Prothrombin Complex Concentrates in Trauma and Perioperative Bleeding

A 3D-Printed Cuttlefish Bone Elastomeric Sponge Rapidly Controlling Noncompressible Hemorrhage

Developing a self-expanding hemostatic sponge with high blood absorption and rapid shape recovery for noncompressible hemorrhage remains a challenge. In this study, a 3D-printed cuttlefish bone elastomeric sponge (CBES) is fabricated, which combined ordered channels and porous structures, presented tunable mechanical strength, and shape memory potentials. The incorporation of cuttlefish bone powder (CBp) plays key roles in concentrating blood components, promoting aggregation of red blood cells and platelets, and activating platelets, which makes CBES show enhanced hemostatic performance compared with commercial gelatin sponges in vivo. Moreover, CBES promotes more histiocytic infiltration and neovascularization in the early stage of degradation than gelatin sponges, which is conducive to the regeneration and repair of injured tissue. To conclude, CBp loaded 3D-printed elastomeric sponges can promote coagulation, present the potential to guide tissue healing, and broaden the hemostatic application of traditional Chinese medicine.

Clinical guideline on reversal of direct oral anticoagulants in patients with life threatening bleeding

BACKGROUND

Anticoagulation is essential for the treatment and prevention of thromboembolic events. Current guidelines recommend direct oral anticoagulants (DOACs) over vitamin K antagonists in DOAC-eligible patients. The major complication of anticoagulation is serious or life-threatening haemorrhage, which may necessitate prompt haemostatic intervention. Reversal of DOACs may also be required for patients in need of urgent invasive procedures. This guideline from the European Society of Anaesthesiology and Intensive Care (ESAIC) aims to provide evidence-based recommendations and suggestions on how to manage patients on DOACs undergoing urgent or emergency procedures including the treatment of DOAC-induced bleeding.

DESIGN

A systematic literature search was performed, examining four drug comparators (dabigatran, rivaroxaban, apixaban, edoxaban) and clinical scenarios ranging from planned to emergency surgery with the outcomes of mortality, haematoma growth and thromboembolic complications. The GRADE (Grading of Recommendations, Assessment, Development and Evaluation) methodology was used to assess the methodological quality of the included studies. Consensus on the wording of the recommendations was achieved by a Delphi process.

RESULTS

So far, no results from prospective randomised trials comparing two active comparators (e.g. a direct reversal agent and an unspecific haemostatic agent such as prothrombin complex concentrate: PCC) have been published yet and the majority of publications were uncontrolled and observational studies. Thus, the certainty of evidence was assessed to be either low or very low (GRADE C). Thirty-five recommendations and clinical practice statements were developed. During the Delphi process, strong consensus (>90% agreement) was achieved in 97.1% of recommendations and consensus (75 to 90% agreement) in 2.9%.

DISCUSSION

DOAC-specific coagulation monitoring may help in patients at risk for elevated DOAC levels, whereas global coagulation tests are not recommended to exclude clinically relevant DOAC levels. In urgent clinical situations, haemostatic treatment using either the direct reversal or nonspecific haemostatic agents should be started without waiting for DOAC level monitoring. DOAC levels above 50 ng ml-1 may be considered clinically relevant necessitating haemostatic treatment before urgent or emergency procedures. Before cardiac surgery under activated factor Xa (FXa) inhibitors, the use of andexanet alfa is not recommended because of inhibition of unfractionated heparin, which is needed for extracorporeal circulation. In the situation of DOAC overdose without bleeding, no haemostatic intervention is suggested, instead measures to eliminate the DOACs should be taken. Due to the lack of published results from comparative prospective, randomised studies, the superiority of reversal treatment strategy vs. a nonspecific haemostatic treatment is unclear for most urgent and emergency procedures and bleeding. Due to the paucity of clinical data, no recommendations for the use of recombinant activated factor VII as a nonspecific haemostatic agent can be given.

CONCLUSION

In the clinical scenarios of DOAC intake before urgent procedures and DOAC-induced bleeding, practitioners should evaluate the risk of bleeding of the procedure and the severity of the DOAC-induced bleeding before initiating treatment. Optimal reversal strategy remains to be determined in future trials for most clinical settings.

Canadian tertiary care pediatric massive hemorrhage protocols: a survey and comprehensive national review

PURPOSE

Hemorrhage is the leading cause of pediatric death in trauma and cardiac arrest during surgery. Adult studies report improved patient outcomes using massive hemorrhage protocols (MHPs). Little is known about pediatric MHP adoption in Canada.

METHODS

After waived research ethics approval, we conducted a survey of Canadian pediatric tertiary care hospitals to study MHP activations. Transfusion medicine directors provided hospital/patient demographic and MHP activation data. The authors extracted pediatric-specific MHP data from requested policy/procedure documents according to seven predefined MHP domains based on the literature. We also surveyed educational and audit tools. The analysis only included MHPs with pediatric-specific content.

RESULTS

The survey included 18 sites (100% response rate). Only 13/18 hospitals had pediatric-specific MHP content: eight were dedicated pediatric hospitals, two were combined pediatric/obstetrical hospitals, and three were combined pediatric/adult hospitals. Trauma was the most common indication for MHP activation (54%), typically based on a specific blood volume anticipated/transfused over time (10/13 sites). Transport container content was variable. Plasma and platelets were usually not in the first container. There was little emphasis on balanced plasma/platelet to red-blood-cell ratios, and most sites (12/13) rapidly incorporated laboratory-guided goal-directed transfusion. Transfusion thresholds were consistent with recent guidelines. All protocols used tranexamic acid and eight sites used an audit tool.

DISCUSSION/CONCLUSION

Pediatric MHP content was highly variable. Activation demographics suggest underuse in nontrauma settings. Our findings highlight the need for a consensus definition for pediatric massive hemorrhage, a validated pediatric MHP activation tool, and prospective assessment of blood component ratios. A national pediatric MHP activation repository would allow for quality improvement metrics.

Antidote vs. unspecific hemostatic agents for the management of direct oral anticoagulant-related bleeding in trauma

PURPOSE OF REVIEW

The advent of direct oral anticoagulants (DOACs) marks a significant milestone in anticoagulant treatment. However, DOACs can exacerbate bleeding, which is challenging for the treating clinician, especially when combined with traumatic injury.

RECENT FINDINGS

In major bleeding associated with DOACs, rapid reversal of the anticoagulant effects is crucial. Recent observational and nonrandomized interventional trials have demonstrated the effectiveness of the specific antidotes andexanet alfa and idarucizumab as well as the unspecific prothrombin complex concentrates (PCCs) to counteract the anticoagulant effects of DOACs. The European Society of Anaesthesiology and Intensive Care guideline for severe perioperative bleeding and the European trauma guideline propose divergent recommendations for the use of andexanet alfa and PCC to obtain hemostasis in Factor Xa inhibitor-related bleeding. The conflicting recommendations are due to limited evidence from clinical studies and the potential increased risk of thromboembolic complications after the administration of andexanet. Regarding dabigatran-associated major bleeding, both guidelines recommend the specific reversal agent idarucizumab as first-line therapy.

