Coagulation management during liver transplantation: monitoring and decision making for hemostatic interventions

PURPOSE OF REVIEW

Rebalanced hemostasis describes the precarious balance of procoagulant and antithrombotic proteins in patients with severe liver failure. This review is aimed to discuss currently available coagulation monitoring tests and pertinent decision-making process for plasma coagulation factor replacements during liver transplantation (LT).

RECENT FINDINGS

Contemporary viscoelastic coagulation monitoring systems have demonstrated advantages over conventional coagulation tests in assessing the patient's coagulation status and tailoring hemostatic interventions. There is increasing interest in the use of prothrombin complex and fibrinogen concentrates, but it remains to be proven if purified factor concentrates are more efficacious and safer than allogeneic hemostatic components. Furthermore, the decision to use antifibrinolytic therapy necessitates careful considerations given the risks of venous thromboembolism in severe liver failure.

SUMMARY

Perioperative hemostatic management and thromboprophylaxis for LT patients is likely to be more precise and patient-specific through a better understanding and monitoring of rebalanced coagulation. Further research is needed to refine the application of these tools and develop more standardized protocols for coagulation management in LT.

[Using Liver Function Indicators to Predict Massive Blood Transfusion in Orthotopic Liver Transplantation]

Objective

To explore the predictive effect of preoperative liver function indicators for intraoperative massive blood transfusion in orthotopic liver transplantation and to establish a prediction model.

Methods

We retrospectively analyzed the relevant data of 607 patients who underwent orthotopic liver transplantation in the Department of Liver Surgery, West China Hospital, Sichuan University between January 1, 2015 and June 30, 2021. According to the intraoperative transfusion volume of leukocyte-reduced red blood cells in additive solution, the patients were divided into a massive blood transfusion (MBT) group and a non-massive blood transfusion (NMBT) group. Univariate and multivariate logistic regressions were performed to analyze the risk factors of intraoperative MBT in orthotopic liver transplantation, the calibration of the predictive model was assessed by Hosmer-Lemeshow test, and the discrimination power of the predictive model was measured by area under the curve ( AUC) of the receiver operating characteristic (ROC) curve.

Results

According to the results of logistic regression, alanine transaminase (ALT), aspartate transaminase (AST), total bilirubin (TBIL), direct bilirubin (DBIL), albumin (ALB), and Child-Pugh score showed no correlation with the risk of MBT in orthotopic liver transplantation operation. Platelet count (PLT) (odds ratio [ OR]=0.90, 95% confidence interval [ CI]: 0.09-0.19, P=0.02), international normalized ratio (INR) ( OR=19.43, 95% CI: 7.64-19.44, P<0.01), prothrombin time (PT) ( OR=1.43, 95% CI: 1.25-1.63, P<0.01), and activated partial thromboplastin time (APTT) ( OR=0.92, 95% CI: 0.90-0.95, P<0.01) were identified as the risk factors of intraoperative MBT in orthotopic liver transplantation. The Hosmer-Lemeshow test showed that the predictive model had good calibration ( χ 2=9.06, P=0.48) and discrimination power ( AUC=0.80, 95% CI 0.766-0.834, P<0.01).

Conclusion

A predictive model based on the preoperative PLT, INR, PT, and APTT of patients undergoing orthotopic liver transplantation was established and can be used to predict the risk of intraoperative MBT in liver transplantation patients.

Efficacy and Safety of Prothrombin Complex Concentrates in Liver Transplantation: Evidence from Observational Studies

The risk/benefit ratio of using prothrombin complex concentrates (PCCs) to correct coagulation defects in patients with end-stage liver disease is still unclear. The primary aim of this review was to assess the clinical effectiveness of PCCs in reducing transfusion requirements in patients undergoing liver transplantation (LT). This systematic review of non-randomized clinical trials was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The protocol was previously registered (PROSPERO:CRD42022357627). The primary outcome was the mean number of transfused units for each blood product, including red blood cells (RBCs), fresh frozen plasma, platelets, and cryoprecipitate. Secondary outcomes included the incidence of arterial thrombosis, acute kidney injury, and haemodialysis, and hospital and intensive care unit length of stay. There were 638 patients from 4 studies considered for meta-analysis. PCC use did not affect blood product transfusions. Sensitivity analysis, including only four-factor PCC, showed a significant reduction of RBC effect size (MD: 2.06; 95%CI: 1.27-2.84) with no true heterogeneity. No significant differences in secondary outcomes were detected. Preliminary evidence indicated a lack of PCC efficacy in reducing blood product transfusions during LT, but further investigation is needed. In particular, future studies should be tailored to establish if LT patients will likely benefit from four-factor PCC therapy.

