Thrombelastography early amplitudes in bleeding and coagulopathic trauma patients: Results from a multicenter study

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

BACKGROUND

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.

METHODS

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 6 months. Logistic regression analyses assessed associations of ROTEM parameters with clinical outcomes after adjusting for ICH severity and hemoglobin concentration.

RESULTS

Of 44 patients analyzed, the mean age was 64 years, 57% were female, and the median ICH volume was 23 mL. 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.

CONCLUSIONS

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.

Admission viscoelastic hemostatic assay parameters predict poor long-term intracerebral hemorrhage outcomes

Background

Viscoelastic hemostatic assays (VHA) provide more comprehensive assessments of coagulation compared to conventional coagulation assays. While 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.

Methods

Spontaneous ICH patients enrolled into a single-center cohort study receiving admission Rotational Thromboelastometry (ROTEM) VHA testing between 2013 and 2020 were assessed. Patients with prior 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 6 months. Logistic regression analyses assessed associations of ROTEM parameters with clinical outcomes after adjusting for ICH severity and hemoglobin concentration.

Results

Of 44 patients analyzed, mean age was 64, 57% were female, and the median ICH volume was 23 mL. Poor 6-month outcome was seen in 64%. In our multivariable regression models, slower, prolonged coagulation kinetics (adjusted OR for every second increase in clot formation time: 1.04, 95% CI: 1.00-1.09, p = 0.04) and weaker clot strength (adjusted OR for every millimeter increase of maximum clot firmness: 0.84, 95% CI: 0.71-0.99, p = 0.03) were separately associated with poor long-term outcomes.

Conclusions

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.

Is ROTEM Diagnostic in Trauma Care Associated with Lower Mortality Rates in Bleeding Patients?—A Retrospective Analysis of 7461 Patients Derived from the TraumaRegister DGU®

Introduction: Death from uncontrolled trauma haemorrhage and subsequent trauma-induced coagulopathy (TIC) is potentially preventable. Point-of-care devices such as rotational thromboelastometry (ROTEM^®) are advocated to detect haemostatic derangements more rapidly than conventional laboratory diagnostics. Regarding reductions in RBC transfusion, the use of ROTEM has been described as being efficient and associated with positive outcomes in several studies. Objective: The effect of ROTEM use was assessed on three different outcome variables: (i) administration of haemostatics, (ii) rate of RBC transfusions and (iii) mortality in severely injured patients. Methods and Material: A retrospective analysis of a large data set of severely injured patients collected into the TraumaRegister DGU^® between 2009 and 2016 was conducted. The data of 7461 patients corresponded to the inclusion criteria and were subdivided into ROTEM-using and ROTEM-non-using groups. Both groups were analysed regarding (i) administration of haemostatics, (ii) rate of RBC transfusions and (iii) mortality. Results: A lower mortality rate in ROTEM-using groups was observed (p = 0.043). Furthermore, more patients received haemostatic medication when ROTEM was used. In ROTEM-using groups, there was a statistically relevant higher application of massive transfusion. Conclusions: In this retrospective study, the use of ROTEM was associated with reduced mortality and an increased application of haemostatics and RBC transfusions. Prospective evidence is needed for further evidence-based recommendations.

Thrombelastography (TEG® 6s) early amplitudes predict maximum amplitude in severely injured trauma patients

