Effect of Fibrinogen Concentrate vs Cryoprecipitate on Blood Component Transfusion After Cardiac Surgery: The FIBRES Randomized Clinical Trial

Safety of Fibrinogen Concentrate for Correcting Perioperative Bleeding-Associated Hypofibrinogenemia in Adults: A Single-Center Experience

Background: Surgery often leads to bleeding associated with hypofibrinogenemia. Supplementation with fibrinogen concentrate appears to be effective and safe, although findings from studies are inconsistent. The primary aim of this study was to assess the safety of fibrinogen concentrate during the perioperative period. Methods: This single-centre, prospective, observational study included adult patients undergoing scheduled or emergency surgery related to bleeding coagulopathy and the administration of fibrinogen concentrate. Patients were followed until their discharge from the institution. Comprehensive data were collected, including age, sex, type of surgery, associated comorbidities, anticoagulant and/or anti-aggregating therapy, and the number of blood transfusions. Laboratory data on plasma fibrinogen concentration, haemoglobin, and platelet count before and after surgery were also collected. The primary outcomes were the mortality rate at discharge and any reported thrombotic or thromboembolic events, including deep vein thrombosis, pulmonary embolism, and myocardial infarction. Results: The study included 91 adult patients who had undergone surgery, with 29 surgeries (32%) conducted in an emergency setting. The mean age was 59.2 years, and 53.8% were male. Major bleeding occurred in 29 cases, mainly in older males and those on anticoagulant therapy. The pre-operative fibrinogen level averaged 161 mg/dL, and the average dosage of fibrinogen concentrate administered was 2.7 g. Eight patients died (8.8%), mostly due to septic or cardiogenic shock, with deaths being more frequent in emergency settings. Thromboembolic events occurred in eight patients, none of whom died. No additional adverse events directly related to the administration of fibrinogen concentrate were reported. Conclusions: Our findings suggest a favourable safety profile for fibrinogen concentrate in surgical patients, as evidenced by a low incidence of deaths and thromboembolic events, which were primarily attributed to other factors. Future research should strive to increase statistical robustness to further illuminate clinically significant patient safety measures.

Trial Of Pathogen-reduced Cryoprecipitate vs. Cryoprecipitated AHF to Lower Operative Transfusions (TOP-CLOT): study protocol for a single center, prospective, cluster randomized trial

BACKGROUND

Intraoperative hemorrhage in cardiac surgery increases risk of morbidity and mortality. Low pre-operative and perioperative levels of fibrinogen, a key clotting factor, are associated with severity of hemorrhage and increased transfusion of blood components. The ability to supplement fibrinogen during hemorrhagic resuscitation is delayed 45-60 min because cryoprecipitated antihemophilic factor (cryo AHF) is stored frozen, due to a short post-thaw shelf life. Pathogen Reduced Cryoprecipitated Fibrinogen Complex (INTERCEPT Fibrinogen Complex, IFC) can be kept thawed, at room temperature, for up to 5 days, making it possible to be immediately available for hemorrhaging patients. This trial will investigate if earlier correction of acquired hypofibrinogenemia with IFC in hemorrhaging cardiac surgery patients reduces the total number of perioperatively transfused allogeneic blood products (red blood cells, plasma, and platelets) as compared to cryo AHF.

METHODS

This is a single center, prospective, cluster randomized trial with an adaptive design. Acquired hypofibrinogenemia will be assessed by rotational thromboelastometry (ROTEM) and the threshold for cryo AHF/IFC transfusion defined as FIBTEM A10 ≤ 10 mm in bleeding patients. IFC/cryo AHF will be randomized by 1-month blocks. Cardiac surgery patients will be enrolled in the study if they have an eligible procedure and at least one dose of a cryo AHF/IFC product (approximately 2 g fibrinogen) is transfused. Data from the electronic health record, including the blood bank and lab information systems, will be prospectively collected from the health system's data warehouse.

DISCUSSION

This trial aims to provide evidence of the clinical efficacy of utilizing readily available thawed IFC during acute bleeding in the cardiac surgery setting compared to traditional cryo AHF.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05711524. Feb 3, 2023.

Postoperative intravenous iron to treat iron-deficiency anaemia in patients undergoing cardiac surgery: a protocol for a pilot, multicentre, placebo-controlled randomized trial (the POAM trial)

Background

Iron-deficiency anaemia, occurring in 30-40% of patients undergoing cardiac surgery, is an independent risk factor for adverse outcomes. Our long-term goal is to assess if postoperative i.v. iron therapy improves clinical outcomes in patients with preoperative iron-deficiency anaemia undergoing cardiac surgery. Before conducting a definitive RCT, we first propose a multicentre pilot trial to establish the feasibility of the definitive trial.

Methods

This internal pilot, double-blinded, RCT will include three centres. Sixty adults with preoperative iron-deficiency anaemia undergoing non-emergency cardiac surgery will be randomised on postoperative day 2 or 3 to receive either blinded i.v. iron (1000 mg ferric derisomaltose) or placebo. Six weeks after surgery, patients who remain iron deficient will receive a second blinded dose of i.v. iron according to their assigned treatment arm. Patients will be followed for 12 months. Clinical practice will not be otherwise modified. For the pilot study, feasibility will be assessed through rates of enrolment, protocol deviations, and loss to follow up. For the definitive study, the primary outcome will be the number of days alive and out of hospital at 90 days after surgery.

Ethics and dissemination

The trial has been approved by the University Health Network Research Ethics Board (REB # 22-5685; approved by Clinical Trials Ontario funding on 22 December 2023) and will be conducted in accordance with the Declaration of Helsinki, Good Clinical Practices guidelines, and regulatory requirements.

Clinical trial registration

NCT06287619.

Cardiac Surgical Bleeding, Transfusion, and Quality Metrics: Joint Consensus Statement by the Enhanced Recovery After Surgery Cardiac Society and Society for the Advancement of Patient Blood Management

BACKGROUND

Excessive perioperative bleeding is associated with major complications in cardiac surgery, resulting in increased morbidity, mortality, and cost.

METHODS

An international expert panel was convened to develop consensus statements on the control of bleeding and management of transfusion and to suggest key quality metrics for cardiac surgical bleeding. The panel reviewed relevant literature from the previous 10 years and used a modified RAND Delphi methodology to achieve consensus.

RESULTS

The panel developed 30 consensus statements in 8 categories, including prioritizing control of bleeding, prechest closure checklists, and the need for additional quality indicators beyond reexploration rate, such as time to reexploration. Consensus was also reached on the need for a universal definition of excessive bleeding, the use of antifibrinolytics, optimal cessation of antithrombotic agents, and preoperative risk scoring based on patient and procedural factors to identify those at greatest risk of excessive bleeding. Furthermore, an objective bleeding scale is needed based on the volume and rapidity of blood loss accompanied by viscoelastic management algorithms and standardized, patient-centered blood management strategies reflecting an interdisciplinary approach to quality improvement.

CONCLUSIONS

Prioritizing the timely control and management of bleeding is essential to improving patient outcomes in cardiac surgery. To this end, a cardiac surgical bleeding quality metric that is more comprehensive than reexploration rate alone is needed. Similarly, interdisciplinary quality initiatives that seek to implement enhanced quality indicators will likely lead to improved patient care and outcomes.

Effect of In Vivo Administration of Fibrinogen Concentrate Versus Cryoprecipitate on Ex Vivo Clot Degradation in Neonates Undergoing Cardiac Surgery

BACKGROUND

Neonates undergoing cardiac surgery require fibrinogen replacement to restore hemostasis after cardiopulmonary bypass (CPB). Cryoprecipitate is often the first-line treatment, but recent studies demonstrate that fibrinogen concentrate (RiaSTAP; CSL Behring) may be acceptable in this population. This investigator-initiated, randomized trial compares cryoprecipitate to fibrinogen concentrate in neonates undergoing cardiac surgery (ClinicalTrials.gov NCT03932240). The primary end point was the percent change in ex vivo clot degradation from baseline at 24 hours after surgery between groups. Secondary outcomes included intraoperative blood transfusions, coagulation factor levels, and adverse events.

METHODS

Neonates were randomized to receive cryoprecipitate (control group) or fibrinogen concentrate (study group) as part of a post-CPB transfusion algorithm. Blood samples were drawn at 4 time points: presurgery (T1), after treatment (T2), arrival to the intensive care unit (ICU) (T3), and 24 hours postsurgery (T4). Using the mixed-effect models, we analyzed the percent change in ex vivo clot degradation from a patient's presurgery baseline at each time point. Intraoperative blood product transfusions, coagulation factor levels, perioperative laboratory values, and adverse events were collected.

RESULTS

Thirty-six neonates were enrolled (intent to treat [ITT]). Thirteen patients in the control group and seventeen patients in the study group completed the study per protocol (PP). After normalizing to the patient's own baseline (T1), no significant differences were observed in clot degradation at T2 or T3. At T4, patients in the study group had greater degradation when compared to those in the control group (826.5%, 95% confidence interval [CI], 291.1-1361.9 vs -545.9%, 95% CI, -1081.3 to -10.4; P < .001). Study group patients received significantly less median post-CPB transfusions than control group patients (ITT, 27.2 mL/kg [19.0-36.9] vs 41.6 [29.2-52.4]; P = .043; PP 26.7 mL/kg [18.8-32.2] vs 41.2 mL/kg [29.0-51.4]; P < .001). No differences were observed in bleeding or thrombotic events.

