stay. Statistical analyses will be performed using t-tests, including the Bonferroni adjustment for multiple comparisons. Discussion: This study will help clarify whether VET can improve individualized patient care in reconstruction surgery. A better understanding of coagulation in relation to flap perfusion disorders may allow real-time adaption of antithrombotic strategies and potentially prevent flap complications.

Point of care coagulation management in anesthesiology and critical care

Point of care (POC) devices are increasingly used in the ICU and in anesthesia. Besides POC-devices for blood gas analysis, several devices are available for coagulation measurements. Although basic principles for thromboelastographic measurements are not novel, some promising developments were made during the last decade improving both user-friendliness and measurement reliability. For instance, POC measurements of activated clotting time (ACT) for heparin monitoring is still regarded as standard-of-care in cardiac interventions and surgery. In the field of anesthesia and intensive care medicine, POC-devices for thromboelastographic and platelet aggregation measurements are widely used. Their impact in case of bleeding and patient blood management for cardiothoracic and trauma surgery is well known. Moreover, there are promising concepts for anticoagulation monitoring including new oral anticoagulant drugs. Coagulation POC-devices may also identify patients at specific risk for thromboembolic events quickly. On the other hand, benefits of POC-devices need to be balanced against limitations, which include technical restrictions and operator related errors, mainly affecting reproducibility and interpretation of results. Therefore, it is recommendable to consider results of POC-coagulation testing in comparison to standard laboratory tests (SLT). Nevertheless, in urgent or emergency situations POC results enable fast decision making to optimize patient care.

Transcriptomic Analysis Reveals Differential Expression of Genes between Lung Capillary and Post Capillary Venules in Abdominal Sepsis

Lung endothelial cell dysfunction plays a central role in septic-induced lung injury. We hypothesized that endothelial cell subsets, capillary endothelial cells (capEC) and post capillary venules (PCV), might play different roles in regulating important pathophysiology in sepsis. In order to reveal global transcriptomic changes in endothelial cell subsets during sepsis, we induced sepsis in C57BL/6 mice by cecal ligation and puncture (CLP). We confirmed that CLP induced systemic and lung inflammation in our model. Endothelial cells (ECs) from lung capillary and PCV were isolated by cell sorting and transcriptomic changes were analyzed by bioinformatic tools. Our analysis revealed that lung capEC are transcriptionally different than PCV. Comparison of top differentially expressed genes (DEGs) of capEC and PCV revealed that capEC responses are different than PCV during sepsis. It was found that capEC are more enriched with genes related to regulation of coagulation, vascular permeability, wound healing and lipid metabolic processes after sepsis. In contrast, PCV are more enriched with genes related to chemotaxis, cell–cell adhesion by integrins, chemokine biosynthesis, regulation of actin filament process and neutrophil homeostasis after sepsis. In addition, we predicted some transcription factor targets that regulate a significant number of DEGs in sepsis. We proposed that targeting certain DEGs or transcriptional factors would be useful in protecting against sepsis-induced lung damage.

Coagulopathy and sepsis: Pathophysiology, clinical manifestations and treatment

Sepsis is a complex syndrome with a high incidence, increasing by 8.7% annually over the last 20 years. Coagulopathy is a leading factor associated with mortality in patients with sepsis and range from slight thrombocytopenia to fatal disorders, such as disseminated intravascular coagulation (DIC). Platelet reactivity increases during sepsis but prospective trials of antiplatelet therapy during sepsis have been disappointing. Thrombocytopenia is a known predictor of worse prognosis during sepsis. The mechanisms underlying thrombocytopenia in sepsis have yet to be fully understood but likely involves decreased platelet production, platelet sequestration and increased consumption. DIC is an acquired thrombohemorrhagic syndrome, resulting in intravascular fibrin formation, microangiopathic thrombosis, and subsequent depletion of coagulation factors and platelets. DIC can be resolved with treatment of the underlying disorder, which is considered the cornerstone in the management of this syndrome. This review presents the current knowledge on the pathophysiology, diagnosis, and treatment of sepsis-associated coagulopathies.

