Viscoelastic Hemostatic Assays Research Articles

What, When, and Why: Viscoelastic Hemostatic Assays and Their Uses in Trauma Resuscitation.

Viscoelastic hemostatic assays (VHAs) have become a valuable tool in guiding transfusion therapy, particularly in trauma care. While various forms of VHA exist, all provide a quantitative assessment of clot kinetics, strength, and dissolution. Studies have demonstrated that VHA can reduce both mortality and utilization of blood products in the general population. Interpreting VHA results requires consideration of specific patient factors, such as age and altered physiological properties as in pregnancy and the process of aging. Further research is needed to establish accurate reference ranges for these specific populations. This review article provides a comprehensive overview of the technical aspects of VHA as well as their clinical uses in trauma resuscitation.

Plasma transfusion in the intensive care unit.

Current guidelines discourage prophylactic plasma use in non-bleeding patients. This study assesses global plasma transfusion practices in the intensive care unit (ICU) and their alignment with current guidelines. This was a sub-study of an international, prospective, observational cohort. Primary outcomes were in-ICU occurrence rate of plasma transfusion, proportion of plasma events of total blood products events, and number of plasma units per event. Secondary outcomes included transfusion indications, INR/PT, and proportion of events for non-bleeding indications. Of 3643 patients included, 356 patients (10%) experienced 547 plasma transfusion events, accounting for 18% of total transfusion events. A median of 2 (IQR 1, 2) units was given per event excluding massive transfusion protocol (MTP) and 3 (IQR 2, 6) when MTP was activated. MTP accounted for 39 (7%) of events. Indications of non-MTP events included active bleeding (54%), prophylactic (25%), and pre-procedure (12%). Target INR/PT was stated for 43% of transfusion events; pre-transfusion INR/PT or visco-elastic hemostatic assays (VHA) were reported for 73%. Thirty-seven percent of events were administered for non-bleeding indications, 54% with a pre-transfusion INR < 3.0 and 30% with an INR < 1.5. Plasma transfusions occurred in 10% of ICU patients. Over a third were given for non-bleeding indications and might have been avoidable. Target INR/PT was not stated in more than half of transfusions, and pre-transfusion INR/PT or VHA was not reported for 27%. Further research and education is needed to optimize guideline implementation and to identify appropriate indications for plasma transfusion.

Viscoelastic haemostatic assays to guide therapy in elective surgery: an updated systematic review and meta-analysis.

Patients undergoing major surgery frequently experience major uncontrolled bleeding. The aim of this systematic review and meta-analysis was to evaluate the clinical efficacy of using viscoelastic haemostatic assays to manage peri-operative bleeding in elective surgery. We searched PubMed/MEDLINE and Embase databases for randomised controlled trials according to pre-determined criteria. The primary outcomes were blood product requirements; duration of stay in the operating theatre or ICU; and surgical reintervention rate. We included 20 randomised controlled trials. The overall risk of bias was low to moderate. Twelve studies used thromboelastography-based transfusion algorithms, while eight used thromboelastometry. Viscoelastic haemostatic assay-guided therapy was associated with a statistically significant reduction in transfusion of red blood cells (standardised mean difference (95%CI) 0.16 (-0.29 to 0.02)), platelets (standardised mean difference (95%CI) -0.33 (-0.56 to -0.10)) and fresh frozen plasma (standardised mean difference (95%CI) -0.64 (-1.01 to -0.28)). There was no evidence of an effect of viscoelastic haemostatic assay-guided therapy on surgical reintervention (relative risk (95%CI) 1.09 (0.70-1.69)). Viscoelastic haemostatic assay-guided therapy was associated with lower blood loss and shorter ICU duration of stay. There was no evidence of any effect on total duration of stay and all-cause mortality. Viscoelastic haemostatic assay-guided therapy may reduce peri-operative blood product transfusion requirements and blood loss during major elective surgery, with no discernible effect on patient-centred outcomes. The overall quality of evidence was modest.

Resuscitation of adult shocked trauma patients using major haemorrhage protocol guided by viscoelastic haemostatic assays versus formulaic approach.