CONCLUSIONS

Neonates who received fibrinogen concentrate, as compared to cryoprecipitate, have similar perioperative ex vivo clot degradation with faster degradation at 24 hours postsurgery, less post-CPB blood transfusions, and no increased bleeding or thrombotic complications. Our findings suggest that fibrinogen concentrate adequately restores hemostasis and reduces transfusions in neonates after CPB without increased bleeding or thrombosis risk.

How do I implement pathogen reduced Cryoprecipitated fibrinogen complex in a tertiary Hospital's blood Bank

BACKGROUND

Kaiser-Permanente Los Angeles Medical Center (LAMC) is a 560 licensed bed facility that provides regional cardiovascular services, including 1200 open heart surgeries annually. In 2021, LAMC explored alternative therapies to offset the impact of pandemic-driven cryo AHF shortages, and implemented Pathogen Reduced Cryoprecipitated Fibrinogen Complex (also known as INTERCEPT Fibrinogen Complex or IFC). IFC is approved to treat and control bleeding associated with fibrinogen deficiency. Unlike cryo AHF, IFC has 5-day post-thaw shelf life with potential operational and clinical benefits. The implementation steps and the operational advantages to the LAMC Blood Bank are described.

STUDY DESIGN AND METHODS

Eighteen months post-implementation, the institution reviewed their product implementation experience and compared IFC with cryo AHF with a retrospective review of transfusion service and cardiac post-op data.

RESULTS

IFC significantly decreased product wastage rates and order-to-issue time. It did not significantly impact post-op product utilization or hospital length of stay (LOS) in cardiac surgery patients when compared with cryo AHF.

DISCUSSION

Implementation of IFC provides improved product supply stability, shorter turnaround times, and reduced wastage.

Implementation and early outcomes with Pathogen Reduced Cryoprecipitated Fibrinogen Complex

OBJECTIVES

Cryoprecipitated antihemophilic factor (cryo) has been used for fibrinogen replacement in actively bleeding patients, dysfibrinogenemia, and hypofibrinogenemia. Cryo has a shelf life of 4 to 6 hours after thawing and a long turnaround time in issuing the product, posing a major limitation of its use. Recently, the US Food and Drug Administration approved Pathogen Reduced Cryoprecipitated Fibrinogen Complex (INTERCEPT Fibrinogen Complex [IFC]) for the treatment of bleeding associated with fibrinogen deficiency, which can be stored at room temperature and has a shelf life of 5 days after thawing.

METHODS

We identified locations and specific end users with high cryoprecipitate utilization and waste. We partnered with our blood supplier to use IFC in these locations. We analyzed waste and turnaround time before and after implementation.

RESULTS

Operative locations had a waste rate that exceeded nonoperative locations (16.7% vs 3%) and were targeted for IFC implementation. IFC was added to our inventory to replace all cryo orders from adult operating rooms, and waste decreased to 2.2% in these locations. Overall waste of cryoprecipitated products across all locations was reduced from 8.8% to 2.4%. The turnaround time for cryoprecipitated products was reduced by 58% from 30.4 minutes to 14.6 minutes.

CONCLUSIONS

There has been a substantial decrease in waste with improved turnaround time after IFC implementation. This has improved blood bank logistics, improved efficiency of patient care, and reduced costly waste.

Prophylactic Transfusion Strategies in Children Supported by Extracorporeal Membrane Oxygenation: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference

OBJECTIVES

To derive systematic-review informed, modified Delphi consensus regarding prophylactic transfusions in neonates and children supported with extracorporeal membrane oxygenation (ECMO) from the Pediatric ECMO Anticoagulation CollaborativE.

DATA SOURCES

A structured literature search was performed using PubMed, EMBASE, and Cochrane Library (CENTRAL) databases from January 1988 to May 2020, with an update in May 2021.

STUDY SELECTION

Included studies assessed use of prophylactic blood product transfusion in pediatric ECMO.

DATA EXTRACTION

Two authors reviewed all citations independently, with a third independent reviewer resolving conflicts. Thirty-three references were used for data extraction and informed recommendations. Evidence tables were constructed using a standardized data extraction form.

MEASUREMENTS AND MAIN RESULTS

The evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation system. Forty-eight experts met over 2 years to develop evidence-informed recommendations and, when evidence was lacking, expert-based consensus statements or good practice statements for prophylactic transfusion strategies for children supported with ECMO. A web-based modified Delphi process was used to build consensus via the Research And Development/University of California Appropriateness Method. Consensus was based on a modified Delphi process with agreement defined as greater than 80%. We developed two good practice statements, 4 weak recommendations, and three expert consensus statements.

CONCLUSIONS

Despite the frequency with which pediatric ECMO patients are transfused, there is insufficient evidence to formulate evidence-based prophylactic transfusion strategies.

[Characterization and risk prediction of cardiovascular surgeries with cardiopulmonary bypass: a cross-sectional study]

Introduction

Cardiovascular surgery risk prediction models are widely applied in medical practice. However, they have been criticized for their low methodological quality and scarce external validation. An additional limitation added in Latin America is that most of these models have been developed in the United States or Europe, which present marked geographical differences. The objective of this study is to characterize the postoperative clinical events of cardiovascular surgeries with the use of cardiopulmonary bypass pump in a local setting and to evaluate the prediction of postoperative mortality using the EuroSCORE II predictive model.

Methods

Cross-sectional study in an urban university hospital in Buenos Aires. Patients ≥21 years of age were included, with a clinical indication for on-pump cardiovascular surgery. Patients with incomplete clinical data regarding EuroSCORE II variables or in-hospital survival, ≥95 years of age, or undergoing heart transplantation were excluded.

Results

195 patients were enrolled. Postoperative mortality estimated by EuroSCORE II presented a clear underestimation of risk (3.0% vs 7.7%). Discrimination (AUC = 0.82; 95% CI 0.74-0.92) and goodness of fit of the model were adequate (χ2 = 7.91; p = 0.4418). The most frequent postoperative complications were postoperative heart failure (35.9%), vasoplegic shock (13.3%), and cardiogenic shock (10.26%).

Conclusion

The EuroSCORE II is an appropriate tool to discriminate between different risk categories in patients undergoing on-pump cardiovascular surgery, although it underestimates the risk.

Delayed cold-stored vs. room temperature stored platelet transfusions in bleeding adult cardiac surgery patients-a randomized multicentre pilot study (PLTS-1)

BACKGROUND

Platelets stored at 1-6 °C are hypothesized to be more hemostatically active than standard room temperature platelets (RTP) stored at 20-24 °C. Recent studies suggest converting RTP to cold-stored platelets (Delayed Cold-Stored Platelets, DCSP) may be an important way of extending platelet lifespan and increasing platelet supply while also activating and priming platelets for the treatment of acute bleeding. However, there is little clinical trial data supporting the efficacy and safety of DCSP compared to standard RTP.

METHODS

This protocol details the design of a multicentre, two-arm, parallel-group, randomized, active-control, blinded, internal pilot trial to be conducted at two cardiac surgery centers in Canada. The study will randomize 50 adult (≥ 18 years old) patients undergoing at least moderately complex cardiac surgery with cardiopulmonary bypass and requiring platelet transfusion to receive either RTP as per standard of care (control group) or DCSP (intervention group). Patients randomized to the intervention group will receive ABO-identical, buffy-coat, pathogen-reduced, platelets in platelet additive solution maintained at 22 °C for up to 4 days then placed at 4 °C for a minimum of 24 h, with expiration at 14 days after collection. The duration of the intervention is from the termination of cardiopulmonary bypass to 24 h after, with a maximum of two doses of DCSP. Thereafter, all patients will receive RTP. The aim of this pilot is to assess the feasibility of a future RCT comparing the hemostatic effectiveness of DCSP to RTP (defined as the total number of allogeneic blood products transfused within 24 h after CPB) as well as safety. Specifically, the feasibility objectives of this pilot study are to determine (1) recruitment of ≥ 15% eligible patients per center per month); (2) appropriate platelet product available for ≥ 90% of patients randomized to the cold-stored platelet group; (3) Adherence to randomization assignment (> 90% of patients administered assigned product).

DISCUSSION

DCSP represents a promising logistical solution to address platelet supply shortages and a potentially more efficacious option for the management of active bleeding. No prospective clinical studies on this topic have been conducted. This proposed internal pilot study will assess the feasibility of a larger definitive study.

TRIAL REGISTRATION

NCT06147531 (clinicaltrials.gov).