Viscoelastometric Testing to Assess Hemostasis of COVID-19: A Systematic Review

Infection by SARS-CoV-2 is associated with a high risk of thrombosis. The laboratory documentation of hypercoagulability and impaired fibrinolysis remains a challenge. Our aim was to assess the potential usefulness of viscoelastometric testing (VET) to predict thrombotic events in COVID-19 patients according to the literature. We also (i) analyzed the impact of anticoagulation and the methods used to neutralize heparin, (ii) analyzed whether maximal clot mechanical strength brings more information than Clauss fibrinogen, and (iii) critically scrutinized the diagnosis of hypofibrinolysis. We performed a systematic search in PubMed and Scopus databases until 31st December 2020. VET methods and parameters, and patients' features and outcomes were extracted. VET was performed for 1063 patients (893 intensive care unit (ICU) and 170 non-ICU, 44 studies). There was extensive heterogeneity concerning study design, VET device used (ROTEM, TEG, Quantra and ClotPro) and reagents (with non-systematic use of heparin neutralization), timing of assay, and definition of hypercoagulable state. Notably, only 4 out of 25 studies using ROTEM reported data with heparinase (HEPTEM). The common findings were increased clot mechanical strength mainly due to excessive fibrinogen component and impaired to absent fibrinolysis, more conspicuous in the presence of an added plasminogen activator. Only 4 studies out of the 16 that addressed the point found an association of VETs with thrombotic events. So-called functional fibrinogen assessed by VETs showed a variable correlation with Clauss fibrinogen. Abnormal VET pattern, often evidenced despite standard prophylactic anticoagulation, tended to normalize after increased dosing. VET studies reported heterogeneity, and small sample sizes do not support an association between the poorly defined prothrombotic phenotype of COVID-19 and thrombotic events.

Development of a Nomogram to Predict 28-Day Mortality of Patients With Sepsis-Induced Coagulopathy: An Analysis of the MIMIC-III Database

Background: Sepsis-induced coagulopathy (SIC) is a common cause for inducing poor prognosis of critically ill patients in intensive care unit (ICU). However, currently there are no tools specifically designed for assessing short-term mortality in SIC patients. This study aimed to develop a practical nomogram to predict the risk of 28-day mortality in SIC patients.

Methods: In this retrospective cohort study, we extracted patients from the Medical Information Mart for Intensive Care III (MIMIC-III) database. Sepsis was defined based on Sepsis 3.0 criteria and SIC based on Toshiaki Iba's criteria. Kaplan–Meier curves were plotted to compare the short survival time between SIC and non-SIC patients. Afterward, only SIC cohort was randomly divided into training or validation set. We employed univariate logistic regression and stepwise multivariate analysis to select predictive features. The proposed nomogram was developed based on multivariate logistic regression model, and the discrimination and calibration were verified by internal validation. We then compared model discrimination with other traditional severity scores and machine learning models.

Results: 9432 sepsis patients in MIMIC III were enrolled, in which 3280 (34.8%) patients were diagnosed as SIC during the first ICU admission. SIC was independently associated with the 7- and 28-day mortality of ICU patients. K–M curve indicated a significant difference in 7-day (Log-Rank: P < 0.001 and P = 0.017) and 28-day survival (Log-Rank: P < 0.001 and P < 0.001) between SIC and non-SIC groups whether the propensity score match (PSM) was balanced or not. For nomogram development, a total of thirteen variables of 3,280 SIC patients were enrolled. When predicted the risk of 28-day mortality, the nomogram performed a good discrimination in training and validation sets (AUROC: 0.78 and 0.81). The AUROC values were 0.80, 0.81, 0.71, 0.70, 0.74, and 0.60 for random forest, support vector machine, sequential organ failure assessment (SOFA) score, logistic organ dysfunction score (LODS), simplified acute physiology II score (SAPS II) and SIC score, respectively, in validation set. And the nomogram calibration slope was 0.91, the Brier value was 0.15. As presented by the decision curve analyses, the nomogram always obtained more net benefit when compared with other severity scores.

Conclusions: SIC is independently related to the short-term mortality of ICU patients. The nomogram achieved an optimal prediction of 28-day mortality in SIC patient, which can lead to a better prognostics assessment. However, the discriminative ability of the nomogram requires validation in external cohorts to further improve generalizability.

Use of Thromboelastography in Clinical Practice

Viscoelastic testing, such as thromboelastography or thromboelastometry, is performed on whole-blood samples, which include both soluble plasma factors as well as blood cells and platelets bearing tissue factor and phospholipid. This methodology allows identification of fibrinolysis and can provide analysis of platelet function. Viscoelastic testing has become increasingly accessible and popular in emergency and critical care settings in recent years and can provide important information for the diagnosis and management of patients with hemostatic disorders. This article discusses the principles and interpretation of viscoelastic testing, application to small animal emergency and critical care medicine, and potential advantages and disadvantages.

Are thromboelastometric and thromboelastographic parameters associated with mortality in septic patients? A systematic review and meta-analysis

BACKGROUND

Thromboelastometry/elastography (ROTEM/TEG) showed promising results for diagnosis of sepsis-induced coagulopathy, but their association with the outcome is unclear. Our aim was to assess any difference in ROTEM/TEG measurements between septic survivors and non-survivors.