SUMMARY

Current guidelines recommend specific antidots and PCCs in DOAC-related major bleeding. Prospective randomized trials comparing specific vs. nonspecific hemostatic agents in the perioperative setting are needed to evaluate the effectiveness and safety of the hemostatic agents.

Ultramassive transfusion and adjunctive therapies in a case of blood bank depletion

Background

We present the case of a patient who presents with a high velocity thoracoabdominal gunshot wound requiring ultramassive transfusion who exhausted the county blood bank requiring adjunctive therapies to balanced blood product transfusion while additional blood products could be obtained.

Summary

Thoracoabdominal gunshot wounds carry a high mortality of 14-37 % because of the risk to produce cardiopulmonary, solid organ as well as major vascular injuries (Mandal and Oparah (1989) [1]). Ultramassive transfusion (>20 units of blood product transfusion) also carries high morbidity and mortality and management has generally centered on balanced transfusion (Matthay et al. (2021) [2]).

Conclusion

Balanced blood product transfusion reduces mortality for patients requiring ultramassive transfusion but when this is not possible utilization of adjuncts to blood products may temporize resuscitation until additional blood products can be obtained.

Use of four-factor prothrombin complex concentrate (4F-PCC) for management of bleeding not associated with therapeutic anticoagulant use

INTRODUCTION

Four-factor prothrombin complex concentrate (4F-PCC) may be an option for patients with bleeding unrelated to therapeutic anticoagulation to help with bleeding cessation and reduce blood component requirements.

MATERIALS AND METHODS

Retrospective, observational study of adult patients who received 4F-PCC for bleeding not associated with therapeutic anticoagulation between June 2019 and July 2021. Primary outcome was to describe off-label 4F-PCC use in patients not on therapeutic anticoagulation for bleeding management in surgical and non-surgical patients. Additional outcomes evaluated were blood product use, chest tube and drainage output, and coagulation studies before and after 4F-PCC administration as well as other hemostatic agent use and thromboembolic events.

RESULTS

Seventy-six patients were included; median age 64 years (IQR 50-69), 66% of bleeding events were associated with surgery, and the majority of 4F-PCC doses ordered by cardiac surgery (68.4%). A total of 110 4F-PCC doses were administered; median 1 dose/patient (IQR 1-2), median total dose 1000 units (IQR 500-1484). Other hemostatic agents commonly administered were protamine (59%), desmopressin (43%), and tranexamic acid (42%). Packed red blood cells, fresh frozen plasma, platelet, and cell saver blood administration and prothrombin time (PT), international normalized ratio (INR), and partial thromboplastin time (aPTT) were significantly reduced following 4F-PCC administration. Eight patients (11%) experienced thromboembolic complications.

CONCLUSION

Relatively low doses of 4F-PCC (median total dose 1000 units) were associated with decreased blood component requirements and improved PT, INR, and aPTT values in patients with bleeding unrelated to therapeutic anticoagulation. Other hemostatic agent use was common and thromboembolic complications occurred.

Activated 4-Factor Prothrombin Complex Concentrate as a Hemostatic Adjunct for Neonatal Cardiac Surgery: A Propensity Score-Matched Cohort Study

BACKGROUND

Prothrombin complex concentrates are an emerging "off-label" therapy to augment hemostasis after cardiopulmonary bypass (CPB), but data supporting their use for neonatal cardiac surgery are limited.

METHODS

We retrospectively reviewed neonates undergoing open heart surgery with first-time sternotomy between May 2014 and December 2018 from a hospital electronic health record database. Neonates who received activated 4-factor prothrombin complex concentrate (a4FPCC) after CPB were propensity score matched (PSM) to neonates who did not receive a4FPCC (control group). The primary efficacy outcome was total volume (mL/kg) of blood products transfused after CPB, including the first 24 hours on the cardiovascular intensive care unit (CVICU). The primary safety outcome was the incidence of 7- and 30-day postoperative thromboembolism. Secondary outcomes included 24 hours postoperative chest tube output, time to extubation, duration of CVICU stay, duration of hospital stay, 30-day mortality, and incidence of acute kidney injury on postoperative day 3. We used linear regression modeling on PSM data for the primary efficacy outcome. For the primary safety outcome, we tested for differences using McNemar test on PSM data. For secondary outcomes, we used linear regression, Fisher exact test, or survival analyses as appropriate, with false discovery rate-adjusted P values.

RESULTS

A total of 165 neonates were included in the final data analysis: 86 in the control group and 79 in the a4FPCC group. After PSM, there were 43 patients in the control group and 43 in the a4FPCC group. We found a statistically significant difference in mean total blood products transfused for the a4FPCC group (47.5 mL/kg) compared with the control group (63.7 mL/kg) for PSM patients (adjusted difference, 15.3; 95% CI, 29.4-1.3; P = .032). We did not find a statistically significant difference in 7- or 30-day thromboembolic rate, postoperative chest tube output, time to extubation, incidence of postoperative acute kidney injury (AKI), or 30-day mortality between the groups. The a4FPCC group had a significantly longer length of intensive care unit stay (32.9 vs 13.3 days; adjusted P = .049) and hospital stay (44.6 vs 24.1 days; adjusted P = .049) compared with the control group.

CONCLUSIONS

We found that the use of a4FPCC as a hemostatic adjunct for post-CPB bleeding in neonatal cardiac surgery was associated with a decrease in mean total blood products transfused after CPB without an increased rate of 7- or 30-day postoperative thromboembolism. Our findings suggest that a4FPCCs can be considered as part of a hemostasis pathway for refractory bleeding in neonatal cardiac surgery.

Patient Blood Management in Vascular Surgery

Patient blood management (PBM) is an evidence-based, multidisciplinary approach aimed at appropriately allocating blood products to patients requiring transfusion while simultaneously minimizing inappropriate transfusions. The 3 pillars of patient blood management are optimizing erythropoiesis, minimizing blood loss, and optimizing physiological reserve of anemia. Benefits seen from PBM include limiting hospital costs and mitigating harm from numerous risks of transfusion.

Reversing direct factor Xa or thrombin inhibitors: Factor V addition to prothrombin complex concentrate is beneficial in vitro

Background

Prothrombin complex concentrate (PCC) is a human plasma‐derived mixture of partially purified vitamin K‐dependent coagulation factors (VKCF). Current therapeutic indication is treatment and perioperative prophylaxis of bleeding in acquired VKCF deficiency. Off‐label uses include treatment of direct factor Xa‐ or thrombin inhibitor‐associated bleeds, treatment of trauma‐induced coagulopathy, and hemorrhagic complications in patients with liver disease.

Objective

Considering PCC as a general prohemostatic drug, we argued that its clinical efficacy can benefit from supplementation with coagulation factors that are absent in the current PCC formulation. In this study, we focused on factor V.