Safety of Fibrinogen Concentrate in Non-Trauma and Non-Obstetric Adult Patients during Perioperative Care: Systematic Review and Meta-Analysis

Background: Low fibrinogen levels are associated with an increased risk of perioperative bleeding. However, there is an ongoing debate over the ideal treatment threshold, the benefits of prophylactic supplementation with fibrinogen concentrate, and the best source of fibrinogen. While fibrinogen concentrate supplementation is being widely used to treat bleeding related to acquired haemostatic deficiencies, there is a lack of evidence regarding its dosage, effectiveness, and safety. This systematic review provides an up-to-date summary of the relationship between fibrinogen concentrate supplementation and safety measures in the perioperative care of non-trauma, non-obstetric adult patients. Methods: A comprehensive online search was conducted on PubMed/Medline, EMBASE, Scopus, Web of Science, the Cochrane Database of Systematic Reviews, and the Cochrane Central Register of Controlled Trials. Results: This systematic review and meta-analysis encompasses ten studies involving 1391 patients. There was a decreased risk of total thromboembolic events in patients treated with fibrinogen compared to the control (OR 0.65, 95% CI 0.43 to 0.98, I2 = 0%). In addition, when fibrinogen was used prophylactically, it resulted in shorter ICU stays (MD -1.50, 95% CI -2.64 to -0.36), when set against its therapeutic use. A sensitivity analysis on cardiovascular surgery studies did not reveal any statistically significant difference. Conclusions: The use of fibrinogen concentrate in the perioperative care of non-trauma and non-obstetric adult patients may lead to potential benefits.

Analyzing and modeling massive transfusion strategies and the role of fibrinogen-How much is the patient actually receiving?

BACKGROUND

Hemorrhage is a leading cause of preventable death in trauma, cardiac surgery, liver transplant, and childbirth. While emphasis on protocolization and ratio of blood product transfusion improves ability to treat hemorrhage rapidly, tools to facilitate understanding of the overall content of a specific transfusion strategy are lacking. Medical modeling can provide insights into where deficits in treatment could arise and key areas for clinical study. By using a transfusion model to gain insight into the aggregate content of massive transfusion protocols (MTPs), clinicians can optimize protocols and create opportunities for future studies of precision transfusion medicine in hemorrhage treatment.

METHODS

The transfusion model describes the individual round and aggregate content provided by four rounds of MTP, illustrating that the total content of blood elements and coagulation factor changes over time, independent of the patient's condition. The configurable model calculates the aggregate hematocrit, platelet concentration, percent volume plasma, total grams and concentration of citrate, percent volume anticoagulant and additive solution, and concentration of clotting factors: fibrinogen, factor XIII, factor VIII, and von Willebrand factor, provided by the MTP strategy.

RESULTS

Transfusion strategies based on a 1:1:1 or whole blood foundation provide between 13.7 and 17.2 L of blood products over four rounds. Content of strategies varies widely across all measurements based on base strategy and addition of concentrated sources of fibrinogen and other key clotting factors.

DISCUSSION

Differences observed between modeled transfusion strategies provide key insights into potential opportunities to provide patients with precision transfusion strategy.

Early Goal-Directed Hemostatic Therapy for Severe Acute Bleeding Management in the Intensive Care Unit: A Narrative Review

This is a narrative review of the published evidence for bleeding management in critically ill patients in different clinical settings in the intensive care unit (ICU). We aimed to describe "The Ten Steps" approach to early goal-directed hemostatic therapy (EGDHT) using point-of-care testing (POCT), coagulation factor concentrates, and hemostatic drugs, according to the individual needs of each patient. We searched National Library of Medicine, MEDLINE for publications relevant to management of critical ill bleeding patients in different settings in the ICU. Bibliographies of included articles were also searched to identify additional relevant studies. English-language systematic reviews, meta-analyses, randomized trials, observational studies, and case reports were reviewed. Data related to study methodology, patient population, bleeding management strategy, and clinical outcomes were qualitatively evaluated. According to systematic reviews and meta-analyses, EGDHT guided by viscoelastic testing (VET) has been associated with a reduction in transfusion utilization, improved morbidity and outcome in patients with active bleeding. Furthermore, literature data showed an increased risk of severe adverse events and poor clinical outcomes with inappropriate prophylactic uses of blood components to correct altered conventional coagulation tests (CCTs). Finally, prospective, randomized, controlled trials point to the role of goal-directed fibrinogen substitution to reduce bleeding and the amount of red blood cell (RBC) transfusion with the potential to decrease mortality. In conclusion, severe acute bleeding management in the ICU is still a major challenge for intensive care physicians. The organized and sequential approach to the bleeding patient, guided by POCT allows for rapid and effective bleeding control, through the rational use of blood components and hemostatic drugs, since VET can identify specific coagulation disorders in real time, guiding hemostatic therapy with coagulation factor concentrates and hemostatic drugs with individual goals.

How do we achieve blinding in modern electronic and paper medical records during the conduct of transfusion trials?

BACKGROUND

Regulatory aspects of transfusion medicine add complexity in blinded transfusion trials when considering various electronic record keeping software and blood administration processes. The aim of this study is to explore strategies when blinding transfusion components and products in paper and electronic medical records.

METHODS

Surveys were collected and interviews were conducted for 18 sites across various jurisdictions in North America to determine solutions applied in previous transfusion randomized control trials.

RESULTS

Sixteen responses were collected of which 11 had previously participated in a transfusion randomized control trial. Various solutions were reported which were specific to the laboratory information system (LIS) and electronic medical record (EMR) combinations although solutions could be grouped into four categories which included the creation of a study product code in the LIS, preventing the transmission of data from the LIS to the EMR, utilizing specialized stickers and labels to conceal product containers and documents in the paper records, and modified bedside procedures and documentation.

DISCUSSION

LIS and EMR combinations varied across sites, so it was not possible to determine combination-specific solutions. The study was able to highlight solutions that may be emphasized in future iterations of LIS and EMR software as well as procedural changes that may minimize the risk of unblinding.

Implementation of a Bleeding Management Algorithm in Liver Transplantation: A Pilot Study

Objectives

The aims of the study were to compare the consumption of blood products before and after the implementation of a bleeding management algorithm in patients undergoing liver transplantation and to determine the feasibility of a multicentre, randomized study.

Background

Liver transplantation remains the only curative therapy for patients with end-stage liver disease, but it carries a high risk of surgical bleeding.

Materials and Methods

Retrospective study of patients treated before (group 1) and after (group 2) implementation of a haemostatic algorithm guided by viscoelastic testing, including use of lyophilized coagulation factor concentrates (prothrombin complex and fibrinogen concentrates). Primary outcome was the number of units of blood products transfused in 24 h after surgery. Secondary outcomes included hospital stay, mortality, and cost.

Results

Data from 30 consecutive patients was analysed; 14 in group 1 and 16 in group 2. Baseline data were similar between groups. Median total blood product consumption 24 h after surgery was 33 U (IQR: 11-57) in group 1 and 1.5 (0-23.5) in group 2 (p = 0.028). Significantly fewer units of red blood cells, fresh frozen plasma, and cryoprecipitate were transfused in group 2 versus group 1. There was no significant difference in complications, hospital stay, or in-hospital mortality between groups. The cost of haemostatic therapy was non-significantly lower in group 2 versus group 1 (7,400 vs. 15,500 USD; p = 0.454).

Conclusion

The haemostatic management algorithm was associated with a significant reduction in blood product use during 24 h after liver transplantation. This study demonstrated the feasibility and provided a sample size calculation for a larger, randomized study.

Controls, comparator arms, and designs for critical care comparative effectiveness research: It's complicated

BACKGROUND

Comparative effectiveness research is meant to determine which commonly employed medical interventions are most beneficial, least harmful, and/or most costly in a real-world setting. While the objectives for comparative effectiveness research are clear, the field has failed to develop either a uniform definition of comparative effectiveness research or an appropriate set of recommendations to provide standards for the design of critical care comparative effectiveness research trials, spurring controversy in recent years. The insertion of non-representative control and/or comparator arm subjects into critical care comparative effectiveness research trials can threaten trial subjects' safety. Nonetheless, the broader scientific community does not always appreciate the importance of defining and maintaining critical care practices during a trial, especially when vulnerable, critically ill populations are studied. Consequently, critical care comparative effectiveness research trials sometimes lack properly constructed control or active comparator arms altogether and/or suffer from the inclusion of "unusual critical care" that may adversely affect groups enrolled in one or more arms. This oversight has led to critical care comparative effectiveness research trial designs that impair informed consent, confound interpretation of trial results, and increase the risk of harm for trial participants.

METHODS/EXAMPLES

We propose a novel approach to performing critical care comparative effectiveness research trials that mandates the documentation of critical care practices prior to trial initiation. We also classify the most common types of critical care comparative effectiveness research trials, as well as the most frequent errors in trial design. We present examples of these design flaws drawn from past and recently published trials as well as examples of trials that avoided those errors. Finally, we summarize strategies employed successfully in well-designed trials, in hopes of suggesting a comprehensive standard for the field.

CONCLUSION

Flawed critical care comparative effectiveness research trial designs can lead to unsound trial conclusions, compromise informed consent, and increase risks to research subjects, undermining the major goal of comparative effectiveness research: to inform current practice. Well-constructed control and comparator arms comprise indispensable elements of critical care comparative effectiveness research trials, key to improving the trials' safety and to generating trial results likely to improve patient outcomes in clinical practice.