The resuscitation of trauma patients with critical bleeding may follow a formulaic approach using high ratios of blood components or a viscoelastic haemostatic assay (VHA) guided approach. The aim of this study was to compare the two strategies for resuscitation of shocked trauma patients. This was a registry-based cohort study including shocked trauma patients from two trauma centres-one practising a formulaic approach, with VHA unavailable during trauma resuscitation and the other practicing a VHA-guided resuscitation strategy. The primary outcome was the total units of blood components transfused in 24 h after adjusting for differences in baseline characteristics and time to death. Between 01 Jan 2020 and 31 Dec 2022, 152 eligible patients were categorised to the formulaic group and 40 to the VHA group. Prehospital times were longer in the formulaic group (2.0 vs. 1.4 h), and more patients in the VHA group (38% vs. 17%) were transfused prehospital blood components. Formulaic resuscitation was associated with significantly more blood components transfused (adjusted incidence rate ratio 1.5; 95%CI: 1.4-1.7, p < 0.001). Using a formulaic approach, patients were administered more red blood cells, plasma and platelets, but fewer cryoprecipitate. There was no significant association of the formulaic approach with in-hospital mortality (adjusted odds ratio 2.4; 95%CI: 0.7-8.0, p = 0.17). Given the cost and potential adverse effects of blood component transfusions, VHA-guided transfusion strategies present an attractive option, particularly among centres managing high volumes of shocked patients. Further trials, enrolling the population most likely to benefit from precision transfusion strategies, are indicated.

Suggested Interdisciplinary Approach for Managing Postpartum Haemorrhage Caused by Uterine Atony-A Call for Updated Guidelines

Postpartum Hemorrhage (PPH) is a significant cause of maternal morbidity and mortality, often exacerbated by inadequate adherence to established guidelines. This article examines the critical role of uterine atony and explores the impact of factors such as inaccurate blood loss estimation and hematological complications. It critiques the existing clinical guidelines for insufficiently addressing the role of hematologists and proposes the integration of early assessment techniques, including viscoelastic hemostatic assays and targeted fibrinogen replacement, to more effectively manage coagulopathy. The article also highlights recent advancements, such as the Alma device, and advocates for a multidisciplinary approach that includes both obstetricians and hematologists to enhance PPH management and improve patient outcomes.

Correction of Trauma-induced Coagulopathy by Goal-directed Therapy: A Secondary Analysis of the ITACTIC Trial.

Trauma hemorrhage induces a coagulopathy with a high associated mortality rate. The Implementing Treatment Algorithms for the Correction of Trauma Induced Coagulopathy (ITACTIC) randomized trial tested two goal-directed treatment algorithms for coagulation management: one guided by conventional coagulation tests and one by viscoelastic hemostatic assays (viscoelastic). The lack of a difference in 28-day mortality led the authors to hypothesize that coagulopathic patients received insufficient treatment to correct coagulopathy. During ITACTIC, two sites were coenrolling patients into an ongoing prospective observational study, which included serial blood sampling at the same intervals as in ITACTIC. The subgroup in both studies had conventional and viscoelastic test results for each patient available for analysis. A goal-directed treatment was defined as one triggered by an ITACTIC algorithm. Coagulopathy was defined as rotational thromboelastometry EXTEM A5 less than 40 mm. The primary outcome was correction of coagulopathy by the 12th unit of erythrocyte transfusion during resuscitation. Full viscoelastic and conventional coagulation test results were available for 133 patients. Of these patients, 71% were coagulopathic on admission, and 16% developed a coagulopathy during resuscitation. ITACTIC viscoelastic hemostatic assay group patients were more likely to receive goal-directed treatment than the standard group (76% vs. 47%; odds ratio, 3.73; 95% CI, 1.64 to 8.49; P = 0.002). However, only 54% of patients received goal-directed treatment, and only 20% corrected their coagulopathy (vs. 0% with empiric treatment alone; not significant). Median time to first goal-directed treatment was 68 (53 to 88) min for viscoelastic and 110 (77 to 123) min for standard (P = 0.005). In ITACTIC, many bleeding trauma patients did not receive an indicated goal-directed treatment. Interventions arrived late during resuscitation and were only partially effective at correcting coagulopathy.

Admission Viscoelastic Hemostatic Assay Parameters Predict Poor Long-Term Intracerebral Hemorrhage Outcomes.