Methods

We mimicked a coagulopathy in vitro by spiking whole blood or derived plasma with the direct oral anticoagulants (DOAC) rivaroxaban or dabigatran. We studied DOAC reversal by PCC and factor V concentrate (FVC) using a thrombin generation assay, thromboelastography, fibrin generation clot lysis test, and microfluidic thrombus formation under flow.

Results

In DOAC‐treated plasma, PCC increased the amount of thrombin generated. The addition of FVC alone or in combination with PCC caused a partial correction of the thrombin generation lag time and clotting time. In DOAC‐treated whole blood, the combination of PCC and FVC synergistically improved clotting time under static conditions, whereas complete correction of fibrin formation was observed under flow. Clot strength and clot resistance toward tissue plasminogen activator‐induced lysis were both increased with PCC and further enhanced by additional FVC.

Conclusion

Our in vitro study demonstrates a beneficial effect of the combined use of PCC and FVC in DOAC reversal.

Hemostatic biomaterials to halt non-compressible hemorrhage

Non-compressible hemorrhage is an unmet clinical challenge, which occurs in inaccessible sites in the body where compression cannot be applied to stop bleeding. Current treatments reliant on blood transfusion are...

Andexanet Alfa Versus Prothrombin Complex Concentrates/Blood Products as Apixaban/Rivaroxaban Reversal Agents: A Survey Among Pediatric Hematologists

Direct oral factor Xa inhibitors (DXIs) are approved for use in adult patients with non-valvular heart disease for stroke prevention, and the treatment/prevention of venous thromboembolism (VTE). Recent pediatric clinical trials have demonstrated safety and efficacy of direct oral anticoagulants (DOACs) in the treatment of VTE. However, there is a lack of evidence regarding the use of andexanet alfa and prothrombin complex concentrates (PCC) for anticoagulation reversal of DXIs in the pediatric population. To better understand current DXI reversal strategies in this age group, a 10-question survey was conducted among pediatric hematology members of the Hemostasis and Thrombosis Research Society. Seventeen percent completed the survey (27 of 163 pediatric hematology members) with 74% (n = 20) reporting their use of DXIs for the treatment and prevention of VTE. Forty-four percent (n = 12) would choose andexanet alfa as first-line treatment for life-threatening bleeding while 52% (n = 14) would use PCC first with one individual choosing recombinant factor VII for DXI reversal. Clinical studies of andexanet alfa and PCC for the management of DXI-associated life-threatening bleeding require further investigation in the pediatric population.

Reversing Rivaroxaban Anticoagulation as Part of a Multimodal Hemostatic Intervention in a Polytrauma Animal Model

BACKGROUND

Life-threatening bleeding requires prompt reversal of the anticoagulant effects of factor Xa inhibitors. This study investigated the effectiveness of four-factor prothrombin complex concentrate in treating trauma-related hemorrhage with rivaroxaban-anticoagulation in a pig polytrauma model. This study also tested the hypothesis that the combined use of a low dose of prothrombin complex concentrate plus tranexamic acid and fibrinogen concentrate could improve its subtherapeutic effects.

METHODS

Trauma (blunt liver injury and bilateral femur fractures) was induced in 48 anesthetized male pigs after 30 min of rivaroxaban infusion (1 mg/kg). Animals in the first part of the study received prothrombin complex concentrate (12.5, 25, and 50 U/kg). In the second part, animals were treated with 12.5 U/kg prothrombin complex concentrate plus tranexamic acid or plus tranexamic acid and fibrinogen concentrate. The primary endpoint was total blood loss postinjury. The secondary endpoints (panel of coagulation parameters and thrombin generation) were monitored for 240 min posttrauma or until death.

RESULTS

The first part of the study showed that blood loss was significantly lower in the 25 U/kg prothrombin complex concentrate (1,541 ± 269 ml) and 50 U/kg prothrombin complex concentrate (1,464 ± 108 ml) compared with control (3,313 ± 634 ml), and 12.5 U/kg prothrombin complex concentrate (2,671 ± 334 ml, all P < 0.0001). In the second part of the study, blood loss was significantly less in the 12.5 U/kg prothrombin complex concentrate plus tranexamic acid and fibrinogen concentrate (1,836 ± 556 ml, P < 0.001) compared with 12.5 U/kg prothrombin complex concentrate plus tranexamic acid (2,910 ± 856 ml), and there were no early deaths in the 25 U/kg prothrombin complex concentrate, 50 U/kg prothrombin complex concentrate, and 12.5 U/kg prothrombin complex concentrate plus tranexamic acid and fibrinogen concentrate groups. Histopathologic analyses postmortem showed no adverse events.

CONCLUSIONS

Prothrombin complex concentrate effectively reduced blood loss, restored hemostasis, and balanced thrombin generation. A multimodal hemostatic approach using tranexamic acid plus fibrinogen concentrate enhanced the effect of low doses of prothrombin complex concentrate, potentially reducing the prothrombin complex concentrate doses required for effective bleeding control.

EDITOR’S PERSPECTIVE

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.

A Comparison of Prothrombin Complex Concentrate and Recombinant Activated Factor VII for the Management of Bleeding With Cardiac Surgery

Bleeding following cardiac surgery that warrants transfusion of blood products is associated with significant complications, including increased mortality at 1 year following surgery. Factor concentrates, such as prothrombin complex concentrate (PCC), or recombinant activated factor VII (rFVIIa) have been used off-label for bleeding in cardiac surgery that is refractory to conventional therapy. The objective of this retrospective study is to assess the hemostatic effectiveness of 4-factor PCC or rFVIIa for bleeding after a broad range of cardiac surgeries. Patients were included if they were at least 18 years of age and had undergone cardiac surgery with bleeding requiring intervention with 4-factor PCC or rFVIIa. There were no differences observed in the number of packed red blood cells (4-factor PCC: 2 units vs. rFVIIa: 2 units), fresh frozen plasma (0 units vs. 1 unit) or platelet (2 units vs. 2 units) transfusions following the administration of 4-factor PCC or rFVIIa. The patients in the rFVIIa group, required more cryoprecipitate than those in the 4-factor PCC group (4-factor PCC: 2 units (range 0-6) vs. rFVIIa: 2 units (range 0-8), p = 0.03). There were no differences in secondary outcomes of chest tube output at 2, 6, 12 and 24 hours, nor was there a difference in reexploration rates or the median length of stay in the intensive care unit. Thromboembolic complications at 30 days were similar between the two groups (4-factor PCC: 13% vs. rFVIIa 26%, p = 0.08). The total median dose requirement for 4-factor PCC was 1000 units (15 units/kg) and 2 mg (20 mcg/kg) for rFVIIa. The results demonstrate feasibility of utilizing the minimum amount of drug in order to achieve a desired effect. Both 4-factor PCC and rFVIIa appear to be safe and effective options for the management of bleeding associated with cardiac surgery.