Prospective, Randomized Study of Fibrinogen Concentrate Versus Cryoprecipitate for Correcting Hypofibrinogenemia in Cardiac Surgery Patients

OBJECTIVE

Cardiac surgery with cardiopulmonary bypass (CPB) is associated with hypofibrinogenemia and severe bleeding requiring transfusion. Guidelines recommend cryoprecipitate or fibrinogen concentrate (FC) for the treatment of acquired hypofibrinogenemia. This study compared cryoprecipitate and FC for the correction of acquired hypofibrinogenemia and the associated costs.

DESIGN

A single-center, prospective, randomized study evaluating patients with hypofibrinogenemia after cardiac surgery. The primary endpoint was direct treatment cost. Secondary endpoints included the change in fibrinogen level after FC and/or cryoprecipitate dosing.

SETTING

A single-center study in Astana, Kazakhstan.

PARTICIPANTS

Participants who underwent CPB from 2021 to 2022 and developed clinically significant bleeding and hypofibrinogenemia.

INTERVENTIONS

Patients were randomized to receive cryoprecipitate or FC.

MEASUREMENTS AND MAIN RESULTS

Eighty-eight adult patients with acquired hypofibrinogenemia (<2.0 g/L) after CPB were randomized to receive cryoprecipitate (N = 40) or FC (N = 48), with similar demographics between groups. Overall, mean ± SD 9.33 ± 0.94 units (range, 8-10) cryoprecipitate or 1.40 ± 0.49 g (1-2) FC was administered to the 2 groups. From before administration to 24 hours after, mean plasma fibrinogen increased by a mean ± SD of 125 ± 65 and 96 ± 65 mg/dL in the cryoprecipitate and FC groups, respectively. At 48 hours after administration, there was no significant difference in fibrinogen levels between groups. The mean direct cost of treatment with FC was significantly lower than with cryoprecipitate (p < 0.0001): $1,505.06 ± $152.40 and $631.75 ± $223.67 per patient for cryoprecipitate and FC, respectively.

CONCLUSION

Analysis of plasma fibrinogen concentration showed that cryoprecipitate and FC had comparable effectiveness. However, FC is advantageous over cryoprecipitate due to its ease of handling, lower cost, and high purity.

The Year in Coagulation and Transfusion: Selected Highlights from 2022

This is an annual review to cover highlights in transfusion and coagulation in patients undergoing cardiovascular surgery. The goal of this article is to provide readers with a focused summary of the most important transfusion and coagulation topics published in 2022. This includes a discussion covering the management of anemia and red blood cell transfusion, the management of factor Xa inhibitors, updates in coagulation testing, updates in the use of factor concentrates, advances in platelet therapy, advances in anticoagulation management of patients on extracorporeal membrane oxygenation and other forms of mechanical circulatory support, and advances in the diagnosis and management of heparin-induced thrombocytopenia.

Efficacy of prompt administration of cryoprecipitate in severe postpartum hemorrhage of preeclampsia patients

AIM

Cryoprecipitate (CRYO) is a concentrated preparation of coagulation factors formulated from fresh frozen plasma (FFP), which can replenish coagulation factors rapidly. Preeclampsia (PE) is frequently associated with postpartum hemorrhage (PPH), and the rapid replenishment of coagulation factors is vital in the management. We conducted a retrospective cohort study to determine the efficacy of administering CRYO irrespective of fibrinogen levels in patients with PE who experienced severe PPH.

METHODS

Patients with PPH accompanied by PE and those who required red blood cell (RBC) transfusion were included. Cases were divided into two groups: those treated with CRYO (N = 16) and those not treated with CRYO (N = 10). The total transfusion volume, blood loss before and after transfusion initiation, duration of hospitalization, presence of pulmonary edema, and performance of either interventional radiology or hysterectomy were compared.

RESULTS

The median fibrinogen levels before transfusion were 2.24 and 2.34 g/L in the CRYO group and the not using group, respectively. Although blood loss before transfusion was comparable between the two groups, blood loss after transfusion was significantly less in the CRYO group (median: 520 vs. 2352 mL, p = 0.015), as well as the total blood loss (median: 2285 vs. 3825 mL, p = 0.005) and total transfusion volume (median: RBC 6 vs. 16 U, p = 0.01, FFP 10 vs. 20 U, p = 0.017).

CONCLUSION

Prompt replenishment of coagulation factors using CRYO to patients with PE who experience severe PPH could decrease further bleeding.

Evaluation of the association of factor XIII at hospital arrival and outcomes in a cohort of severely injured patients

BACKGROUND

Severe traumatic bleeding depletes coagulation factor XIII (FXIII) and fibrinogen. However, the role of FXIII level in bleeding-related outcomes is unknown.

OBJECTIVES

To evaluate the association between FXIII levels at hospital arrival and critical administration threshold (≥3 red blood cell units in 1 hour within the first 24 hours), bleeding-related outcomes, death, and baseline characteristics.

METHODS

A retrospective cohort study was conducted in severely injured adult patients (Injury Severity Score of ≥22 or ≥2 red blood cell units transfused in 24 hours) admitted to a level 1 trauma center. Clinical and laboratory data were collected. Baseline FXIII antigen levels were measured in banked patient plasma. Multivariable logistic and linear regression models were used to estimate the association between FXIII levels, outcomes, and baseline characteristics.

RESULTS

Three hundred sixty-four of 1730 subjects admitted during a 2-year period were analyzed. Median age was 44 years (IQR, 27-62 years), and median Injury Severity Score was 29 (IQR, 22-34). FXIII levels were not associated with critical administration threshold (odds ratio [OR], 1.06; 95% CI, 0.97-1.17) or death (OR, 0.98; 95% CI, 0.90-1.07). FXIII was associated with major bleeding (OR, 1.10; 95% CI, 1.02-1.2) and massive transfusion (OR, 1.25; 95% CI, 1.08-1.44). Lower baseline FXIII levels were associated with arrival from a referring hospital (FXIII level, -0.07 U/mL; 95% CI, -0.11 to -0.03), hemoglobin (FXIII level, -0.05 U/mL; 95% CI, -0.07 to -0.03), fibrinogen level (FXIII level, -0.05 U/mL; 95% CI, -0.08 to -0.02), and platelet count (FXIII level, -0.02 U/mL; 95% CI, -0.04 to -0.008).

CONCLUSIONS

Baseline FXIII levels in severely injured patients were inconsistently associated with bleeding-related outcomes and mortality. However, their association with major bleeding warrants further investigation of the role of FXIII in massively transfused patients with trauma.

Early Fibrinogen Replacement to Treat the Endotheliopathy of Trauma: Novel Resuscitation Strategies in Severe Trauma

The authors provide a comprehensive review of the endothelial glycocalyx, the components that may be targeted to improve clinical outcomes, and the next steps for evaluation in human subjects.

Real-World Experience with a Human Fibrinogen Concentrate: Clinical Data from Adult and Pediatric Patients Requiring Fibrinogen for Bleeding Control and Prevention

Human fibrinogen concentrate (Fibryga) received temporary approval for fibrinogen replacement therapy in France (2017), with subsequent full approval for congenital and acquired hypofibrinogenemia. We evaluated real-world use for on-demand treatment of bleeding and prophylaxis to enhance our knowledge on fibrinogen concentrate as an option for fibrinogen replacement. Data were retrospectively collected from adult and pediatric patients with fibrinogen deficiency. The primary end point was indication for fibrinogen concentrate use; the secondary end point was treatment success for on-demand treatment/perioperative prophylaxis. The study included 150 adult (median age, 62 years; range, 18-94 years) and 50 pediatric (median age, 3 years; range, 0.01-17 years) patients with acquired fibrinogen deficiency. Fibrinogen concentrate was administered to 47.3% for nonsurgical bleeding, 22.7% for surgical bleeding, and 30.0% for perioperative prophylaxis in adult patients, and to 4.0% for surgical bleeding and 96.0% for perioperative prophylaxis in pediatric patients. Cardiac surgeries accounted for 79.5%/75.0% perioperative prophylaxis and 82.4%/100.0% surgical bleeding cases in adult/pediatric patients, respectively. The mean ± standard deviation (SD, median) total fibrinogen doses were 3.06 ± 1.69 g (32.61 mg/kg), 2.09 ± 1.36 g (22.99 mg/kg), and 2.36 ± 1.25 g (29.67 mg/kg) for adult nonsurgical bleeding, surgical bleeding, and perioperative prophylaxis, respectively; doses of 0.75 ± 0.35 g (47.64 mg/kg) and 0.83 ± 0.62 g (55.56 mg/kg) were used for pediatric surgical bleeding and perioperative prophylaxis, respectively. Treatment success was 85.7%/97.1/93.3% in adults and 50.0%/87.5% in pediatrics for nonsurgical bleeding (adults only), surgical bleeding, and perioperative prophylaxis, respectively. Fibrinogen concentrate demonstrated favorable effectiveness and safety across the age groups. This study contributes to evidence supporting fibrinogen concentrate for bleeding control/prevention in real-world clinical practice, particularly for patients with acquired fibrinogen deficiency.

Perioperative Management of Heart Transplantation: A Clinical Review

In this clinical review, the authors summarize the perioperative management of heart transplant patients with a focus on hemodynamics, immunosuppressive strategies, hemostasis and hemorrage, and the prevention and treatment of infectious complications.