Viscoelastic hemostatic assays (VHAs) provide more comprehensive assessments of coagulation compared with conventional coagulation assays. Although VHAs have enabled guided hemorrhage control therapies, improving clinical outcomes in life-threatening hemorrhage, the role of VHAs in intracerebral hemorrhage (ICH) is unclear. If VHAs can identify coagulation abnormalities relevant for ICH outcomes, this would support the need to investigate the role of VHAs in ICH treatment paradigms. Thus, we investigated whether VHA assessments of coagulation relate to long-term ICH outcomes. Patients with spontaneous ICH enrolled into a single-center cohort study receiving admission Rotational Thromboelastometry (ROTEM) VHA testing between 2013 and 2020 were assessed. Patients with previous anticoagulant use or coagulopathy on conventional coagulation assays were excluded. Primary ROTEM exposure variables were coagulation kinetics and clot strength assessments. Poor long-term outcome was defined as modified Rankin Scale ≥ 4 at 6months. Logistic regression analyses assessed associations of ROTEM parameters with clinical outcomes after adjusting for ICH severity and hemoglobin concentration. Of 44 patients analyzed, the mean age was 64years, 57% were female, and the median ICH volume was 23mL. Poor 6-month outcome was seen in 64% of patients. In our multivariable regression models, slower, prolonged coagulation kinetics (adjusted odds ratio for every second increase in clot formation time 1.04, 95% confidence interval 1.00-1.09, p = 0.04) and weaker clot strength (adjusted odds ratio for every millimeter increase of maximum clot firmness 0.84, 95% confidence interval 0.71-0.99, p = 0.03) were separately associated with poor long-term outcomes. Slower, prolonged coagulation kinetics and weaker clot strength on admission VHA ROTEM testing, not attributable to anticoagulant use, were associated with poor long-term outcomes after ICH. Further work is needed to clarify the generalizability and the underlying mechanisms of these VHA findings to assess whether VHA-guided treatments should be incorporated into ICH care.

Postpartum hemorrhage and viscoelastic hemostatic assays

Postpartum hemorrhage and viscoelastic hemostatic assays

Does the Use of Viscoelastic Hemostatic Assays for Periprocedural Hemostasis Management in Liver Disease Improve Clinical Outcomes?

Routine hemostasis parameters such as prothrombin time and fibrinogen are frequently abnormal in patients with chronic liver disease and have been demonstrated to be poor predictors for periprocedural bleeding. Alterations in procoagulant and anticoagulant factors in this population result in a state of rebalanced hemostasis, which is not reflected by routine hemostatic measures. Viscoelastic hemostatic assays (VHA) present a point of care measure of global hemostasis with an emerging role in guiding transfusion in the liver transplant setting. The potential role for VHA in guiding periprocedural transfusion is unknown. Here we critically appraise the available limited evidence on the use of VHA to guide prophylactic treatment in patients with cirrhosis undergoing procedures. We assess whether the impact of a VHA-guided approach improves clinical outcomes. Suggested areas for future research with a focus on clinically relevant outcomes, particularly periprocedural bleeding, are highlighted.

Changing hemostatic management in post-partum hemorrhage.

Early and fast assessment of hemostasis during postpartum hemorrhage (PPH) is essential to allow early characterization of coagulopathy, estimate bleeding severity and improve outcome. During PPH, fibrinogen decrease occurs earlier than other coagulation factors deficiency and hypofibrinogenemia is an early marker of PPH severity of progression. With good evidence in the context of PPH, point-of-care viscoelastic (VET) hemostatic assays have been shown to provide rapid assessment of hemostatic disorders, low fibrinogen levels, and allow VET-guided fibrinogen replacement. Further studies are needed to define the thresholds for the other coagulation parameters.

