Assessment of standard laboratory tests and rotational thromboelastometry for the prediction of postoperative bleeding in liver transplantation

Low factor XIII levels and altered fibrinolysis in patients with multiple myeloma

BACKGROUND

Acquired factor FXIII (FXIII) deficiency can be immune- or non-immune mediated and may cause severe bleeding symptoms. The incidence of acquired FXIII deficiency and its etiology in patients with multiple myeloma (MM) are poorly understood.

OBJECTIVES

To assess FXIII levels and the balance of fibrinolysis in newly diagnosed, untreated MM and monoclonal gammopathy of undetermined significance (MGUS) patients.

METHODS

FXIII activity, mixing studies, FXIII-A2B2 antigen, total FXIII-B antigen were measured in platelet-poor plasma from 17 untreated MM patients, 33 untreated MGUS patients, and 30 age and sex-matched healthy controls. Besides routine laboratory measurements, the balance of coagulation and fibrinolysis was evaluated using quantitative fibrin monomer (FM) test, thrombin-antithrombin assay, α2-antiplasmin activity, plasmin-α2-antiplasmin (PAP) complex, D-dimer, plasmin generation assay, clot lysis assay, and ClotPro-TPA test.

RESULTS

FXIII-A2B2 levels were significantly lower in MM patients compared to controls [median (IQR):14.6 (11.2-19.4) vs. 21.8 (17.1-26.4) mg/L, p = 0.0015], whereas total FXIII-B did not differ between groups. Decrease in FXIII activity was parallel to the decrease in FXIII-A2B2. An immune-mediated inhibitory mechanism was ruled out. Free/total FXIII-B was significantly higher in MM patients compared to MGUS and healthy controls, suggesting an etiology of FXIII-A consumption. In MM and MGUS patients, FM, D-dimer, and PAP complex were significantly elevated compared to controls, indicating hypercoagulability and ongoing fibrinolysis.

CONCLUSIONS

Low FXIII levels due to consumption were observed in MM patients at diagnosis. Hypercoagulability and ongoing fibrinolysis were detected in MM and MGUS, indicating that a disturbed hemostasis balance is already present in the latter benign condition.

Exploration of rotational thromboelastometry (ROTEM) to characterize the coagulation profiles of newly diagnosed pediatric leukemia patients

BACKGROUND

Viscoelastic testing has been used in adult hematologic malignancies in conjunction with conventional coagulation tests (CCTs) to predict coagulopathies and tailor blood product replacement. However, there is a paucity of similar pediatric studies.

OBJECTIVES

Analyze and correlate leukemia-associated coagulopathy in newly diagnosed pediatric leukemia patients using CCT's and Rotational Thromboelastometry (ROTEM).

METHODS

Pediatric patients with newly diagnosed acute leukemia underwent testing with ROTEM and CCTs on days 0, 15 and 29 of induction chemotherapy.

RESULTS

Sixty-two patients were enrolled. At presentation, 54.8 % of patients had platelets <50 K/μL, 73 % had prolonged PT, 1.6 % had fibrinogen <150 mg/dL. Fifteen patients (24.2 %) had WHO grade 1 bleeding and two patients (3 %) had WHO grade 4 bleeding. EXTEM/INTEM values at presentation (day 0) reflected hypocoagulability, however FIBTEM revealed hypercoagulability. Patients showed a progressive hypocoagulability in all ROTEM assays by day 15 (day 0 vs day 15, p < 0.001), with improvement by day 29 (day 15 vs day 29, p < 0.001). Day 0 ROTEM parameters were comparable to day 29. Fibrinogen strongly correlated with ROTEM at all three time points (p < 0.0001), along with platelet count with moderate correlations (p < 0.001).

CONCLUSION

Fibrinogen and platelets appear to be the drivers of leukemia associated coagulopathy in the pediatric population, suggesting the utility of using CCTs and ROTEM in this population to better evaluate hemostatic function and guide blood product replacement.

Bleeding management: rFVIIIFc in hemophilia A and liver transplantation

BACKGROUND

In patients with severe hemophilia A prolonged bleeding may occur even in cases of minor trauma or surgery.

OBJECTIVE

To investigate the feasibility and efficacy of a recombinant extended half-life (EHL) FVIII concentrate for perioperative bleeding management in a patient with severe hemophilia A undergoing liver transplantation.

