Goal-directed coagulation management of major trauma patients using thromboelastometry (ROTEM)-guided administration of fibrinogen concentrate and prothrombin complex concentrate

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.

Four-factor prothrombin complex concentrate in adjunct to whole blood in trauma-related hemorrhage: Does whole blood replace the need for factors?

BACKGROUND

The use of whole blood (WB) for the treatment of hemorrhagic shock and coagulopathy is increasing in civilian trauma patients. Four-factor prothrombin complex concentrate (4-PCC) in adjunct to component therapy showed improved outcomes in trauma patients. Our study aims to evaluate the outcomes of trauma patients who received 4-PCC and WB (4-PCC-WB) compared with WB alone.

METHODS

We performed a 3-year (2015-2017) analysis of the American College of Surgeons-Trauma Quality Improvement Program database. All adult (age, ≥18 years) trauma patients who received WB were included. We excluded patients who were on preinjury anticoagulants. Patients were stratified into two groups, 4-PCC-WB versus WB alone, and matched in a 1:2 ratio using propensity score matching. Outcome measures were packed red blood cells, plasma, platelets, and cryoprecipitate transfused, in-hospital complications, hospital and intensive care unit (ICU) length of stay (LOS) among survivors, and mortality.

RESULTS

A total of 252 patients (4-PCC-WB, 84; WB alone, 168) were matched. The mean ± SD age was 47 ± 21 years, 63% were males, median Injury Severity Score was 30 (21-40), and 87% had blunt injuries. Patients who received 4-PCC-WB had decreased requirement for packed red blood cell (8 U vs. 10 U, p = 0.04) and fresh frozen plasma (6 U vs. 8 U, p = 0.01) transfusion, lower rates of acute kidney injury (p = 0.03), and ICU LOS (5 days vs. 8 days, p = 0.01) compared with WB alone. There was no difference in the platelet transfusion (p = 0.19), cryoprecipitate transfusion (p = 0.37), hospital LOS (p = 0.72), and in-hospital mortality (p = 0.72) between the two groups.

CONCLUSION

Our study demonstrates that the use of 4-PCC as an adjunct to WB is associated with a reduction in transfusion requirements and ICU LOS compared with WB alone in the resuscitation of trauma patients. Further studies are required to evaluate the role of PCC with WB in the resuscitation of trauma patients.

LEVEL OF EVIDENCE

Therapeutic, level III.

Portuguese Consensus and Recommendations for Acquired Coagulopathic Bleeding Management (CCBM)

We aimed to determine how Portuguese physicians handle major bleeding. We also aim to establish global diagnostic and therapeutic recommendations to be followed in clinical practice by using a step-wise approach of evidence generation. This study followed a three-step process: a steering committee desk review, a Delphi technique, an expert panel meeting. A modified 3-round Delphi including 31 statements was performed. Questions were answered in a five-point Likert-type scale. Consensus threshold was established as a percentage of agreement among participants ≥90% in the first round, and ≥85% in the second and third rounds. The level of consensus achieved by panelists was discussed with the scientific committee (January-2020). Fifty-one physicians participated in the study (compliance rate >90%). Analyzing the three rounds, consensus was reached on 20 items (64.5%) in the first, 4/11 items (36.4%) in the second and 6/7 items (85.7%) in the third. One statement about administration of clotting factor concentrates for bleeding control did not reach consensus. A high level of consensus was reached toward the need for implementing Patient Blood Management strategies in Portuguese hospitals, reduce exposure to allogeneic blood components, to use goal directed therapies for acquired bleeding management, and the need for evaluating blood transfusion indirect costs. A final version with 12 recommendations was built, according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE). Our results provide critically appraised and updated evidence on bleeding coagulopathies management in Portugal. Additional studies, mainly about indirect costs of blood transfusion, are needed.

Thromboelastography is a Marker for Clinically Significant Progressive Hemorrhagic Injury in Severe Traumatic Brain Injury

BACKGROUND

Coagulopathy in traumatic brain injury (TBI) is associated with increased risk of poor outcomes, but accurate prediction of clinically significant progressive hemorrhagic injury (PHI) in patients with severe TBI remains a challenge. Thromboelastography (TEG) is a real-time test of whole blood coagulation that provides dynamic information about global hemostasis. This study aimed to identify differences in TEG values between patients with severe TBI who did or did not experience clinically significant PHI.

METHODS

This was a single-center retrospective cohort study of adult patients with severe TBI. Patients were eligible for inclusion if initial Glasgow coma scale (GCS) was ≤ 8 and baseline head computed tomography (CT) imaging and TEG were available. Exclusion criteria included receipt of hemostatic agents prior to TEG. PHI was defined as bleeding expansion on CT within 24 h associated with 2-point drop in GCS, neurosurgical intervention, or mortality within 24 h. The primary endpoint was TEG value differences between patients with and without PHI. Secondary endpoints included differences in conventional coagulation tests (CCTs) between groups.

RESULTS

Of the 526 patients evaluated, 141 met inclusion criteria. The most common reason for exclusion was lack of baseline TEG and receipt of reversal product prior to TEG. Sixty-four patients experienced PHI in the first 24 h after presentation. K time (2.03 min vs. 1.33 min, P = 0.035) and alpha angle (65° vs. 69°, P = 0.015) were found to be significantly different in patients experiencing PHI. R time (5.25 min vs. 4.71 min), maximum amplitude (61 mm vs. 63 mm), and clot lysis at 30 min after maximum clot strength (3.5% vs. 1.7%) were not significantly different between groups. Of the CCTs, only activated partial thromboplastin time (30.3 s vs. 27.6 s, P = 0.014) was found to be different in patients with PHI.

CONCLUSIONS

Prolonged K time and narrower alpha angle were found to be associated with developing clinically significant PHI in patients with severe TBI. Despite differences detected in alpha angle, median values in both groups were within normal reference ranges. These abnormalities may reflect pathologic hypoactivity of fibrinogen, and further study is warranted to evaluate TEG-guided cryoprecipitate administration in this patient population.

Development of an Optical Method for the Evaluation of Whole Blood Coagulation

Blood coagulation is a defense mechanism, which is activated in case of blood loss, due to vessel damage, or other injury. Pathological cases arise from malfunctions of the blood coagulation mechanism, and rapid growth of clots results in partially or even fully blocked blood vessel. The aim of this work is to characterize blood coagulation, by analyzing the time-dependent structural properties of whole blood, using an inexpensive design and robust processing approaches. The methods used in this work include brightfield microscopy and image processing techniques, applied on finger-prick blood samples. The blood samples were produced and directly utilized in custom-made glass microchannels. Color images were captured via a microscopy-camera setup for a period of 35 min, utilizing three different magnifications. Statistical information was extracted directly from the color components and the binary conversions of the images. The main advantage in the current work lies on a Boolean classification approach utilized on the binary data, which enabled to identify the interchange between specific structural elements of blood, namely the red blood cells, the plasma and the clotted regions, as a result of the clotting process. Coagulation indices produced included a bulk coagulation index, a plasma-reduction based index and a clot formation index. The results produced with the inexpensive design and the low computational complexity in the current approach, show good agreement with the literature, and a great potential for a robust characterization of blood coagulation.

Trauma-Induced Coagulopathy: Overview of an Emerging Medical Problem from Pathophysiology to Outcomes

Coagulopathy induced by major trauma is common, affecting approximately one-third of patients after trauma. It develops independently of iatrogenic, hypothermic, and dilutive causes (such as iatrogenic cause in case of fluid administration), which instead have a pejorative aspect on coagulopathy. Notwithstanding the continuous research conducted over the past decade on Trauma-Induced Coagulopathy (TIC), it remains a life-threatening condition with a significant impact on trauma mortality. We reviewed the current evidence regarding TIC diagnosis and pathophysiological mechanisms and summarized the different iterations of optimal TIC management strategies among which product resuscitation, potential drug administrations, and hemostatis-focused approaches. We have identified areas of ongoing investigation and controversy in TIC management.

Emergency administration of fibrinogen concentrate for hemorrhage: A protocol for systematic review and meta-analysis

INTRODUCTION

The occurrence of massive hemorrhages in various emergency situations increases the need for blood transfusions and the risk of mortality. Use of fibrinogen concentrate (FC) may increase plasma fibrinogen levels more rapidly than the use of fresh-frozen product or cryoprecipitate. However, thus far, the efficacy of FC in significantly improving the risk of mortality and significantly reducing transfusion requirements has not been effectively demonstrated in several systematic reviews and meta-analyses.