Abstract TP158: Baseline Viscoelastic Hemostatic Assays and Associations With Poor Long-Term Intracerebral Hemorrhage Outcomes

Introduction: Viscoelastic hemostatic assays can detect coagulopathy relevant for intracerebral hemorrhage (ICH) patients at risk for hematoma expansion. However, it is unclear whether these assays associate with long term ICH outcomes. We sought to assess whether baseline coagulopathy detectable via viscoelastic hemostatic assay associates with poor 6-month neurological outcomes after ICH. Methods: Spontaneous ICH patients enrolled in a single-center prospective observational study from 2013 to 2020 who received baseline viscoelastic hemostatic assay testing via Rotational Thromboelastometry (ROTEM) were included. Patients with prior anticoagulant use were excluded. ROTEM assessments of coagulation kinetics and clot strength were the primary exposure variables. Poor 6-month neurological outcome was defined as modified Rankin Scale (mRS) 4-6. Multivariable logistic regression analyses assessed the relationships of ROTEM parameters with 6-month outcomes after adjusting for ICH score, hemoglobin, and sex. Results: Of 44 patients included for analysis, the mean age was 64, 57% were female, 52% had deep ICH, and the median ICH volume was 23.3 mL. Poor 6-month outcome was seen in 61%. We identified that slower coagulation kinetics was associated with poor 6-month outcome as assessed in both extrinsic and intrinsic pathways (EXTEM CFT: adjusted OR 1.06, 95% CI: 1.02-1.12, p=0.02; INTEM CFT: adjusted OR 1.05, 95% CI: 1.01-1.10, p=0.05, respectively). Weaker clot strength was also associated with poor 6-month outcome (EXTEM MCF: adjusted OR 0.78, 95% CI: 0.59-0.93, p=0.03; INTEM MCF: adjusted OR 0.83, 95% CI: 0.68-0.97). We did not identify similar relationships using conventional coagulation assays (ie., PT/PTT/INR, platelet count). Conclusions: We identified that baseline impaired coagulation kinetics and weaker clot strength seen using ROTEM testing associate with poor 6-month ICH outcomes. Further work is needed to clarify the generalizability of these findings and the mechanisms driving these relationships to assess whether viscoelastic guided therapies can potentially be used to improve long-term ICH outcomes.

Abstract TP159: Baseline Viscoelastic Hemostatic Assays and Associations With DWI Ischemic Lesions in Intracerebral Hemorrhage Patients

Introduction: Remote ischemic lesions identified on MRI neuroimaging after intracerebral hemorrhage (ICH) may be related to microthrombosis. We sought to evaluate whether hypercoagulability identified on viscoelastic hemostatic assay relates to these ischemic lesions. Methods: Spontaneous ICH patients enrolled in a single-center prospective observational study from 2009 to 2019 receiving baseline viscoelastic hemostatic assay: Rotational Thromboelastometry (ROTEM) and MRI neuroimaging were included. The presence and count of ischemic lesions identified on DWI imaging &gt;10 mm from the ICH were the outcome variables. ROTEM assessments of clot strength were the primary exposure variable. Logistic and linear regression assessed the association of ROTEM clot strength with DWI lesion presence and count after adjusting for ICH severity, ICH location, and anticoagulant use. Relationships of ROTEM assessments of coagulation kinetics and lysis with DWI lesions were explored. Results: Of 19 patients assessed, the mean age was 68, 37% were female, and DWI lesions were identified in 42%. Associations of greater ROTEM clot strength (FIBTEM MCF) with DWI lesions were imprecise (adjusted OR 1.16, 95%CI: 0.98-1.37, p=0.08). However, we identified that greater FIBTEM MCF significantly associated with increased DWI lesion count (adjusted β 0.16, 95%CI: 0.02-0.30, p=0.02). Exploratory analyses revealed that slower intrinsic pathway coagulation kinetics (INTEM CT) associated with increased DWI lesion count (adjusted β 0.06, 95% CI: 0.01-0.10, p=0.01). Conclusions: Baseline hypercoagulable ROTEM tracings may associate with DWI ischemic lesions after ICH. Further work is needed to clarify the generalizability of these findings and if specific coagulopathy mechanisms drive DWI lesion formation to assess whether there are relevant therapeutic targets to prevent secondary brain injury after ICH.

Patient blood management guideline for adults with critical bleeding.