Cardiovascular manifestation of end-stage liver disease and perioperative echocardiography for liver transplantation: anesthesiologist’s view

Liver transplantation (LT) is the curative therapy for decompensated cirrhosis. However, anesthesiologists can find it challenging to manage patients undergoing LT due to the underlying pathologic conditions of patients with end-stage liver disease and the high invasiveness of the procedure, which is frequently accompanied by massive blood loss. Echocardiography is a non-invasive or semi-invasive imaging tool that provides real-time information about the structural and functional status of the heart and is considered to be able to improve outcomes by enabling accurate and detailed assessments. This article reviews the pathophysiologic changes of the heart accompanied by cirrhosis that mainly affect hemodynamics. We also present a comparative review of the diagnostic criteria for cirrhotic cardiomyopathy published by the World Congress of Gastroenterology in 2005 and the Cirrhotic Cardiomyopathy Consortium in 2019. This article discusses the conditions that could affect hemodynamic stability and postoperative outcomes, such as coronary artery disease, left ventricular outflow tract obstruction, portopulmonary hypertension, hepatopulmonary syndrome, pericardial effusion, cardiac tamponade, patent foramen ovale, and ascites. Finally, we cover a number of intraoperative factors that should be considered, including intraoperative blood loss, rapid reaccumulation of ascites, manipulation of the inferior vena cava, post-reperfusion syndrome, and adverse effects of excessive fluid infusion and transfusion. This article aimed to summarize the cardiovascular manifestations of cirrhosis that can affect hemodynamics and can be evaluated using perioperative echocardiography. We hope that this article will provide information about the hemodynamic characteristics of LT recipients and stimulate more active use of perioperative echocardiography.

Roles of Four-Factor Prothrombin Complex Concentrate in the Management of Critical Bleeding

Four-factor prothrombin complex concentrate (4F-PCC) is the term used to describe a pathogen-reduced, lyophilized concentrate that contains therapeutic amounts of at least 4 coagulation factors: Factor II (FII), Factor VII (FVII), Factor IX (FIX), and Factor X (FX). 4F-PCC has proven to be an effective hemostatic agent compared to plasma transfusion in several prospective randomized trials in acute warfarin reversal. In recent years, 4F-PCC has been used in various acquired coagulopathies including post-cardiopulmonary bypass bleeding, trauma-induced coagulopathy, coagulopathy in liver failure, and major bleeding due to anti-FXa (anti-Xa) inhibitors (eg, rivaroxaban and apixaban). As transfusion of frozen plasma (FP) has not been found efficacious in the above critical bleeding scenarios, there is increasing interest in expanding the use of 4F-PCC. However, efficacy, safety, and clinical implications of expanded use of 4F-PCC have not been fully elucidated. Prothrombin time and international normalized ratio are commonly used to assess dose effects of 4F-PCC. Prothrombin time/international normalized ratio are standardly use for warfarin titration, but they are not suited for real-time monitoring of complex coagulopathies. Optimal dosing of 4F-PCC outside of the current approved use for vitamin K antagonist reversal is yet to be determined. In this review, we will discuss the use of 4F-PCC in four critical bleeding settings: cardiac surgery, major trauma, end-stage liver disease, and oral anti-Xa reversal. We will discuss recent studies in each area to explore the dosing, efficacy, and safety of 4F-PCC.

Transfusion-Related Acute Lung Injury During Liver Transplantation: A Scoping Review

Liver transplantation is associated with significant blood loss, often requiring massive blood product transfusion. Transfusion-related acute lung injury (TRALI) is a devastating cause of transfusion-related deaths. While reports have investigated the general incidence of TRALI, the incidence of TRALI specifically following transfusion during liver transplant remains unclear. This scoping review summarizes existing literature regarding TRALI during the liver transplantation perioperative period. Databases were searched for all articles and abstracts reporting on TRALI after liver transplantation. Data collected included number of patients studied, patient characteristics, incidences of TRALI, TRALI characteristics, and patient outcomes. The primary outcome investigated was the incidence of TRALI in the setting of liver transplantation. Thirteen full-text citations were included in this review. The incidence of TRALI post-liver transplant was 0.68% (65 of 9,554). Based on reported transfusion data, patients diagnosed with TRALI received an average of 10.92 ± 10.81 units of packed red blood cells (pRBC), 20.05 ± 15.72 units of fresh frozen plasma, and 5.75 ± 10.00 units of platelets. Common interventions following TRALI diagnosis included mechanical ventilation with positive end-expiratory pressure, inhaled high-flow oxygen, inhaled pulmonary vasodilator, and pharmacologic treatment using pressors or inotropes, corticosteroids, or diuretics. Based on reported mortality data, 26.67% of patients (12 of 45) diagnosed with TRALI died during the postoperative period. This scoping review underscores the importance of better understanding the incidence and presentation of TRALI after liver transplant surgery. The clinical implications of these results warrant the development of identification and management strategies for liver transplant patients at increased risk for developing TRALI.