MATERIAL AND METHODS

Prior to transplantation FVIII activity and perioperatively required FVIII supply were estimated. In an individualized approach efmoroctocog alfa was supplemented if the intrinsic clotting time in the thrombelastometry was > 170 s.

RESULTS

The patient perioperatively received a total of 28,000 IU efmoroctocog alfa. No signs of hemorrhage or complications were detected and no further intervention was necessary.

CONCLUSION

The present case demonstrates that the use of an EHL FVIII is suitable for a successful perioperative bleeding control even in hemophilia patients at a high bleeding risk during major surgery. Due to the EHL constant FVIII levels could be achieved with relatively few injections. In order to confirm the obtained results, more real-world data in different operative settings are essential. Further research is needed on the use of thrombelastometry to guide substitution of factor VIII perioperatively.

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.

Development and validation of a prediction tool for intraoperative blood transfusion in brain tumor resection surgery: a retrospective analysis

Early identification of a patient with a high risk of blood transfusion during brain tumor resection surgery is difficult but critical for implementing preoperative blood-saving strategies. This study aims to develop and validate a machine learning prediction tool for intraoperative blood transfusion in brain tumor resection surgery. A total of 541 patients who underwent brain tumor resection surgery in our hospital from January 2019 to December 2021 were retrospectively enrolled in this study. We incorporated demographics, preoperative comorbidities, and laboratory risk factors. Features were selected using the least absolute shrinkage and selection operator (LASSO). Eight machine learning algorithms were benchmarked to identify the best model to predict intraoperative blood transfusion. The prediction tool was established based on the best algorithm and evaluated with discriminative ability. The data were randomly split into training and test groups at a ratio of 7:3. LASSO identified seven preoperative relevant factors in the training group: hemoglobin, diameter, prothrombin time, white blood cell count (WBC), age, physical status of the American Society of Anesthesiologists (ASA) classification, and heart function. Logistic regression, linear discriminant analysis, supporter vector machine, and ranger all performed better in the eight machine learning algorithms with classification errors of 0.185, 0.193, 0.199, and 0.196, respectively. A nomogram was then established, and the model showed a better discrimination ability [0.817, 95% CI (0.739, 0.895)] than hemoglobin [0.663, 95% CI (0.557, 0.770)] alone in the test group (P = 0.000). Hemoglobin, diameter, prothrombin time, WBC, age, ASA status, and heart function are risk factors of intraoperative blood transfusion in brain tumor resection surgery. The prediction tool established using the logistic regression algorithm showed a good discriminative ability than hemoglobin alone for predicting intraoperative blood transfusion in brain tumor resection surgery.

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.

Patient Blood Management in Liver Transplant—A Concise Review

Transfusion of blood products in orthotopic liver transplantation (OLT) significantly increases post-transplant morbidity and mortality and is associated with reduced graft survival. Based on these results, an active effort to prevent and minimize blood transfusion is required. Patient blood management is a revolutionary approach defined as a patient-centered, systematic, evidence-based approach to improve patient outcomes by managing and preserving a patient’s own blood while promoting patient safety and empowerment. This approach is based on three pillars of treatment: (1) detecting and correcting anemia and thrombocytopenia, (2) minimizing iatrogenic blood loss, detecting, and correcting coagulopathy, and (3) harnessing and increasing anemia tolerance. This review emphasizes the importance of the three-pillar nine-field matrix of patient blood management to improve patient outcomes in liver transplant recipients.

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.

Preoperative Fibrinogen Level and Bleeding in Liver Transplantation for End-stage Liver Disease: A Cohort Study

BACKGROUND

Liver transplantation is a high-risk surgery associated with important perioperative bleeding and transfusion needs. Uncertainties remain on the association between preoperative fibrinogen level and bleeding in this population.

METHODS

We conducted a cohort study that included all consecutive adult patients undergoing a liver transplantation for end-stage liver disease in 1 center. We analyzed the association between the preoperative fibrinogen level and bleeding-related outcomes. Our primary outcome was intraoperative blood loss, and our secondary outcomes were estimated perioperative blood loss, intraoperative and perioperative red blood cell transfusions, reinterventions for bleeding and 1-y graft and patient survival. We estimated linear regression models and marginal risk models adjusted for all important potential confounders. We used restricted cubic splines to explore potential nonlinear associations and reported dose-response curves.