METHODS AND ANALYSIS

We will conduct a systematic review and meta-analysis of FC for hemorrhages in emergency situations. We will include controlled trials, but will exclude randomized controlled trials in elective surgeries. We will include patients with hemorrhages in emergency situations. Intervention will be emergency supplementation of FC. The control group will be administered with ordinal transfusion or placebo. The primary outcome of the study is in-hospital mortality.We will search in electronic databases such as MEDLINE (PubMed), Web of Science, and the Cochrane Central Register of Controlled Trials. Two reviewers will independently screen the title and abstract, retrieve the full text of the selected articles, and extract the essential data. We will apply uniform criteria for evaluating the risk of bias associated with individual randomized controlled trial based on the Cochrane risk of bias tool. Values of the risk ratio will be expressed as a point estimate with 95% confidence intervals (CIs). Data of continuous variables will be expressed as the mean difference along with their 95% CIs and P values. We will assess the strength of evidence using the Grading of Recommendations Assessment, Development and Evaluation approach.

ETHICS AND DISSEMINATION

This systematic review will provide physicians with updated information on the efficacy and safety of using FC for hemorrhage in emergency settings. Approval from the ethics board and patient consent were not required in our study.This study protocol has been funded through a protocol registry. The registry number is UMIN000041598.

The effects of human prothrombin complex concentrate on hemorrhagic shock-induced lung injury in rats: Implications for testing human blood products in rodents

BACKGROUND

Hemorrhagic shock (HS) and trauma can result in an endotheliopathy of trauma, characterized by endothelial compromise, inflammation, and aberrant coagulation. Kcentra, a prothrombin concentrate, has been demonstrated to mitigate pulmonary vascular leak in a murine model of HS. We investigated the effects of Kcentra in a rat model of HS, to achieve physiologic endpoints of relevance.

METHODS

Rats subjected to a grade intravenous splenic injury and controlled hemorrhage for 60 minutes were resuscitated with shed volumes of (1) Lactated Ringer's (LR) solution, (2) LR + 20 IU/kg Kcentra, (3) LR + 50 IU/kg Kcentra, (4) rat fresh frozen plasma (RFFP), or (5) human fresh frozen plasma (HFFP). Blood was harvested for monitoring metabolic and coagulation function. Rat lungs were evaluated for lung injury and permeability.

RESULTS

Animals resuscitated with LR displayed a significant increase in pulmonary vascular permeability (sham, 407.9 ± 122.4; shock + LR, 2040 ± 1462). Resuscitation with RFFP (606.5 ± 169.3) reduced leak; however, treatment with Kcentra (HS + Kcentra [20 IU/kg]: 1792 ± 903.4, HS + Kcentra [50 IU/kg]: 1876 ± 1103), and HFFP (1450 ± 533.2) had no significant effect on permeability. Kcentra modestly altered clotting parameters. Metabolic measures, such as lactate, pH, and base deficit, were restored to baseline levels by both RFFP and HFFP, but not Kcentra or LR.

CONCLUSION

Kcentra did not alter pulmonary vascular permeability, but modestly increased clotting potential in injured rats. This suggests that there may be a xenogenic reaction of human products in rats and that the effects of Kcentra on vascular stability may be distinct from its ability to modulate clotting. Our data indicate that the species chosen and utilized for in vivo preclinical testing of human derived blood products is of critical importance in determining their efficacy in animal models and is the primary impetus to communicate these results.

Use of fibrinogen concentrate for trauma-related bleeding: A systematic-review and meta-analysis

BACKGROUND

Trauma-induced coagulopathy contributes to significant morbidity and mortality in patients who experience trauma-related bleeding. This study aimed to synthesize the evidence supporting the efficacy and safety of preemptive and goal-directed fibrinogen concentrate (FC) in the management of trauma-related hemorrhage.

METHODS

PubMed, Medline, EMBASE, Web of Science, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, and the WHO International Clinical Trials Registry Platform were systematically searched. All trial designs, except individual case reports, which evaluated the preemptive or goal-directed use of FC for trauma-related bleeding/coagulopathy, in patients older than 16 years, were included in the systematic review. For the included randomized controlled trials comparing FC with control, meta-analysis was performed and a risk-of bias-assessment was completed using the Cochrane Methodology and Preferred Reporting Items Systematic Reviews and Meta-analysis guidelines.

RESULTS

A total of 2,743 studies were identified; 26 were included in the systematic review, and 5 randomized controlled trials (n = 238) were included in the meta-analysis. For the primary outcome of mortality, there was no statistically significant difference between the groups, with 22% and 23.4% in the FC and comparator arms, respectively (risk ratio, 1.00 [95% confidence interval, 0.39 to 2.56]; p = 0.99). In addition, there was no statistical difference between FC and control in packed red blood cell, fresh frozen plasma, or platelet transfusion requirements, and thromboembolic events. Overall, the quality of evidence was graded as low to moderate because of concerns with risk of bias, imprecision, and inconsistency.

CONCLUSION

Further high-quality, adequately powered studies are needed to assess the impact of FC in trauma, with a focus on administration as early as possible from the point of entry into the trauma system of care.

LEVEL OF EVIDENCE

Systematic review and Meta-analysis, level II.

Fibrinogen Early In Severe Trauma studY (FEISTY): results from an Australian multicentre randomised controlled pilot trial

Background: Haemorrhage is a major cause of death in severe trauma. Fibrinogen plays a critical role in maintaining haemostasis in traumatic haemorrhage, and early replacement using fibrinogen concentrate (FC) or cryoprecipitate (Cryo) is recommended by several international trauma guidelines. Limited evidence supports one product over the other, with widespread geographic and institutional variation in practice. Two previous trials have investigated the feasibility of rapid FC administration in severely injured trauma patients, with conflicting results. Objective: To compare the time to fibrinogen replacement using FC or Cryo in severely injured trauma patients with major haemorrhage and hypofibrinogenaemia. Design, setting, patients and interventions: A multicentre controlled pilot trial in which adult trauma patients with haemorrhage were randomly assigned (1:1) to receive FC or Cryo for fibrinogen replacement, guided by FIBTEM A5 (functional fibrinogen assessment at 5 minutes after clot formation, using rotational thromboelastometry). Main outcome measures: The primary outcome was time to commencement of fibrinogen replacement. Secondary outcomes included effects of the intervention on plasma fibrinogen levels and clinical outcomes including transfusion requirements and mortality. Results: Of the 100 randomly assigned patients, 62 were hypofibrinogenaemic and received the intervention (n = 37) or Cryo (n = 25). Median (interquartile range [IQR]) time to delivery of FC was 29 min (23-40 min) compared with 60 min (40-80 min) for Cryo (P = 0.0001). All 62 patients were hypofibrinogenaemic before receiving FC or Cryo (FC: median FIBTEM A5, 8 mm [IQR, 7-9 mm]; Cryo: median FIBTEM A5, 9 mm [IQR, 5-10 mm]). In the FC arm patients received a median of 3 g FC (IQR, 2-4 g), and in the Cryo arm patients received a median of 8 units of Cryo (IQR, 8-14 units). Restoration of fibrinogen levels was achieved in both arms after the intervention. Blood product transfusion, fluid resuscitation and thromboembolic complications were similar in both arms. Overall mortality was 15.3%, with more deaths in the FC arm. Conclusion: Fibrinogen replacement in severely injured trauma patients with major haemorrhage and hypofibrinogenaemia was achieved substantially faster using FC compared with Cryo. Fibrinogen levels increased appropriately using either product. The optimal method for replacing fibrinogen in traumatic haemorrhage is controversial. Our results will inform the design of a larger trial powered to assess patient-centred outcomes.

Whole Blood, Fixed Ratio, or Goal-Directed Blood Component Therapy for the Initial Resuscitation of Severely Hemorrhaging Trauma Patients: A Narrative Review

This narrative review explores the pathophysiology, geographic variation, and historical developments underlying the selection of fixed ratio versus whole blood resuscitation for hemorrhaging trauma patients. We also detail a physiologically driven and goal-directed alternative to fixed ratio and whole blood, whereby viscoelastic testing guides the administration of blood components and factor concentrates to the severely bleeding trauma patient. The major studies of each resuscitation method are highlighted, and upcoming comparative trials are detailed.

Age-related differences in the impact of coagulopathy in patients with isolated traumatic brain injury: An observational cohort study

BACKGROUND

Although age and coagulopathy are well-known predictors of poor outcome after traumatic brain injury (TBI), the interaction effect of these two predictors remains unclear.

OBJECTIVES

We assessed age-related differences in the impact of coagulopathy on the outcome following isolated TBI.

METHODS

We conducted a retrospective observational study in two tertiary emergency critical care medical centers in Japan from 2013 to 2018. A total of 1036 patients with isolated TBI (head Abbreviated Injury Scale ≥ 3 and other Abbreviated Injury Scale < 3) were selected and divided into the nonelderly (n = 501, 16-64 years) and elderly group (n = 535, age ≥65 years). We further evaluated the impact of coagulopathy (international normalized ratio, >1.2) on the outcomes (Glasgow Outcome Scale-Extended [GOS-E] scores, in-hospital mortality, and ventilation-free days) in both groups using univariate and multivariate models. Further, we conducted an age-based assessment of the impact of TBI-associated coagulopathy on GOS-E using a generalized additive model.