Patient blood management in India - Review of current practices and feasibility of applying appropriate standard of care guidelines. A position paper by an interdisciplinary expert group

In a developing country like India, with limited resources and access to healthcare facilities, dealing with massive hemorrhage is a major challenge. This challenge gets compounded by pre-existing anemia, hemostatic disorders, and logistic issues of timely transfer of such patients from peripheral hospitals to centers with adequate resources and management expertise. Despite the awareness amongst healthcare providers regarding management modalities of bleeding patients, no uniform Patient Blood Management (PBM) or perioperative bleeding management protocols have been implemented in India, yet. In light of this, an interdisciplinary expert group came together, comprising of experts working in transfusion medicine, hematology, obstetrics, anesthesiology and intensive care, to review current practices in management of bleeding in Indian healthcare institutions and evaluating the feasibility of implementing uniform PBM guidelines. The specific intent was to perform a gap analysis between the ideal and the current status in terms of practices and resources. The expert group identified interdisciplinary education in PBM and bleeding management, bleeding history, viscoelastic and platelet function testing, and the implementation of validated, setting-specific bleeding management protocols (algorithms) as important tools in PBM and perioperative bleeding management. Here, trauma, major surgery, postpartum hemorrhage, cardiac and liver surgery are the most common clinical settings associated with massive blood loss. Accordingly, PBM should be implemented as a multidisciplinary and practically applicable concept in India in a timely manner in order to optimize the use the precious resource blood and to increase patients' safety.

The Association of Increased FFP:RBC Transfusion Ratio to Primary Graft Dysfunction in Bleeding Lung Transplantation Patients

OBJECTIVES

Lung transplantation is associated with a significant risk of needed transfusion. Although algorithm-based transfusion strategies that promote a high fresh frozen plasma:red blood cells (FFP:RBC) ratio have reduced overall blood product requirements in other populations, large-volume transfusions have been linked to primary graft dysfunction (PGD) in lung transplantation, particularly use of platelets and plasma. The authors hypothesized that in lung transplant recipients requiring large-volume transfusions, a higher FFP:RBC ratio would be associated with increased PGD severity at 72 hours.

DESIGN

Observational retrospective review.

SETTING

Single tertiary academic center.

PARTICIPANTS

Adult patients undergoing bilateral or single orthotopic lung transplantation and receiving >4 U PRBC in the first 72 hours from February 2014 to March 2019.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patient demographics, operative characteristics, blood transfusions, and outcomes including PGD scores and length of stay were collected. Eighty-nine patients received >4U PRBC, had available 72-hour PGD data, and were included in the study. These patients were grouped into a high-ratio (>1:2 units of FFP:RBC, N = 38) or low-ratio group (<1:2 units of FFP:RBC, N = 51). Patients in the high-ratio group received more transfusions and factor concentrates and had significantly longer case length. The high-ratio group had a higher rate of severe PGD at 72 hours (60.5% v 23.5%, p = 0.0013) and longer hospital length of stay (40 v 32 days, p = 0.0273).

CONCLUSIONS

In bleeding lung transplantation patients at high risk for PGD, a high FFP:RBC transfusion ratio was associated with worsened 72-hour PGD scores when compared with the low-ratio cohort.

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

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

Risk Factors for Transfusion after Orthotopic Liver Transplantation

Background

Transfusion of blood products during orthotopic liver transplantation (OLT) is associated with increased morbidity and mortality. Although risk factors associated with intraoperative transfusion requirements have been widely assessed, published data on the prediction of postoperative transfusion requirements are sparse.

Objectives

The aim of this study was to evaluate risk factors for postoperative allogeneic transfusion requirements in OLT.

Methods

Clinical characteristics and intraoperative parameters of 645 consecutive adult patients undergoing OLT were retrospectively reviewed. Multivariate logistic regression was used to determine the main determinants for postoperative transfusion requirements.

