Point-of-care, goal-directed management of bleeding in trauma patients

Altered thrombin generation with prothrombin complex concentrate is not detected by viscoelastic testing: an in vitro study

BACKGROUND

Bleeding guidelines currently recommend use of viscoelastic testing (VET) to direct haemostatic resuscitation in severe haemorrhage. However, VET-derived parameters of clot initiation, such as clotting time (CT) and activated clotting time (ACT), might not adequately reflect a clinically relevant interaction of procoagulant and anticoagulant activity, as revealed by thrombin generation assays. The aim of this study was to evaluate the ability of CT and ACT to indicate thrombin generation activity.

METHODS

Citrated whole blood obtained from 13 healthy volunteers underwent a 50% crystalloid dilution (DL-50%), followed by spiking with four-factor prothrombin complex concentrate (DL-50% + 4F-PCC). Changes in thrombin generation activity were compared with the VET parameters CT and ACT derived from four commercially available viscoelastic devices (ROTEM® Delta, ClotPro®, TEG®6s, and Quantra®) and standard coagulation tests.

RESULTS

Dilution of whole blood resulted in a marked increase in velocity index, peak height, and endogenous thrombin potential (all P<0.01), with a further substantial increase after spiking with 4F-PCC (all P<0.001). In contrast, CT and ACT were significantly prolonged in response to DL-50% on all devices (all P<0.05). Subsequent spiking of diluted blood with 4F-PCC had no impact on CT and ACT derived from VET analysers, but it restored standard coagulation tests without reaching baseline values (all P<0.01).

CONCLUSIONS

Upregulated thrombin generation parameters after PCC spiking were not displayed by CT, ACT, or standard tests. Our results do not support treatment algorithms using prolonged CT or ACT as a trigger for administration of PCC to augment thrombin generation.

Individualized and targeted coagulation management in bleeding trauma patients

PURPOSE OF REVIEW

This review aims to summarize current evidence on hemostatic management of bleeding trauma patients, with a focus on resuscitation strategies using either coagulation factor concentrates or fixed-ratio transfusion concepts. It discusses the potential benefits and limitations of both approaches.

RECENT FINDINGS

Recent studies have shown that coagulopathy caused by massive traumatic hemorrhage often cannot be reversed by empiric treatment. During initial resuscitation, a fixed-ratio transfusion approach uses the allogeneic blood products red blood cells, plasma, and platelets to mimic 'reconstituted whole blood'. However, this one-size-fits-all strategy risks both overtransfusion and undertransfusion in trauma patients.Many European trauma centers have shifted toward individualized hemostatic therapy based on point-of-care diagnostics, particularly using viscoelastic tests. These tests provide rapid insight into the patient's hemostatic deficiencies, enabling a more targeted and personalized treatment approach.

SUMMARY

Individualized, goal-directed hemostatic management offers several advantages over fixed-ratio transfusion therapy for trauma patients. However, there is a paucity of data regarding the direct comparison of these two approaches.

Advances in resuscitation and deresuscitation

PURPOSE OF REVIEW

This review aims to provide a perspective on fluid resuscitation strategies and emerging trends in deresuscitation, with a particular emphasis on fluid stewardship, monitoring, and personalized fluid management.

RECENT FINDINGS

Recent studies underscore a paradigm shift in resuscitation strategies. Notably, aggressive plasma volume expansion has been linked to higher morbidity and mortality, favoring conservative fluid resuscitation. Dynamic parameters, such as pulse pressure variation (PPV) and stroke volume variation (SVV) outperform static markers like central venous pressure (CVP) in predicting preload responsiveness. Advances in hemodynamic monitoring and automated closed-loop fluid administration demonstrate efficacy in optimizing resuscitation. Fluid stewardship, supported by machine learning, is reshaping deresuscitation practices, and promoting negative fluid balance to reduce complications. Moreover, next-generation closed-loop systems and fluid management personalization as part of precision medicine are emerging as future directions.

SUMMARY

Advances in fluid resuscitation challenge traditional practices, with evidence favoring personalized and goal-directed strategies. Technological innovations in hemodynamic monitoring, automated fluid control, and machine learning are driving precision fluid management. Fluid stewardship and deresuscitation aim to mitigate fluid accumulation syndrome and improve patient outcomes.

A comprehensive review of massive transfusion and major hemorrhage protocols: origins, core principles and practical implementation

Until the beginning of the century, bleeding management was similar in elective surgeries or exsanguination scenarios: clotting tests were used to guide blood product orders and, while awaiting these results, an aggressive resuscitation with crystalloids was recommended. The high mortality rate in severe hemorrhages managed with this strategy endorsed the need for a special resuscitation plan. As a result, modifications were recommended to develop a new clinical approach to these patients, called "Damage Control Resuscitation". This strategy includes four principles: damage control surgery, minimization of crystalloids, permissive hypotension and hemostatic resuscitation. The latter involves the use of antifibrinolytics, correction of preconditions of hemostasis (calcium, pH and temperature) and the early and rapid restoration of intravascular volume with blood products. To enable timely availability and transfusion of blood products, specific actions in different hospital areas need to be synchronized, which are usually organized through Massive Transfusion Protocols or, as they have recently been rebranded, Major Hemorrhage Protocols (MHPs). Although these bundles of actions represent a paradigm change, essential aspects such as their historical evolution, theoretical foundations, terminology and operational elements have yet to be well explored. Considering the wide application range of these tools (emergency departments, interventional radiology, operating rooms and military fields), it is essential to integrate all professionals involved with severe hemorrhage scenarios in the implementation of the aforementioned protocols, from conception to execution and management. This review paper addresses MHP aspects relevant to anesthesiologists, transfusion services and other areas involved with the care of patients with severe bleeding.