RESULTS

The multivariate model showed a significant association of age and TBI-associated coagulopathy with lower GOS-E scores, in-hospital mortality, and shorter ventilation-free days in the nonelderly group; however, significant impact of coagulopathy was not observed for all the outcomes in the elderly group. There was a decrease in the correlation degree between coagulopathy and GOS-E scores decreased with those older than 65 years.

CONCLUSION

There was a low impact of coagulopathy on functional and survival outcomes in geriatric patients with isolated TBI.

LEVEL OF EVIDENCE

Therapeutic study, Level IV.

Viscoelastic haemostatic assay augmented protocols for major trauma haemorrhage (ITACTIC): a randomized, controlled trial

PURPOSE

Contemporary trauma resuscitation prioritizes control of bleeding and uses major haemorrhage protocols (MHPs) to prevent and treat coagulopathy. We aimed to determine whether augmenting MHPs with Viscoelastic Haemostatic Assays (VHA) would improve outcomes compared to Conventional Coagulation Tests (CCTs).

METHODS

This was a multi-centre, randomized controlled trial comparing outcomes in trauma patients who received empiric MHPs, augmented by either VHA or CCT-guided interventions. Primary outcome was the proportion of subjects who, at 24 h after injury, were alive and free of massive transfusion (10 or more red cell transfusions). Secondary outcomes included 28-day mortality. Pre-specified subgroups included patients with severe traumatic brain injury (TBI).

RESULTS

Of 396 patients in the intention to treat analysis, 201 were allocated to VHA and 195 to CCT-guided therapy. At 24 h, there was no difference in the proportion of patients who were alive and free of massive transfusion (VHA: 67%, CCT: 64%, OR 1.15, 95% CI 0.76-1.73). 28-day mortality was not different overall (VHA: 25%, CCT: 28%, OR 0.84, 95% CI 0.54-1.31), nor were there differences in other secondary outcomes or serious adverse events. In pre-specified subgroups, there were no differences in primary outcomes. In the pre-specified subgroup of 74 patients with TBI, 64% were alive and free of massive transfusion at 24 h compared to 46% in the CCT arm (OR 2.12, 95% CI 0.84-5.34).

CONCLUSION

There was no difference in overall outcomes between VHA- and CCT-augmented-major haemorrhage protocols.

Early administration of fibrinogen concentrate in patients with polytrauma with thromboelastometry suggestive of hypofibrinogenemia: A randomized feasibility trial

OBJECTIVE

To evaluate the clinical effects of early administration of fibrinogen concentrate in patients with severe trauma and hypofibrinogenemia.

METHODS

We conducted an open randomized feasibility trial between December 2015 and January 2017 in patients with severe trauma admitted to the emergency department of a large trauma center. Patients presented with hypotension, tachycardia, and FIBTEM findings suggestive of hypofibrinogenemia. The intervention group received fibrinogen concentrate (50 mg/kg), and the control group did not receive early fibrinogen replacement. The primary outcome was feasibility assessed as the proportion of patients receiving the allocated treatment within 60 min after randomization. The secondary outcomes were transfusion requirements and other exploratory outcomes. Randomization was performed using sequentially numbered and sealed opaque envelopes. ClinicalTrials.gov: NCT02864875.

RESULTS

Thirty-two patients were randomized (16 in each group). All patients received the allocated treatment within 60 min after randomization (100%, 95% confidence interval, 86.7%-100%). The median length of intensive care unit stay was shorter in the intervention group (8 days, interquartile range [IQR] 5.75-10.0 vs. 11 days, IQR 8.5-16.0; p=0.02). There was no difference between the groups in other clinical outcomes. No adverse effects related to treatment were recorded in either group.

CONCLUSION

Early fibrinogen replacement with fibrinogen concentrate was feasible. Larger trials are required to properly evaluate clinical outcomes.

Use of viscoelastic monitoring and prothrombin complex concentrate in a paediatric patient with polytrauma and severe traumatic brain injury

Viscoelastic monitoring (VEM) tools, such as rotational thrombelastometry, have been used extensively to measure coagulopathy in adults but have received less attention in paediatric care. The presented case involves a 5-year-old boy who was brought to the emergency department after a motor vehicle collision with a Glasgow Coma Scale score of 6T and extensive injuries, including a subdural hematoma. VEM was used to monitor the patient's coagulopathy and to inform treatment measures by allowing real-time visualisation of the patient's coagulation status. VEM was additionally used to direct blood product replacement in preparation for neurosurgical intervention, and 4-factor prothrombin complex concentrate (PCC) was used to help reverse the coagulopathy. The patient underwent successful hemicraniectomy after improvement of his coagulopathy. In paediatrics, VEM and PCC are increasingly being used for post-trauma coagulopathy, and this case highlights their potential promise and the need for further research.

Physicians' Perceptions of a Situation Awareness-Oriented Visualization Technology for Viscoelastic Blood Coagulation Management (Visual Clot): Mixed Methods Study

Background

Viscoelastic tests enable a time-efficient analysis of coagulation properties. An important limitation of viscoelastic tests is the complicated presentation of their results in the form of abstract graphs with a multitude of numbers. We developed Visual Clot to simplify the interpretation of presented clotting information. This visualization technology applies user-centered design principles to create an animated model of a blood clot during the hemostatic cascade. In a previous simulation study, we found Visual Clot to double diagnostic accuracy, reduce time to decision making and perceived workload, and improve care providers’ confidence.

Objective

This study aimed to investigate the opinions of physicians on Visual Clot technology. It further aimed to assess its strengths, limitations, and clinical applicability as a support tool for coagulation management.

Methods

This was a researcher-initiated, international, double-center, mixed qualitative-quantitative study that included the anesthesiologists and intensive care physicians who participated in the previous Visual Clot study. After the participants solved six coagulation scenarios using Visual Clot, we questioned them about the perceived pros and cons of this new tool. Employing qualitative research methods, we identified recurring answer patterns, and derived major topics and subthemes through inductive coding. Based on them, we defined six statements. The study participants later rated their agreement to these statements on five-point Likert scales in an online survey, which represented the quantitative part of this study.

Results

A total of 60 physicians participated in the primary Visual Clot study. Among these, 36 gave an interview and 42 completed the online survey. In total, eight different major topics were derived from the interview field note responses. The three most common topics were “positive design features” (29/36, 81%), “facilitates decision making” (17/36, 47%), and “quantification not made” (17/36, 47%). In the online survey, 93% (39/42) agreed to the statement that Visual Clot is intuitive and easy to learn. Moreover, 90% (38/42) of the participants agreed that they would like the standard result and Visual Clot displayed on the screen side by side. Furthermore, 86% (36/42) indicated that Visual Clot allows them to deal with complex coagulation situations more quickly.

Conclusions

A group of anesthesia and intensive care physicians from two university hospitals in central Europe considered Visual Clot technology to be intuitive, easy to learn, and useful for decision making in situations of active bleeding. From the responses of these possible future users, Visual Clot appears to constitute an efficient and well-accepted way to streamline the decision-making process in viscoelastic test–based coagulation management.

The role of cryoprecipitate in massively transfused patients: Results from the Trauma Quality Improvement Program database may change your mind

BACKGROUND

Cryoprecipitate was developed for the treatment of inherited and acquired coagulopathies. The role of cryoprecipitate in hemorrhaging trauma patients is still speculative. The aim of our study was to assess the role of cryoprecipitate as an adjunct to transfusion in trauma patients.

METHODS

We performed a 2-year (2015-2016) analysis of the American College of Surgeons-Trauma Quality Improvement Program data set and included all adult trauma patients who received 4 or greater packed red blood cells (pRBCs)/4 hours. Patients were stratified based on receipt of cryoprecipitate within the first 24 hours (cryoprecipitate vs. no-cryoprecipitate). Outcomes were blood products transfused, in-hospital complications, and mortality. Regression analyses were performed.