RESULTS

We included 613 patients. We observed that a lower fibrinogen level was associated with a higher intraoperative blood loss, a higher estimated perioperative blood loss and a higher risk of intraoperative and perioperative red blood cell transfusions (nonlinear effects). Based on an exploratory analysis of the dose-response curves, these effects were observed below a threshold value of 3 g/L for these outcomes. We did not observe any association between preoperative fibrinogen level and reinterventions, 1-y graft survival or 1-y patient survival.

CONCLUSIONS

This study suggests that a lower fibrinogen level is associated with bleeding in liver transplantation. The present results may help improving the selection of patients for further studies on preoperative fibrinogen administration in liver transplant recipients with end-stage liver disease.

Rotational Thromboelastometry Predicts Transfusion Requirements in Total Joint Arthroplasties

The frequency of red blood cell (RBC) transfusions is high in total joint arthroplasties, and the hemorrhagic risk is associated with both surgery- and patient-related factors. This study aims to assess the ability of rotational thromboelastometry (ROTEM) to identify patients at high risk for transfusion and excessive bleeding. A prospective observational study was conducted including 206 patients who underwent total knee or hip arthroplasties. Assessment of the coagulation status was performed preoperatively and immediately postoperatively using ROTEM analysis and conventional coagulation tests. The number of RBC transfusions and the postoperative hemoglobin drop were recorded. ROTEM findings were compared between transfused and nontransfused patients, and also between patients with and without excessive bleeding. Higher values of postoperative FIBTEM maximum clot firmness (MCF) were associated with lower risks of transfusion (odds ration [OR]: 0.66, 95% confidence interval [CI]: 0.57-0.78, p<0.001) and excessive bleeding (OR: 0.58, 95% CI: 0.36-0.94, p=0.028). A postoperative FIBTEM MCF value ≤10mm had 80.1% (95% CI: 73.1-85.9%) sensitivity with 75.5% (95% CI: 60.4-87.1%) specificity to predict transfusion requirements, and 70.5% (95% CI: 63.6-76.8%) sensitivity with 88.8% (95% CI: 51.7-99.7%) specificity to predict excessive bleeding. The estimated average probability of transfusion in patients with FIBTEM MCF values of 0 to 4mm is 86.3%. ROTEM assay demonstrated high predictive ability for transfusion and excessive bleeding. Identification of patients at risk for transfusion could allow blood banks to ensure adequate blood supply, while also more intense blood-salvaging strategies could be implemented in these patients.

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.

Is ROTEM Diagnostic in Trauma Care Associated with Lower Mortality Rates in Bleeding Patients?—A Retrospective Analysis of 7461 Patients Derived from the TraumaRegister DGU®

Introduction: Death from uncontrolled trauma haemorrhage and subsequent trauma-induced coagulopathy (TIC) is potentially preventable. Point-of-care devices such as rotational thromboelastometry (ROTEM^®) are advocated to detect haemostatic derangements more rapidly than conventional laboratory diagnostics. Regarding reductions in RBC transfusion, the use of ROTEM has been described as being efficient and associated with positive outcomes in several studies. Objective: The effect of ROTEM use was assessed on three different outcome variables: (i) administration of haemostatics, (ii) rate of RBC transfusions and (iii) mortality in severely injured patients. Methods and Material: A retrospective analysis of a large data set of severely injured patients collected into the TraumaRegister DGU^® between 2009 and 2016 was conducted. The data of 7461 patients corresponded to the inclusion criteria and were subdivided into ROTEM-using and ROTEM-non-using groups. Both groups were analysed regarding (i) administration of haemostatics, (ii) rate of RBC transfusions and (iii) mortality. Results: A lower mortality rate in ROTEM-using groups was observed (p = 0.043). Furthermore, more patients received haemostatic medication when ROTEM was used. In ROTEM-using groups, there was a statistically relevant higher application of massive transfusion. Conclusions: In this retrospective study, the use of ROTEM was associated with reduced mortality and an increased application of haemostatics and RBC transfusions. Prospective evidence is needed for further evidence-based recommendations.

