Point-of-care haemostasis monitoring during liver transplantation reduces transfusion requirements and improves patient outcome

Multicenter evaluation of the Quantra with the QStat Cartridge in adult patients undergoing liver transplantation

Blood loss and transfusion of blood products are key concerns during liver transplantation. Whole-blood viscoelastic testing devices have been used to monitor hemostatic function and guide the transfusion of blood products in this patient population. The Quantra System with the QStat Cartridge is a new point-of-care, closed-system viscoelastic testing device that measures changes in clot stiffness during coagulation and fibrinolysis using ultrasound detection of resonance. The aim of this multicenter prospective observational study was to evaluate the Quantra System against the ROTEM delta device in monitoring coagulation and fibrinolysis in patients undergoing liver transplantation. One hundred twenty-five (125) adult subjects (above 18 y old) were enrolled across 5 medical centers in the US. Blood samples were collected at a minimum of 3-time points: preincision (baseline), during the anhepatic phase, and after the start of reperfusion. Performance was assessed as the correlation of equivalent measurements from the QStat Cartridge and ROTEM delta INTEM, EXTEM, and FIBTEM assays. In addition, a clinical concordance analysis was performed to assess the agreement between the 2 devices related to the detection of fibrinolysis. The correlation between the 2 viscoelastic testing devices was strong, with r -values ranging between 0.88 and 0.95, and the overall agreement with respect to detecting fibrinolysis was 90.3% (CI, 86.9%-93.2%). The results indicate that the Quantra with the QStat Cartridge provides comparable information as the ROTEM delta in the assessment of hemostatic function during a liver transplant. Quantra's simplicity of use and availability of rapid results may provide clinicians with a faster, more convenient means to assess coagulation and fibrinolysis status in the operating room and critical care setting.

Viscoelastometry to Manage Bleeding in Liver Disease

A state of "re-balanced haemostasis" describes complex coagulation changes that arise in patients with liver disease. Changes include alterations in procoagulant and anticoagulant proteins, platelets and von Willebrand factor, as well as the fibrinolytic system. Various circumstances including infection, trauma, or surgery may disrupt this balance and predispose an individual to bleeding or thrombosis. The prothrombin time, international normalised ratio, and activated partial thromboplastin time are conventional coagulation screening tests that are routinely employed by clinicians to investigate unexplained bleeding, monitor anticoagulation, and inform preoperative assessments of bleeding risk. These standard coagulation tests assess quantitative defects in procoagulant clotting factors and are insensitive to levels of natural anticoagulants, which together with procoagulant factors, are often perturbed in liver disease. Therefore, the prolongation of clotting times measured by these tests often does not reflect the multifaceted alterations of haemostasis in these patients. Viscoelastic testing (VET) provides a more encompassing assessment of clotting function by recording real-time viscoelastic changes in whole blood and includes parameters that provide information on coagulation factor function, platelet contribution to clot formation, as well as fibrinolysis. To date, VET has been employed to predict and inform transfusion support in obstetric, trauma, and cardiac surgical fields, and its use in patients undergoing liver transplantation is well established. The ability of VET to accurately predict bleeding risk and precisely guide transfusion algorithms for patients with liver disease undergoing other invasive procedures or experiencing bleeding complications has been the topic of research over the last decade. This review is a critical summary of this data and provides a detailed snapshot of the position of VET as a clinical tool in patients with liver disease.

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.

Viscoelastic Management of Coagulopathy during the Perioperative Period of Liver Transplantation

Viscoelastic testing (VET) in liver transplantation (LT) has been used since its origin, in combination with standard laboratory testing (SLT). There are only a few, small, randomized controlled trials that demonstrated a reduction in transfusion rates using VET to guide coagulation management. Retrospective analyses contrasting VET to SLT have demonstrated mixed results, with a recent concern for overtreatment and the increase in postoperative thrombotic events. An oversight of many studies evaluating VET in LT is a single protocol that does not address the different phases of surgery, in addition to pre- and postoperative management. Furthermore, the coagulation spectrum of patients entering and exiting the operating room is diverse, as these patients can have varying anatomic and physiologic risk factors for thrombosis. A single transfusion strategy for all is short sighted. VET in combination with SLT creates the opportunity for personalized resuscitation in surgery which can address the many challenges in LT where patients are at a paradoxical risk for both life-threatening bleeding and clotting. With emerging data on the role of rebalanced coagulation in cirrhosis and hypercoagulability following LT, there are numerous potential roles in VET management of LT that have been unaddressed.

Emerging technology for early detection and management of postpartum hemorrhage to prevent morbidity

Despite advances in hemorrhage detection and management, postpartum hemorrhage remains the single leading cause of maternal death worldwide. Within the United States, hemorrhage is the leading cause of maternal death on the day of delivery and within the first week after delivery. Blood transfusion after hemorrhage represents a large proportion of severe maternal morbidity during and after delivery. Blood loss during delivery has historically been assessed visually by inspecting soiled pads, linens, and laparotomy sponges. These methods underestimate the volume of blood loss by as much as 40%, becoming increasingly inaccurate as blood loss increases. Young, healthy obstetrical patients compensate for blood loss via peripheral vasoconstriction, maintaining heart rate and blood pressure in a normal range until over 1 L of blood has been lost. A significant decrease in blood pressure along with marked tachycardia (>120 bpm) may not be seen until 30% to 40% of blood volume has been lost, or 2.0 to 2.6 L in a healthy term pregnant patient, after which the patient may rapidly decompensate. In resource-poor settings especially, the narrow window between the emergence of significant vital sign abnormalities and clinical decompensation may prove catastrophic. Once hemorrhage is detected, decisions regarding blood product transfusion are routinely made on the basis of inaccurate estimates of blood loss, placing patients at risk of underresuscitation (increasing the risk of hemorrhagic shock and end-organ damage) or overresuscitation (increasing the risk of transfusion reaction, fluid overload, and alloimmunization). We will review novel technologies that have emerged to assist both in the early and accurate detection of postpartum hemorrhage and in decisions regarding blood product transfusion.