Severely injured trauma patients are often coagulopathic and early hemostatic resuscitation is essential. Previous studies have revealed linear relationships between thrombelastography (TEG^®) five- and ten-min amplitudes (A5 and A10), and maximum amplitude (MA), using TEG^® 5000 technology. We aimed to investigate the performance of A5 and A10 in predicting low MA in severely injured trauma patients and identify optimal cut-off values for hemostatic intervention based on early amplitudes, using the cartridge-based TEG^® 6s technology. Adult trauma patients with hemorrhagic shock were included in the iTACTIC randomized controlled trial at six European Level I trauma centers between 2016 and 2018. After admission, patients were randomized to hemostatic therapy guided by conventional coagulation tests (CCT) or viscoelastic hemostatic assays (VHA). Patients with available admission-TEG^® 6s data were included in the analysis, regardless of treatment allocation. Low MA was defined as <55 mm for Kaolin TEG^® and RapidTEG^®, and <17 mm for TEG^® functional fibrinogen (FF). One hundred eighty-seven patients were included. Median time to MA was 20 (Kaolin TEG^®), 21 (RapidTEG^®) and 12 (TEG^® FF) min. For Kaolin TEG^®, the optimal Youden index (YI) was at A5 < 36 mm (100/93% sensitivity/specificity) and A10 < 47 mm (100/96% sensitivity/specificity). RapidTEG^® optimal YI was at A5 < 34 mm (98/92% sensitivity/specificity) and A10 < 45 mm (96/95% sensitivity/specificity). TEG^® FF optimal YI was at A5 < 12 mm (97/93% sensitivity/specificity) and A10 < 15 mm (97/99% sensitivity/specificity). In summary, we found that TEG^® 6s early amplitudes were sensitive and specific predictors of MA in severely injured trauma patients. Intervening on early amplitudes can save valuable time in hemostatic resuscitation.

Viscoelastic Hemostatic Assays for Orthopedic Trauma and Elective Procedures

The application of viscoelastic hemostatic assays (VHAs) (e.g., thromboelastography (TEG) and rotational thromboelastometry (ROTEM)) in orthopedics is in its relative infancy when compared with other surgical fields. Fortunately, several recent studies describe the emerging use of VHAs to quickly and reliably analyze the real-time coagulation and fibrinolytic status in both orthopedic trauma and elective orthopedic surgery. Trauma-induced coagulopathy—a spectrum of abnormal coagulation phenotypes including clotting factor depletion, inadequate thrombin generation, platelet dysfunction, and dysregulated fibrinolysis—remains a potentially fatal complication in severely injured and/or hemorrhaging patients whose timely diagnosis and management are aided by the use of VHAs. Furthermore, VHAs are an invaluable compliment to common coagulation tests by facilitating the detection of hypercoagulable states commonly associated with orthopedic injury and postoperative status. The use of VHAs to identify hypercoagulability allows for an accurate venous thromboembolism (VTE) risk assessment and monitoring of VTE prophylaxis. Until now, the data have been insufficient to permit an individualized approach with regard to dosing and duration for VTE thromboprophylaxis. By incorporating VHAs into routine practice, orthopedic surgeons will be better equipped to diagnose and treat the complete spectrum of coagulation abnormalities faced by orthopedic patients. This work serves as an educational primer and up-to-date review of the current literature on the use of VHAs in orthopedic surgery.

Viscoelastic Hemostatic Assays: A Primer on Legacy and New Generation Devices

Viscoelastic hemostatic assay (VHAs) are whole blood point-of-care tests that have become an essential method for assaying hemostatic competence in liver transplantation, cardiac surgery, and most recently, trauma surgery involving hemorrhagic shock. It has taken more than three-quarters of a century of research and clinical application for this technology to become mainstream in these three clinical areas. Within the last decade, the cup and pin legacy devices, such as thromboelastography (TEG^® 5000) and rotational thromboelastometry (ROTEM^® delta), have been supplanted not only by cartridge systems (TEG^® 6S and ROTEM^® sigma), but also by more portable point-of-care bedside testing iterations of these legacy devices (e.g., Sonoclot^®, Quantra^®, and ClotPro^®). Here, the legacy and new generation VHAs are compared on the basis of their unique hemostatic parameters that define contributions of coagulation factors, fibrinogen/fibrin, platelets, and clot lysis as related to the lifespan of a clot. In conclusion, we offer a brief discussion on the meteoric adoption of VHAs across the medical and surgical specialties to address COVID-19-associated coagulopathy.