Role of Viscoelastic and Conventional Coagulation Tests for Management of Blood Product Replacement in the Bleeding Patient

An important aim of viscoelastic testing (VET) is to implement transfusion algorithms based on coagulation test results to help reduce transfusion rates and improve patient outcomes. Establishing a rapid diagnosis and providing timely treatment of coagulopathy is the cornerstone of management of severely bleeding patients in trauma, postpartum hemorrhage, and major surgery. As the nature of acute bleeding and trauma leads to an unstable and tenuous physiologic state, conventional coagulation tests (CCTs) are too slow to diagnose, manage, and also course correct any hemostatic abnormalities that accompany an acute critical illness. Viscoelastic point-of-care tests strongly correlate with results from standard laboratory tests but are designed to enable clinicians to make timely, informed bleeding management decisions when time to intervene is critical. These assays provide an individualized and goal-oriented approach to patient blood management and are increasingly becoming involved in transfusion algorithms. The scope of this review aims to evaluate the current literature on VETs and their impact on actionable outputs in clinical decision making and their relationship to CCT.

Plasma Transfusion in Septic Shock—A Secondary Analysis of a Retrospective Single-Center Cohort

In sepsis, both beneficial and detrimental effects of fresh frozen plasma (FFP) transfusion have been reported. The aim of this study was to analyze the indication for and effect of FFP transfusion in patients with septic shock. We performed a secondary analysis of a retrospective single-center cohort of all patients treated for septic shock at the interdisciplinary surgical intensive care unit (ICU) of the Heidelberg University Hospital. Septic shock was defined according to sepsis-3 criteria. To assess the effects of FFP administration in the early phase of septic shock, we compared patients with and without FFP transfusion during the first 48 h of septic shock. Patients who died during the first 48 h of septic shock were excluded from the analysis. Primary endpoints were 30- and 90-day mortality. A total of 261 patients were identified, of which 100 (38.3%) received FFP transfusion within the first 48 h after septic shock onset. The unmatched analysis showed a trend toward higher 30- and 90-d mortality in the FFP group (30 d: +7% p = 0.261; 90 d: +11.9% p = 0.061). In the propensity-matched analysis, 30- and 90-day mortality were similar between groups. Plasma administration did not influence fluid or vasopressor need, lactate levels, ICU stay, or days on a ventilator. We found no significant harm or associated benefit of FFP use in the early phase of septic shock. Finally, plasma should only be used in patients with a strong indication according to current recommendations, as a conclusive evaluation of the risk-benefit ratio for plasma transfusion in septic shock cannot be made based on the current data.

The Edge of Unknown: Postoperative Critical Care in Liver Transplantation

Perioperative care of patients undergoing liver transplantation (LT) is very complex. Metabolic derangements, hypothermia, coagulopathy and thromboses, severe infections, and graft dysfunction can affect outcomes. In this manuscript, we discuss several perioperative problems that can be encountered in LT recipients. The authors present the most up-to-date information regarding predicting and treating hemodynamic instability, coagulation monitoring and management, postoperative ventilation strategies and early extubation, management of infections, and ESLD-related pulmonary complications. In addition, early post-transplant allograft dysfunction will be discussed.

Application of Rotational Thromboelastometry in Patients with Acute Promyelocytic Leukemia

Introduction

Hemorrhagic early death (HED) remains a major cause of treatment failure among patients with acute promyelocytic leukemia (APL). We aimed to investigate the prognostic potential of rotational thromboelastometry (ROTEM) for bleeding in patients with APL.

Materials and Methods

31 newly-diagnosed APL patients (median age of 40 years; 14 female/17 male) that underwent treatment at the Clinic of Hematology UCCS from 2016-2020 with all-trans retinoic acid and anthracyclines were recruited. CBCs (complete blood count), conventional coagulation tests (CCTs), and ROTEM parameters obtained before treatment initiation were evaluated.

Results

All patients demonstrated at least one ROTEM parameter out of the reference range. ROTEM parameters associated with significant hemorrhage were EXTEM clotting time (CT) (P = 0.041) and INTEM amplitude 10 (A10) (P = 0.039), however, only EXTEM CT (P = 0.036) was associated with HED. Among CBCs and CCTs, only platelets were associated with significant bleeding (P = 0.015), while D-dimer was associated with both bleeding and HED (P = 0.001 and P = 0.002, respectively).