RESULTS

A total of 19,643 (cryoprecipitate, 4,945; no-cryoprecipitate, 14,698) were included. Mean age was 40 ± 22 years, median Injury Severity Score was 27 [18-40], and Glasgow Coma Scale score was 9 [3-14]. The overall complication rate was 45%, mortality was 47%, and 29% of the patients died in the first 24 hours. Patients in the cryoprecipitate group received a lower volume of plasma (p < 0.01), and pRBCs (p < 0.01). Additionally, patients who received cryoprecipitate had lower rates of 24-hour mortality (p < 0.01) and in-hospital mortality (p < 0.01). However, there was no difference between the two groups regarding complications (p = 0.36) or volume of platelet transfused (p = 0.22). On multivariate logistic regression, the use of cryoprecipitate was associated with decreased (odds ratio [OR], 0.78 [0.63-0.84]; p = 0.02), in-hospital mortality (OR, 0.79 [0.77-0.87]; p = 0.01), but had no association with in-hospital complications (OR, 1.48 [0.71-1.99]; p = 0.31). On linear regression analysis, the use of cryoprecipitate was not associated with 24-hour pRBCs (β = -0.12 [-0.28 to 0.27], p = 0.47), 24-hour plasma (β = -0.06 [-0.21 to 0.43], p = 0.29), and 24-hour platelets (β = -0.24 [-0.09 to 0.33], p = 0.17) transfusion requirements.

CONCLUSION

The adjunctive use of cryoprecipitate in hemorrhaging trauma patients may reduce mortality without affecting in-hospital complications and transfusion requirements. Further studies are needed to better understand its potentially beneficial effects.

LEVEL OF EVIDENCE

Therapeutic, level IV.

Effectiveness of prothrombin complex concentrate for the treatment of bleeding: A systematic review and meta-analysis

Prothrombin complex concentrate (PCC) is increasingly being used as a treatment for major bleeding in patients who are not taking anticoagulants. The aim of this systematic review and meta-analysis is to evaluate the effectiveness of PCC administration for the treatment of bleeding in patients not taking anticoagulants. Studies investigating the effectivity of PCC to treat bleeding in adult patients and providing data on either mortality or blood loss were eligible. Data were pooled using Mantel-Haenszel random effects meta-analysis or inverse variance random effects meta-analysis. From 4668 identified studies, 17 observational studies were included. In all patient groups combined, PCC administration was not associated with mortality (odds ratio = 0.83; 95% confidence interval [CI], 0.66-1.06; P = .13; I2  = 0%). However, in trauma patients, PCC administration, in addition to fresh frozen plasma, was associated with reduced mortality (odds ratio = 0.64; CI, 0.46-0.88; P = .007; I2  = 0%). PCC administration was associated with a reduction in blood loss in cardiac surgery patients (mean difference: -384; CI, -640 to -128, P = .003, I2  = 81%) and a decreased need for red blood cell transfusions when compared with standard care across a wide range of bleeding patients not taking anticoagulants (mean difference: -1.80; CI, -3.22 to -0.38; P = .01; I2  = 92%). In conclusion, PCC administration was not associated with reduced mortality in the whole cohort but did reduce mortality in trauma patients. In bleeding patients, PCC reduced the need for red blood cell transfusions when compared with treatment strategies not involving PCC. In bleeding cardiac surgery patients, PCC administration reduced blood loss.

Early thromboelastography in acute traumatic coagulopathy: an observational study focusing on pre-hospital trauma care

Background

Major brain injury and uncontrolled blood loss remain the primary causes of early trauma-related mortality. One-quarter to one-third of trauma patients exhibit trauma-induced coagulopathy (TIC). Thromboelastometry (ROTEM) and thrombelastography (TEG) are valuable alternatives to standard coagulation testing, providing a more comprehensive overview of the coagulation process.

Purpose

Evaluating thromboelastographic profile, the incidence of fibrinolysis (defined as Ly30 > 3%) in severe trauma patients, and factors influencing pathological coagulation pattern.

Methods

Prospective observational 2 years cohort study on severe trauma patients assisted by Helicopter Emergency Medical System (HEMS) and Level 1 Trauma Center, in a tertiary referral University Hospital.

Results

Eighty three patients were enrolled, mean NISS (new injury severity score) 36 (± 13). Mean R value decreased from 7.25 (± 2.6) to 6.19 (± 2.5) min (p < 0.03); 48 (60%) patients had a reduction in R from T₀ to T₁. In NISS 25–40 and NISS > 40 groups, changes in R value increased their significance (p = 0.04 and p < 0.03, respectively). Pathological TEG was found in 71 (88.8%) patients at T₀ and 74 (92.5%) at T₁. Hypercoagulation was present in 57 (71.3%) patients at T_0, and in 66(82.5%) at T₁. 9 (11.3%) patients had hyperfibrinolysis at T₀, 7 (8.8%) patients at T₁. Prevalence of StO₂ < 75% at T₀ was greater in patients whose TEG worsened (7 patients, 46.7%) against whose TEG remained stable or improved (8 patients, 17.4%) from T₀ to T₁ (p = 0.02). 48 (57.8%) patients received < 1000 mL of fluids, while 35 (42.2%) received ≥ 1000 mL. The first group had fewer patients with hypercoagulation (20, 41.6%) than the second (6, 17.6%) at T₁ (p < 0.03). No differences were found for same TEG pattern at T₀, nor other TEG pattern.

Conclusion

Our population is representative of a non-hemorrhagic severe injury subgroup. Almost all of our trauma population had coagulation abnormalities immediately after the trauma; pro-coagulant changes were the most represented regardless of the severity of injury. NISS appears to affect only R parameter on TEG. Hyperfibrinolysis has been found in a low percentage of patients. Hypoperfusion parameters do not help to identify patients with ongoing coagulation impairment. Small volume resuscitation and mild hypotermia does not affect coagulation, at least in the early post-traumatic phase.

Electronic supplementary material

The online version of this article (10.1007/s00068-020-01493-z) contains supplementary material, which is available to authorized users.

Trauma-Induced Coagulopathy and Massive Bleeding: Current Hemostatic Concepts and Treatment Strategies

Hemorrhage after trauma remains a significant cause of preventable death. Trauma-induced coagulopathy (TIC) at the time of hospital admission is associated with an impaired outcome. Rather than a universal phenotype, TIC represents a complex hemostatic disorder, and standard coagulation tests are not designed to adequately reflect the complexity of TIC. Viscoelastic testing (VET) has gained increasing interest for the characterization of TIC because it provides a more comprehensive depiction of the coagulation process. Thus, VET has been established as a point-of-care-available hemostatic monitoring tool in many trauma centers. Damage-control resuscitation and early administration of tranexamic acid provide the basis for treating TIC. To improve survival, ratio-driven massive transfusion protocols favoring early and high-dose plasma transfusion have been implemented in many trauma centers around the world. Although plasma contains all coagulation factors and inhibitors, only high-volume plasma transfusion allows for adequate substitution of lacking coagulation proteins. However, high-volume plasma transfusion has been associated with several relevant risks. In some European trauma facilities, a more individualized hemostatic therapy concept has been implemented. The hemostatic profile of the bleeding patient is evaluated by VET. Subsequently, goal-directed hemostatic therapy is primarily based on coagulation factor concentrates such as fibrinogen concentrate or prothrombin complex concentrate. However, a clear difference in survival benefit between these two treatment strategies has not yet been shown. This concise review aims to summarize current evidence for different diagnostic and therapeutic strategies in patients with TIC.

Effect of fibrinogen concentrate administration on early mortality in traumatic hemorrhagic shock: A propensity score analysis

BACKGROUND

Fibrinogen concentrate is widely used in traumatic hemorrhagic shock despite weak evidence in the literature. The aim of the study was to evaluate the effect of fibrinogen concentrate administration within the first 6 hours on 24-hour all-cause mortality in traumatic hemorrhagic shock using a causal inference approach.

METHODS

Observational study from a French multicenter prospective trauma registry was performed. Hemorrhagic shock was defined as transfusion of four or more red blood cell units within the first 6 hours after admission. The confounding variables for the outcome (24-hour all-cause mortality) and treatment allocation (fibrinogen concentrate administration within the first 6 hours) were chosen by a Delphi method. The propensity score was specified with a data-adaptive algorithm and a doubly-robust approach with inverse proportionality of treatment weighting allowed to compute the average treatment effect. Sensitivity analyses were performed.

RESULTS

Of 14,336 patients in the registry during the study period, 1,027 in hemorrhagic shock were analyzed (758 receiving fibrinogen concentrate within 6 hours and 269 not receiving fibrinogen concentrate). The average treatment effect, expressed as a risk difference, was -0.031 (95% confidence interval, -0.084 to 0.021). All sensitivity analysis confirmed the results.

CONCLUSIONS

Fibrinogen concentrate administration within the first 6 hours of a traumatic hemorrhagic shock did not decrease 24-hour all-cause mortality.

LEVEL OF EVIDENCE

Prognostic, level III.

Effect of Coagulation Factor Concentrates on Markers of Endothelial Cell Damage in Experimental Hemorrhagic Shock

BACKGROUND

Plasma-based resuscitation showed protective effects on the endothelial glycocalyx compared with crystalloid resuscitation. There is paucity of data regarding the effect of coagulation factor concentrates (CFC) on the glycocalyx in hemorrhagic shock (HS). We hypothesized that colloid-based resuscitation supplemented with CFCs offers a therapeutic value to treat endothelial damage following HS.