Combination Therapy Using Prothrombin Complex Concentrate and Vitamin K in Anticoagulated Patients with Traumatic Intracranial Hemorrhage Prevents Progressive Hemorrhagic Injury: A Historically Controlled Study

Warfarin remains crucially involved in the treatment of patients at thrombotic or thromboembolic risk. However, warfarin increases the mortality rate among patients with traumatic intracranial hemorrhage (TICH) through progressive hemorrhagic injury (PHI). Therefore, a rapid anticoagulation reversal could be required in patients with TICH to prevent PHI. Differences in the warfarin reversal effect between combination therapy of prothrombin complex concentrate (PCC) with vitamin K (VK) and VK monotherapy remain unclear. However, studies have reported that PCC has greater effectiveness and safety for warfarin reversal compared with fresh frozen plasma (FFP). This retrospective study aimed to evaluate the warfarin reversal effects of combination therapy of PCC with VK and VK monotherapy on TICH. We compared the clinical outcomes between the periods before and after the PCC introduction in our hospital. There were 13 and 7 patients who received VK monotherapy and PCC with VK, respectively. PHI predictors were evaluated using univariate regression analyses. Warfarin reversal using PCC had a significant negative association with PHI (odds ratio: 0.03, 95% confidence interval: 0.00-0.41, P = 0.004). None of the patients presented with thrombotic complications. Warfarin reversal through a combination of PCC with VK could be more effective for inhibiting post-trauma PHI compared with VK monotherapy. This could be attributed to a rapid and stable warfarin reversal. PCC should be administered to patients with TICH taking warfarin for PHI prevention.

Four-Factor Prothrombin Complex Concentrate: An Indispensable Adjunct in Coagulopathy of Trauma Management - A Comparative Review of the Literature over 2 Decades

BACKGROUND

Damage control resuscitation forms the cornerstone of management in trauma surgery. Several blood products have been widely used for preoperative transfusions prior to emergency surgeries and for hemorrhage control in trauma. Prothrombin complex concentrate (PCC) is now being introduced as an essential component of damage control resuscitation.

SUMMARY

We did a comparative descriptive analysis of several single and multi-institutional clinical trials and retrospective cohort studies. The primary focus of these studies was a comparison between PCC and other transfusion modalities including recombinant factor VIIa, fresh-frozen plasma, and fibrinogen based on several vital parameters. The parameters included rapid international normalized ratio reversal, hospital length of stay, cost-effectiveness, mortality rate, and rate of thromboembolic complications.

KEY POINTS

Although still awaiting its approval from the FDA for use in traumatic coagulopathy, 4-factor PCC has shown far more convincing results in contrast to former transfusion modalities, even 3-factor PCC. However, more prospective extensive clinical trials on national levels are needed to compare its effectiveness to 3-factor PCC and gather promising recognition in the trauma care fraternity.

3-Factor Versus 4-Factor PCC in Coagulopathy of Trauma: Four is Better Than Three

INTRODUCTION

Coagulopathy of trauma (COT) is common and highly lethal. Prothrombin complex concentrate (PCC) has been advocated for correction of COT. However, the difference in efficacy between three-factor PCC (3-PCC) versus four-factor PCC (4-PCC) remains unclear. The aim of our study was to compare efficacy of 3-PCC versus 4-PCC in COT.

METHODS

Five-year (2013-2017) review of coagulopathic trauma patients at our Level-I trauma center who received 3- or 4-PCC. Patients were divided into two groups (4-PCC and 3-PCC) and matched in 1:1 ratio using propensity-score-matching for demographics, injury parameters, admission vitals, and hematological parameters. Primary outcomes were time to correction of international normalized ratio (INR), blood products transfusion, thromboembolic complications, and mortality. Secondary outcomes were hospital-length of stay (LOS), intensive care unit (ICU)-LOS, cost of therapy, and total hospital cost.

RESULTS

Six hundred fifty-seven patients met inclusion criteria of whom 250 patients (4-PCC:125; 3-PCC:125) were matched. The mean age was 50 ± 19.4 y, 64% were male, and median-injury severity score was 24[15-33]. 4-PCC was associated with accelerated correction of INR (365 vs. 428 min, P = 0.01), decrease in red blood cells (7 units vs. 10 units, P = 0.04) and FFP (6 units vs. 8 units, P = 0.03) transfused. There was no difference in platelet transfusion, thromboembolic complications, mortality, hospital, and ICU-LOS. 4-PCC was associated with higher cost of PCC therapy, and lower cost of transfusion. There was no difference regarding the total hospital cost between the two groups.

CONCLUSION

Compared with 3-factor PCC, the use of 4-factor PCC is associated with a rapid reversal of INR and reduction in transfusion requirement without increasing the overall hospital cost or the risk of thromboembolic events. 4-PCC may be preferred as an adjunct for the resuscitation of coagulopathic trauma patients.

Management of oral anticoagulants prior to emergency surgery or with major bleeding: A survey of perioperative practices in North America: Communication from the Scientific and Standardization Committees on Perioperative and Critical Care Haemostasis and Thrombosis of the International Society on Thrombosis and Haemostasis

BACKGROUND

There is limited information on real-world practice versus current clinical practice guidelines for oral anticoagulant reversal before emergency surgery.

OBJECTIVE

To identify current practice/knowledge gaps for oral anticoagulant reversal emergency surgery among anesthesiologists.

METHODS

A 22-question survey covering aspects of clinical practice relating to oral anticoagulant reversal was sent to American Society of Anesthesiology members with weekly reminders during data collection from October to December 2018.

RESULTS

Responses were received from 2315 anesthesiologists of which 86% of respondents were United States based. Emergency surgery was defined as occurring within 4 hours of the decision to operate by 60% of respondents. Fresh frozen plasma (FFP) was used by 75% of respondents for vitamin K antagonist (VKA) reversal and by 54% for direct oral anticoagulant (DOAC) reversal in emergency surgery and 67% in major operative bleeding. Only 32% of institutions had emergency anticoagulant reversal protocols, and 54% of respondents selected an international normalized ration (INR) ratio goal for VKA reversal of ≤1.5. Only 13% initially consulted or coordinated management with hematologists, and the final decision regarding coagulation management was made by the respondent in 26% of cases. A coordinated approach with hematologists and cardiologists was reported by 64%, and over half (51%) required approval for prothrombin complex concentrate administration for emergency procedures.

CONCLUSIONS

Despite recommendations to the contrary, FFP is extensively used for emergency VKA and DOAC reversal. There is a clear need for institutions to develop guideline-informed recommendations/management algorithms based on input from medical professionals routinely involved in management of these patients.

Hemostatic agents for prehospital hemorrhage control: a narrative review

Hemorrhage is the leading cause of preventable death in combat trauma and the secondary cause of death in civilian trauma. A significant number of deaths due to hemorrhage occur before and in the first hour after hospital arrival. A literature search was performed through PubMed, Scopus, and Institute of Scientific Information databases for English language articles using terms relating to hemostatic agents, prehospital, battlefield or combat dressings, and prehospital hemostatic resuscitation, followed by cross-reference searching. Abstracts were screened to determine relevance and whether appropriate further review of the original articles was warranted. Based on these findings, this paper provides a review of a variety of hemostatic agents ranging from clinically approved products for human use to newly developed concepts with great potential for use in prehospital settings. These hemostatic agents can be administered either systemically or locally to stop bleeding through different mechanisms of action. Comparisons of current hemostatic products and further directions for prehospital hemorrhage control are also discussed.