Conclusion

Our results indicate that ROTEM parameters may reveal hypocoagulability in APL patients and have the potential to improve current hemorrhage prognostic methods. Additionally, these results suggest the combination of ROTEM and CCTs might be useful in identifying patients at risk for HED.

The Prognostic Performance of Rotational Thromboelastometry for Excessive Bleeding and Increased Transfusion Requirements in Hip Fracture Surgeries

BACKGROUND

 Hip fracture surgeries are associated with considerable blood loss, while the perioperative coagulopathy is associated with the bleeding risk of these patients. We aimed to evaluate the ability of rotational thromboelastometry (ROTEM) to detect patients at high risk for excessive bleeding and increased transfusion requirements.

METHODS

 We conducted a prospective observational study of 221 patients who underwent hip fracture surgeries. ROTEM analysis was performed preoperatively and immediately postoperatively. Blood loss parameters including blood loss volume, number of transfused red blood cell (RBC) units, and drop in hemoglobin levels were recorded. ROTEM parameters were compared between patients with and without excessive bleeding, and between patients with and without increased transfusion requirements (i.e., ≥2 RBC units).

RESULTS

 The postoperative FIBTEM MCF value ≤15 mm had 66.6% (95% confidence interval [CI]: 59.7-74.1%) sensitivity and 92.0% (95% CI: 80.7-97.7%) specificity to prognose excessive bleeding, and preoperative FIBTEM MCF value ≤15 mm had 80.4% (95% CI: 73.5-86.2%) sensitivity and 91.2% (95% CI: 80.7-97.0%) specificity to prognose increased transfusion requirements. Preoperative FIBTEM MCF ≤11 mm and postoperative FIBTEM MCF ≤15 mm were associated with considerably increased risks of excessive bleeding (odds ratio [OR]: 44.8, 95% CI: 16.5-121.3, p < 0.001; and OR: 23.0, 95% CI: 7.8-67.0, p < 0.001, respectively).

CONCLUSION

 ROTEM parameters demonstrated high prognostic accuracy for excessive bleeding and increased transfusion requirements. This can enable implementation of blood sparing strategies in high-risk patients, while blood banks could be better prepared to ensure adequate blood supply.

Perioperative Viscoelastic Assay Use for Monitoring Coagulation Among US Liver Transplantation Centers

BACKGROUND

Viscoelastic assay has been used in liver transplantation since 1985 and shown to be beneficial in detecting coagulopathy and to guide transfusion. The objective of this study was to review and evaluate the current uses of viscoelastic assay among US liver transplantation programs.

METHODS

Anesthesia program directors at all 137 liver transplantation centers in the United States were contacted via email and asked to complete a 21-item survey. The primary outcome measure was the percentage of viscoelastic assay used in the perioperative management of liver transplantation. Secondary outcome measures were institutional demographics, physician training level, and device demographics.

RESULTS

Sixty-one of 137 (46%) centers responded. Liver transplantations were performed in the university setting at 48 of the 61 centers (77%), with a modal value of 11 to 50 liver transplantations a year and 74% in adult patients only. Most of the institutions (n = 57, 92%) had access to either rotational thromboelastometry or thrombelastography during liver transplantation. Most centers (n = 54; 87%) also used viscoelastic monitoring routinely (>60% of the time), including 42 (67.7%) that always used viscoelastic assay intraoperatively during liver transplantation. Thirty-five centers (59%) used it preoperatively, and 51 (84%) used it postoperatively. Most viscoelastic assay users (68%) learned how to use it through self-education and 10.5% learned during their fellowship or from a superuser or colleagues.

CONCLUSION

Currently, viscoelastic monitoring is widely available and routinely used in most US liver transplantation centers regardless of university or private practice setting, but training in it is limited. Only 21.1% of respondents reported that they received any type of official training in viscoelastic assay interpretation.