Viscoelastic monitoring in trauma resuscitation

BACKGROUND

Traumatic injury results in both physical and physiologic insult. Successful care of the trauma patient depends upon timely correction of both physical and biochemical injury. Trauma-induced coagulopathy is a derangement of hemostasis and thrombosis that develops rapidly and can be fatal if not corrected. Viscoelastic monitoring (VEM) assays have been developed to provide rapid, accurate, and relatively comprehensive depictions of an individual's coagulation profile. VEM are increasingly being integrated into trauma resuscitation guidelines to provide dynamic and individualized guidance to correct coagulopathy.

STUDY DESIGN AND METHODS

We performed a narrative review of the search terms viscoelastic, thromboelastography, thromboelastometry, TEG, ROTEM, trauma, injury, resuscitation, and coagulopathy using PubMed. Particular focus was directed to articles describing algorithms for management of traumatic coagulopathy based on VEM assay parameters.

RESULTS

Our search identified 16 papers with VEM-guided resuscitation strategies in adult patients based on TEG, 12 such protocols in adults based on ROTEM, 1 protocol for children based on TEG, and 2 protocols for children based on ROTEM.

CONCLUSIONS

This review presents evidence to support VEM use to detect traumatic coagulopathy, discusses the role of VEM in trauma resuscitation, provides a summary of proposed treatment algorithms, and discusses pending questions in the field.

Getting hit by the bus around the world - a global perspective on goal directed treatment of massive hemorrhage in trauma

PURPOSE OF REVIEW

Major trauma remains one of the leading causes of death worldwide with traumatic brain injury and uncontrolled traumatic bleeding as the main determinants of fatal outcome. Interestingly, the therapeutic approach to trauma-associated bleeding and coagulopathy shows differences between geographic regions, that are reflected in different guidelines and protocols.

RECENT FINDINGS

This article summarizes main principles in coagulation diagnostics and compares different strategies for treatment of massive hemorrhage after trauma in different regions of the world. How would a bleeding trauma patient be managed if they got hit by the bus in the United States, United Kingdom, Germany, Switzerland, Austria, Denmark, Australia, or in Japan?

SUMMARY

There are multiple coexistent treatment standards for trauma-induced coagulopathy in different countries and different trauma centers. Most of them initially follow a protocol-based approach and subsequently focus on predefined clinical and laboratory targets.

Massive Hemorrhage: The Role of Whole Blood Viscoelastic Assays

Viscoelastic whole blood tests are increasingly used to guide hemostatic therapy in bleeding patients in the perioperative, trauma, and obstetric settings. Compared with standard laboratory tests of hemostasis, they have a shorter turnaround time and provide simultaneous information on various aspects of clot formation and lysis. The two available brands TEG (thromboelastography) and ROTEM (rotational thromboelastometry) provide devices that are either manually operated or fully automated. The automation allows for the assays to be used as point-of-care tests increasing their usefulness in massively bleeding patients with rapidly changing hemostatic profiles. While the number of research papers on the subject and the number of published treatment algorithms increase rapidly, the influence of the use of these devices on patient outcome needs yet to be established. In this article, we first review the technology of these devices and the parameters provided by the assays. Next, we present the problems encountered when choosing cut-off values that trigger intervention. Furthermore, we discuss the studies examining their influence on clinical outcomes, and finally, we briefly highlight some of the most important limitations and pitfalls inherent to these assays.

Accelerating availability of clinically-relevant parameter estimates from thromboelastogram point-of-care device

BACKGROUND

Modeling approaches offer a novel way to detect and predict coagulopathy in trauma patients. A dynamic model, built and tested on thromboelastogram (TEG) data, was used to generate a virtual library of over 160,000 simulated RapidTEGs. The patient-specific parameters are the initial platelet count, platelet activation rate, thrombus growth rate, and lysis rate (P(0), k1, k2, and k3, respectively).