Combined Platelet and Red Blood Cell Recovery during On-pump Cardiac Surgery Using same™ by i-SEP Autotransfusion Device: A First-in-human Noncomparative Study (i-TRANSEP Study)

BACKGROUND

Centrifugation-based autotransfusion devices only salvage red blood cells while platelets are removed. The same™ device (Smart Autotransfusion for ME; i-SEP, France) is an innovative filtration-based autotransfusion device able to salvage both red blood cells and platelets. The authors tested the hypothesis that this new device could allow a red blood cell recovery exceeding 80% with a posttreatment hematocrit exceeding 40%, and would remove more than 90% of heparin and 75% of free hemoglobin.

METHODS

Adults undergoing on-pump elective cardiac surgery were included in a noncomparative multicenter trial. The device was used intraoperatively to treat shed and residual cardiopulmonary bypass blood. The primary outcome was a composite of cell recovery performance, assessed in the device by red blood cell recovery and posttreatment hematocrit, and of biologic safety assessed in the device by the washout of heparin and free hemoglobin expressed as removal ratios. Secondary outcomes included platelet recovery and function and adverse events (clinical and device-related adverse events) up to 30 days after surgery.

RESULTS

The study included 50 patients, of whom 18 (35%) underwent isolated coronary artery bypass graft, 26 (52%) valve surgery, and 6 (12%) aortic root surgery. The median red blood cell recovery per cycle was 86.1% (25th percentile to 75th percentile interquartile range, 80.8 to 91.6) with posttreatment hematocrit of 41.8% (39.7 to 44.2). Removal ratios for heparin and free hemoglobin were 98.9% (98.2 to 99.7) and 94.6% (92.7 to 96.6), respectively. No adverse device effect was reported. Median platelet recovery was 52.4% (44.2 to 60.1), with a posttreatment concentration of 116 (93 to 146) · 109/l. Platelet activation state and function, evaluated by flow cytometry, were found to be unaltered by the device.

CONCLUSIONS

In this first-in-human study, the same™ device was able to simultaneously recover and wash both platelets and red blood cells. Compared with preclinical evaluations, the device achieved a higher platelet recovery of 52% with minimal platelet activation while maintaining platelet ability to be activated in vitro.

EDITOR’S PERSPECTIVE

Comparison of coagulation parameters associated with fibrinogen concentrate and cryoprecipitate for treatment of bleeding in patients undergoing cytoreductive surgery for pseudomyxoma peritonei: Subanalysis from a randomized, controlled phase 2 study

Background and Aims

The FORMA-05 study compared the efficacy and safety of human fibrinogen concentrate (HFC) versus cryoprecipitate for hemostasis in bleeding patients undergoing cytoreductive surgery for pseudomyxoma peritonei (PMP). This subanalysis explores coagulation parameters in the FORMA-05 patients, with a focus on the seven patients who developed thromboembolic events (TEEs).

Methods

FORMA-05 was a prospective, randomized, controlled phase 2 study in which patients with predicted blood loss ≥2 L received HFC (4 g) or cryoprecipitate (two pools of five units), repeated as needed. Plasma fibrinogen, platelet count, factor (F) XIII, FVIII, von Willebrand Factor (VWF) antigen and ristocetin cofactor activity levels, EXTEM A20, FIBTEM A20, and endogenous thrombin potential (ETP) were measured perioperatively.

Results

Fibrinogen, platelet count, EXTEM and FIBTEM A20, FXIII, FVIII, VWF levels, and ETP were maintained throughout surgery in both the HFC group (N = 21) and the cryoprecipitate group (N = 23). Seven TEEs were observed in the cryoprecipitate group. The two patients developing deep vein thromboses (DVT) appeared to have a procoagulant status preoperatively, with distinctively higher fibrinogen level, FIBTEM A20, and platelet levels, all of which persisted perioperatively. The five patients developing pulmonary embolism (PE) had slightly higher VWF levels preoperatively, with a disproportionate increase intraoperatively (postcryoprecipitate administration) and postoperatively.

Conclusions

Patients treated with HFC versus cryoprecipitate showed broad overlaps in coagulation parameters. Patients with PE experienced a disproportionate VWF rise following cryoprecipitate administration, whereas patients developing DVT displayed a procoagulant status before and following surgery. Preoperative testing may allow these patients to be identified.

Differences in coagulation-relevant parameters: Comparing cryoprecipitate and a human fibrinogen concentrate

BACKGROUND

Variable fibrinogen content within cryoprecipitate makes accurate dosing challenging in patients with coagulopathic bleeding, in addition to pathogen transmission risks associated with its administration. Purified and standardized human fibrinogen concentrates (HFCs) represent reliable alternatives. Full cryoprecipitate characterization is required to inform selection of an appropriate fibrinogen source for supplementation therapy.

METHODS

Extended biochemical comparison of pooled cryoprecipitate and HFC (Fibryga, Octapharma) was performed using commercially available assays to determine levels of variability in cryoprecipitate and HFC. In addition to standard procoagulant factors, measurements included activities of platelet-derived microparticles (PMPs) and plasminogen, and levels of fibrin degradation products.

RESULTS

Cryoprecipitate contains lower fibrinogen levels than HFC (4.83 vs.19.73 g/L; p<0.001), translating to approximately half the amount of fibrinogen per standard cryoprecipitate dose (two pools, pre-pooled from five donations each) vs. HFC (2.14 vs. 3.95 g; p<0.001). Factor XIII (FXIII) levels were also lower in cryoprecipitate vs. HFC (192.17 vs. 328.33 IU/dL; p = 0.002). Levels of procoagulants in cryoprecipitate, such as von Willebrand Factor (VWF) and factor VIII (FVIII), were highly variable, as was PMP activity. A standard cryoprecipitate dose contains significantly higher levels of measured plasminogen and D-dimer fragments than a standard HFC dose.

CONCLUSION

The tested HFC is a more reliable fibrinogen and FXIII source for accurate dosing compared with cryoprecipitate. Cryoprecipitate appears considerably less predictable for bleeding management due to wide variation in pro- and anticoagulation factors, the presence of PMPs, and the potential to elevate VWF and FVIII to prothrombotic levels.

Blood Product Replacement for Postpartum Hemorrhage

Consideration for blood products replacement in postpartum hemorrhage should be given when blood loss exceeds 1.5 L or when an estimated 25% of blood has been lost. In cases of massive hemorrhage, standardized transfusion protocols have been shown to improve maternal morbidity and mortality. Most protocols recommend a balanced transfusion involving a 1:1:1 ratio of packed red blood cells, platelets, and fresh frozen plasma. Alternatives such as cryoprecipitate, fibrinogen concentrate, and prothrombin complex concentrates can be used in select clinical situations. Although transfusion of blood products can be lifesaving, it does have associated risks.

Factor VIII: A Dynamic Modulator of Hemostasis and Thrombosis in Trauma

A trace amount of thrombin cleaves factor VIII (FVIII) into an active form (FVIIIa), which catalyzes FIXa-mediated activation of FX on the activated platelet surface. FVIII rapidly binds to von Willebrand factor (VWF) after secretion and becomes highly concentrated via VWF-platelet interaction at a site of endothelial inflammation or injury. Circulating levels of FVIII and VWF are influenced by age, blood type (nontype O > type O), and metabolic syndromes. In the latter, hypercoagulability is associated with chronic inflammation (known as thrombo-inflammation). In acute stress including trauma, releasable pools of FVIII/VWF are secreted from the Weibel-Palade bodies in the endothelium and then augment local platelet accumulation, thrombin generation, and leukocyte recruitment. Early systemic increases of FVIII/VWF (>200% of normal) levels in trauma result in a lower sensitivity of contact-activated clotting time (activated partial thromboplastin time [aPTT] or viscoelastic coagulation test [VCT]). However, in severely injured patients, multiple serine proteases (FXa plasmin and activated protein C [APC]) are locally activated and may be systemically released. Severity of traumatic injury correlates with prolonged aPTT and elevated activation markers of FXa, plasmin, and APC, culminating in a poor prognosis. In a subset of acute trauma patients, cryoprecipitate that contains fibrinogen, FVIII/VWF, and FXIII is theoretically advantageous over purified fibrinogen concentrate to promote stable clot formation, but comparative efficacy data are lacking. In chronic inflammation or subacute phase of trauma, elevated FVIII/VWF contributes to the pathogenesis of venous thrombosis by enhancing not only thrombin generation but also augmenting inflammatory functions. Future developments in coagulation monitoring specific to trauma patients, and targeted to enhancement or inhibition of FVIII/VWF, are likely to help clinicians gain better control of hemostasis and thromboprophylaxis. The main goal of this narrative is to review the physiological functions and regulations of FVIII and implications of FVIII in coagulation monitoring and thromboembolic complications in major trauma patients.

Management of severe peri-operative bleeding: Guidelines from the European Society of Anaesthesiology and Intensive Care: Second update 2022

BACKGROUND

Management of peri-operative bleeding is complex and involves multiple assessment tools and strategies to ensure optimal patient care with the goal of reducing morbidity and mortality. These updated guidelines from the European Society of Anaesthesiology and Intensive Care (ESAIC) aim to provide an evidence-based set of recommendations for healthcare professionals to help ensure improved clinical management.