Viscoelastic versus conventional coagulation tests to reduce blood product transfusion in patients undergoing liver transplantation: A systematic review and meta-analysis

BACKGROUND

Recent literature suggests viscoelastic test (VET)-guided transfusion management could be associated with reduced blood product administration in patients undergoing liver transplantation.

OBJECTIVES

To assess the effectiveness of coagulation management guided by VETs compared with conventional coagulation tests (CCTs) in reducing blood product transfusion in patients undergoing liver transplantation.

DESIGN

Systematic review and meta-analysis of randomised (RCTs) and nonrandomised clinical trials performed according to PRISMA guidelines. The protocol was previously published (PROSPERO: CRD42021230213).

DATA SOURCES

The Cochrane Central Library, PubMed/MEDLINE, Embase and the Transfusion Evidence Library were searched up to 30 th January 2022.

ELIGIBILITY CRITERIA

Setting: operating room. Patients: liver transplantation recipients. Intervention: use of VETs versus CCTs. Main outcome measures: the primary outcome was the mean number of transfused units for each blood product including red blood cells (RBCs), fresh frozen plasma (FFP), platelets (PLTs) and cryoprecipitate. Secondary outcomes included mortality rate, intensive care unit (ICU) and hospital length of stay (LOS).

RESULTS

Seventeen studies ( n  = 5345 patients), 15 observational and two RCTs, were included in this review. There was a mean difference reduction in RBCs [mean difference: -1.40, 95% confidence interval (95% CI), -1.87 to -0.92; P  < 0.001, I2  = 61%) and FFP units (mean difference: -2.98, 95% CI, -4.61 to -1.35; P  =  < 0.001; I2  = 98%) transfused in the VETs group compared with the CCTs one. A greater amount of cryoprecipitate was administered in the VETs group (mean difference: 2.71, 95% CI, 0.84 to 4.58; P  = 0.005; I2  = 91%). There was no significant difference in the mean number of PLT units, mortality, hospital and ICU-LOS.

CONCLUSION

Our meta-analysis demonstrated that VETs implementation was associated with reduced RBC and FFP consumption in liver transplantation patients without effects on mortality and hospital and ICU-LOS. The certainty of evidence ranged from moderate to very low. Further well conducted RCTs are needed to improve the certainty of evidence.

Individualized Management of Coagulopathy in Patients with End-Stage Liver Disease

Over the last decades, individualized approaches and a better understanding of coagulopathy complexity in end-stage liver disease (ESLD) patients has evolved. The risk of both thrombosis and bleeding during minimally invasive interventions or surgery is associated with a worse outcome in this patient population. Despite deranged quantitative and qualitative coagulation laboratory parameters, prophylactic coagulation management is unnecessary for patients who do not bleed. Transfusion of red blood cells (RBCs) and blood products carries independent risks for morbidity and mortality, including modulation of the immune system with increased risk for nosocomial infections. Optimal coagulation management in these complex patients should be based on the analysis of standard coagulation tests (SCTs) and viscoelastic tests (VETs). VETs represent an individualized approach to patients and can provide information about coagulation dynamics in a concise period of time. This narrative review will deliver the pathophysiology of deranged hemostasis in ESLD, explore the difficulties of evaluating the coagulopathies in liver disease patients, and examine the use of VET assays and management of coagulopathy using coagulation factors. Methods: A selective literature search with PubMed as the central database was performed with the following.

A brief history of liver transplantation and transplant anesthesia

In this review, we describe the major milestones in the development of organ transplantation with a specific focus on hepatic transplantation. For many years, the barriers preventing successful organ transplantation in humans seemed insurmountable. Although advances in surgical technique provided the technical ability to perform organ transplantation, limited understanding of immunology prevented successful organ transplantation. The breakthrough to success was the result of several significant discoveries between 1950 and 1980 involving improved surgical techniques, the development of effective preservative solutions, and the suppression of cellular immunity to prevent graft rejection. After that, technical innovations and laboratory and clinical research developed rapidly. However, these advances alone could not have led to improved transplant outcomes without parallel advances in anesthesia and critical care. With increasing organ demand, it proved necessary to expand the donor pool, which has been achieved with the use of living donors, split grafts, extended criteria organs, and organs obtained through donation after cardiac death. Given this increased access to organs and organ resources, the number of transplantations performed every year has increased dramatically. New regulatory organizations and transplant societies provide critical oversight to ensure equitable organ distribution and a high standard of care and also perform outcome analyses. Establishing dedicated transplant anesthesia teams results in improved organ transplantation outcomes and provides a foundation for developing new standards for other subspecialties in anesthesiology, critical care, and medicine overall. Through a century of discovery, the success we enjoy at the present time is the result of the work of well-organized multidisciplinary teams following standardized protocols and thereby saving thousands of lives worldwide each year. With continuing innovation, the future is bright.