METHODS

Eighty-four rats were subjected to pressure-controlled (mean arterial pressure (MAP) 30-35 mm Hg) and lab-guided (targeted cutoff: lactate >2.2. mmol/L and base deficit > 5.5 mmol/L) HS. Animals were resuscitated with fresh frozen plasma (FFP), human albumin (HA) or Ringer's lactate (RL) and RL or HA supplemented with fibrinogen concentrate (FC) or prothrombin complex concentrate (PCC). Serum epinephrine and the following markers of endothelial damage were assessed at baseline and at the end-of-observation (120 min after shock was terminated): syndecan-1, heparan sulfate, and soluble vascular endothelial growth factor receptor 1 (sVEGFR 1).

RESULTS

Resuscitation with FFP had no effect on sVEGFR1 compared with crystalloid-based resuscitation (FFP: 19.3 ng/mL vs. RL: 15.9 ng/mL; RL+FC: 19.7 ng/mL; RL+PCC: 18.9 ng/mL; n.s.). At the end-of-observation, syndecan-1 was similar among all groups. Interestingly, HA+FC treated animals displayed the highest syndecan-1 concentration (12.07 ng/mL). Resuscitation with FFP restored heparan sulfate back to baseline (baseline: 36 ng/mL vs. end-of-observation: 36 ng/mL).

CONCLUSION

The current study revealed that plasma-based resuscitation normalized circulating heparan sulfate but not syndecan-1. Co-administration of CFC had no further effect on glycocalyx shedding suggesting a lack of its therapeutic potential.

LEVEL OF EVIDENCE

VExperimental in vivo study.

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.

Site-Of-Care Viscoelastic Assay in Major Trauma Improves Outcomes and Is Cost Neutral Compared with Standard Coagulation Tests

Major hemorrhage is often associated with trauma-induced coagulopathy. Targeted blood product replacement could achieve faster hemostasis and reduce mortality. This study aimed to investigate whether thromboelastography (TEG^®) goal-directed transfusion improved blood utilization, reduced mortality, and was cost effective. Data were prospectively collected in a U.K. level 1 trauma center, in patients with major hemorrhage one year pre- and post-implementation of TEG^® 6s Hemostasis Analyzers. Mortality, units of blood products transfused, and costs were compared between groups. Patient demographics in pre-TEG (n = 126) and post-TEG (n = 175) groups were similar. Mortality was significantly lower in the post-TEG group at 24 h (13% vs. 5%; p = 0.006) and at 30 days (25% vs. 11%; p = 0.002), with no difference in the number or ratio of blood products transfused. Cost of blood products transfused was comparable, with the exception of platelets (average £38 higher post-TEG). Blood product wastage was significantly lower in the post-TEG group (1.8 ± 2.1 vs. 1.1 ± 2.0; p = 0.002). No statistically significant difference in cost was observed between the two groups (£753 ± 651 pre-TEG; £830 ± 847 post-TEG; p = 0.41). These results demonstrate TEG 6s-driven resuscitation algorithms are associated with reduced mortality, reduced blood product wastage, and are cost neutral compared to standard coagulation tests.

Hypothermia-Associated Coagulopathy: A Comparison of Viscoelastic Monitoring, Platelet Function, and Real Time Live Confocal Microscopy at Low Blood Temperatures, an in vitro Experimental Study

Introduction

Hypothermia has notable effects on platelets, platelet function, fibrinogen, and coagulation factors. Common laboratory techniques cannot identify those effects, because blood samples are usually warmed to 37°C before analysis and do not fully reflect the in vivo situation. Multiple aspects of the pathophysiological changes in humoral and cellular coagulation remain obscure. This in vitro experimental study aimed to compare the measurements of thromboelastometry (TEM), multiple-electrode aggregometry (MEA) and Real Time Live Confocal Imaging for the purpose of identifying and characterizing hypothermia-associated coagulopathy.

Methods

Blood samples were drawn from 18 healthy volunteers and incubated for 30 min before being analyzed at the target temperatures (37, 32, 24, 18, and 13.7°C). At each temperature thromboelastometry and multiple-electrode aggregometry were measured. Real Time Live Confocal Imaging was performed at 4, 24, and 37°C. The images obtained by Real Time Live Confocal Imaging were compared with the functional results of thromboelastometry and multiple-electrode aggregometry.

Results

Thromboelastometry standard parameters were impaired at temperatures below baseline 37°C (ANOVA overall effect, p < 0.001): clotting time was prolonged by 27% at 13.7°C and by 60% at 18°C (p < 0.044); clot formation time was prolonged by 157% (p < 0.001). A reduction in platelet function with decreasing temperatures was observed (p < 0.001); the area under the curve at 13.7°C was reduced by 96% (ADP test), 92% (ASPI test), and 91% (TRAP test) of the baseline values. Temperature-associated changes in coagulation were visualized with Real Time Live Confocal Imaging. Molecular changes such as the temperature-associated decrease in the fibrin network are paralleled by cellular effects like the lesser activity of the platelets as a result of decreased temperature. The maximum clot firmness (MCF) in TEM only changed slightly within the temperature range tested.

Conclusion

The inhibitory effects of temperature on clot formation were visualized with Real Time Live Confocal Microscopy and compared with standard point-of-care testing. Inhibition of clotting factors and impaired platelet function are probably a result of hypothermia-induced impairment of thrombin. Measurement of MCF in TEM does not fully concur with Real Time Live Confocal Microscopy or MEA in hypothermia.

Comparison between the new fully automated viscoelastic coagulation analysers TEG 6s and ROTEM Sigma in trauma patients: A prospective observational study

BACKGROUND

Viscoelastic coagulation testing is increasingly used to diagnose trauma-induced coagulopathy. Two fully automated analysers, TEG 6s and ROTEM Sigma, were launched recently. No previous studies have compared these devices in trauma paients.

OBJECTIVE

The aim of this study was to evaluate whether both fully automatic devices deliver comparable results.

DESIGN

Prospective observational study.

SETTING

Level one trauma centre from August 2017 to September 2018.

PATIENTS

A total of 105 blood samples from 67 trauma patients were analysed simultaneously on TEG 6s and ROTEM Sigma.

MAIN OUTCOME MEASURES

TEG 6s assays kaolin (CK), RapidTEG (CRT), kaolin with heparinase (CKH) and functional fibrinogen were compared with ROTEM Sigma assays INTEM, EXTEM, HEPTEM and FIBTEM. TEG 6s functional fibrinogen level was compared with plasma fibrinogen concentration, measured using the Clauss method. Correlations were classified as weak (Spearman correlation coefficient 0.20 to 0.39), moderate (0.40 to 0.59), strong (0.60 to 0.79) or very strong (≥0.80).

RESULTS

The TEG 6s parameters reaction time, kinetic time and α-angle (CK, CRT and CKH assays) mostly showed strong correlations with the corresponding ROTEM parameters clotting time, clot formation time and α-angle (INTEM, EXTEM and HEPTEM assays). The exceptions were CRT reaction time vs. EXTEM clotting time, and CK α-angle vs. INTEM α-angle, which correlated moderately. Absolute values for many of these parameters showed significant differences between the two devices. Very strong correlations and similar absolute values were observed between TEG 6s maximum amplitude (CRT, CK and CKH assays) and ROTEM maximum clot firmness (EXTEM, INTEM and HEPTEM assays). Correlations were also very strong for functional fibrinogen maximum amplitude vs. FIBTEM maximum clot firmness and functional fibrinogen level vs. Clauss fibrinogen concentration, but absolute values were significantly different.

CONCLUSION

Strong to very strong correlations were observed between corresponding TEG 6s and ROTEM Sigma parameters. However, absolute values showed significant differences for most of the measurements.