METHODS

Patient data from both STAAMP (n = 182 patients) and PAMPer (n = 111 patients) clinical trials were collected. A total of 873 RapidTEGs were analyzed. One hundred sixteen TEGs indicated maximum amplitude (MA) below normal and 466 TEGs indicated lysis percent above normal. Each patient's TEG response was compared against the virtual library of TEGs to determine library trajectories having the least sum-of-squared error versus the patient TEG up to each specified evaluation time ∈ (3, 4, 5, 7.5, 10, 15, 20 minutes). Using 10 nearest-neighbor trajectories, a logistic regression was performed to predict if the patient TEG indicated MA below normal (<50 mm), lysis percent 30 minutes after MA (LY30) greater than 3%, and/or blood transfusion need using the parameters from the dynamic model.

RESULTS

The algorithm predicts abnormal MA values using the initial 3 minutes of RapidTEG data with a median area under the curve of 0.95, and improves with more data to 0.98 by 10 minutes. Prediction of future platelet and packed red blood cell transfusion based on parameters at 4 and 5 minutes, respectively, provides equivalent predictions to the traditional TEG parameters in significantly less time. Dynamic model parameters could not predict abnormal LY30 or future fresh-frozen plasma transfusion.

CONCLUSION

This analysis could be incorporated into TEG software and workflow to quickly estimate if the MA would be below or above threshold value within the initial minutes following a TEG, along with an estimate of what blood products to have on hand.

LEVEL OF EVIDENCE

Therapeutic/Care Management: Level IV.

Point-of-Care Diagnostics in Coagulation Management

This review provides a comprehensive and up-to-date overview of point-of-care (POC) devices most commonly used for coagulation analyses in the acute settings. Fast and reliable assessment of hemostasis is essential for the management of trauma and other bleeding patients. Routine coagulation assays are not designed to visualize the process of clot formation, and their results are obtained only after 30-90 m due to the requirements of sample preparation and the analytical process. POC devices such as viscoelastic coagulation tests, platelet function tests, blood gas analysis and other coagulometers provide new options for the assessment of hemostasis, and are important tools for an individualized, goal-directed, and factor-based substitution therapy. We give a detailed overview of the related tests, their characteristics and clinical implications. This review emphasizes the evident advantages of the speed and predictive power of POC clot measurement in the context of a goal-directed and algorithm-based therapy to improve the patient's outcome. Interpretation of viscoelastic tests is facilitated by a new visualization technology.

Establishment of thromboelastography reference intervals by indirect method and relevant factor analyses

Thromboelastography (TEG) as a global coagulation test has been continuously developed for many decades in either research or clinical practice. The versatility of TEG test leads to difficulty in standardization and result interpretation. Reference intervals (RIs) of TEG may be one of the most controversial factors that influence its wide applications. RIs establishment with the traditional method is time‐consuming and laborious as well as beyond general laboratory capability. Indirect method using stored data and with statistical calculation and small cost is emerging as an alternative approach for RIs determination. Gender, age, or both affect RIs and must be taken into account before RIs estimation. The present study retrospectively collected a total of 930 TEG results as subjects and established RIs with indirect method for Kaolin‐activated TEG, including the parameters of R, K, αAngle, MA, and CI. Furthermore, gender, age, and gender‐dependent age subsets analyses were performed to determine their effects on RIs of TEG. In this study, we found that TEG parameters showed more hypercoagulability in female than male, most of the measured TEG variables were significantly associated with aging, but only in male statistical significance was found among different age stratification and 60‐year‐old could be considered as cutting point to differentiate coagulation ability in male. In addition, RIs of TEG were estimated by indirect method suitably and verified to be valid in our study. Finally, the RIs of TEG by indirect method were basically significantly different to the RIs recommended by manufacturer, but the consistent percentage is relatively high in the most of measured parameters. In conclusion, it is suggestive that the indirect method for RIs establishment is feasible, but relevant factors, such as gender and age, specifically gender‐dependent age effect, should be considered before RIs determinations.

