Efficacy of platelet transfusion in cardiac surgery

Hemostatic conditions following autologous transfusion of fresh vs stored platelets in experimental endotoxemia: an open-label randomized controlled trial with healthy volunteers

Background

Platelet increment is reportedly lower for maximum stored platelet concentrates (PCs) and during pyrexia, and in vitro function differs between fresh and stored PCs. However, little is known about the function of fresh and stored platelets during inflammation.

Objectives

The aim was to study differences in hemostatic function after transfusion of fresh or stored PCs in a human model of experimental endotoxemia.

Methods

Thirty-six healthy male subjects received either 2 ng/kg lipopolysaccharide (LPS) or a control (physiological saline 0.9%) and were randomly assigned to subsequently receive an autologous transfusion of either fresh (2-days-old) or stored (7-days-old) platelets, or saline control. Extracellular vesicles (EVs) were determined using flow cytometry, thrombin-antithrombin complex (TATc) was assessed using enzyme-linked immunosorbent assay, and hemostatic function was assessed using rotational thromboelastometry (ROTEM).

Results

LPS infusion caused a marked increase in TATc, EVs and fibrinolysis. Thromboelastometry data revealed that following infusion of LPS, subjects exhibited in general a hypocoagulable state compared with those not receiving LPS. Platelet transfusions led to a reduced clotting time and an augmentation in clot strength, indicated by maximum clot firmness, solely among subjects undergoing endotoxemia. There were no significant differences in TATc or amount of EVs release after transfusion of fresh or stored platelets.

Conclusion

A significant increase in TATc and EVs as well as a difference in hemostatic function after endotoxemia were observed. During endotoxemia, platelet transfusion resulted in enhanced coagulation and hemostatic function; however, no substantial differences were observed between transfusion of fresh or stored PCs.

State of the art, trends, hotspots, and prospects of injection materials for controlling bleeding

Traumatic haemorrhage is a prevalent clinical condition, and effective and timely haemostasis is crucial for the preservation of patients' lives. In recent years, injectable hemostatic materials have gained significant attention due to their excellent hemostatic efficacy, biocompatibility, and biodegradability, making them widely applied in the treatment of incompressible traumatic haemorrhage. Systematic analysis of injectable hemostatic materials is crucial for research in this area. This article provides a comprehensive review of the development and research trends of injectable hemostatic materials over the past 20 years using visualization techniques. Analysis of collaboration and co-citation networks revealed localized research collaboration networks, highlighting the need for enhanced international collaboration in the field of injectable hemostatic materials. Current research focuses primarily on hemostatic materials, hemostatic processes, and hemostatic mechanisms. Injectable hemostatic materials with excellent performance offer promising strategies for wound healing. This review provides a comprehensive and systematic summary of injectable hemostatic materials, offering valuable guidance for the development and clinical application of novel injectable hemostatic materials. Additionally, visualized methodology and mapping analysis are effective data mining methods that provide approaches and strategies for clear knowledge network analysis. These methods facilitate better understanding and interpretation of research dynamics in the field of injectable hemostatic materials, thereby guiding and inspiring future research.

What's in Your Transfusion? A Bedside Guide to Blood Products and Their Preparation

An understanding of the contents of blood products and how they are modified before transfusion will help any physician. This article will review five basic blood products and the five most common product modifications.

Supplemental fibrinogen restores thrombus formation in cardiopulmonary bypass-induced platelet dysfunction ex vivo

BACKGROUND

Major cardiac surgery related blood loss is associated with increased postoperative morbidity and mortality. Platelet dysfunction is believed to contribute to post-cardiopulmonary bypass (CPB)-induced microvascular bleeding. We hypothesised that moderately hypothermic CPB induces platelet dysfunction and that supplemental fibrinogen can restore in vitro thrombus formation.

METHODS

Blood from 18 patients, undergoing first-time elective isolated aortic valve surgery was drawn before CPB, 30 min after initiation of CPB, and after CPB and protamine administration, respectively. Platelet aggregation was quantified by optical aggregometry, platelet activation by flow-cytometric detection of platelet surface expression of P-selectin, annexin V, and activated glycoprotein IIb/IIIa, thrombus formation under flow and effect of supplemental fibrinogen (4 mg ml-1) on in vitro thrombogenesis.

RESULTS

Post-CPB adenosine-diphosphate and TRAP-6-induced aggregation decreased by 40% and 10% of pre-CPB levels, respectively (P<0.0001). Although CPB did not change glycoprotein IIb/IIIa receptor expression, it increased the percentage of unstimulated P-selectin (1.2% vs 7%, P<0.01) positive cells and annexin V mean fluorescence intensity (15.5 vs 17.2, P<0.05), but decreased percentage of stimulated P-selectin (52% vs 26%, P<0.01) positive cells and annexin V mean fluorescence intensity (508 vs 325, P<0.05). Thrombus area decreased from 6820 before CPB to 5230 after CPB (P<0.05, arbitrary units [a.u.]). Supplemental fibrinogen increased thrombus formation to 20 324 and 11 367 a.u. before CPB and after CPB, respectively (P<0.001), thereby restoring post-CPB thrombus area to levels comparable with or higher than pre-CPB baseline.

CONCLUSIONS

Single valve surgery using moderately hypothermic CPB induces partial platelet dysfunction. Thrombus formation was restored in an experimental study design by ex vivo supplementation of fibrinogen.

Efficacy of autologous plateletpheresis in adult aortic surgery: study protocol for a randomised controlled trial

INTRODUCTION

Perioperative coagulopathy is common in patients undergoing aortic surgery, increasing the risk of excessive blood loss and subsequent allogeneic transfusion. Blood conservation has become a vital part of cardiovascular surgery, but measures to protect platelets from destruction by cardiopulmonary bypass (CPB) are still lacking. Autologous platelet concentrate (APC) may have potential benefits for intraoperative blood preservation, but its efficacy has not been studied extensively. This study aims to evaluate the efficacy of APC as a blood conservation technique to reduce blood transfusion in adult aortic surgery.

METHODS AND ANALYSIS

This is a prospective, single-centre, single-blind randomised controlled trial. A total of 344 adult patients undergoing aortic surgery with CPB will be enrolled and randomised to either the APC group or the control group with a 1:1 randomisation ratio. Patients in the APC group will receive autologous plateletpheresis before heparinisation, while those in the control group will not. The primary outcome is the perioperative packed red blood cell (pRBC) transfusion rate. Secondary endpoints include the volume of perioperative pRBC transfusion; drainage volume within 72 hours post-surgery; postoperative coagulation and platelet function; and the incidence of adverse events. Data will be analysed according to the intention-to-treat principle.

ETHICS AND DISSEMINATION

This study was approved by the institutional review board of Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College (no. 2022-1806). All procedures included in this study will be performed in adherence to the Helsinki Declaration. The results of the trial will be published in an international peer-reviewed journal.

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Register (ChiCTR2200065834).

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.