Implementation of Thromboelastometry for Coagulation Management in Isolated Traumatic Brain Injury Patients Undergoing Craniotomy

BACKGROUND Coagulopathy (CP) is a modifiable factor linked with secondary brain damage and poor outcome of traumatic brain injury (TBI). A shift towards goal-directed coagulation management has been observed recently. We investigated whether rotational thromboelastometry (ROTEM) based management could be successfully implemented in TBI patients and improve outcomes. MATERIAL AND METHODS A prospective, case-control study was performed. Adult patients with isolated TBI requiring craniotomy were included in this study. All patients underwent standard coagulation tests (SCT). Patients were identified as either in control group or in case group. Patients in the case group were additionally tested with ROTEM to specify their coagulation status. Management of the patients in the control group was based on SCT, whereas management of patients in the case group was guided by ROTEM. Outcome measures were as follows: CP rate, protocol adhesion, blood loss, transfusions, progressive hemorrhagic injury (PHI), re-intervention, Glasgow coma score (GCS) and Glasgow outcome score (GOS) at discharge, and in-hospital mortality. RESULTS There were 134 patients enrolled (65 patients in the control group and 69 patients in the case group). Twenty-six patients in the control group (40%) were found to be coagulopathic (control-CP subgroup) and 34 patients in the case group (49.3%) were found to be coagulopathic (case-CP subgroup). Twenty-five case-CP patients had ROTEM abnormalities triggering protocolized intervention, and 24 of them were treated. Overall ROTEM-based protocol adhesion rate was 85.3%. Postoperative ROTEM parameters of case-CP patients significantly improved, and the number of coagulopathic patients decreased. The incidence of PHI (control versus case group) and neurosurgical re-intervention (control-CP versus case-CP subgroup) was in favor of ROTEM guidance (P<0.05). Mortality and GCS and GOS at discharge did not differ significantly between groups. CONCLUSIONS ROTEM led to consistent coagulation management, improved clot quality, and decreased incidence of PHI and neurosurgical re-intervention. Further studies are needed to confirm benefits of ROTEM in cases of TBI.

Mortality in civilian trauma patients and massive blood transfusion treated with high vs low plasma: red blood cell ratio. Systematic review and meta-analysis

Introduction: Massive bleeding in civilian trauma patients leads to dilutional coagulopathy. Transfusion with high plasma: red blood cell (RBC) ratio has been effective in reducing mortality in war trauma patients. However, in civilian trauma the evidence is controversial. Objective: To assess the impact on mortality of high vs low plasma: RBC ratio transfusion, in civilian trauma patients with massive bleeding. Methods: A systematic review and meta-analysis, including observational studies and clinical trials, was conducted. Databases were systemically searched for relevant studies between January 2007 and June 2019. The main outcome was early (24-hours) and late (30-day) mortality. Fixed and random effects models were used. Results: Out of 1295 studies identified, 33 were selected: 2 clinical trials and 31 observational studies. The analysis of observational trials showed both decreased early mortality (odds ratio [OR] 0.67; 95% confidence interval [CI], 0.60–0.75) and late mortality (OR 0.79; 95% CI, 0.71–0.87) with the use of high plasma:RBC ratio transfusion, but there were no differences when clinical trials were evaluated (OR 0.89; 95% CI, 0.64–1.26). The exclusion of patients who died within the first 24hours was a source of heterogeneity. The Injury Severity Score (ISS) altered the association between high plasma: RBC ratio and mortality, with a reduced protective effect when the ISS was high. Conclusion: The use of high vs low plasma: RBC ratio transfusion, in patients with massive bleeding due to civil trauma, has a protective effect on early and late mortality in observational studies. The exclusion of patients who died within the first 24 hours was a source of heterogeneity.

Review of massive transfusion protocols in the injured, bleeding patient

PURPOSE OF REVIEW

Massive haemorrhage is a significant cause of mortality and morbidity in a variety of clinical settings, although most research has been related to trauma patients. Military studies from recent conflicts found that higher ratios of plasma to red blood cells (RBCs) were associated with increased survival in injured soldiers, and subsequent trials in civilian populations showed similar decreased mortality. Over the last decade, massive transfusion protocols (MTPs) have become an important component in the treatment of the massively bleeding patient. This review is intended to summarize the more recent findings and trends in massive transfusion.

RECENT FINDINGS

There have been several observational studies suggesting that higher ratios of plasma to RBC and platelets to RBC are associated with improved survival but there is a paucity of randomized studies relating to specific ratios, dosages, timing, and guidance. Other studies have developed and assessed scoring systems used to initiate MTPs and specific tests used to guide MTPs. Finally, the specific blood components and adjuncts that constitute a MTP are the subject of further ongoing research.

SUMMARY

The absence of a universal definition of massive bleeding or massive transfusion, heterogeneity in patients suffering from massive bleeding, and the difficulty in predicting which patients will require a massive transfusion all contribute to the difficulty of studying massive transfusion. However, there is evidence that higher plasma : RBC ratios correlate with improved survival, and that adjuncts to transfusion play a key role. Furthermore, recent validations of massive haemorrhage scoring systems should allow more consistent and appropriate triggering of massive transfusions.

Patient blood management (PBM) in pregnancy and childbirth: literature review and expert opinion

PURPOSE

Patient blood management [PBM] has been acknowledged and successfully introduced in a wide range of medical specialities, where blood transfusions are an important issue, including anaesthesiology, orthopaedic surgery, cardiac surgery, or traumatology. Although pregnancy and obstetrics have been recognized as a major field of potential haemorrhage and necessity of blood transfusions, there is still little awareness among obstetricians regarding the importance of PBM in this area. This review, therefore, summarizes the importance of PBM in obstetrics and the current evidence on this topic.

METHOD

We review the current literature and summarize the current evidence of PBM in pregnant women and postpartum with a focus on postpartum haemorrhage (PPH) using PubMed as literature source. The literature was reviewed and analysed and conclusions were made by the Swiss PBM in obstetrics working group of experts in a consensus meeting.

RESULTS

PBM comprises a series of measures to maintain an adequate haemoglobin level, improve haemostasis and reduce bleeding, aiming to improve patient outcomes. Despite the fact that the WHO has recommended PBM early 2010, the majority of hospitals are in need of guidelines to apply PBM in daily practice. PBM demonstrated a reduction in morbidity, mortality, and costs for patients undergoing surgery or medical interventions with a high bleeding potential. All pregnant women have a significant risk for PPH. Risk factors do exist; however, 60% of women who experience PPH do not have a pre-existing risk factor. Patient blood management in obstetrics must, therefore, not only be focused on women with identified risk factor for PPH, but on all pregnant women. Due to the risk of PPH, which is inherent to every pregnancy, PBM is of particular importance in obstetrics. Although so far, there is no clear guideline how to implement PBM in obstetrics, there are some simple, effective measures to reduce anaemia and the necessity of transfusions in women giving birth and thereby improving clinical outcome and avoiding complications.

CONCLUSION

PBM in obstetrics is based on three main pillars: diagnostic and/or therapeutic interventions during pregnancy, during delivery and in the postpartum phase. These three main pillars should be kept in mind by all professionals taking care of pregnant women, including obstetricians, general practitioners, midwifes, and anaesthesiologists, to improve pregnancy outcome and optimize resources.

Efficacy of fibrinogen concentrate in major abdominal surgery - A prospective, randomized, controlled study in cytoreductive surgery for pseudomyxoma peritonei

BACKGROUND

Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy for pseudomyxoma peritonei (PMP) is associated with excessive bleeding and acquired fibrinogen deficiency. Maintaining plasma fibrinogen may support hemostasis.

OBJECTIVES

To compare hemostatic efficacy and safety of human fibrinogen concentrate (HFC) vs cryoprecipitate as fibrinogen sources for bleeding patients with acquired fibrinogen deficiency undergoing PMP CRS.

METHODS

FORMA-05 was an off-label single-center, prospective, randomized, controlled phase 2 study. Patients undergoing PMP surgery with predicted intraoperative blood loss ≥2 L received human fibrinogen concentrate (HFC; 4 g) or cryoprecipitate (two pools of 5 units, containing approximately 4.0-4.6 g fibrinogen), repeated as needed. The primary endpoint was a composite of intraoperative and postoperative efficacy, graded using objective 4-point scales and adjudicated by an independent committee.

RESULTS

One hundred percent of patients receiving HFC (95% confidence interval: 83.9-100.0, n = 21) or cryoprecipitate (84.6-100.0, n = 22) achieved hemostatic success. HFC demonstrated noninferior efficacy (P = .0095; post hoc) and arrived in the operating room 46 minutes faster. There were significantly greater mean increases with HFC vs cryoprecipitate in plasma fibrinogen (0.78 vs 0.35 g/L; P < .0001) and FIBTEM A20 (3.33 vs 0.93 mm; P = .003). Factor XIII, factor VIII, and von Willebrand factor activity were maintained throughout surgery. Only red blood cells were transfused intraoperatively (median units: HFC group, 1.0; cryoprecipitate group, 0.5). Thromboembolic events were detected with cryoprecipitate only. Safety was otherwise comparable between groups.

CONCLUSIONS

Human fibrinogen concentrate was hemostatically efficacious in patients undergoing major abdominal PMP surgery, with a favorable safety profile. These results are relevant to other surgical settings where bleeding and acquired fibrinogen deficiency occur.