Intraoperative transfusion management, antifibrinolytic therapy, coagulation monitoring and the impact on short-term outcomes after liver transplantation-A systematic review of the literature and expert panel recommendations

BACKGROUND

Liver transplantation (LT) is frequently complicated by coagulopathy associated with end-stage liver disease (ESLD), that is, often multifactorial.

OBJECTIVES

The objective of this systematic review was to identify evidence based intraoperative transfusion and coagulation management strategies that improve immediate and short-term outcomes after LT.

METHODS

PRISMA-guidelines and GRADE-approach were followed. Three subquestions were formulated. (Q); Q1: transfusion management; Q2: antifibrinolytic therapy; and Q3: coagulation monitoring.

RESULTS

Sixteen studies were included for Q1, six for Q2, and 10 for Q3. Q1: PRBC and platelet transfusions were associated with higher mortality. The use of prothrombin complex concentrate (PCC) and fibrinogen concentrate (FC) were not associated with reductions in intraoperative transfusion or increased thrombotic events. The use of cell salvage was not associated with hepatocellular carcinoma (HCC) recurrence or mortality. Cell salvage and transfusion education significantly decreased blood product transfusions. Q2: Epsilon-aminocaproic acid (EACA) and tranexamic acid (TXA) were not associated with decreased blood product transfusion, improvements in patient or graft survival, or increases in thrombotic events. Q3: Viscoelastic testing (VET) was associated with decreased allogeneic blood product transfusion compared to conventional coagulation tests (CCT) and is likely to be cost-effective. Coagulation management guided by VET may be associated with increases in FC and PCC use.

CONCLUSION

Q1: A specific blood product transfusion practice is not recommended (QOE; low | Recommendation; weak). Cell salvage and educational interventions are recommended (QOE: low | Grade of Recommendation: moderate). Q2: The routine use of antifibrinolytics is not recommended (QOE; low | Recommendation; weak). Q3: The use of VET is recommended (QOE; low-moderate | Recommendation; strong).

The effect of a viscoelastic-guided bleeding algorithm implementation on blood products use in adult liver transplant patients. A propensity score-matched before-after study

BACKGROUND

Perioperative blood products transfusion is correlated with increased morbidity and mortality in liver transplantation (LTx). The objectives of our study are to assess the effect of a standardized viscoelastic test (VET)-guided bleeding management algorithm implementation on intraoperative bleeding, allogenic blood products and factor concentrates requirements and on early postoperative complications in LTx.

METHODS

Retrospective before-after study comparing two matched cohorts of patients undergoing LTx before (control cohort) and after (intervention cohort) the implementation of a VET-based bleeding algorithm in a single center academic hospital.

RESULTS

After propensity score matching, we included 94 patients in each cohort. Patients in intervention cohort received significantly less blood products, fresh frozen plasma (FFP), and cryoprecipitate (p < 0.001 for each), while the amount of fibrinogen concentrate used was significantly higher (p < 0.001). Postoperatively, intervention cohort patients had significantly lower postoperative hemoglobin and fibrinogen levels and longer prothrombin time compared to control cohort. There were no significant differences in red blood cells transfusions, intraoperative bleeding, early postoperative complications, and short term survival.

CONCLUSIONS

The implementation of a VET-guided bleeding algorithm decreases allogenic blood products requirements, mainly FFP use and allows a more restrictive management of coagulopathy in patients with chronic liver disease undergoing LTx.

Viscoelastic tests in liver disease: where do we stand now?

Hemostasis is a complex physiological process based on the balance between pro-coagulant and anticoagulant systems to avoid pathological bleeding or thrombosis. The changes in standard coagulation tests in liver disease were assumed to reflect an acquired bleeding disorder, and cirrhotic patients were considered naturally anticoagulated. In the light of the new evidence, the theory of rebalanced hemostasis replaced the old concept. According to this model, the hemostatic alteration leads to a unique balance between pro-coagulant, anticoagulant, and fibrinolytic systems. But the balance is fragile and may prone to bleeding or thrombosis depending on various risk factors. The standard coagulation tests [INR (international normalized ratio), platelet count and fibrinogen] only explore parts of the hemostasis, not offering an entire image of the process. Rotational thromboelastometry (ROTEM) and thromboelastography (TEG) are both point of care viscoelastic tests (VET) that provide real-time and dynamic information about the entire hemostasis process, including clot initiation (thrombin generation), clot kinetics, clot strength, and clot stability (lysis). Despite prolonged PT/INR (international normalized ratio of prothrombin time) and low platelet counts, VET is within the normal range in many patients with both acute and chronic liver disease. However, bleeding remains the dominant clinical issue in patients with liver diseases, especially when invasive interventions are required. VET has been shown to asses more appropriately the risk of bleeding than conventional laboratory tests, leading to decrial use of blood products transfusion. Inappropriate clotting is common but often subtle and may be challenging to predict even with the help of VET. Although VET has shown its benefit, more studies are needed to establish cut-off values for TEG and ROTEM in these populations and standardization of transfusion guidelines before invasive interventions in cirrhotic patients/orthotopic liver transplantation.