Comparison between thromboelastography and thromboelastometry

Two of the most commonly used viscoelastic hemostatic assays, thromboelastometry (ROTEM) and thrombelastography (TEG), have proven to decrease allogenic blood transfusions with cost reduction and possibly decrease mortality and morbidity in cardiac, trauma, and other bleeding patients. This article compares the two devices to provide guidance on the selection and use of these monitoring systems. Their second-generation assays, TEG 6S and ROTEM Sigma, are also discussed.

Multiple electrode aggregometry and thromboelastography in thrombocytopenic patients with haematological malignancies

BACKGROUND

In thrombocytopenic patients better assessment of bleeding risk than that provided by platelet count alone is required. Multiplate® aggregometry and thromboelastography (TEG) could be used, but information on their role in such patients is limited. The primary aim of this study was to investigate the feasibility of Multiplate® analyses in patients with haematological malignancies. A secondary aim was to explore whether a multiple logistic regression model combining Multiplate®, TEG, clinical and laboratory variables was associated with risk of bleeding.

MATERIALS AND METHODS

This was an exploratory, prospective observational study of thrombocytopenic patients with haematological malignancies. Total platelet count (TPC), white blood cell count, C-reactive protein (CRP) level, temperature and bleeding status were recorded daily. TEG and Multiplate® analyses with four agonists were performed on weekdays.

RESULTS

Ten patients were enrolled into the study. The median number of days in a study period was 21. Bleeding was observed on 64 of 298 study days. TPC <20×109/L and <10×109/L occurred on 119 and 25 days, respectively. When TPC was <33×109/L, many samples showed no aggregation, regardless of bleeding status. Despite this, the odds of World Health Organization (WHO) grade 2 bleeding decreased significantly as aggregation increased and Multiplate® had a negative predictive value (NPV) of 96% and a positive predictive value (PPV) of 19% for significant bleeding. In the multiple logistic regression model collagen-activated Multiplate® aggregation, TEG angle, TEG reaction time and CRP significantly affected the odds of WHO grade 2 bleeding. The combined model had a NPV of 99% and a PPV of 19%.

DISCUSSION

Our findings suggest that the markers of platelet function and haemostasis provided by Multiplate® aggregometry and TEG may add information to support prediction of bleeding, although platelet count still remains the most accessible analysis for routine testing.

Viscoelastic Monitoring to Guide the Correction of Perioperative Coagulopathy and Massive Transfusion in Patients with Life-Threatening Hemorrhage

The resuscitation of patients with traumatic hemorrhage remains a challenging clinical scenario. The appropriate and aggressive support of the patient's coagulation is of critical importance. Conventional coagulation assays present several shortcomings in this setting. The integration of viscoelastic monitoring in clinical practice has the potential to result in significant improvements. In order to be successful, the provider must understand basics of the methodology, read outs, and the limitations of the technique.

Whole exome sequencing in the diagnostic workup of patients with a bleeding diathesis

INTRODUCTION

Bleeding assessment tools and laboratory phenotyping often remain inconclusive in patients with a haemorrhagic diathesis.

AIM

To describe the phenotype and genetic profile of patients with a bleeding tendency.

METHODS

Whole exome sequencing (WES) was incorporated in the routine diagnostic pathway of patients with thrombocytopenia (n = 17), platelet function disorders (n = 19) and an unexplained bleeding tendency (n = 51). The analysis of a panel of 126 OMIM (Online Mendelian Inheritance in Man) genes involved in thrombosis and haemostasis was conducted, and if negative, further exome-wide analysis was performed if informed consent given.

RESULTS

Eighteen variants were detected in 15 patients from a total of 87 patients (17%). Causative variants were observed in MYH9 (two cases), SLFN14, P2RY12 and GP9. In addition, one case was considered solved due to combined carriership of F7 and F13A1 variants and one with combined carriership of F2, F8 and VWF, all variants related to secondary haemostasis protein aberrations. Two variants of uncertain significance (VUS) were found in two primary haemostasis genes: GFI1B and VWF. Eight patients were carriers of autosomal recessive disorders. Exome-wide analysis was performed in 54 cases and identified three variants in candidate genes.