The management of patients with critical bleeding requires a multidisciplinary approach to achieve haemostasis, optimise physiology, and guide blood component use. The 2011 Patient blood management guidelines: module 1 - critical bleeding/massive transfusion were updated and published. Systematic reviews were conducted for pre-specified research questions, and recommendations were based on meta-analyses of included studies. The critical bleeding/massive transfusion guideline includes seven recommendations and 11 good practice statements addressing: major haemorrhage protocols (MHPs) facilitating a multidisciplinary approach to haemorrhage control, correction of coagulopathy and normalisation of physiological derangement; measurement of physiological, biochemical and metabolic parameters in critical bleeding/massive transfusion; the optimal ratio of red blood cells to other blood components; the use of tranexamic acid; viscoelastic haemostatic assays; and cell salvage. The new guideline recommends MHPs be established as standard of care in all institutions managing patients with critical bleeding. In addition to routine physiological markers, the new guideline recommends temperature, biochemistry and coagulation profiles be measured early and frequently, providing parameters that define critical derangements. Ratio-based MHPs should include no fewer than four units of fresh frozen plasma and one adult unit of platelets for every eight units of red blood cells. In the setting of trauma and obstetric haemorrhage, administration of tranexamic acid within three hours of bleeding onset is recommended. The use of recombinant activated factor VII (rFVIIa) is not recommended. There was insufficient evidence to make recommendations on the use of viscoelastic haemostatic assays or cell salvage as part of MHPs.

Comparison of Two Viscoelastic Testing Devices in a Parturient Population

Background: Viscoelastic hemostatic assays (VHAs) have become an integral diagnostic tool in guiding hemostatic therapy, offering new opportunities in personalized hemostatic resuscitation. This study aims to assess the interchangeability of ClotPro® and ROTEM® delta in the unique context of parturient women. Methods: Blood samples from 217 parturient women were collected at three timepoints. A total of 631 data sets were eligible for our final analysis. The clotting times were analyzed via extrinsic and intrinsic assays, and the clot firmness parameters A5, A10, and MCF were analyzed via extrinsic, intrinsic, and fibrin polymerization assays. In parallel, the standard laboratory coagulation statuses were obtained. Device comparison was assessed using regression and Bland–Altman plots. The best cutoff calculations were used to determine the VHA values corresponding to the established standard laboratory cutoffs. Results: The clotting times in the extrinsic and intrinsic assays showed notable differences between the devices, while the extrinsic and intrinsic clot firmness results demonstrated interchangeability. The fibrinogen assays revealed higher values in ClotPro® compared to ROTEM®. An ROC analysis identified VHA parameters with high predictive values for coagulopathy exclusion and yet low specificity. Conclusions: In the obstetric setting, the ROTEM® and ClotPro® parameters demonstrate a significant variability. Device- and indication-specific transfusion algorithms are essential for the accurate interpretation of measurements and adequate hemostatic therapy.

User Perceptions of Visual Clot in a High-Fidelity Simulation Study: Mixed Qualitative-Quantitative Study.

Viscoelastic hemostatic assays, such as rotational thromboelastometry (ROTEM) or thromboelastography, enable prompt diagnosis and accelerate targeted treatment. However, the complex interpretation of the results remains challenging. Visual Clot-a situation awareness-based visualization technology-was developed to assist clinicians in interpreting viscoelastic tests. Following a previous high-fidelity simulation study, we analyzed users' perceptions of the technology, to identify its strengths and limitations from clinicians' perspectives. This is a mixed qualitative-quantitative study consisting of interviews and a survey. After solving coagulation scenarios using Visual Clot in high-fidelity simulations, we interviewed anesthesia personnel about the perceived advantages and disadvantages of the new tool. We used a template approach to identify dominant themes in interview responses. From these themes, we defined 5 statements, which were then rated on Likert scales in a questionnaire. We interviewed 77 participants and 23 completed the survey. We identified 9 frequently mentioned topics by analyzing the interview responses. The most common themes were "positive design features," "intuitive and easy to learn," and "lack of a quantitative component." In the survey, 21 respondents agreed that Visual Clot is easy to learn and 16 respondents stated that a combination of Visual Clot and ROTEM would help them manage complex hemostatic situations. A group of anesthesia care providers found Visual Clot well-designed, intuitive, and easy to learn. Participants highlighted its usefulness in emergencies, especially for clinicians inexperienced in coagulation management. However, the lack of quantitative information is an area for improvement.

Comparison of two viscoelastic testing devices in a porcine model of surgery, hemorrhage and resuscitation.