Rotational thromboelastometry reduces blood loss and blood product usage after lung transplantation

BACKGROUND

The shortage of blood products has become a worldwide problem, especially during the COVID-19 Pandemic. Here, we investigated whether a point of care (POC) approach to perioperative bleeding and coagulopathy based on rotational thromboelastometry (ROTEM) results could decrease perioperative blood loss and the perioperative consumption of blood products during lung transplantation.

METHODS

Patients undergoing bilateral lung transplantation were randomized into two groups: In the first group, designated the "non POC" group, the management of perioperative bleeding and coagulopathy was based on the clinical experience of the anesthesiologist; in the second group, designated the "POC" group, the management of perioperative bleeding, and coagulopathy was based on the ROTEM results.

RESULTS

After performing an interim statistical analysis, the project was prematurely terminated as the results were significantly in favor of the POC approach. Data were analyzed for the period January 2018 until June 2020 when 67 patients were recruited into the study. There was significantly decreased perioperative blood loss in the POC group (n = 31 patients) with p = 0.013, decreased perioperative consumption of RBC with p = 0.009, and decreased perioperative consumption of fresh frozen plasma with p < 0.0001 (practically no fresh frozen plasma was used in the POC group) without deteriorating clot formation in secondary and primary hemostasis as compared to the non POC group (n = 36).

CONCLUSION

POC management of perioperative bleeding and coagulopathy based on ROTEM results is a promising strategy to decrease perioperative blood loss and the consumption of blood products in lung transplantation.

Thromboelastography does not reduce transfusion requirements in liver transplantation: A propensity score-matched study

STUDY OBJECTIVE

To compare total blood product requirements in liver transplantation (LT) assisted by thromboelastography (TEG) or conventional coagulation tests (CCTs).

DESIGN

Retrospective observational study.

SETTING

A tertiary care referral center for LT.

PATIENTS

Adult patients undergoing LT from deceased donor.

INTERVENTION

Hemostasis was monitored by TEG or CCTs and corresponding transfusion algorithms were adopted.

MEASUREMENTS

Number and types of blood products (red blood cells, RBC; fresh-frozen plasma, FFP; platelets, PLT) transfused from the beginning of surgery until the admission to the intensive care unit.

METHODS

We compared data retrospectively collected in 226 LTs, grouped according to the type of hemostasis monitoring (90 with TEG and 136 with CCTs, respectively). Confounding variables affecting transfusion needs (recipient age, sex, previous hepatocellular carcinoma surgery, Model for End Stage Liver Disease - MELD, baseline hemoglobin, fibrinogen, creatinine, veno-venous by pass, and trans-jugular intrahepatic portosystemic shunt) were managed by propensity score match (PSM).

MAIN RESULTS

The preliminary analysis showed that patients in the TEG group received fewer total blood products (RBC + FFP + PLT; p = 0.001, FFP (p = 0.001), and RBC (p = 0.001). After PSM, 89 CCT patients were selected and matched to the 90 TEG patients. CCT and TEG matched patients received similar amount of total blood products. In a subgroup of 39 patients in the top MELD quartile (MELD ≥25), the TEG use resulted in lower consumption of FFP units and total blood products. Nevertheless, due to the low number of patients, any meaningful conclusion could be achieved in this subgroup.

CONCLUSIONS

In our experience, TEG-guided transfusion in LT does not reduce the intraoperative blood product consumption. Further studies are warranted to assess an advantage for TEG in either the entire LT population or the high-MELD subgroup of patients.

Guidelines on the use of liver biopsy in clinical practice from the British Society of Gastroenterology, the Royal College of Radiologists and the Royal College of Pathology

Liver biopsy is required when clinically important information about the diagnosis, prognosis or management of a patient cannot be obtained by safer means, or for research purposes. There are several approaches to liver biopsy but predominantly percutaneous or transvenous approaches are used. A wide choice of needles is available and the approach and type of needle used will depend on the clinical state of the patient and local expertise but, for non-lesional biopsies, a 16-gauge needle is recommended. Many patients with liver disease will have abnormal laboratory coagulation tests or receive anticoagulation or antiplatelet medication. A greater understanding of the changes in haemostasis in liver disease allows for a more rational, evidence-based approach to peri-biopsy management. Overall, liver biopsy is safe but there is a small morbidity and a very small mortality so patients must be fully counselled. The specimen must be of sufficient size for histopathological interpretation. Communication with the histopathologist, with access to relevant clinical information and the results of other investigations, is essential for the generation of a clinically useful report.