Comment on Băetu et al. Beyond Trauma-Induced Coagulopathy: Detection of Auto-Heparinization as a Marker of Endotheliopathy Using Rotational Thromboelastometry. J. Clin. Med. 2024, 13, 4219

With great interest, we read the recent study by Baetu et al [...].

Monitoring the efficiency of reversal on anti-Xa direct oral anticoagulants using point-of-care viscoelastic testing

Bleeding events in patients receiving direct oral anticoagulation (DOAC) can be life-threatening even at therapeutic DOAC plasma concentrations, as anticoagulation impairs hemostasis and should therefore be identified immediately after hospital admission. The anticoagulatory effects of DOAC are typically not measurable in standard coagulation tests, such as PT or aPTT. Specific calibrated anti-FXa-tests allow specific drug monitoring, but they are too time-consuming for critical bleeding events and are commonly not available for 24 h/7 days in routine care. However, recent advances in point-of-care (POC) viscoelastic testing (VET) have shown a promising approach for rapid and quantitative detection of DOAC plasma concentrations using the Russell viper venom factor V activator (RVV for FXa-inhibitors) test or the ecarin clotting time (thrombin inhibitors). In acute bleeding situations, direct FXa inhibitors can be reversed by specific antidote andexanet alfa or hemostasis can be improved by prothrombin complex factor concentrates (PCCs). After reversal, confirmation of reversal efficacy is often requested, but no routine assays are currently available. Thus, the emergency management of bleeding DOAC patients is usually "blinded" with regard to reversal efficacy. POC VET laboratory assays might therefore also be helpful for measuring DOAC effects after reversal. We present a case series demonstrating the usefulness of RVV-clotting time post-DOAC reversal with andexanet alfa.

Mitochondrial dysfunction in platelets from severe trauma patients - A prospective case-control study

INTRODUCTION

Trauma-induced coagulopathy (TIC) refers to an abnormal coagulation process, an imbalance between coagulation and fibrinolysis due to several pathological factors, such as haemorrhage and tissue injury. Platelet activation and subsequent clot formation are associated with mitochondrial activity, suggesting a possible role for mitochondria in TIC. Comprehensive studies of mitochondrial dysfunction in platelets from severe trauma patients have not yet been performed.

METHODS

In this prospective case-control study, patients with severe trauma (ISS≥16) had venous blood samples taken at arrival to the Emergency Unit of a Level 1 Trauma Centre. Mitochondrial functional measurements (Oxygraph-2k, Oroboros) were performed to determine oxygen consumption in different respiratory states, the H2O2 production and extramitochondrial Ca2+ movements. In addition, standard laboratory and coagulation tests, viscoelastometry (ClotPro) and aggregometry (Multiplate) were performed. Measurements data were compared with age and sex matched healthy control patients.

RESULTS

Severe trauma patients (n = 113) with a median age of 38 years (IQR, 20-51), a median ISS of 28 (IQR, 20-48) met our inclusion criteria. Oxidative phosphorylation in platelet mitochondria from severe trauma patients significantly decreased compared to controls (34.7 ± 8.8 pmol/s/mL vs. 48.0 ± 19.7 pmol/s/mL). The mitochondrial H2O2 production significantly increased and greater endogenous Ca2+ release was found in the polytrauma group. Consistent with these results, clotting time (CT) increased while maximum clot firmness (MCF) decreased with the EX-test and FIB-test in severe trauma samples. Multiplate aggregometry showed significantly decreased ADP-test (38 ± 12 AUC vs. 112 ± 14 AUC) and ASPI test (78 ± 22 AUC vs. 84 ± 28 AUC) also tended to decrease in mitochondria of polytrauma patients as compared with controls. Significant strong correlation has been demonstrated between mitochondrial OxPhos and MCF while it was negatively correlated with ISS (R2=0.448, P˂0.05), INR, CT and lactate level of patients.

CONCLUSIONS

The present study revealed that severe trauma is associated with platelet mitochondrial dysfunction resulting in reduced ATP synthesis and impaired extramitochondrial Ca2+ movement. These factors are required for platelet activation, recruitment and clot stability likely thus, platelet mitochondrial dysfunction contributes to the development of TIC.

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

Introduction

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.