Viscoelastic hemostatic assays (VHA) are integral in contemporary hemostatic resuscitation, offering insights into clot formation, firmness, and lysis for rapid diagnosis and targeted therapy. Large animal models, particularly swine, provide anatomical and physiological analogies for coagulation research. Despite the growing use of VHAs, the ClotPro® device's applicability in porcine models remains unexplored. This study investigates ClotPro® in a porcine model of abdominal surgery, severe hemorrhage, and resuscitation, comparing it with the established ROTEM® delta system. Twenty-seven healthy pigs underwent abdominal surgery, hemorrhage and resuscitation. ClotPro® and ROTEM® were used to assess viscoelastic hemostatic properties at baseline, after surgery, 60min after shock induction, 60 and 120min after resuscitation. Clotting times in extrinsically and intrinsically stimulated assays exhibited fair to moderate correlation. Clot firmness in extrinsically stimulated tests could be used interchangeably while fibrin polymerization assays revealed significant differences between the devices. Fibrin polymerization assays in ClotPro® consistently yielded higher values than ROTEM®. Furthermore, the study evaluated the ClotPro® TPA-test's applicability in porcine blood, revealing failure of lysis induction in porcine blood samples. This research contributes valuable insights into the use of ClotPro® in porcine models of hemorrhage and coagulopathy, highlighting both its applicability and limitations in comparison to ROTEM® delta. The observed differences, especially in fibrin polymerization assays, emphasize the importance of understanding device-specific characteristics when interpreting results. Due to its inapplicability, TPA-test should not be used in porcine blood to evaluate fibrinolytic potential. The study provides a foundation for future investigations into the use of different viscoelastic hemostatic assays in porcine animal models.

CT-001, a novel fast-clearing factor VIIa, enhanced the hemostatic activity in postpartum samples

AbstractThe hemostatic system is upregulated to protect pregnant mothers from hemorrhage during childbirth. Studies of the details just before and after delivery, however, are lacking. Recombinant factor VIIa (rFVIIa) has recently been granted approval by the European Medicines Agency for the treatment of postpartum hemorrhage (PPH). A next-generation molecule, CT-001, is being developed as a potentially safer and more efficacious rFVIIa-based therapy. We sought to evaluate the peripartum hemostatic status of pregnant women and assess the ex vivo hemostatic activity of rFVIIa and CT-001 in peripartum blood samples. Pregnant women from 2 study sites were enrolled in this prospective observational study. Baseline blood samples were collected up to 3 days before delivery. Postdelivery samples were collected 45 (±15) minutes after delivery. Between the 2 time points, soluble fibrin monomer and D-dimer increased whereas tissue factor, FVIII, FV, and fibrinogen decreased. Interestingly, the postdelivery lag time and time to peak in the thrombin generation assay were shortened, and the peak thrombin generation capacity was maintained despite the reduced levels of coagulation proteins after delivery. Furthermore, both rFVIIa and CT-001 were effective in enhancing clotting activity of postdelivery samples in activated partial thromboplastin time, prothrombin time, thrombin generation, and viscoelastic hemostatic assays, with CT-001 demonstrating greater activity. In conclusion, despite apparent ongoing consumption of coagulation factors at the time of delivery, thrombin output was maintained. Both rFVIIa and CT-001 enhanced the upregulated hemostatic activity in postdelivery samples, and consistent with previous studies comparing CT-001 and rFVIIa in vitro and in in vivo, CT-001 demonstrated greater activity than rFVIIa.

Transfusion practices in intensive care units: An Australian and New Zealand point prevalence study

ObjectiveTo describe current transfusion practices in intensive care units (ICUs) in Australia and New Zealand, compare them against national guidelines, and describe how viscoelastic haemostatic assays (VHAs) are used in guiding transfusion decisions. Design, setting and participantsProspective, multicentre, binational point-prevalence study. All adult patients admitted to participating ICUs on a single day in 2021. Main outcome measuresTransfusion types, amounts, clinical reasons, and triggers; use of anti-platelet medications, anti-coagulation, and VHA. ResultsOf 712 adult patients in 51 ICUs, 71 (10%) patients received a transfusion during the 24hr period of observation. Compared to patients not transfused, these patients had higher Acute Physiology and Chronic Health Evaluation II scores (19 versus 17, p = 0.02), a greater proportion were mechanically ventilated (49.3% versus 37.3%, p < 0.05), and more had systemic inflammatory response syndrome (70.4% versus 51.3%, p < 0.01). Overall, 63 (8.8%) patients received red blood cell (RBC) transfusions, 10 (1.4%) patients received platelet transfusions, 6 (0.8%) patients received fresh frozen plasma (FFP), and 5 (0.7%) patients received cryoprecipitate. VHA was available in 42 (82.4%) sites but only used in 6.6% of transfusion episodes when available. Alignment with guidelines was found for 98.6% of RBC transfusions, but only 61.6% for platelet, 28.6% for FFP, and 20% for cryoprecipitate transfusions. ConclusionsNon-RBC transfusion decisions are often not aligned with guidelines and VHA is commonly available but rarely used to guide transfusions. Better evidence to guide transfusions in ICUs is needed.