DESIGN

A systematic literature search from 2015 to 2021 of several electronic databases was performed without language restrictions. Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used to assess the methodological quality of the included studies and to formulate recommendations. A Delphi methodology was used to prepare a clinical practice guideline.

RESULTS

These searches identified 137 999 articles. All articles were assessed, and the existing 2017 guidelines were revised to incorporate new evidence. Sixteen recommendations derived from the systematic literature search, and four clinical guidances retained from previous ESAIC guidelines were formulated. Using the Delphi process on 253 sentences of guidance, strong consensus (>90% agreement) was achieved in 97% and consensus (75 to 90% agreement) in 3%.

DISCUSSION

Peri-operative bleeding management encompasses the patient's journey from the pre-operative state through the postoperative period. Along this journey, many features of the patient's pre-operative coagulation status, underlying comorbidities, general health and the procedures that they are undergoing need to be taken into account. Due to the many important aspects in peri-operative nontrauma bleeding management, guidance as to how best approach and treat each individual patient are key. Understanding which therapeutic approaches are most valuable at each timepoint can only enhance patient care, ensuring the best outcomes by reducing blood loss and, therefore, overall morbidity and mortality.

CONCLUSION

All healthcare professionals involved in the management of patients at risk for surgical bleeding should be aware of the current therapeutic options and approaches that are available to them. These guidelines aim to provide specific guidance for bleeding management in a variety of clinical situations.

Cost-effectiveness of Fibrinogen Concentrate vs Cryoprecipitate for Treating Acquired Hypofibrinogenemia in Bleeding Adult Cardiac Surgical Patients

Importance

Excessive bleeding requiring fibrinogen replacement is a serious complication of cardiac surgery. However, the relative cost-effectiveness of the 2 available therapies-fibrinogen concentrate and cryoprecipitate-is unknown.

Objective

To determine cost-effectiveness of fibrinogen concentrate vs cryoprecipitate for managing active bleeding in adult patients who underwent cardiac surgery.

Design, Setting, and Participants

A within-trial economic evaluation of the Fibrinogen Replenishment in Surgery (FIBERS) randomized clinical trial (February 2017 to November 2018) that took place at 4 hospitals based in Ontario, Canada, hospitals examined all in-hospital resource utilization costs and allogeneic blood product (ABP) transfusion costs incurred within 28 days of surgery. Participants included a subset of 495 adult patients from the FIBERS trial who underwent cardiac surgery and developed active bleeding and acquired hypofibrinogenemia requiring fibrinogen replacement.

Interventions

Fibrinogen concentrate (4 g per dose) or cryoprecipitate (10 units per dose) randomized (1:1) up to 24 hours postcardiopulmonary bypass.

Main Outcomes and Measures

Effectiveness outcomes included number of ABPs administered within 24 hours and 7 days of cardiopulmonary bypass. ABP transfusion (7-day) and in-hospital resource utilization (28-day) costs were evaluated and a multivariable net benefit regression model built for the full sample and predefined subgroups.

Results

Patient level costs for 495 patients were evaluated (mean [SD] age 59.2 [15.4] years and 69.3% male.) Consistent with FIBERS, ABP transfusions and adverse events were similar in both treatment groups. Median (IQR) total 7-day ABP cost was CAD $2280 (US dollars [USD] $1697) (CAD $930 [USD $692]-CAD $4970 [USD $3701]) in the fibrinogen concentrate group and CAD $2770 (USD $1690) (IQR, CAD $1140 [USD $849]-CAD $5000 [USD $3723]) in the cryoprecipitate group. Median (interquartile range) total 28-day cost was CAD $38 180 (USD $28 431) $(IQR, CAD $26 350 [USD $19 622]-CAD $65 080 [USD $48 463]) in the fibrinogen concentrate group and CAD $38 790 (USD $28 886) (IQR, CAD $26 180 [USD $19 495]-CAD $70 380 [USD $52 409]) in the cryoprecipitate group. After exclusion of patients who were critically ill before surgery (11%) due to substantial variability in costs, the incremental net benefit of fibrinogen concentrate vs cryoprecipitate was positive (probability of being cost-effective 86% and 97% at $0 and CAD $2000 (USD $1489) willingness-to-pay, respectively). Net benefit was highly uncertain for nonelective and patients with critical illness.

Conclusions and Relevance

Fibrinogen concentrate is cost-effective when compared with cryoprecipitate in most bleeding adult patients who underwent cardiac surgery with acquired hypofibrinogenemia requiring fibrinogen replacement. The generalizability of these findings outside the Canadian health system needs to be verified.

Cryoprecipitate Transfusion After Cardiac Surgery

OBJECTIVES

The association of cryoprecipitate transfusion with patient outcomes after cardiac surgery is unclear. We aimed to investigate the predictors of, and outcomes associated with, postoperative cryoprecipitate transfusion in cardiac surgery patients.

METHODS

We used the Medical Information Mart for Intensive Care III and IV databases. We included adults undergoing cardiac surgery, and propensity score matched cryoprecipitate-treated patients to controls. Using the matched cohort, we investigated the association of cryoprecipitate use with clinical outcomes. The primary outcome was in-hospital mortality. Secondary outcomes were infection, acute kidney injury, intensive care unit length of stay, hospital length of stay, and chest tube output at 2-hour intervals.

RESULTS

Of 12,043 eligible patients, 283 (2.35%) patients received cryoprecipitate. The median dose was 5.83 units (IQR 4.17-7.24) given at a median first transfusion time of 1.75 hours (IQR 0.73-4.46) after intensive care unit admission. After propensity scoring, we matched 195 cryoprecipitate recipients to 743 controls. Postoperative cryoprecipitate transfusion was not significantly associated with in-hospital mortality (odds ratio [OR] 1.10; 99% confidence interval [CI] 0.43-2.84; p=0.791), infection (OR 0.77; 99% CI 0.45-1.34; p=0.220), acute kidney injury (OR 1.03; 99% CI 0.65-1.62; p=0.876) or cumulative chest tube output (adjusted mean difference 8 hrs post transfusion, 11 mL; 99% CI -104 to 125; p=0.804).

CONCLUSIONS

Although cryoprecipitate was typically given to sicker patients with more bleeding, its administration was not associated with worse outcomes. Large, multicentred studies are warranted to further elucidate cryoprecipitate's safety profile and patterns of use in cardiac surgery.

Potential for prolongation of fibrinogen concentrates post-reconstitution

BACKGROUND AND OBJECTIVES

Reconstituted fibrinogen concentrate is considered stable for 8-24 h based on product monographs. Given the long half-life of fibrinogen in vivo (3-4 days), we hypothesized that reconstituted sterile fibrinogen protein would remain stable longer than 8-24 h. Extending the expiry date for reconstituted fibrinogen concentrate could decrease wastage and facilitate reconstitution in advance to minimize turnaround times. We performed a pilot study to define the stability of reconstituted fibrinogen concentrates over time.

MATERIALS AND METHODS

Reconstituted Fibryga® (Octapharma AG) from 64 vials was stored in the temperature-controlled refrigerator (4 °C) for up to 7 days with functional fibrinogen concentration measured serially using the automated Clauss method. The samples were frozen, then thawed and diluted with pooled normal plasma in order for them to be batch tested.

RESULTS

Reconstituted fibrinogen samples stored in the refrigerator showed no significant reduction in functional fibrinogen concentration for the entire 7-day study period (p = 0.63). Duration of initial freezing had no detrimental effect on functional fibrinogen levels (p = 0.23).

CONCLUSION

Fibryga® can be stored at 2-8 °C post-reconstitution for up to one week with no loss in functional fibrinogen activity based on Clauss fibrinogen assay. Further studies with other fibrinogen concentrate formulations and clinical in vivo studies may be warranted.

Effect of fibrinogen replacement therapy on bleeding outcomes and 1-year mortality in patients undergoing thoracic aortic surgery: a retrospective cohort study

PURPOSE

This study aimed to examine the effect of fibrinogen replacement therapy with cryoprecipitate or fibrinogen concentrate on bleeding outcomes and 1-year mortality in patients undergoing thoracic aortic surgery.

METHODS

We retrospectively studied 439 consecutive patients who underwent thoracic aortic surgery with cardiopulmonary bypass between January 1st, 2010 and December 31st, 2019 and identified patients who received cryoprecipitate or fibrinogen concentrate (the fibrinogen replacement group) and those who did not (the control group). Multivariate analyses were performed to examine the associations of fibrinogen replacement therapy with perioperative major bleeding (i.e., excessive hemorrhage or blood transfusion), re-exploration for bleeding, and 1-year mortality.