Methods

Twenty-seven healthy pigs underwent abdominal surgery, hemorrhage and resuscitation. ClotPro® and ROTEM® were used to assess viscoelastic hemostatic properties at baseline, after surgery, 60 min after shock induction, 60 and 120 min after resuscitation.

Results

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.

Conclusion

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.

Development and validation of the tic score for early detection of traumatic coagulopathy upon hospital admission: a cohort study

BACKGROUND

Critically injured patients need rapid and appropriate hemostatic treatment, which requires prompt identification of trauma-induced coagulopathy (TIC) upon hospital admission. We developed and validated the performance of a clinical score based on prehospital resuscitation parameters and vital signs at hospital admission for early diagnosis of TIC.

METHODS

The score was derived from a level-1 trauma center registry (training set). It was then validated on data from two other level-1 trauma centers: first on a trauma registry (retrospective validation set), and then on a prospective cohort (prospective validation set). TIC was defined as a PTratio > 1.2 at hospital admission. Prehospital (vital signs and resuscitation care) and admission data (vital signs and laboratory parameters) were collected. We considered parameters independently associated with TIC in the score (binomial logistic regression). We estimated the score's performance for the prediction of TIC.

RESULTS

A total of 3489 patients were included, and among these a TIC was observed in 22% (95% CI 21-24%) of cases. Five criteria were identified and included in the TIC Score: Glasgow coma scale < 9, Shock Index > 0.9, hemoglobin < 11 g.dL-1, prehospital fluid volume > 1000 ml, and prehospital use of norepinephrine (yes/no). The score, ranging from 0 and 9 points, had good performance for the identification of TIC (AUC: 0.82, 95% CI: 0.81-0.84) without differences between the three sets used. A score value < 2 had a negative predictive value of 93% and was selected to rule-out TIC. Conversely, a score value ≥ 6 had a positive predictive value of 92% and was selected to indicate TIC.

CONCLUSION

The TIC Score is quick and easy to calculate and can accurately identify patients with TIC upon hospital admission.

Fibrinogen contribution to clot strength in patients with sepsis and hematologic malignancies and thrombocytopenia-a prospective, single-center, analytical, cross-sectional study

Background

Patients with hematological malignancies (HM) frequently present thrombocytopenia and higher risk of bleeding. Although transfusion is associated with higher risk of adverse events and poor outcomes, prophylactic transfusion of platelets is a common practice to prevent hemorrhagic complications. Thromboelastometry has been considered a better predictor for bleeding than isolated platelet counts in different settings. In early stages of sepsis, hypercoagulability may occur due to higher fibrinogen levels.

Objectives

To evaluate the behavior of coagulation in patients with HM who develop sepsis and to verify whether a higher concentration of fibrinogen is associated with a proportional increase in maximum clot firmness (MCF) even in the presence of severe thrombocytopenia.

Methods

We performed a unicentric analytical cross-sectional study with 60 adult patients with HM and severe thrombocytopenia, of whom 30 had sepsis (sepsis group) and 30 had no infections (control group). Coagulation conventional tests and specific coagulation tests, including thromboelastometry, were performed. The main outcome evaluated was MCF.

Results

Higher levels of fibrinogen and MCF were found in sepsis group. Both fibrinogen and platelets contributed to MCF. The relative contribution of fibrin was significantly higher (60.5 ± 12.8% vs 43.6 ± 9.7%; P < .001) and that of platelets was significantly lower (39.5 ± 12.8% vs 56.4 ± 9.7%; P < .001) in the sepsis group compared with the control group.

Conclusion

Patients with sepsis and HM presented higher concentrations of fibrinogen than uninfected patients, resulting in greater MCF amplitudes even in the presence of thrombocytopenia.

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.

Comparison of Cerebral Saturation and Brain Net Water Uptake After Moderate Traumatic Brain Injury

The aim was to study the relationship between net water uptake (NWU) and cerebral oxygenation in patients with posttraumatic ischaemia (PTI) foci after moderate traumatic brain injury (moTBI).

MATERIALS AND METHODS

Perfusion computed tomography (PCT) was performed for 72 patients with PTI foci after moTBI in 2013-2022. The mean age of the patients was 32.7 ± 12.5 years (from 18 to 65 years), 25 women and 47 men. Cerebral tissue oxygen saturation (SctO2) was evaluated using Fore-Sight 2030 (CAS Medical Systems Inc., USA) in the region of the frontal lobe pole (FLP). NWU was calculated from non-contrast CT. Data are shown as a median [interquartile range]. P < 0.05 was considered statistically significant.

RESULTS

SctO2 in FLP varied within the range from 61% to 88%. It was 62% [55.4;72.1] over the lesion frontal lobe with PTI and 64% [58.5;73.7] over the opposite FLP side. The average NWU in the FLP cortex on the PTI side was 4.98% [2.21;7.39]. In the case when there were no focal injuries in the frontal lobes, SctO2 was significantly correlated with higher NWU (R = -0.780, p < 0.00001).

CONCLUSIONS

The cerebral oxygen tissue saturation correlates with net water uptake in patients with PTI after moTBI (p < 0.005).