Thrombin generation and bleeding in cardiac surgery: a clinical narrative review

This narrative review discusses the role of thrombin generation in coagulation and bleeding in cardiac surgery, the laboratory methods for clinical detection of impaired thrombin generation, and the available hemostatic interventions that can be used to improve thrombin generation. Coagulopathy after cardiopulmonary bypass (CPB) is associated with excessive blood loss and adverse patient outcomes. Thrombin plays a crucial role in primary hemostasis, and impaired thrombin generation can be an important cause of post-CPB coagulopathy. Existing coagulation assays have significant limitations in assessing thrombin generation, but whole-blood assays designed to measure thrombin generation at the bed-side are under development. Until then, clinicians may need to institute therapy empirically for non-surgical bleeding in the setting of normal coagulation measures. Available therapies for impaired thrombin generation include administration of plasma, prothrombin complex concentrate, and bypassing agents (recombinant activated factor VII and factor eight inhibitor bypassing activity). In vitro experiments have explored the relative potency of these therapies, but clinical studies are lacking. The potential incorporation of thrombin generation assays into clinical practice and treatment algorithms for impaired thrombin generation must await further clinical development.

Prothrombin Complex Concentrate-induced Disseminated Intravascular Coagulation Can Be Prevented by Coadministering Antithrombin in a Porcine Trauma Model

BACKGROUND

The risk of thromboembolic complications with prothrombin complex concentrates (PCCs) appears low when used for reversal of vitamin K antagonists but might be different in other indications (e.g., trauma). A difference in risk could arise from the plasma ratio of pro- versus anticoagulant proteins. This study used a porcine trauma model to investigate combined treatment with PCC and antithrombin. The hypothesis was that antithrombin can modulate prothrombotic effects and prevent adverse events of PCC.

METHODS

Nine treatment groups (n = 7 per group) were included: control (placebo), PCC (50 IU/kg), PCC plus antithrombin (three groups, with antithrombin doses of 12.5, 25, or 50 IU/kg), fibrinogen concentrate (100 mg/kg) plus PCC, fibrinogen concentrate plus PCC plus antithrombin dose of 50 IU/kg, tranexamic acid (15 mg/kg) plus fibrinogen concentrate plus PCC, and tranexamic acid plus fibrinogen concentrate plus PCC plus antithrombin dose of 50 IU/kg. In each group, bilateral femur fractures and thorax contusion were followed 60 min later by blunt liver injury. Study treatment was then administered, and animals were subsequently observed for 210 min.

RESULTS

Total blood loss (mean ± SD) was statistically significantly lower in all three PCC plus antithrombin groups (PCC plus antithrombin dose of 50 IU/kg, 672 ± 63 ml; PCC plus antithrombin dose of 25 IU/kg, 535 ± 72 ml; and PCC plus antithrombin dose of 12.5 IU/kg, 538 ± 50 ml) than in the PCC group (907 ± 132 ml), which in turn had statistically significantly reduced bleeding versus the control group (1,671 ± 409 ml). Signs of disseminated intravascular coagulation were apparent with PCC monotherapy, and early deaths occurred with fibrinogen concentrate plus PCC, attributable to pulmonary emboli. Antithrombin was protective against both of these effects: signs of disseminated intravascular coagulation were absent from the PCC plus antithrombin groups, and there were no early deaths in the group with fibrinogen concentrate plus PCC plus antithrombin dose of 50 IU/kg.

CONCLUSIONS

According to this trauma model, 50 IU/kg PCC increases the risk of disseminated intravascular coagulation and other thromboembolic complications, most notably when coadministered with fibrinogen concentrate. The addition of antithrombin appears to reduce this risk.

Safety and effectiveness of a prothrombin complex concentrate in approved and off-label indications

OBJECTIVE

To evaluate the effectiveness and safety of prothrombin complex concentrates (PCCs) in approved and off-label indications.

BACKGROUND

PCCs are approved for the urgent reversal of vitamin K antagonists (VKAs). Data concerning the efficacy, safety and dosing for off-label indications are limited, but they are included in massive bleeding protocols.

METHODS

This was a retrospective review of cases treated with four-factor PCCs (4F-PCCs) between January 2009 and 2016. Efficacy end-points include: (i) VKA reversal efficacy assessed by international normalised ratio (INR) normalisation (<1·5) and (ii) clinical efficacy as bleeding cessation and/or decreased number of transfused blood components and 24-h mortality in bleeding coagulopathy. The safety end-point is the incidence of thromboembolic events.

RESULTS

A total of 328 patients were included (51·8% male, median age 78 years old). Indications were as follows: VKA reversal (66·6%), bleeding coagulopathy (30·5%) and direct anticoagulant (DOAC) reversal due to bleeding (2·5%). VKA reversal was effective in 97·1% of patients, and 76·5% demonstrated complete reversal (INR < 1·5); only 34·3% patients needed hemoderivatives. Prior to emergency procedures, PCCs achieved global responses in 83% of patients, with no bleeding complication during intervention. DOAC reversal was effective in 88·9% of patients. Bleeding cessation was associated with the dose administered (P = 0·002). In coagulopathy bleeding, haemorrhage cessation, established by the International Society of Thrombosis and Haemostais (ISTH) definition, occurred in 56·7% of massive bleeding events and in 42·5% of other coagulopathies; 24-h mortality was 30%, mainly related to active bleeding. Ten thrombotic episodes were observed (3·1%).

CONCLUSION

4F-PCC was effective as adjuvant treatment with an acceptable safety profile, not only for the emergent reversal of VKAs but also for refractory coagulopathy associated with major bleeding.

The use of new procoagulants in blunt and penetrating trauma

PURPOSE OF REVIEW

Uncontrolled bleeding in trauma secondary to a combination of surgical bleeding and trauma-induced complex coagulopathy is a leading cause of death. Prothrombin complex concentrates (PCCs), recombinant activated factor seven (rFVIIa) and recombinant human prothrombin act as procoagulants by increasing thrombin generation and fibrinogen concentrate aids stable clot formation. This review summarizes the current evidence for procoagulant use in the management of bleeding in trauma, and data and evidence gaps for routine clinical use.

RECENT FINDINGS

Retrospective and prospective studies of PCCs (±fibrinogen concentrate) have demonstrated a decreased time to correction of trauma coagulopathy and decreased red cell transfusion with no obvious effect on mortality or thromboembolic outcomes. PCCs in a porcine model of dilutional coagulopathy demonstrated a sustained increase in thrombin generation, unlike recombinant human prothrombin which showed a transient increase and has been studied only in animals. In other retrospective studies, there is a suggestion that lower doses of PCCs may be effective in the setting of acquired coagulopathy.