Results

Determinants of postoperative transfusion requirements of any blood product in the postoperative period were the number of blood products transfused in the intraoperative period (OR 1.17, 95% CI 1.08-1.28), warm ischemia time (OR 1.05, 95% CI 1.02-1.08), MELD score (OR 1.05, 95% CI 1.01-1.08) and hepatocellular carcinoma (OR 0.45, 95% CI 0.28-0.72). A dose-dependent effect between the number of units transfused in the intraoperative period and transfusion requirements in the postoperative period was also observed. The relative risk of postoperative allogeneic transfusion of any blood component was 5.9 (95% CI 3.4-10.4) for patients who received 1-2 units in the intraoperative period, 7.3 (95% CI 3.6-14.7) for those who received 3-5 units in the intraoperative period, and 11.1 (95% CI 4.7-26.4) for those who received 6 or more units, when compared to no intraoperative blood transfusion.

Conclusion

Our study demonstrated an association between intraoperative transfusion and warm ischemia time with postoperative transfusion requirements. The identification of risk factors for transfusion in the postoperative period may improve management of these patients by increasing awareness to bleeding complications in this high-risk population and by expanding hemostasis monitoring to the postoperative period.

Finding the Optimal Regimen for Oral Tranexamic Acid Administration in Primary Total Hip Arthroplasty: A Randomized Controlled Trial

BACKGROUND

Previous studies have confirmed that, compared with intravenous and intra-articular formulations, oral tranexamic acid (TXA) provides equivalent reduction in blood loss, at a substantially reduced cost and greater ease of administration. However, the optimal oral dosage regimen to achieve maximum blood-loss reduction remains unclear. The aim of this study was to assess the efficacy of a regimen of multiple doses of oral TXA on blood loss in primary total hip arthroplasty.

METHODS

In this randomized controlled trial, 200 patients were randomized to 1 of 4 interventions. Group A received a single dose of 2.0 g of TXA orally at 2 hours preoperatively. In addition to this same preoperative dose, Group B received 1.0 g of TXA orally at 3 hours postoperatively, Group C received 1.0 g of TXA orally at 3 and 9 hours postoperatively, and Group D received 1.0 g of TXA orally at 3, 9, and 15 hours postoperatively. All patients received a 1.0-g topical dose of TXA. The primary outcome was total blood loss. Secondary outcomes included hemoglobin reduction, transfusion rate, thromboembolic complications, and adverse events.

RESULTS

The mean total blood loss (and standard deviation) was significantly less in Groups B, C, and D (792.2 ± 293.0, 630.8 ± 229.9, and 553.0 ± 186.1 mL, respectively) than in Group A (983.6 ± 286.7 mL) (p < 0.001). Moreover, Groups C and D had a lower mean reduction in hemoglobin than did Groups A and B. However, no differences were identified between Groups C and D for blood loss and hemoglobin reduction. Additionally, no differences were observed among the groups regarding thromboembolic complications and transfusions.

CONCLUSIONS

The multiple postoperative doses of oral TXA further reduced blood loss compared with a single preoperative bolus. The regimen of a preoperative dose and 3 postoperative doses of oral TXA produced maximum effective reduction of blood loss in total hip arthroplasty.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Acute heart failure after Orthotopic liver transplantation: a case series from one center

Background

Patients undergoing liver transplantation (LT) can develop acute heart failure (HF) in the postoperative period despite having had a normal cardiac evaluation prior to surgery. End-stage liver disease is often associated with underlying cardiac dysfunction which, while not identified during preoperative testing, manifests itself during or immediately after surgery.

Case presentation

We describe three cases of non-ischemic acute HF developing shortly after LT in patients who had a normal preoperative cardiac evaluation. The challenges associated with both diagnosis and management of acute HF in the setting of a newly implanted graft will be discussed.

Conclusions

Diastolic dysfunction, QTc interval prolongation, and an increase in BNP may be predictive of postoperative HF. Current recommendations for preoperative cardiovascular evaluation of transplant candidates does not include studies examining these risk factors and should be revised. Further investigations are necessary to evaluate these findings.

Analysis of Acute Transfusion Reactions and Their Occurrence Times

Acute transfusion reactions (ATRs) are significantly relevant to the morbidity and mortality of patients. ATRs are mostly not severe and rarely cause severe conditions, including anaphylactic shock. The aim of this study was to clarify the frequency of ATRs and the time of event occurrence. A total of 18,745 transfusions were administered to 11,718 patients during a 3-year period. Adverse reactions including at least one sign or symptom were collected through a report system in 143 of 2,478 (5.7%) platelet concentrate transfusions, 105 of 6,629 (1.6%) red blood cell component transfusions and 51 of 2,307 (2.2%) fresh frozen plasma transfusions. Allergic signs and symptoms accounted for 70% of all adverse events. Severe signs and symptoms were observed in 7.1% of patients. These events appeared significantly earlier than those of non-severe signs and symptoms (median time 20 min vs 100 min, P < 0.05). For patients who have had repetitive transfusion-associated adverse events, preventive treatments for adverse events should be proactively promoted.