RESULTS

There were 285 patients in the fibrinogen replacement group who received 2.2 ± 1.0 g of concentrated fibrinogen amount and 154 patients in the control group. The incidence of major bleeding in the fibrinogen replacement group was less than that in the control group in patients with fibrinogen level < 150 mg/dL during cardiopulmonary bypass (49.7% versus 74.6%, p = 0.0007, multivariate odds ratio; 0.33, 95% confidence intervals; 0.12-0.91, p = 0.03), but not in patients with fibrinogen level ≥ 150 mg/dL (25.0% versus 29.6%, p = 0.51). No significant difference was found in re-exploration for bleeding (1.0% versus 1.3%, p = 1.00) or 1-year mortality (10.4% versus 5.3%, multivariate Cox proportional-hazard ratio; 1.03, 95% confidence intervals; 0.82-1.31, p = 0.74) between the fibrinogen replacement group and the control group.

CONCLUSIONS

The results of this study indicate that 2-3 g of fibrinogen replacement reduces the incidence of major bleeding in patients with hypofibrinogenemia during cardiopulmonary bypass in thoracic aortic surgery.

Impact of Preoperative Hematocrit, Body Mass Index, and Red Cell Mass on Allogeneic Blood Product Usage in Adult Cardiac Surgical Patients: Report From a Statewide Quality Initiative

OBJECTIVE

The study aims were to evaluate current blood transfusion practice in cardiac surgical patients and to explore associations between preoperative anemia, body mass index (BMI), red blood cell (RBC) mass, and allogeneic transfusion.

DESIGN

Multicenter retrospective study.

SETTING

Academic and non-academic centers.

PARTICIPANTS AND INTERVENTIONS

After Institutional Review Board approval, 26,499 patients who underwent coronary artery bypass grafting ± valve replacement/repair between 2011 and 2019 were included from the Maryland Cardiac Surgery Quality Initiative database. Patients were stratified into BMI categories (<25, 25 to <30, and ≥30 kg/m²), and a multivariable logistic regression model was fit to determine if preoperative hematocrit, BMI, and RBC mass were associated independently with allogeneic transfusion.

RESULTS

Preoperative anemia was found in 55.4%, and any transfusion was administered to 49.3% of the entire cohort. Females and older patients had lower BMI and RBC mass. Increased RBC and cryoprecipitate transfusions occurred more frequently after surgery in the lower BMI group. After adjustments, increased transfusion was associated with a BMI <25 relative to a BMI ≥30 at an odds ratio (OR) of 1.26 (95% confidence interval [CI]: 1.08-1.39). For each 1% increase in preoperative hematocrit, transfusion was decreased by 9% (OR: 0.91; 95% CI: 0.90-0.92). For every 500 mL increase in RBC mass, there was a 43% reduction of transfusion (OR: 0.57; 95% CI: 0.55-0.58).

CONCLUSIONS

Transfusion probability modeling based on calculated RBC mass eliminated sex differences in transfusion risk based on preoperative hematocrit, and may better delineate which patients may benefit from more rigorous perioperative blood conservation strategy.

Major haemorrhage: past, present and future

Major haemorrhage is a leading cause of morbidity and mortality worldwide. Successful treatment requires early recognition, planned responses, readily available resources (such as blood products) and rapid access to surgery or interventional radiology. Major haemorrhage is often accompanied by volume loss, haemodilution, acidaemia, hypothermia and coagulopathy (factor consumption and fibrinolysis). Management of major haemorrhage over the past decade has evolved to now deliver a 'package' of haemostatic resuscitation including: surgical or radiological control of bleeding; regular monitoring of haemostasis; advanced critical care support; and avoidance of the lethal triad of hypothermia, acidaemia and coagulopathy. Recent trial data advocate for a more personalised approach depending on the clinical scenario. Fresh frozen plasma should be given as early as possible in major trauma in a 1:1 ratio with red blood cells until the results of coagulation tests are available. Tranexamic acid is a cheap, life-saving drug and is advocated in major trauma, postpartum haemorrhage and surgery, but not in patients with gastrointestinal bleeding. Fibrinogen levels should be maintained > 2 g.l-1 in postpartum haemorrhage and > 1.5 g.l-1 in other haemorrhage. Improving outcomes after major traumatic haemorrhage is now driving research to include extending blood-product resuscitation into prehospital care.

The Future of Cardiothoracic Surgical Critical Care Medicine as a Medical Science: A Call to Action

Cardiothoracic surgical critical care medicine (CT-CCM) is a medical discipline centered on the perioperative care of diverse groups of patients. With an aging demographic and an increase in burden of chronic diseases the utilization of cardiothoracic surgical critical care units is likely to escalate in the coming decades. Given these projections, it is important to assess the state of cardiothoracic surgical intensive care, to develop goals and objectives for the future, and to identify knowledge gaps in need of scientific inquiry. This two-part review concentrates on CT-CCM as its own subspeciality of critical care and cardiothoracic surgery and provides aspirational goals for its practitioners and scientists. In part one, a list of guiding principles and a call-to-action agenda geared towards growth and promotion of CT-CCM are offered. In part two, an evaluation of selected scientific data is performed, identifying gaps in CT-CCM knowledge, and recommending direction to future scientific endeavors.

Strategies for post-cardiac surgery acute kidney injury prevention: A network meta-analysis of randomized controlled trials

Objects

Cardiac surgery is associated with acute kidney injury (AKI). However, the effects of various pharmacological and non-pharmacological strategies for AKI prevention have not been thoroughly investigated, and their effectiveness in preventing AKI-related adverse outcomes has not been systematically evaluated.

Methods

Studies from PubMed, Embase, and Medline and registered trials from published through December 2021 that evaluated strategies for preventing post-cardiac surgery AKI were identified. The effectiveness of these strategies was assessed through a network meta-analysis (NMA). The secondary outcomes were prevention of dialysis-requiring AKI, mortality, intensive care unit (ICU) length of stay (LOS), and hospital LOS. The interventions were ranked using the P-score method. Confidence in the results of the NMA was assessed using the Confidence in NMA (CINeMA) framework.

Results

A total of 161 trials (involving 46,619 participants) and 53 strategies were identified. Eight pharmacological strategies {natriuretic peptides [odds ratio (OR): 0.30, 95% confidence interval (CI): 0.19-0.47], nitroprusside [OR: 0.29, 95% CI: 0.12-0.68], fenoldopam [OR: 0.36, 95% CI: 0.17-0.76], tolvaptan [OR: 0.35, 95% CI: 0.14-0.90], N-acetyl cysteine with carvedilol [OR: 0.37, 95% CI: 0.16-0.85], dexmedetomidine [OR: 0.49, 95% CI: 0.32-0.76;], levosimendan [OR: 0.56, 95% CI: 0.37-0.84], and erythropoietin [OR: 0.62, 95% CI: 0.41-0.94]} and one non-pharmacological intervention (remote ischemic preconditioning, OR: 0.76, 95% CI: 0.63-0.92) were associated with a lower incidence of post-cardiac surgery AKI with moderate to low confidence. Among these nine strategies, five (fenoldopam, erythropoietin, natriuretic peptides, levosimendan, and remote ischemic preconditioning) were associated with a shorter ICU LOS, and two (natriuretic peptides [OR: 0.30, 95% CI: 0.15-0.60] and levosimendan [OR: 0.68, 95% CI: 0.49-0.95]) were associated with a lower incidence of dialysis-requiring AKI. Natriuretic peptides were also associated with a lower risk of mortality (OR: 0.50, 95% CI: 0.29-0.86). The results of a sensitivity analysis support the robustness and effectiveness of natriuretic peptides and dexmedetomidine.

Conclusion

Nine potentially effective strategies were identified. Natriuretic peptide therapy was the most effective pharmacological strategy, and remote ischemic preconditioning was the only effective non-pharmacological strategy. Preventive strategies might also help prevent AKI-related adverse outcomes. Additional studies are required to explore the optimal dosages and protocols for potentially effective AKI prevention strategies.

Cryoprecipitate transfusion in trauma patients attenuates hyperfibrinolysis and restores normal clot structure and stability: Results from a laboratory sub-study of the FEISTY trial

BACKGROUND

Fibrinogen is the first coagulation protein to reach critical levels during traumatic haemorrhage. This laboratory study compares paired plasma samples pre- and post-fibrinogen replacement from the Fibrinogen Early In Severe Trauma studY (FEISTY; NCT02745041). FEISTY is the first randomised controlled trial to compare the time to administration of cryoprecipitate (cryo) and fibrinogen concentrate (Fg-C; Riastap) in trauma patients. This study will determine differences in clot strength and fibrinolytic stability within individuals and between treatment arms.

METHODS

Clot lysis, plasmin generation, atomic force microscopy and confocal microscopy were utilised to investigate clot strength and structure in FEISTY patient plasma.

RESULTS

Fibrinogen concentration was significantly increased post-transfusion in both groups. The rate of plasmin generation was reduced 1.5-fold post-transfusion of cryo but remained unchanged with Fg-C transfusion. Plasminogen activator inhibitor 1 activity and antigen levels and Factor XIII antigen were increased post-treatment with cryo, but not Fg-C. Confocal microscopy analysis of fibrin clots revealed that cryo transfusion restored fibrin structure similar to those observed in control clots. In contrast, clots remained porous with stunted fibres after infusion with Fg-C. Cryo but not Fg-C treatment increased individual fibre toughness and stiffness.