Tranexamic Acid in Trauma Management: A Review of Evidence

Hemorrhage is the leading cause of death in trauma patients and trauma induced coagulopathy (TIC) is a major contributor to bleeding mortality. TIC has a diverse pathophysiology triggered by injury and hypoperfusion, including platelet dysfunction, endotheliopathy, fibrinogen or thrombin abnormalities, and dysregulated fibrinolysis. Early fluid resuscitation, appropriate blood transfusion, and definitive control of bleeding are essential components of initial management for TIC. Additionally, tranexamic acid (TXA), an antifibrinolytic agent, has emerged as a potential adjunctive therapy following the 2010 landmark trial that demonstrated the benefit of early administration of TXA in reducing trauma patient mortality (CRASH-2). This review provides an analysis of the current literature on the use of TXA in trauma patients. It critically evaluates the evidence on the effect of TXA on TIC and other clinical outcomes, emphasizing the time-sensitive nature of TXA administration and the variation of its effect depending on the severity and location of injury. It also discusses the optimal dosage, timing, and safety of TXA, as well as the challenges and limitations of existing studies. Furthermore, it highlights the importance of individualized treatment approaches based on the fibrinolysis status of TIC and the value of goal-directed therapy guided by viscoelastic hemostatic assays for the appropriate use of TXA.

Abstract 17313: Evaluating the Predictive Accuracy of Viscoelastic Blood Coagulation Measurements for Postoperative Bleeding in Cardiac Surgery: A Diagnostic Accuracy Meta-Analysis

Introduction: Postoperative bleeding in cardiac surgery significantly impacts patient morbidity and mortality. Viscoelastic blood coagulation measurements, such as point-of-care (POC) viscoelastic hemostatic assays (VHAs), are proposed tools for predicting this complication and enabling proactive management. However, thoroughly evaluating existing evidence is essential to confirm their effectiveness. Hypothesis: This study aims to evaluate the diagnostic accuracy of viscoelastic blood coagulation measurements in predicting postoperative bleeding following cardiac surgery. Methods: A systematic search of studies published up to May 2022 was conducted, employing databases such as PubMed, EMBASE, and the Cochrane Library. Included studies implemented viscoelastic blood coagulation measurements in cardiac surgery settings, providing data on diagnostic accuracy for predicting postoperative bleeding. Major postoperative blood loss, as defined within each study setting, was used as the reference standard. Statistical analysis was performed using R software (version 4.0.3) with mada package. This analysis enabled various diagnostic accuracy metrics pooling, all presented with a 95% Confidence Interval (CI). Results: This analysis incorporated 10 studies comprising 2048 patients, 374 of them experienced confirmed postoperative bleeding after cardiac surgery. The pooled sensitivity and specificity of viscoelastic blood coagulation measurements for predicting postoperative bleeding were found to be 65% (95% CI: 42.9-82%, I2=89.4%) and 85% (95% CI: 69.7-93.3%, I2=95.1%) respectively. The false-positive rate was identified as 15% (95% CI: 6.7-30.3%). The diagnostic odds ratio was 10.50 (95% CI: 2.93-37.57). The positive and negative Likelihood Ratios were 4.34 (95% CI: 1.89-9.95) and 0.42 (95% CI: 0.23-0.75), respectively. Conclusions: Despite moderate sensitivity, viscoelastic blood coagulation measurements exhibit high specificity in predicting postoperative bleeding in cardiac surgery, potentially enhancing patient management through early intervention. However, due to the observed heterogeneity, further large-scale studies are required to confirm these results and assess their impact on patient outcomes.