Thromboelastography versus standard coagulation testing in the assessment and reversal of coagulopathy among cirrhotics: a systematic review and meta-analysis

The utility of thromboelastography/thromboelastometry currently has unvalidated clinical benefit in the assessment and reversal of coagulopathy among cirrhotic patients as compared to standard coagulation testing. A novel systematic review and meta-analysis was conducted in order to assess pooled outcome data among patients receiving thromboelastography/thromboelastometry as compared to standard coagulation testing. As compared to standard coagulation testing, there was a significant reduction in the number of patients requiring pRBC, platelet, and fresh frozen plasma transfusions among thromboelastography/thromboelastometry group with pooled OR 0.53 (95% CI 0.32-0.85; P = 0.009), 0.29 (95% CI 0.12-0.74; P = 0.009), and 0.19 (95% CI 0.12-0.31; P < 0.00001), respectively. Similarly, there was a significant reduction in number of pRBC, platelet, and fresh frozen plasma units transfused in the thromboelastography/thromboelastometry group with pooled MD -1.53 (95% CI -2.86 to -0.21; P = 0.02), -0.57 (95% CI -1.06 to -0.09; P = 0.02), and -2.71 (95% CI -4.34 to -1.07; P = 0.001), respectively. There were significantly decreased total bleeding events with pooled OR 0.54 (95% CI 0.31-0.94; P = 0.03) and amount of intraoperative bleeding during liver transplantation with pooled MD -1.46 (95% CI -2.49 to -0.44; P = 0.005) in the thromboelastography/thromboelastometry group. Overall, there was no significant difference in mortality between groups with pooled OR 0.91 (95% CI 0.63-1.30; P = 0.60). As compared to standard coagulation testing, a thromboelastography/thromboelastometry-guided approach to the assessment and reversal of cirrhotic coagulopathy improves overall number of patients exposed to blood product transfusions, quantity of transfusions, and bleeding events.

Modern Management of Bleeding, Clotting, and Coagulopathy in Trauma Patients: What Is the Role of Viscoelastic Assays?

Purpose of Review

The purpose of this review is to briefly outline the current state of hemorrhage control and resuscitation in trauma patients with a specific focus on the role viscoelastic assays have in this complex management, to include indications for use across all phases of care in the injured patient.

Recent Findings

Viscoelastic assay use to guide blood-product resuscitation in bleeding trauma patients can reduce mortality by up to 50%. Viscoelastic assays also reduce total blood products transfused, reduce ICU length of stay, and reduce costs. There are a large number of observational and retrospective studies evaluating viscoelastic assay use in the initial trauma resuscitation, but only one randomized control trial. There is a paucity of data evaluating use of viscoelastic assays in the operating room, post-operatively, and during ICU management in trauma patients, rendering their use in these settings extrapolative/speculative based on theory and data from other surgical disciplines and settings.

Summary

Both hypocoagulable and hypercoagulable states exist in trauma patients, and better indicate what therapy may be most appropriate. Further study is needed, particularly in the operating room and post-operative/ICU settings in trauma patients.

Transfusion of Older Red Blood Cells Increases the Risk of Acute Kidney Injury After Orthotopic Liver Transplantation: A Propensity Score Analysis

BACKGROUND

Acute kidney injury (AKI) is a common and serious complication of orthotopic liver transplantation (OLT). Transfusion of older red blood cells (RBCs) has been implicated in poor outcomes in trauma, cardiac surgery, and critically ill patients. However, whether transfusion of older RBCs plays any role in post-OLT AKI remained unknown. The aim of this study was to investigate the effect of the age of transfused RBCs on post-OLT AKI.

METHODS

The clinical data of consecutive adult patients who received donation after cardiac death and underwent OLT from December 2011 to December 2015 were analyzed. These patients were divided into 2 groups: the newer blood group, who received exclusively RBCs that had been stored for <14 days; and the older blood group, who received RBCs that had been stored for 14 days or more. The incidence of post-OLT AKI, severe AKI, lengths of intensive care unit and hospital stay, and in-hospital mortality after OLT were analyzed.

RESULTS

Postoperative AKI occurred in 65.1% of patients in the older blood group and 40.5% of patients in the newer blood group (P < .01). The incidence of severe AKI after OLT was significantly higher, and the duration of intensive care unit stay was significantly longer, in the older blood group. After adjustment by the multivariable regression logistic analysis, transfusion of older blood was independently associated with post-OLT AKI (odds ratio [OR] = 2.47 [95% confidence interval {CI}, 1.13-5.41]; P = .024) and severe AKI (OR = 5.88 [95% CI, 2.06-16.80]; P = .001). After adjustment by the inverse probability of treatment weighting analysis, patients in the older blood group still had significantly higher incidences of postoperative AKI (OR = 2.13 [95% CI, 1.07-4.22]; P = .030) and severe AKI (OR = 3.34 [95% CI, 1.47-7.60]; P = .003) than those in the newer blood group.

CONCLUSIONS

Transfusion of older RBCs significantly increased the risk of postoperative AKI in liver transplant recipients.

Point-of-care haemostasis monitoring during liver transplantation is cost effective

Background Optimal haemostasis management in orthotropic liver transplant (OLT) could reduce blood loss and transfusion volume, improve patient outcomes and reduce cost. Methods We performed a study including 336 OLTs to evaluate the clinical and cost effectiveness of a new point-of-care (POC)-based haemostatic management approach in OLT patients. Results In terms of health benefit we found that the new approach showed a significant reduction in transfusion requirements (red blood cell transfusion units were reduced from 5.3±4.6 to 2.8±2.9 [p<0.001], free frozen plasma from 3.1±3.3 to 0.4±1.0 [p<0.001] and platelets from 2.9±3.9 to 0.4±0.9 [p<0.001], transfusion avoidance, 9.7% vs. 29.1% [p<0.001] and massive transfusion, 14.5% vs. 3.8% [p=0.001]); we also found a significant improvement in patient outcomes, such, reoperation for bleeding or acute-kidney-failure (8.3% vs. 2.4%, p=0.015; 33.6% vs. 5.4%, p<0.001), with a significant reduction in the length of the hospital total stay (40.6±13.8 days vs. 38.2±14.4 days, p=0.001). The lowest cost incurred was observed with the new approach (€73,038.80 vs. €158,912.90) with significant patient saving associated to transfusion avoidance (€1278.36), ICU-stay (€3037.26), total-stay (€3800.76) and reoperation for bleeding (€80,899.64). Conclusions POC haemostatic monitoring during OLT is cost effective.