SUMMARY

There is increasing evidence that early correction of coagulopathy has survival benefits, and the use of procoagulants as first-line therapy has the potential benefit of rapid access and timely treatment. This requires confirmation in prospective studies.

The role of evidence-based algorithms for rotational thromboelastometry-guided bleeding management

Rotational thromboelastometry (ROTEM) is a point-of-care viscoelastic method and enables to assess viscoelastic profiles of whole blood in various clinical settings. ROTEM-guided bleeding management has become an essential part of patient blood management (PBM) which is an important concept in improving patient safety. Here, ROTEM testing and hemostatic interventions should be linked by evidence-based, setting-specific algorithms adapted to the specific patient population of the hospitals and the local availability of hemostatic interventions. Accordingly, ROTEM-guided algorithms implement the concept of personalized or precision medicine in perioperative bleeding management (‘theranostic’ approach). ROTEM-guided PBM has been shown to be effective in reducing bleeding, transfusion requirements, complication rates, and health care costs. Accordingly, several randomized-controlled trials, meta-analyses, and health technology assessments provided evidence that using ROTEM-guided algorithms in bleeding patients resulted in improved patient’s safety and outcomes including perioperative morbidity and mortality. However, the implementation of ROTEM in the PBM concept requires adequate technical and interpretation training, education and logistics, as well as interdisciplinary communication and collaboration.

In Situ Cold Perfusion of the Liver on Cardiopulmonary Bypass: Coagulopathy and Its Correction: A Case Report

We report a case of profound coagulopathy after the dual insult of cold in-situ perfusion of the liver and cardiopulmonary bypass in a patient undergoing complex hepatobiliary and cardiovascular surgery. Management of this coagulopathy with conventional blood products was hindered by elevated venous pressures, thought to contribute to persistent bleeding and risked liver and right ventricular dysfunction, necessitating a change in strategy. Anesthesiologists should consider fluid-restrictive strategies to correct coagulopathy in combined liver and cardiac surgery.

Prothrombin Complex Concentrates for Coagulopathy in Liver Disease: Single-Center, Clinical Experience in 105 Patients

Patients with liver disease frequently develop coagulopathy, and fresh frozen plasma is traditionally used for correction of coagulopathy to manage and prevent bleeding. Prothrombin complex concentrates (PCCs) offer an attractive alternative because they are more readily available and avoid large-volume transfusion. This retrospective, single-center study reviewed clinical use of PCC in patients with acute/chronic liver disease. A total of 105 patients with 194 episodes of PCC administration were reviewed. Data pertaining to indication, dosing, effectiveness, and safety were collected. The effect of PCC on coagulation was analyzed in patients for whom coagulation results were available 7 hours before and after PCC. Data on thromboembolic events and mortality within 4 weeks of PCC administration were captured. Most patients (77%) had chronic liver disease; the remainder had acute liver failure. Indications for PCC were preprocedure prophylaxis and treatment for active/recent bleeding in 48% and 52% of 194 treatment episodes, respectively. The median dose of PCC administered was 22 IU/kg (interquartile range, 16-29 IU/kg). Before PCC administration, 45% of patients had an international normalized ratio (INR) greater than 2.0, and 36% had fibrinogen levels of at least 1.5 g/L. PCC produced statistically significant reductions in prothrombin time and INR (coadministration with fibrinogen or cryoprecipitate: 3.1 versus 1.9; P < 0.001; no coadministration: 2.3 versus 1.8; P < 0.001). Three patients with multiple risk factors developed thrombotic events (hepatic artery thrombosis, incidental bilateral pulmonary embolism, nonocclusive portal vein thrombosis); there were no cardiovascular or cerebrovascular adverse events. Overall, 46 patients died of causes unrelated to PCC treatment. Conclusion: In patients with liver disease, PCC therapy was effective in improving coagulation test results without an excess of thrombotic events. Further assessment of PCC as hemostatic therapy in this setting is required.

Comparative Analysis of Prothrombin Complex Concentrate and Fresh Frozen Plasma in Coronary Surgery

BACKGROUND

Recent studies suggested that prothrombin complex concentrate (PCC) might be more effective than fresh frozen plasma (FFP) to reduce red blood cell (RBC) transfusion requirement after cardiac surgery.

METHODS

This is a comparative analysis of 416 patients who received FFP postoperatively and 119 patients who received PCC with or without FFP after isolated coronary artery bypass grafting (CABG).

RESULTS

Mixed-effects regression analyses adjusted for multiple covariates and participating centres showed that PCC significantly decreased RBC transfusion (67.2% vs. 87.5%, adjusted OR 0.319, 95%CI 0.136-0.752) and platelet transfusion requirements (11.8% vs. 45.2%, adjusted OR 0.238, 95%CI 0.097-0.566) compared with FFP. The PCC cohort received a mean of 2.7±3.7 (median, 2.0, IQR 4) units of RBC and the FFP cohort received a mean of 4.9±6.3 (median, 3.0, IQR 4) units of RBC (adjusted coefficient, -1.926, 95%CI -3.357-0.494). The use of PCC increased the risk of KDIGO (Kidney Disease: Improving Global Outcomes) acute kidney injury (41.4% vs. 28.2%, adjusted OR 2.300, 1.203-4.400), but not of KDIGO acute kidney injury stage 3 (6.0% vs. 8.0%, OR 0.850, 95%CI 0.258-2.796) when compared with the FFP cohort.

CONCLUSIONS

These results suggest that the use of PCC compared with FFP may reduce the need of blood transfusion after CABG.

Perioperative management of the bleeding patient

Perioperative bleeding remains a major complication during and after surgery, resulting in increased morbidity and mortality. The principal causes of non-vascular sources of haemostatic perioperative bleeding are a preexisting undetected bleeding disorder, the nature of the operation itself, or acquired coagulation abnormalities secondary to haemorrhage, haemodilution, or haemostatic factor consumption. In the bleeding patient, standard therapeutic approaches include allogeneic blood product administration, concomitant pharmacologic agents, and increasing application of purified and recombinant haemostatic factors. Multiple haemostatic changes occur perioperatively after trauma and complex surgical procedures including cardiac surgery and liver transplantation. Novel strategies for both prophylaxis and therapy of perioperative bleeding include tranexamic acid, desmopressin, fibrinogen and prothrombin complex concentrates. Point-of-care patient testing using thromboelastography, rotational thromboelastometry, and platelet function assays has allowed for more detailed assessment of specific targeted therapy for haemostasis. Strategic multimodal management is needed to improve management, reduce allogeneic blood product administration, and minimize associated risks related to transfusion.

Blood products and procoagulants in traumatic bleeding: use and evidence

PURPOSE OF REVIEW

Death from uncontrolled haemorrhage is one of the leading causes of trauma-related mortality and is potentially preventable. Advances in understanding the mechanisms of trauma-induced coagulopathy (TIC) have focused attention on the role of blood products and procoagulants in mitigating the sequelae of TIC and how these therapies can be improved.