METHODS

Pubmed, Web of Science, Embase and Cochrane Library databases were investigated. The research aimed to include any randomized or observational study: i) on septic adult patients admitted to Intensive Care Unit (ICU) or Emergency Department (ED); ii) including ROTEM/TEG; iii) assessing mortality.

RESULTS

Seven prospective and four retrospective observational studies (952 patients) were included. According to the INTEM/kaolin-assay, clotting time (CT)/R (standardized mean difference(SMD) -0.29, 95% CI -0.49 to -0.09, p = 0.004) and clot formation time (CFT)/K (SMD -0.42, 95% CI -0.78 to -0.06, p = 0.02) were shorter in survivors. According to the EXTEM-assay, CT was shorter (MD -11.66 s, 95% CI -22.59 to -0.73, p = 0.04), while MCF was higher (MD 3.49 mm, 95% CI 0.43 to 6.55, p = 0.03) in survivors. A hypocoagulable profile was more frequent in non-survivors (OR 0.31, 95%CI 0.18 to 0.55, p < 0.0001). Overall, the risk of bias of the included studies was moderate and the quality of evidence low.

CONCLUSIONS

Hypocoagulability and lower MCF in EXTEM may be associated with higher mortality in sepsis.

Management of the thrombotic risk associated with COVID-19: guidance for the hemostasis laboratory

Coronavirus disease 2019 (COVID-19) is associated with extreme inflammatory response, disordered hemostasis and high thrombotic risk. A high incidence of thromboembolic events has been reported despite thromboprophylaxis, raising the question of a more effective anticoagulation. First-line hemostasis tests such as activated partial thromboplastin time, prothrombin time, fibrinogen and D-dimers are proposed for assessing thrombotic risk and monitoring hemostasis, but are vulnerable to many drawbacks affecting their reliability and clinical relevance. Specialized hemostasis-related tests (soluble fibrin complexes, tests assessing fibrinolytic capacity, viscoelastic tests, thrombin generation) may have an interest to assess the thrombotic risk associated with COVID-19. Another challenge for the hemostasis laboratory is the monitoring of heparin treatment, especially unfractionated heparin in the setting of an extreme inflammatory response. This review aimed at evaluating the role of hemostasis tests in the management of COVID-19 and discussing their main limitations.

High D dimers and low global fibrinolysis coexist in COVID19 patients: what is going on in there?

BACKGROUD

COVID-19 coagulopathy linked to increased D-dimer levels has been associated with high mortality (Fei Z et al. in Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. Lancet (London, England) 395(10229):1054-62, 2020). While D-dimer is accepted as a disseminated intravascular coagulation marker, rotational thromboelastometry (ROTEM) also detects fibrinolysis (Wright FL et al. in Fibrinolysis shutdown correlates to thromboembolic events in severe COVID-19 infection. J Am Coll Surg (2020). Available from https://pubmed.ncbi.nlm.nih.gov/32422349/ [cited 14 Jun 2020]; Schmitt FCF et al. in Acute fibrinolysis shutdown occurs early in septic shock and is associated with increased morbidity and mortality: results of an observational pilot study. Ann Intensive Care 9(1):19, 2019). We describe the ROTEM profile in severely ill COVID-19 patients and compare it with the standard laboratory coagulation test.

METHODS

Adult patients diagnosed with COVID-19 admitted to the ICU were prospectively enrolled after Ethics Committee approval (HCB/2020/0371). All patients received venous thromboembolism prophylaxis; those on therapeutic anticoagulation were excluded. The standard laboratory coagulation test and ROTEM were performed simultaneously at 24-48 h after ICU admission. Sequential organ failure assessment (SOFA), disseminated intravascular coagulation (DIC) and sepsis-induced coagulopathy (SIC) scores were calculated at sample collection.

RESULTS

Nineteen patients were included with median SOFA-score of 4 (2-6), DIC-score of 1 (0-3) and SIC-score of 1.8 (0.9). Median fibrinogen, D-dimer levels and platelet count were 6.2 (4.8-7.6 g/L), 1000 (600-4200 ng/ml) and 236 (136-364 10⁹/L), respectively. Clot firmness was above the normal range in the EXTEM and FIBTEM tests while clot lysis was decreased. There was no significant correlation between ROTEM or D-dimer parameters and the SOFA score.

CONCLUSION

In COVID-19 patients, the ROTEM pattern was characterized by a hypercoagulable state with decreased fibrinolytic capacity despite a paradoxical increase in D-dimer levels. We suggest that, in COVID-19 patients, the lungs could be the main source of D-dimer, while a systemic hypofibrinolytic state coexists. This hypothesis should be confirmed by future studies.