Critically Ill Patients with End-Stage Liver Disease

Patients with end-stage liver disease (ESLD) who require intensive care unit admission have high rates of mortality. This article reviews the pathophysiology and emergency department assessment and management of the most frequent conditions and complications encountered in critically ill ESLD patients including hepatic encephalopathy, gastrointestinal bleeding, sepsis and bacterial peritonitis, hepatorenal syndrome, severe coagulopathy, and hepatic hydrothorax.

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.

Rotational thromboelastometry (ROTEM) 24 hours post liver transplantation predicts early allograft dysfunction

Early allograft dysfunction (EAD) represents one of the most common and serious complications after liver transplantation (LT).

Methods

One hundred sixty-four patients who underwent LT were prospectively included in the present study. Patient demographics, intraoperative blood loss and transfusion were recorded at the time of LT. Lactate levels were recorded during surgery and daily for the first 3 postoperative days. Standard and derived rotational thromboelastometry (ROTEM) parameters were recorded 24 hours after LT. EAD was diagnosed according to Nanashima criteria and post anaesthesia care unit length of stay was recorded.

Results

Forty-seven patients (28.6%) developed EAD. Intraoperative blood loss (p = 0.01), packed red blood cells (p = 0.04) and fresh frozen plasma (p = 0.01) transfusion represented intraoperative risk factors for EAD. Lactate levels were significantly higher in patients with EAD at all time points. Patients with EAD demonstrated an increased clot formation time and decreased maximum clot firmness in both intrinsically (p < 0.01) and extrinsically (p < 0.01) activated assay, a decreased thrombin potential index (p < 0.01), area under the curve (p < 0.01) and clot elasticity (p < 0.01) on ROTEM assay.

Conclusion

Our results show that both standard and derived ROTEM parameters may indicate early signs of graft failure and can aid in the diagnosis of EAD.

Perioperative Single-Donor Platelet Apheresis and Red Blood Cell Transfusion Impact on 90-Day and Overall Survival in Living Donor Liver Transplantation

Background:

Although many previous studies have confirmed that perioperative blood transfusion is associated with poor outcomes after liver transplantation (LT), few studies described the influence of single-donor platelet apheresis transfusion in living donor LT (LDLT). This study aimed to assess the effect of blood products on outcomes for LDLT recipients, focusing on apheresis platelets.

Methods:

This retrospective study included 126 recipients who underwent their first adult-to-adult LDLT. Twenty-four variables including consumption of blood products of 126 LDLT recipients were assessed for their link to short-term outcomes and overall survival. Kaplan-Meier survival curve and the log-rank test were used for recipient survival analysis. A multivariate Cox proportional-hazard model and a propensity score analysis were applied to adjust confounders after potential risk factors were identified by a univariate Cox analysis.

Results:

Patients who received apheresis platelet transfusion had a lower 90-day cumulative survival (78.9% vs. 94.2%, P = 0.009), but had no significant difference in overall survival in the Cox model, compared with those without apheresis platelet transfusion. Units of apheresis platelet transfusion (hazard ratio [HR] = 3.103, 95% confidence interval [CI]: 1.720–5.600, P < 0.001) and preoperative platelet count (HR = 0.170, 95% CI: 0.040–0.730, P = 0.017) impacted 90-day survival independently. Multivariate Cox regression analysis also found that units of red blood cell (RBC) transfusion (HR = 1.036, 95% CI: 1.006–1.067, P = 0.018), recipient's age (HR = 1.045, 95% CI: 1.005–1.086, P = 0.025), and ABO blood group comparison (HR = 2.990, 95% CI: 1.341–6.669, P = 0.007) were independent risk factors for overall survival after LDLT.

Conclusions:

This study suggested that apheresis platelets were only associated with early mortality but had no impact on overall survival in LDLT. Units of RBC, recipient's age, and ABO group comparison were independent predictors of long-term outcomes.

Management of Coagulopathy during Bleeding and Invasive Procedures in Patients with Liver Failure

Alterations in hemostasis are a characteristic feature of advanced liver disease. Patients with coagulopathy of advanced liver disease are prone to bleedings and also thromboembolic events. Under stable conditions, cirrhosis patients show alterations in both pro- and anticoagulatory pathways, frequently resulting in a rebalanced hemostasis. This review summarizes current recommendations of management during bleeding and prior to invasive procedures in patients with cirrhosis.

Bleeding and thrombotic complications of pediatric liver transplant

BACKGROUND

Pediatric patients undergoing liver transplant are at significant risk for bleeding and thrombotic complications due to the complex nature of rebalanced hemostasis in patients with liver disease.