RECENT FINDINGS

A host of preclinical and clinical studies have evaluated blood product availability and efficacy in trauma. Recently published randomized controlled trials have investigated the ratio of platelet:plasma:red cell transfusion and the role of early cryoprecipitate in trauma. Demand for readily available plasma has led to changes particularly in the use of thawed group A plasma. Furthermore, ex-vivo and early clinical work has demonstrated variations in the haemostatic activity of different plasma, platelet and whole blood products. A number of multicentre trials are in progress aiming to answer key questions regarding tranexamic acid, procoagulant factor and fibrinogen concentrates and their effect on trauma outcomes.

SUMMARY

There are promising results from ex-vivo studies in manufacturing and storage of blood products to optimize haemostatic activity and availability, particularly with alternative plasma and platelet products and whole blood. There is an urgent need for these products needs to be tested prospectively.

Emergency care of patients receiving non-vitamin K antagonist oral anticoagulants

Non-vitamin K antagonist oral anticoagulants (NOACs), which inhibit thrombin (dabigatran) and factor Xa (rivaroxaban, apixaban, edoxaban) have been introduced in several clinical indications. Although NOACs have a favourable benefit-risk profile and can be used without routine laboratory monitoring, they are associated-as any anticoagulant-with a risk of bleeding. In addition, treatment may need to be interrupted in patients who need surgery or other procedures. The objective of this article, developed by a multidisciplinary panel of experts in thrombosis and haemostasis, is to provide an update on the management of NOAC-treated patients who experience a bleeding episode or require an urgent procedure. Recent advances in the development of targeted reversal agents are expected to help streamline the management of NOAC-treated patients in whom rapid reversal of anticoagulation is required.

A reduction of prothrombin conversion by cardiac surgery with cardiopulmonary bypass shifts the haemostatic balance towards bleeding

Cardiac surgery with cardiopulmonary bypass (CPB) is associated with blood loss and post-surgery thrombotic complications. The process of thrombin generation is disturbed during surgery with CPB because of haemodilution, coagulation factor consumption and heparin administration. We aimed to investigate the changes in thrombin generation during cardiac surgery and its underlying pro- and anticoagulant processes, and to explore the clinical consequences of these changes using in silico experimentation. Plasma was obtained from 29 patients undergoing surgery with CPB before heparinisation, after heparinisation, after haemodilution, and after protamine administration. Thrombin generation was measured and prothrombin conversion and thrombin inactivation were quantified. In silico experimentation was used to investigate the reaction of patients to the administration of procoagulant factors and/or anticoagulant factors. Surgery with CPB causes significant coagulation factor consumption and a reduction of thrombin generation. The total amount of prothrombin converted and the rate of prothrombin conversion decreased during surgery. As the surgery progressed, the relative contribution of α2-macroglobulin-dependent thrombin inhibition increased, at the expense of antithrombin-dependent inhibition. In silico restoration of post-surgical prothrombin conversion to pre-surgical levels increased thrombin generation excessively, whereas co-administration of antithrombin resulted in the normalisation of post-surgical thrombin generation. Thrombin generation is reduced during surgery with cardiopulmonary bypass because of a balance shift between prothrombin conversion and thrombin inactivation. According to in silico predictions of thrombin generation, this new balance increases the risk of thrombotic complications with prothrombin complex concentrate administration, but not if antithrombin is co-administered.

Coagulation Management During Liver Transplantation: Use of Fibrinogen Concentrate, Recombinant Activated Factor VII, Prothrombin Complex Concentrate, and Antifibrinolytics

Coagulation management, and transfusion practice in liver transplantation (LT) have been evolving in the recent years due to better understanding of coagulation abnormalities in end-stage liver disease, and clinical management of LT patients. Avoidance of allogeneic blood components is feasible in some patients, but multi-modal coagulation therapies may be necessary in others who develop complex coagulopathy due to hemorrhage, hemodilution, hypothermia, and acid-base disturbances. Transfusions of plasma and cryoprecipitate remain to be the mainstay therapy for procoagulant factor replacement during LT. Clinical efficacy and safety of these products are limited by logistic issues (eg, thawing), and mostly noninfectious complications. Considering potential alternatives to conventional transfusion is thus important to improve hemostatic resuscitation in complex LT cases. The present review is mainly focused on procoagulant properties of plasma and platelet transfusion, and currently available plasma-derived and recombinant factor concentrates, and antifibrinolytic agents in LT patients. The role of viscoelastic coagulation tests to guide specific component therapies will be also discussed.

Theoretical Modeling of Coagulation Management With Therapeutic Plasma or Prothrombin Complex Concentrate

Supplemental Digital Content is available in the text.

Published ahead of print August 24, 2017.

Prothrombin complex concentrates (PCCs) have been associated with a possible risk of thromboembolic complications, potentially attributable to an increased ratio of the plasma concentration of factor II (FII) to antithrombin (AT). We developed a mathematical model to examine the relationship between amounts of PCC or therapeutic plasma administered, and plasma levels of FII and AT. The model showed that PCC produces substantial increases in plasma levels of FII but only small changes in AT, increasing the FII:AT ratio. Therapeutic plasma was shown to have only modest effects on levels of FII or AT, unless high doses are used.

Transfusion Medicine and Coagulation Management in Organ Transplantation

Organ transplantation recipients present unusual challenges with regard to blood transfusion. Although this patient population requires a larger proportion of blood product resources, liberal transfusion of allogeneic blood products can lead to a plethora of complications. Recent trends suggest that efforts to minimize bleeding, conserve products, and target transfusion to specific deficits and needs are increasingly becoming the standard practice; these must all occur with optimization of graft function and preservation in mind. With newer monitoring modalities and factor concentrates, the approach toward transfusion and bleeding in organ transplantation has rapidly improved in recent years.

Current use of factor concentrates in pediatric cardiac anesthesia

Excessive bleeding following pediatric cardiopulmonary bypass is associated with increased morbidity and mortality, both from the effects of hemorrhage and the therapies employed to achieve hemostasis. Neonates and infants are especially at risk because their coagulation systems are immature, surgeries are often complex, and cardiopulmonary bypass technologies are inappropriately matched to patient size and physiology. Consequently, these young children receive substantial amounts of adult-derived blood products to restore adequate hemostasis. Adult and pediatric data demonstrate associations between blood product transfusions and adverse patient outcomes. Thus, efforts to limit bleeding after pediatric cardiopulmonary bypass and minimize allogeneic blood product exposure are warranted. The off-label use of factor concentrates, such as fibrinogen concentrate, recombinant activated factor VII, and prothrombin complex concentrates, is increasing as these hemostatic agents appear to offer several advantages over conventional blood products. However, recognizing that these agents have the potential for both benefit and harm, well-designed studies are needed to enhance our knowledge and to determine the optimal use of these agents. In this review, our primary objective was to examine the evidence regarding the use of factor concentrates to treat bleeding after pediatric CPB and identify where further research is required. PubMed, MEDLINE/OVID, The Cochrane Library and the Cochrane Central Register of Controlled Trials (CENTRAL) were systematically searched to identify existing studies.