Using Rotational Thromboelastometry to Identify Early Allograft Dysfunction after Living Donor Liver Transplantation

Background: Diagnostic tests for early allograft dysfunction (EAD) after living donor liver transplantation (LDLT) vary widely. We aimed to evaluate the predictive value of rotational thromboelastometry (ROTEM)-derived parameters in EAD. Materials and Methods: A total of 121 patients were reviewed. The definition of EAD proposed by Olthoff et al. included the presence of any of the following at postoperative day 7: bilirubin level ≥ 10 mg/dL, INR ≥ 1.6, or serum AST or ALT levels > 2000 IU/L. All patients underwent ROTEM assay, which consisted of an extrinsically activated thromboelastometric test (EXTEM) before and 24 h after LDLT. Results: The 1-year/2-year OS were 68.%8/64.5% and 94.4%/90.8% for the EAD and non-EAD groups, respectively (p = 0.001). Two independent risks were identified for EAD, the postoperative clotting time (CT, p = 0.026) and time to maximum clot firmness (maximum clot firmness (MCF)-t, p = 0.009) on the EXTEM. CT yielded a specificity of 82.0% and negative predictive value of 83.0%, and MCF-t displayed a specificity of 76.4% and negative predictive value of 81.9% in diagnosing EAD. The use of the 24 h post-LDLT ROTEM increased the effectiveness of predicting overall survival (OS) compared to using the Olthoff’s EAD criteria alone (p < 0.001). Conclusion: We conclude that CT and MCF on EXTEM were independent predictors of EAD. The 24 h post-LDLT ROTEM can be used with conventional laboratory tests to diagnose EAD. It increases the effectiveness of predicting OS.

Intensive care management of acute-on-chronic liver failure

The syndrome of acute-on-chronic liver failure combines deterioration of liver function in a patient with chronic liver disease, with the development of extrahepatic organ failure and high short-term mortality. Its successful management demands a rapid and coherent response to the development of dysfunction and failure of multiple organ systems in an intensive care unit setting. This response recognises the features that distinguish it from other critical illness and addresses the complex interplay between the precipitating insult, the many organ systems involved and the disordered physiology of underlying chronic liver disease. An evidence base is building to support the approaches currently adopted and outcomes for patients with this condition are improving, but mortality remains unacceptably high. Herein, we review practical considerations in critical care management, as well as discussing key knowledge gaps and areas of controversy that require further focussed research.

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.

Massive Hemorrhage: The Role of Whole Blood Viscoelastic Assays

Viscoelastic whole blood tests are increasingly used to guide hemostatic therapy in bleeding patients in the perioperative, trauma, and obstetric settings. Compared with standard laboratory tests of hemostasis, they have a shorter turnaround time and provide simultaneous information on various aspects of clot formation and lysis. The two available brands TEG (thromboelastography) and ROTEM (rotational thromboelastometry) provide devices that are either manually operated or fully automated. The automation allows for the assays to be used as point-of-care tests increasing their usefulness in massively bleeding patients with rapidly changing hemostatic profiles. While the number of research papers on the subject and the number of published treatment algorithms increase rapidly, the influence of the use of these devices on patient outcome needs yet to be established. In this article, we first review the technology of these devices and the parameters provided by the assays. Next, we present the problems encountered when choosing cut-off values that trigger intervention. Furthermore, we discuss the studies examining their influence on clinical outcomes, and finally, we briefly highlight some of the most important limitations and pitfalls inherent to these assays.

Clinical and pathophysiologic aspects of ECMO-associated hemorrhagic complications

Extracorporeal membrane oxygenation (ECMO) is increasingly used to treat severe cases of acute respiratory or cardiac failure. Hemorrhagic complications represent one of the most common complications during ECMO, and can be life threatening. The purpose of this study was to elucidate pathophysiological mechanisms of ECMO-associated hemorrhagic complications and their impact on standard and viscoelastic coagulation tests. The study cohort included 27 patients treated with VV-ECMO or VA-ECMO. Hemostasis was evaluated using standard coagulation tests and viscoelastic parameters investigated with rotational thromboelastometry. Anticoagulation and hemorrhagic complications were analyzed for up to seven days depending on ECMO duration. Hemorrhagic complications developed in 16 (59%) patients. There were 102 discrete hemorrhagic episodes among 116 24-hour-intervals, of which 27% were considered to be clinically significant. The highest number of ECMO-associated hemorrhages occurred on the 2^nd and 3^rd day of treatment. Respiratory tract bleeding was the most common hemorrhagic complication, occurring in 62% of the 24-hour intervals. All 24-hours-intervals were divided into two groups: “with bleeding” and “without bleeding”. The probability of hemorrhage was significantly associated with abnormalities of four parameters: increased international normalized ratio (INR, sensitivity 71%, specificity 94%), increased prothrombin time (PT, sensitivity 90%, specificity 72%), decreased intrinsic pathway maximal clot firmness (MCFin, sensitivity 76%, specificity 89%), and increased extrinsic pathway clot formation time (CFTex, sensitivity 77%, specificity 87%). In conclusions, early ECMO-associated hemorrhagic complications are related to one traditional and two novel viscoelastic coagulation abnormalities: PT/INR elevation, reduced maximum clot firmness due to intrinsic pathway dysfunction (MCFin), and prolonged clot formation time due to extrinsic pathway dysfunction (CFTex). When managing hemostasis during ECMO, derangements in PT/INR, MCFin and CFT_ex should be focused on.