METHODS/OBJECTIVES

We reviewed records of 92 pediatric liver and multivisceral transplant cases at Duke University Medical Center between January 2009 and December 2015. The goal was to define the nature and incidence of bleeding and thrombotic complications in this cohort and define potential risk factors.

RESULTS

There were 24 major bleeding events in 19 transplants (incidence 20.7%) and 30 thrombotic events in 23 transplants (incidence 25%). Five of the 10 retransplantations were for vascular thrombotic complications. Thirty-day mortality was 4.9%, and three of these four deaths were due to vascular thrombosis. No bleeding events led to retransplantation or mortality. Prophylactic aspirin was associated with decreased risk of thrombosis without increased bleeding. Prophylactic heparin did not increase bleeding risk. Laboratory assays predicted events poorly, apparently failing to capture the nuanced and dynamic interplay between pro- and anticoagulant factors in the posttransplant patient.

CONCLUSIONS

Both bleeding and thrombosis are frequent in this population, but only thrombotic complications contributed to retransplantation and mortality. A standardized approach to coagulation testing and antithrombotic therapy may be useful in predicting and reducing adverse outcomes. Alternative approaches to monitoring hemostasis need to be prospectively investigated in this complex patient population.

Bleeding Risk with Invasive Procedures in Patients with Cirrhosis and Coagulopathy

PURPOSE OF REVIEW

Previous perceptions of cirrhosis as a hypocoagulable state have resulted in empirical blood product transfusions prior to invasive procedures. We evaluate procedure-related bleeding risks in patients with cirrhosis, assess the utility of conventional and newer global coagulation tests, and explore evidence surrounding prophylactic transfusion strategies.

RECENT FINDINGS

Recent literature supports the concept of a rebalanced, albeit fragile, haemostasis equilibrium in cirrhosis, with a potential hypercoagulable tendency in stable patients. Standard coagulation tests provide a poor reflection of bleeding risks and yet are relied upon for transfusion thresholds. Consequently, a sizeable proportion of patients receive unnecessary blood products. The role of viscoelastic tests to guide transfusions requires further evaluation. In stable cirrhotic patients, procedure-related bleeding rates appear low. Prophylactic transfusion strategies based on arbitrary thresholds lack evidence of clinical benefit. There is a pressing need for point-of-care coagulation tests that represent the complex coagulopathy of cirrhosis and well-powered randomised controlled trials to develop evidence-based pre-procedure transfusion guidelines.

The Utility of Viscoelastic Testing in Patients Undergoing IR Procedures

Whole-blood viscoelastic testing can identify patient-specific coagulation disturbances, allowing for targeted repletion of necessary coagulation factors and differentiation between coagulopathy and surgical bleeding that requires intervention. Viscoelastic testing complements standard coagulation tests and has been shown to decrease transfusion requirements and improve survival in bleeding patients. Viscoelastic testing also can be used to predict bleeding and improve the care of patients undergoing interventional radiology (IR) procedures.

Monitoring and Treatment of Coagulation Disorders in End-Stage Liver Disease

BACKGROUND

Patients with end-stage liver disease (ESLD) are assumed to be at high risk of bleeding when undergoing any kind of invasive intervention (any kind of operation, including transplantation or minimally invasive interventions). Both bleeding and thrombosis are associated with a poor outcome.

METHODS

A selective literature research was conducted with the following key words: 'cirrhosis', 'coagulation', 'bleeding', 'INR' (international normalized ratio), 'aPTT' (activated partial thromboplastin time), and 'thrombocytopenia'. PubMed was used as the basic database.

RESULTS

Pathological values of standard laboratory tests (SLT) and thrombocytopenia have traditionally been regarded as indicators of a high risk for bleeding in all patients, and especially in those with ESLD. However, this approach has been challenged in recent years. The conventional approach in assessing a bleeding risk was based on pathological values of SLT. A 1.5-fold increase of INR or aPTT or platelets < 50/nl is assumed as pathological. The traditional approach of reducing the risk of excessive bleeding during an invasive procedure was to transfuse fresh frozen plasma (FFP) or platelet concentrates in order to improve hemostasis and to avoid bleeding complications. In the recent 20 years, several studies have provided us with a basis for questioning this approach. Their results indicated that SLT were not able to predict hypocoagulation and bleeding complications. Moreover, transfusion of various blood products has been associated with an increased risk for acute lung injury, transfusion-associated circulation overload, bacterial infections, and modulation of the immune system with increased numbers of nosocomial infections. Furthermore, a high volume overload, which is required to correct a hemostasis disorder if FFP are being used in ESLD patients, may increase portal venous pressure. This might significantly increase bleeding in these ESLD patients. Although the first publication about the successful use of a viscoelastic test (VET) in liver transplantation dates back to 1985, physicians are still very reluctant to use VETs (Thrombelastography™ and/or ROTEM™) for the perioperative optimization of hemostasis. However, some very recent studies demonstrated that the use of VETs for assessing the risk of bleeding avoids futile transfusion with a similar safety profile. The implementation of ROTEM-based coagulation management and the use of coagulation factors (prothrombin complex, fibrinogen concentrate) have led to a highly significant reduction of FFP and red blood cell transfusions, without an increased incidence of thrombosis or bleeding.