Targeted Coagulation Management in Severe Trauma: The Controversies and the Evidence

Hemorrhage in the setting of severe trauma is a leading cause of death worldwide. The pathophysiology of hemorrhage and coagulopathy in severe trauma is complex and remains poorly understood. Most clinicians currently treating trauma patients acknowledge the presence of a coagulopathy unique to trauma patients-trauma-induced coagulopathy (TIC)-independently associated with increased mortality. The complexity and incomplete understanding of TIC has resulted in significant controversy regarding optimum management. Although the majority of trauma centers utilize fixed-ratio massive transfusion protocols in severe traumatic hemorrhage, a widely accepted "ideal" transfusion ratio of blood to blood products remains elusive. The recent use of viscoelastic hemostatic assays (VHAs) to guide blood product replacement has further provoked debate as to the optimum transfusion strategy. The use of VHA to quantify the functional contributions of individual components of the coagulation system may permit targeted treatment of TIC but remains controversial and is unlikely to demonstrate a mortality benefit in light of the heterogeneity of the trauma population. Thus, VHA-guided algorithms as an alternative to fixed product ratios in trauma are not universally accepted, and a hybrid strategy starting with fixed-ratio transfusion and incorporating VHA data as they become available is favored by some institutions. We review the current evidence for the management of coagulopathy in trauma, the rationale behind the use of targeted and fixed-ratio approaches and explore future directions.

Hemostatic Therapy Using Tranexamic Acid and Coagulation Factor Concentrates in a Model of Traumatic Liver Injury

BACKGROUND

The potential clinical benefits of targeted therapy with coagulation factor concentrates (e.g., fibrinogen) and antifibrinolytic agents (e.g., tranexamic acid [TXA]) for the treatment of trauma-induced coagulopathy are increasingly recognized. We hypothesized that human fibrinogen concentrate (FC) and prothrombin complex concentrate (PCC), administered as combined therapy with TXA, would provide additive effects for reducing blood loss in an animal trauma model.

METHODS

Thirty-six pigs were subjected to 2 consecutive blunt liver injuries, resulting in severe hemorrhagic shock and coagulopathy. Intervention comprised saline (control group); TXA (15 mg kg, TXA group); TXA and FC (90 mg kg, TXA-FC); or TXA, FC, and PCC (20 U kg, TXA-FC-PCC). Blood loss, thromboelastometry (ROTEM), measures of thrombin generation, platelet activation, and global coagulation variables were monitored for 4 hours. Tissue sections were examined to determine the occurrence of thromboembolic events.

RESULTS

Total blood loss was similar in the TXA-FC and TXA-FC-PCC groups (mean ± SD: 1012 ± 86 mL and 1037 ± 118 mL, respectively; P = 1.000). These values were both lower (P < 0.001) than the TXA group (1579 ± 306 mL). Blood loss in all 3 intervention groups was lower (P < 0.001) than in the control group (2376 ± 478 mL). After trauma and resuscitation, but before study intervention, plasma fibrinogen levels were severely depleted (median for the whole study population: 66 mg dL; interquartile range: 51-108 mg dL) and clot strength was decreased (EXTEM whole-blood maximum clot firmness [MCF]: 53 ± 5 mm). Compared with controls, TXA inhibited fibrinolysis and stabilized MCF and clotting time. The addition of FC restored and stabilized hemostasis to a greater extent than TXA alone; the addition of PCC had no statistically significant impact on blood loss, clot strength (MCF), or clotting time, but it increased thrombin generation. There were no significant differences among the study groups regarding platelet activation. No thrombi or microthrombi were observed in any group at necropsy.

CONCLUSIONS

The early use of TXA and FC reduced blood loss and improved coagulation measurements in a porcine model of blunt liver injury and hemorrhagic shock. FC, administered in addition to TXA, was highly effective in reducing blood loss. The lack of statistically significant reduction in blood loss when PCC was added to TXA and FC may be attributable to the absence of thrombin generation impairment in this model.

Adjuncts to Blood Component Therapies for the Treatment of Bleeding in the Intensive Care Unit

Patients who are critically ill following surgical or traumatic injury often present with coagulopathy as a component of the complex multisystem dysfunction that clinicians must rapidly diagnose and treat in the intensive care environment. Failure to recognize coagulopathy while volume resuscitation with crystalloid or colloid takes place, or an unbalanced transfusion strategy focused on packed red blood cell transfusion can all significantly worsen coagulopathy, leading to increased transfusion requirements and poor outcomes. Even an optimized transfusion strategy directed at correcting coagulopathy and maintaining clotting factor levels carries the risk of a number of transfusion reactions including transfusion-related acute lung injury, transfusion-related circulatory overload, anaphylaxis, and septic shock. A number of adjunctive strategies can be used either to augment a balanced transfusion approach or as alternatives to blood component therapy. Coupled with an appropriate and timely laboratory testing, this approach can quickly diagnose a patient's specific coagulopathy and work to correct it as quickly as possible, minimizing the requirement of blood transfusion and the pathophysiologic effects of excessive bleeding and fibrinolysis. We will review the literature supporting this approach and provide insight into how these approaches can be best used to care for bleeding patients in the intensive care unit. Finally, the increasing use of several novel oral anticoagulants, novel antiplatelet drugs, and low-molecular weight heparin to clinical practice has complicated the care of the coagulopathic patient when these drugs are involved. Many clinicians familiar with heparin and warfarin reversal are not familiar with the optimal way to reverse the action of these new drugs. Patients treated with these drugs for a wide variety of conditions including atrial fibrillation, stroke, coronary artery stent, deep venous thrombosis, and pulmonary embolism will present for emergency surgery and will require management of pharmacologically induced postoperative coagulopathy. We will discuss optimized strategies for reversal of these agents and strategies that are currently under development.

The Use of 3- and 4-Factor Prothrombin Complex Concentrate in Patients With Elevated INR

BACKGROUND

PCC (Kcentra®) is an Food and Drug Administration (FDA)-approved 4-factor PCC used for the treatment of warfarin-related coagulopathy (WRC), but it has also been used off-label to treat non-WRC. Three-factor PCC in the form of coagulation factor IX human (Bebulin®) has also been used for WRC and off-label to treat non-WRC. It is unclear whether the use of 3- or 4-factor PCCs is effective for the treatment of non-WRC,.

OBJECTIVE

Our aim is to characterize the use of 3- and 4-factor PCCs for patients identified with a non-WRC.

METHODS

A retrospective analysis of patients who received PCCs for both WRC and non-WRC between January 2012 and July 2015 was conducted.

RESULTS

A total of 187 patients with elevated international normalized ratio (INR) who received PCCs were analyzed; 53.9% of patients in the WRC group and 27.7% in the non-WRC group corrected to an INR of 1.3 or less after 3- or 4-factor PCC administration. In those patients with non-WRC and who had underlying liver disease, 3- and 4-factor PCCs reduced mean INR by 0.98 and 1.43, respectively.

CONCLUSION

Three and 4-factor PCCs can reduce INR in patients with WRC and in those with non-WRC secondary to liver disease.