Clinical controversies in anticoagulation monitoring and antithrombin supplementation for ECMO

During extracorporeal membrane oxygenation (ECMO), a delicate balance is required to titrate systemic anticoagulation to prevent thrombotic complications within the circuit and prevent bleeding in the patient. Despite focused efforts to achieve this balance, the frequency of both thrombotic and bleeding events remains high. Anticoagulation is complicated to manage in this population due to the complexities of the hemostatic system that are compounded by age-related developmental hemostatic changes, variable effects of the etiology of critical illness on hemostasis, and blood-circuit interaction. Lack of high-quality data to guide anticoagulation management in ECMO patients results in marked practice variability among centers. One aspect of anticoagulation therapy that is particularly challenging is the use of antithrombin (AT) supplementation for heparin resistance. This is especially controversial in the neonatal and pediatric population due to the baseline higher risk of bleeding in this cohort. The indication for AT supplementation is further compounded by the potential inaccuracy of the diagnosis of heparin resistance based on the standard laboratory parameters used to assess heparin effect. With concerns regarding the adverse impact of bleeding and thrombosis, clinicians and institutions are faced with making difficult, real-time decisions aimed at optimizing anticoagulation in this setting. In this clinically focused review, the authors discuss the complexities of anticoagulation monitoring and therapeutic intervention for patients on ECMO and examine the challenges surrounding AT supplementation given both the historical and current perspectives summarized in the literature on these topics.

Effect of Platelet Transfusion on Clot Strength in Dengue Fever with Thrombocytopenia Related Bleeding: A Thromboelastography-Based Study

Platelet transfusions are often administered in dengue illness complicated by thrombocytopenia-related bleeding. However, whether this practice results in an improvement of clot strength is not clear. This study assessed the impact of platelet transfusion on the control of bleeding and improvement in clot strength as assessed by thromboelastography among 74 patients with dengue. The effect of either weight-based random donor platelets or 1 unit of single donor aphaeresis units was studied. Transfusion of weight-based random donor platelets resulted in a mean platelet count increase of 10,210 cells per mm³ at 24 h from pretransfusion values, which reached marginal statistical significance (p = 0.031). Patients who received single donor platelets achieved a mean platelet increment of 22,874 cells per mm³ at 24 h, and the difference observed had a high statistical significance (p < 0.001). However, no significant improvement in clot strength was observed in thromboelastography. The mean increment in maximum amplitude value at 24 h was only 2 mm in the random donor platelet group and 5 mm in the single donor group, both of which did not reach statistical significance. Furthermore, the majority of patients had ongoing bleeding despite the administration of platelets. This study observed that platelet transfusion in dengue patients with bleeding complication improved the absolute platelet count with no improvement in clot strength.

Early administration of fibrinogen concentrate is associated with improved survival among severe trauma patients: a single-centre propensity score-matched analysis

Background

Fibrinogen plays an important role in haemostasis during the early phase of trauma, and low fibrinogen levels after severe trauma are associated with haemostatic impairment, massive bleeding, and poor outcomes. Aggressive fibrinogen supplementation may improve haemostatic function, as fibrinogen levels deteriorate before other routine coagulation parameters in this setting. Therefore, we evaluated whether early administration of fibrinogen concentrate (FC) was associated with improved survival in severe trauma patients.

Methods

This single-centre retrospective study evaluated patients with severe trauma (injury severity score ≥ 16) who were admitted to our emergency department between January 2010 and July 2018. The exclusion criteria included age < 18 years, cardiac arrest before emergency department arrival, cervical spinal cord injury not caused by a high-energy accident, and severe burn injuries. The FC and control groups included trauma patients who received and did not receive FC within 1 h after emergency department arrival, respectively. Propensity scores were used to balance the two groups based on the trauma and injury severity score (TRISS), heart rate at emergency department admission, and age. The primary outcome was the in-hospital survival rate.

Results

The propensity scoring model had a c-statistic of 0.734, the Hosmer-Lemeshow chi-squared value was 7.036 (degrees of freedom = 8), and the non-significant p value of 0.533 indicated a good model fit. The propensity score matching created 31 matched pairs of patients, who had appropriately balanced characteristics. The FC group had a significantly higher in-hospital survival rate than the control group (log-rank p = 0.013). The FC group also used significantly higher amounts of red blood cells and fresh frozen plasma within 6 h after emergency department admission. However, the two groups had similar transfusion amounts between 6 and 24 h after emergency department admission.

Conclusions

The present study revealed that early FC administration was associated with a favourable survival rate among severe trauma patients. Therefore, FC may be useful for the early management of trauma-induced coagulopathy and may improve outcomes in this setting.

Clinical utility of rotational thromboelastometry in detecting hemostatic disorders

Hemostasis represents an equilibrium between procoagulant and anticoagulant processes, but once this balance is shifted to one side, it leads to coagulopathy presented by pathological bleeding or thrombosis. Many conditions could cause coagulopathy. The most common are sepsis, severe traumas and malignancies. Widely used conventional coagulation tests (CCTs), focused only on clot initiation, are primary used to detect hypocoagulability. Viscoelastographic tests (VET), like rotational thromboelastometry (ROTEM), can detect problems in different stages of coagulation, from initiation thought clot elongation and propagation, to the clot lysis and might reveal both, hypercoagulability and hypocoagulability. Rotational thromboelastometry have gained popularity in the care of patients with TIC, as a tool to guide transfusion support. Nowadays it is widely used in other medical specialties, as well. Several studies in septic patients pointed out hypocoagulable ROTEM pattern as a predictor of poor prognosis. Additionally, there is great interest of ROTEM usage in malignancies, although limited research is currently available. It suggests ROTEM have the ability to identify a patient in high risk of thrombosis. Further investigation trough randomized studies is needed to confirm ROTEM utility and to help in making a consensus about its use in different medical occasions.

Impact of a goal-directed factor-based coagulation management on thromboembolic events following major trauma

BACKGROUND

A factor-based coagulation management following major trauma is recommended as standard of care by the European Trauma Treatment Guidelines. However, concerns about the thromboembolic risk of this approach are still prevalent. Our study therefore aims to assess if such a haemostatic management is associated with an increased risk for thromboembolic events.

METHODS

In this retrospective observational study carried out at the University Hospital Zurich we compared two three-year periods before (period 1: 2005-2007) and after (period 2: 2012-2014) implementation of a factor-based coagulation algorithm. We included all adult patients following major trauma primarily admitted to the University Hospital Zurich. Thromboembolic events were defined as a new in-hospital appearance of any peripheral thrombosis, arterial embolism, pulmonary embolism, stroke or myocardial infarction. A logistic regression was performed to investigate the association of thromboembolic events with possible confounders such as age, sex, specific Abbreviated Injury Scale (AIS) subgroups, allogeneic blood products, and the coagulation management.

RESULTS

Out of 1138 patients, 772 met the inclusion criteria: 344 patients in period 1 and 428 patients in period 2. Thromboembolic events were present in 25 patients (7.3%) of period 1 and in 42 patients (9.8%) of period 2 (raw OR 1.39, 95% CI 0.83 to 2.33, p = 0.21). Only AIS extremities (adjusted OR 1.26, 95% CI 1.05 to 1.52, p = 0.015) and exposure to allogeneic blood products (adjusted OR 2.39, 95% CI 1.33 to 4.30, p = 0.004) were independently associated with thromboembolic events in the logistic regression, but the factor-based coagulation management was not (adjusted OR 1.60, 95% CI 0.90-2.86, p = 0.11).

CONCLUSION

There is no evidence that a goal-directed, factor-based coagulation management is associated with an increased risk for thromboembolic events following major trauma.

Early coagulation support protocol: A valid approach in real-life management of major trauma patients. Results from two Italian centres

INTRODUCTION

Early coagulation support (ECS) includes prompt infusion of tranexamic acid, fibrinogen concentrate, and packed red blood cells for initial resuscitation of major trauma patients. The aim of this study was to determine the effects, in terms of blood product consumption, length of stay, and in-hospital mortality, of the ECS protocol, compared to the massive transfusion protocol (MTP) in the treatment of major trauma patients.

PATIENTS AND METHODS

A retrospective analysis was conducted using the registry data of two Italian trauma centres. Adult major trauma patients with, or at risk of, active bleeding who were managed according to the MTP during the years 2011-2012, or the ECS protocol during the years 2013-2014 and were considered at risk of multiple transfusions, were enrolled. The primary endpoint was to determine whether the ECS protocol reduces the use of blood products in the acute management of trauma patients. Secondary endpoints were the outcome measures of length of stay in ICU, length of stay in hospital, and mortality at 24-hours and 28-days after hospital admission.

RESULTS

Among the 518 major trauma patients admitted to the trauma centres during the study period, 235 patients (118 in the pre-ECS period and 117 in the ECS period) matched one of the inclusion criteria and were enrolled in the study. Compared with the pre-ECS period, the ECS period showed a reduction in the average consumption of packed red blood cells (-1.87 units, 95% confidence interval [CI], -2.40, -1.34), platelets (-1.28 units; 95% CI, -1.64, -0.91), and fresh frozen plasma (-1.69; 95% CI, -2.14, -1.25) in the first 24-hours. Furthermore, during the ECS period, we recorded a 10-day reduction in the hospital length of stay (-10 days, 95% CI, -11.6, -8.4) and a non-significant 28-day mortality increase.