CONCLUSION

Patients with ESLD often show pathological values of conventional parameters used to analyze coagulation hemostasis. Without overt signs of excessive bleeding, however, they do not require coagulation treatment. The use of FFP, which is associated with fluid overload and increase in portal venous pressure, should be avoided. The preferable coagulation treatment should be based on VET-guided administration of coagulation factor concentrates.

[Rotational thromboelastometry for the diagnosis of coagulation disorders]

BACKGROUND

Compared to conventional coagulation assays, as prothrombin time (PT) or activated partial thromboplastin time (aPTT), viscoelastic methods of coagulation analysis, including rotational thromboelastometry (ROTEM®, Tem International GmbH, Munich, Germany), yield prognostic benefits. Results of ROTEM® in citrated whole blood could be generated within 10-12 min and allow for a qualitative and semiquantitative characterisation of clot kinetics. Based on ROTEM® results, the switch between empiric approaches of treating coagulopathy to a goal-directed approach could be accelerated. Introduction of ROTEM® reduces transfusion requirements and the need for single factor concentrates. Thus, ROTEM® reduces transfusion-related adverse events, and additionally implement therapeutic cost effectiveness.

OBJECTIVES

This review provides a short introduction in the methodology of ROTEM®, showing how the combination of assays with different commercially available ROTEM® reagents allows for rapid differential diagnosis of common coagulopathies in clinical practice. Furthermore, prognostic benefits and limitations of ROTEM® diagnostics are described. Finally, we discuss the potential fields of ROTEM® application in different surgical settings.

CONCLUSION

ROTEM® appears to be a contemporary, applicable and effective method in diagnosing coagulopathy and for subsequent algorithm-based goal-directed therapy.

Predictive factors of short term outcome after liver transplantation: A review

Liver transplantation represents a fundamental therapeutic solution to end-stage liver disease. The need for liver allografts has extended the set of criteria for organ acceptability, increasing the risk of adverse outcomes. Little is known about the early postoperative parameters that can be used as valid predictive indices for early graft function, retransplantation or surgical reintervention, secondary complications, long intensive care unit stay or death. In this review, we present state-of-the-art knowledge regarding the early post-transplantation tests and scores that can be applied during the first postoperative week to predict liver allograft function and patient outcome, thereby guiding the therapeutic and surgical decisions of the medical staff. Post-transplant clinical and biochemical assessment of patients through laboratory tests (platelet count, transaminase and bilirubin levels, INR, factor V, lactates, and Insulin Growth Factor 1) and scores (model for end-stage liver disease, acute physiology and chronic health evaluation, sequential organ failure assessment and model of early allograft function) have been reported to have good performance, but they only allow late evaluation of patient status and graft function, requiring days to be quantified. The indocyanine green plasma disappearance rate has long been used as a liver function assessment technique and has produced interesting, although not univocal, results when performed between the 1^th and the 5^th day after transplantation. The liver maximal function capacity test is a promising method of metabolic liver activity assessment, but its use is limited by economic cost and extrahepatic factors. To date, a consensual definition of early allograft dysfunction and the integration and validation of the above-mentioned techniques, through the development of numerically consistent multicentric prospective randomised trials, are necessary. The medical and surgical management of transplanted patients could be greatly improved by using clinically reliable tools to predict early graft function.

Is viscoelastic coagulation monitoring with ROTEM or TEG validated?

Recent years have seen increasing worldwide interest in the use of viscoelastic coagulation monitoring tests, performed using devices such as ROTEM and TEG. The use of such tests to guide haemostatic therapy may help reduce transfusion of allogeneic blood products in bleeding patients and is supported in European guidelines for managing trauma and severe perioperative bleeding. In addition, viscoelastic tests form the basis of numerous published treatment algorithms. However, some publications have stated that viscoelastic tests are not validated. A specific definition of the term validation is lacking and regulatory requirements of the US Food and Drug Administration (FDA) and European Medicines Agency (EMA) have been fulfilled by ROTEM and TEG assays. Viscoelastic tests have been used in pivotal clinical trials, and they are approved for use in most of the world's countries. Provided that locally approved indications are adhered to, the regulatory framework for clinicians to use viscoelastic tests in routine clinical practice is in place.

Reducing transfusion requirements in liver transplantation

Liver transplantation (LT) was historically associated with massive blood loss and transfusion. Over the past two decades transfusion requirements have reduced dramatically and increasingly transfusion-free transplantation is a reality. Both bleeding and transfusion are associated with adverse outcomes in LT. Minimising bleeding and reducing unnecessary transfusions are therefore key goals in the perioperative period. As the understanding of the causes of bleeding has evolved so too have techniques to minimize or reduce the impact of blood loss. Surgical “piggyback” techniques, anaesthetic low central venous pressure and haemodilution strategies and the use of autologous cell salvage, point of care monitoring and targeted correction of coagulopathy, particularly through use of factor concentrates, have all contributed to declining reliance on allogenic blood products. Pre-emptive management of preoperative anaemia and adoption of more restrictive transfusion thresholds is increasingly common as patient blood management (PBM) gains momentum. Despite progress, increasing use of marginal grafts and transplantation of sicker recipients will continue to present new challenges in bleeding and transfusion management. Variation in practice across different centres and within the literature demonstrates the current lack of clear transfusion guidance. In this article we summarise the causes and predictors of bleeding and present the evidence for a variety of PBM strategies in LT.