CONCLUSION

Based on our findings, we conclude that performing WES at the end of the diagnostic trajectory can be of additive value to explain the complete bleeding phenotype in patients without a definite diagnosis after conventional laboratory tests. Discovery of combinations of (novel) genes that predispose to bleeding will increase the diagnostic yield in patients with an unexplained bleeding diathesis.

Comparison of Thrombelastography (TEG) in Patients with Acute Cerebral Hemorrhage and Cerebral Infarction

Background

The aim of this study was to analyze the changing role of thrombelastography (TEG) by detecting the indexes of TEG in patients with acute cerebral hemorrhage and cerebral infarction, combined with pathogenesis, and to find objective laboratory indexes for the diagnosis and treatment of cerebrovascular diseases.

Material/Methods

Data from 150 patients were collected, including 69 cases identified as the cerebral infarction group and 81 cases identified as the cerebral hemorrhage group. In addition, 50 healthy adults were selected as a control group. The cerebral hemorrhage group was divided into 3 subgroups according to the amount of bleeding: small hemorrhage group, moderate hemorrhage group, and large hemorrhage group. The diagnosis for each participant was mainly based on computed tomography (CT) and magnetic resonance imaging (MRI). TEG indexes [R value (coagulation reaction time), K value (coagulation time), Angle (reflecting the formation rate of blood clot and the function of fibrinogen), MA (maximum thrombus amplitude), CI (coagulation index)] were measured by TEG YZ5000 instrument.

Results

The cerebral infarction group had lower R and K values and higher Angle and CI (P<0.05). The cerebral hemorrhage group had higher K value; the Angle and MA were lower in the moderate hemorrhage group and in the large hemorrhage groups (P<0.05). In the cerebral hemorrhage group, Angle and MA were negatively correlated with the amount of cerebral hemorrhage (r=−0.475, −0.394 respectively, P<0.05), and the K value was positively correlated with the amount of cerebral hemorrhage (r=0.337, P<0.05), while the R value had no significant correlation with the amount of cerebral hemorrhage (r=0.251, P>0.05). R and K values in the cerebral infarction group were significantly lower, while Angle, MA, and CI were significantly higher in the cerebral hemorrhage group.

Conclusions

K value, Angle, and MA may be of value in the assessment of the amount of cerebral hemorrhage.

Rapid TEG efficiently guides hemostatic resuscitation in trauma patients

BACKGROUND

Several thrombelastography functional assays have been developed to guide transfusion in injured patients, but how this acceleration of thrombelastography affects its ability to predict massive transfusion is unknown. The objective of this study is to compare citrated native, citrated kaolin, and citrated rapid thromboelastographies for their prediction of massive transfusion after trauma. We hypothesized that citrated native thrombelastography best predicts massive transfusion.

METHODS

Data were collected as part of a prospective study of trauma activation patients. All patients received citrated native, citrated kaolin, or citrated rapid thromboelastographies. Logistic regression was used to assess the predictive performance of different thrombelastography assays for massive transfusion.

RESULTS

Measurements for all three TEG activating systems was available for 343 patients; 57 (16.6%) required a massive transfusion. Compared to citrated rapid thromboelastographies, citrated kaolin thromboelastographies performed better for activated clotting time/rapid and citrated native thromboelastographies for maximum amplitude and angle. Yet, the 95% confidence intervals overlapped considerably, suggesting the citrated rapid thromboelastographies produced comparable results to the other assays for activated clotting time/reaction time, maximum amplitude, and angle.

CONCLUSION

There was substantial overlap in the performance of the different thrombelastography assays, suggesting citrated rapid thrombelastography is a quick and effective method to guide hemostatic resuscitation in trauma patients and does not perform inferiorly to the citrated native or citrated kaolin thrombelastography despite the addition of activation factors.