CONCLUSIONS

The ECS protocol was effective in reducing blood product consumption compared to the MTP and confirmed the importance of early fibrinogen administration as a strategy of rapid coagulation. This novel approach may be adopted in real-life management of major trauma patients.

Relationship of Coagulopathy and Platelet Dysfunction to Transfusion Needs After Traumatic Brain Injury

BACKGROUND

Coagulopathy and platelet dysfunction commonly develop after traumatic brain injury (TBI). Thromboelastography (TEG) and platelet function assays (PFAs) are often performed at the time of admission; however, their roles in assessing post-TBI coagulopathy have not been investigated. We hypothesized that compared to blunt TBI, penetrating TBI would (1) demonstrate greater coagulopathy by TEG, (2) be associated with abnormal PFA results, and (3) require more blood product transfusions.

METHODS

We performed a retrospective study of patients admitted to the neuroscience intensive care unit of a level 1 trauma center from 2013 to 2015 with head Abbreviated Injury Scale ≥3. Patients were compared by mechanism of injury (blunt vs. penetrating). Admission demographics, injury characteristics, and laboratory parameters were evaluated. VerifyNow^® Aspirin and P2Y12 tests were used for platelet function analysis.

RESULTS

Five hundred and thirty-four patients were included in the analysis. There were no differences between groups in platelet count or international normalized ratio; however, patients with penetrating TBI were more coagulopathic by TEG, with all of the TEG parameters being significantly different except for R time. Patients with penetrating head trauma were not more likely than their blunt counterparts to have abnormal PFA results, and PFA results did not correlate with any TEG parameter in either group. The penetrating cohort received more units of blood products in the first 4 and 24 h than the blunt cohort.

CONCLUSIONS

Patients presenting with penetrating TBI demonstrated increased coagulopathy compared to those with blunt TBI as measured by TEG and need for transfusion. PFA results did not correlate with TEG findings in this population.

Diagnostic performance of thromboelastometry in trauma-induced coagulopathy: a comparison between two level I trauma centres using two different devices

PURPOSE

The implementation of a ROTEM^®-based algorithm requires reliable thresholds to mirror a prothrombin time (PT) ratio > 1.2 and/or a fibrinogen concentration < 1.5 g l^-1. Our goal was to compare the diagnostic performances of two devices (ROTEM^® Sigma and Delta, IL Werfen, Munich, Germany) in two level-I trauma centres for the diagnostic of post-traumatic coagulopathy.

METHODS

We conducted a retrospective analysis of two registries across two periods of time: from September 2014 to December 2015 in Lyon-Sud university trauma centre and from April 2016 to January 2018 in the Grenoble Alps Trauma Centre. Accuracies of EXTEM and FIBTEM assays to detect patients with coagulation disorders were tested for each device using receiver operating characteristic (ROC) analyses.

RESULTS

Within the study period, 74 trauma patients in the Grenoble cohort and 75 trauma patients in the Lyon cohort had concomitant ROTEM^® and standard coagulation testing on admission. No statistically significant difference was found between the two ROC curves for FIBTEM amplitude at 5 min (A5), FIBTEM maximum clot firmness, EXTEM clotting time (CT) and EXTEM A5 for ROTEM^® Sigma and Delta to diagnose post-traumatic coagulation disorders. The best threshold for FIBTEM A5 to predict low fibrinogen concentration was 7 mm for each device. EXTEM CT thresholds to diagnose PT ratio > 1.2 were 78 s and 74 s for ROTEM^® Sigma and Delta, respectively.

CONCLUSIONS

These results suggest that ROTEM^®-based algorithms may be transposed from one trauma centre to another independently of the setting and the ROTEM^® device in use.

Trauma-induced coagulopathy: The past, present, and future

Trauma remains a leading cause of death worldwide, and most early preventable deaths in both the civilian and military settings are due to uncontrolled hemorrhage, despite paradigm advances in modern trauma care. Combined tissue injury and shock result in hemostatic failure, which has been identified as a multidimensional molecular, physiologic and clinical disorder termed trauma-induced coagulopathy (TIC). Understanding the biology of TIC is of utmost importance, as it is often responsible for uncontrolled bleeding, organ failure, thromboembolic complications, and death. Investigations have shown that TIC is characterized by multiple phenotypes of impaired hemostasis due to altered biology in clot formation and breakdown. These coagulopathies are attributable to tissue injury and shock, and encompass underlying endothelial, immune and inflammatory perturbations. Despite the recognition and identification of multiple mechanisms and mediators of TIC, and the development of targeted treatments, the mortality rates and associated morbidities due to hemorrhage after injury remain high. The purpose of this review is to examine the past and present understanding of the multiple distinct but highly integrated pathways implicated in TIC, in order to highlight the current knowledge gaps and future needs in this evolving field, with the aim of reducing morbidity and mortality after injury.

In vitro effects of a kaolin-coated hemostatic dressing on anticoagulated blood

BACKGROUND

The use of kaolin-coated dressings has become common and have efficacy in normal patients, but their increased use will inevitably include use on bleeding patients taking anticoagulants. We hypothesize that kaolin coating material (KCM) will improve clotting regardless of anticoagulation medication.

METHODS

A prospective study was performed on blood from patients who were on a vitamin K antagonist (VKA), unfractionated heparin (UH), an antiplatelet (AP) agent, a Xa inhibitor (Xa), or a direct thrombin inhibitor (DTI). None were on more than one type of anticoagulation medication. Viscoelastic testing was performed with and without KCM. All p values were adjusted for multiple comparisons.

RESULTS

The addition of KCM significantly decreased the time for initial clot formation (CT) in all groups. The mean CT for controls was decreased from 692 to 190.8 s (p < 0.0001). KCM decreased the initial clot formation time by about 1.5 times in those on DTI (p = 0.043) and 2.5 times in those taking AP medication (p < 0.001). The most profound effect was seen in those on UH (no KCM 1,602 s vs. KCM 440 s; p < 0.001), VKA (no KCM 1,152 s vs. 232 s; p < 0.01), and Xa (no KCM 1,342 s vs. 287 s; p < 0.001). Analysis of other clot formation parameters revealed that KCM significantly improved the clot formation kinetics (CFT) only in patients taking Xa (p = 0.03). KCM improved maximum clot strength in patients on Xa inhibitors (p = 0.05). Patients on UH had a larger effect size with an increase in clot strength from 24.35 mm to 43.35 mm whereas those on Xa had an increase of 38.7 mm to 49.85 mm.

CONCLUSION

In this in vitro analysis, the addition of KCM to the blood of patients taking any of these anticoagulation medications significantly improved the time to initial clot formation, indicating that kaolin-based hemostatic dressings will be effective in initiating clot formation in patients on anticoagulants.

LEVEL OF EVIDENCE

Therapeutic, level IV.

Comparison of the Effects of Albumin 5% versus Ringer's Lactate on Blood Loss and Coagulation after Vascular Surgery Using Thromboelastography

AIM

Comparing the effects of Albumin 5% versus Ringer's lactate on blood loss and coagulation after vascular surgery using.

METHODS

In this randomised study, 60 patients, aged (18-60 years) ASA physical status (I-III) undergoing vascular surgery were included in the study and randomly allocated into two groups using a random number generator, to receive either Human albumin or Ringer lactate after obtaining written informed consent. Group A received 1-2 ml per minute of human albumin 5% combined with normal saline (0.9%). Group B received Ringer's lactate only as of the main solution. Variables were measured after administration of fluids as postoperative measures. The amount of blood needed for testing was 4 ml drawn before the operation and at the end of surgery with a citrate tube (blue tube) from the venous line or using a regular needle. The standard time of 15 minutes was considered to begin processing.

RESULTS

There was no statistically significant difference observed between both groups regarding demographic data, surgical wound drainage, haemoglobin level, hematocrit level and coagulation profile. Regarding ROTEM thermoelectrometry variables showed that there was no statistically significant difference was found between the two groups In-TEM variables (Ex-TEM Clotting time, TEM Clot Formation Time) but In-TEM Alpha Angel measured in degrees showed a Statistically significant difference between the two groups. P < 0.001 and Ex-TEM Maximum Clotting Firmness MCF values measured in mm, there was a statistically significant difference between the two groups P = 0.045.

CONCLUSION

This study concluded that the use of human albumin (5%) in vascular surgeries before reaching the trigger point for blood transfusion didn't improve blood loss or coagulation profile compared to the use of ringer lactate only. Therefore, ringer lactate can be used as a good replacement for human albumin. Ringer lactate is readily available and inexpensive while human albumin may be costly.