CONCLUSIONS

In summary, our data indicate that cryo transfusion restores key fibrinolytic regulators and limits plasmin generation to form stronger clots in an ex vivo laboratory study. This is the first study to investigate differences in clot stability and structure between cryo and Fg-C and demonstrates that the additional factors in cryo allow formation of a stronger and more stable clot.

Coagulation and Transfusion Updates From 2021

2021 and the COVID 19 pandemic have brought unprecedented blood shortages worldwide. These deficits have propelled national efforts to reduce blood usage, including limiting elective services and accelerating Patient Blood Management (PBM) initiatives. A host of research dedicated to blood usage and management within cardiac surgery has continued to emerge. The intent of this review is to highlight this past year's research pertaining to PBM and COVID-19-related coagulation changes.

Reoperation for bleeding after cardiac surgery

BACKGROUND

Postoperative cardio-surgical haemostatic management is centre-specific and experience-based, which leads to a variability in patient care. This study aimed to identify which postoperative haemostatic interventions may reduce the need for reoperation after cardiac surgery in adults.

METHODS

A retrospective case-control study in a tertiary centre. Adult, elective, primary cardiac surgical patients were selected (n = 2098); cases (n = 42) were patients who underwent reoperation within 72 h after the initial surgery. Interventions administered to control surgical bleeding were compared for the need to re-operate using multiple logistic regression.

RESULTS

Rate of cardiac surgical reoperation was 2% in the study population. Three variables were found to be associated with cardiac reoperation: preoperative administration of fresh frozen plasma (OR 5.45, CI 2.34-12.35), cumulative volume of chest tube drainage and cumulative count of packed red blood cells transfusion on ICU (OR 1.98, CI 1.56-2.51).

CONCLUSION

No significant difference among specific types of postoperative haemostatic interventions was found between patients who needed reoperation and those who did not. Perioperative transfusion of fresh frozen plasma, postoperative transfusion of packed cells and cumulative volume of chest tube drainage were associated with reoperation after cardiac surgery. These variables could help predict the need for reoperation.

Fibrinogen Supplementation for the Trauma Patient: Should You Choose Fibrinogen Concentrate Over Cryoprecipitate?

INTRODUCTION

Trauma-induced coagulopathy is frequently associated with hypofibrinogenemia. Cryoprecipitate (Cryo), and fibrinogen concentrate (FC) are both potential means of fibrinogen supplementation. The aim of this study was to compare the outcomes of traumatic hemorrhagic patients who received fibrinogen supplementation using FC versus Cryo.

METHODS

We performed a 2-year (2016-2017) retrospective cohort analysis of the American College of Surgeons (ACS) Trauma Quality Improvement Program database. All adult trauma patients (≥18 years) who received FC or Cryo as an adjunct to resuscitation were included. Patients with bleeding disorders, chronic liver disease, and those on preinjury anticoagulants were excluded. Patients were stratified into those who received FC, and those who received Cryo. Propensity score matching (1:2) was performed. Outcome measures were transfusion requirements, major complications, hospital, and ICU lengths of stay (LOS), and mortality.

RESULTS

A matched cohort of 255 patients who received fibrinogen supplementation (85 in FC, 170 in Cryo) was analyzed. Overall, the mean age was 41 ± 19 years, 74% were male, 74% were white and median ISS was 26 [22-30]. Compared to the Cryo group, the FC group required less units of packed red blood cells (pRBC), fresh frozen plasma (FFP), and platelets, and had shorter in-hospital and ICU LOS. There were no significant differences between the two groups in terms of major in-hospital complications and mortality.

CONCLUSIONS

Fibrinogen supplementation in the form of FC for the traumatic hemorrhagic patient is associated with improved outcomes and reduced transfusion requirements as compared to Cryo. Further studies are required to evaluate the optimal method of fibrinogen supplementation in the resuscitation of trauma patients.

LEVEL OF EVIDENCE

III Therapeutic/Care Management.

Immediate Higher-Dose Prothrombin Complex Concentrate Without Fresh Frozen Plasma or Fibrinogen Concentrate for Significant Coagulopathic Cardiac Surgical Field Bleeding

BACKGROUND

Treatment of significant coagulopathic cardiac surgical field bleeding with immediate higher-dose prothrombin complex concentrate (PCC) without fresh frozen plasma (FFP) or fibrinogen concentrate is unexplored.

AIMS

To study characteristics, chest drainage, and clinical outcomes of patients with significant coagulopathic surgical field bleeding treated with immediate higher-dose (defined at >15 IU/kg based on factor IX) PCC without FFP or fibrinogen concentrate.

METHODS

We screened sequential cardiac surgery patients. We reviewed electronic blood bank data, Australian Society of Cardiothoracic Surgery database information and anaesthetic, intensive care unit (ICU), ward and radiological charts and electronic data. We identified patients deemed by the operating surgeon to require treatment for significant coagulopathic surgical field bleeding who underwent immediate higher-dose PCC without FFP or fibrinogen concentrate.

RESULTS

Among 168 patients, we identified 30 who underwent immediate higher-dose PCC without FFP or fibrinogen concentrate. Median age was 68 years, 23 were male, 17 underwent coronary artery bypass surgery and three underwent complex surgery (David procedure, redo mitral valve surgery, and redo thoraco-abdominal aneurysm repair). Median dose of PCC was 2,500 IU. In addition, 27% underwent platelets and one underwent cryoprecipitate. Chest drainage at 24 hours was 505 ml. Survival to hospital discharge was 100%. There were no cases of pulmonary embolism, stroke, or other thrombotic events. Stage 1 AKI occurred in one patient.

CONCLUSION

In a pilot cohort of patients with significant coagulopathic surgical field bleeding, immediate higher-dose PCC without FFP or fibrinogen concentrate was feasible and had an acceptable efficacy and safety profile, which justifies future controlled studies.

Practice patterns of ABO-matching for cryoprecipitate and patient outcomes after ABO-compatible versus incompatible cryoprecipitate

BACKGROUND AND OBJECTIVES

This sub-study of the FIBRES trial sought to examine the patterns of ABO-compatible cryoprecipitate administration and to identify adverse consequences of ABO-incompatible cryoprecipitate.

MATERIALS AND METHODS

This was a post hoc analysis of data collected from the FIBRES randomized clinical trial comparing fibrinogen concentrate with cryoprecipitate in the treatment of bleeding related to hypofibrinogenemia after cardiac surgery. The primary outcome was the percentage of administered cryoprecipitate that was ABO-compatible. Secondary outcomes were adverse events at 28 days. A follow-up survey was distributed to the FIBRES participating sites to examine the rationale behind the identified cryoprecipitate ABO-matching practice patterns.

RESULTS

A total of 363 patients were included: 53 (15%) received ABO-incompatible cryoprecipitate and 310 (85%) received ABO-compatible cryoprecipitate. There was an increased incidence of post-operative anaemia in the ABO-incompatible group (15; 28.3%) in comparison to the ABO-compatible (44; 14.2%) group (p = 0.01) at 28 days, which was unrelated to haemolysis, without a significant difference in transfusion requirement. In the multivariable logistic regression models accounting for clustering by site, there was no observed statistically significant association between the administration of ABO-incompatible cryoprecipitate and any other adverse outcomes. Nine out of 11 sites did not have a policy requiring ABO-matched cryoprecipitate.

CONCLUSION

This sub-study demonstrated that most cryoprecipitate administered in practice is ABO-compatible, despite the absence of guidelines or blood bank policies to support this practice. A signal towards increased risk of post-operative anaemia may be explained by higher rates of urgent surgery (vs. elective) in the ABO-incompatible group. Future studies should prospectively examine the impact of ABO-compatible versus incompatible cryoprecipitate to conclusively establish if there is a meaningful clinical impact associated with the administration of ABO-incompatible cryoprecipitate.

Modeling current practices in critical care comparative effectiveness research

Objective: To determine whether contemporaneous practices are adequately represented in recent critical care comparative effectiveness research studies. Design: All critical care comparative effectiveness research trials published in the New England Journal of Medicine from April 2019 to March 2020 were identified. To examine studies published in other high impact medical journals during the same period, such trials were subsequently also identified in the Journal of the American Medical Association and The Lancet. All cited sources were reviewed, and the medical literature was searched to find studies describing contemporary practices. Then, the designated control group or the comparable therapies studied were examined to determine if they represented contemporaneous critical care practices as described in the medical literature. Results: Twenty-five of 332 randomised clinical trials published in these three journals during this 1-year period described critical care comparative effectiveness research that met our inclusion criteria. Seventeen characterised current practices before enrolment (using surveys, observational studies and guidelines) and then incorporated current practices into one or more study arm. In the other eight, usual care arms appeared insufficient. Four of these trials randomly assigned patients to one of two fixed approaches at either end of a range of usually titrated care. However, due to randomisation, different subgroups within each arm received care that was inappropriate for their specific clinical conditions. In the other four of these trials, common practices influencing treatment choice were not reflected in the trial design, despite a prior effort to characterise usual care. Conclusion: One-third of critical care comparative effectiveness research trials published in widely read medical journals during a recent year did not include a designated control arm or comparable therapies representative of contemporary practices. Failure to incorporate contemporary practices into critical care comparative effectiveness trials appears to be a widespread design weakness.