Association between intraoperative rotational thromboelastometry or conventional coagulation tests and bleeding in liver transplantation: an observational exploratory study

INTRODUCTION

Liver transplantation is associated with major blood loss and transfusions. Our objective was to evaluate the association between coagulation results (rotational thromboelastometry (ROTEM) and conventional coagulation tests) and intraoperative bleeding or perioperative red blood cell (RBC) transfusions in liver transplantation.

METHODS

We measured ROTEM values and conventional coagulation tests at the beginning of surgery, after graft reperfusion and at the end of surgery. We did bivariate correlation and multivariable regression analyses to explore the association between test results and either intraoperative bleeding or perioperative RBC transfusions.

RESULTS

We enrolled 75 consecutive patients. Median [Q1-Q3] intraoperative blood loss was 1400 mL [675-2300] and 59% of patients did not receive any RBC transfusion either intraoperatively or postoperatively. In multivariable analyses, FIBTEM maximal clot firmness (MCF) measured at the beginning of surgery was associated with lower intraoperative blood loss (ß = -106 mL for each mm; 95% CI, -203 to -9 mL). Both a higher haemoglobin concentration (multiplicative factor = 0.89 for each g/L; 95% CI, 0.84 to 0.95) and FIBTEM MCF measured at the end of surgery (multiplicative factor = 0.68 for each mm; 95% CI, 0.48 to 0.95) were associated with fewer postoperative RBC transfusions.

CONCLUSION

FIBTEM MCF was strongly associated with intraoperative blood loss and postoperative transfusions while other coagulation results were not. This study might inform future clinical trials on ROTEM-based interventions in liver transplantation.

STUDY REGISTRATION

Clinical Trials.gov: NCT02356068.

Plasma Transfusion Practice in Adult Surgical Patients: Systematic Review of the Literature

Background

Plasma transfusions are most commonly used therapeutically for bleeding or prophylactically in non-bleeding patients prior to invasive procedures or surgery. Although plasma transfusions generally seem to decline, plasma usage for indications that lack evidence of efficacy prevail.

Summary

There is wide international, interinstitutional, and interindividual variance regarding the compliance with guidelines based on published references, supported by appropriate testing. There is furthermore a profound lack of evidence from randomized controlled trials comparing the effect of plasma transfusion with that of other therapeutic interventions for most indications, including massive bleeding. The expected benefit of a plasma transfusion needs to be balanced carefully against the associated risk of adverse events. In light of the heterogeneous nature of bleeding conditions and their rapid evolvement over time, fibrinogen and factor concentrate therapy, directed at specific phases of coagulation identified by alternative laboratory assays, may offer advantages over conventional blood product ratio-driven resuscitation. However, their outcome benefit has not been demonstrated in well-powered prospective trials. This systematic review will detail the current evidence base for plasma transfusion in adult surgical patients.

Viscoelastic Tests as Point-of-Care Tests in the Assessment and Management of Bleeding and Thrombosis in Liver Disease

Viscoelastic point-of-care (VET POC) tests provide a global assessment of hemostasis and have an increasing role in the management of bleeding and blood component delivery across several clinical settings. VET POC tests have a rapid turnaround time, provide a better overall picture of hemostasis, predict bleeding more accurately than conventional coagulation tests, and reduce blood component usage and health care costs. Despite commonly having abnormal conventional coagulation tests, most patients with chronic liver disease have a "rebalanced" hemostasis. However, this hemostatic balance is delicate and these patients are predisposed to both bleeding and thromboembolic events. Over recent years, VET POC tests have been increasingly studied for their potential as better functional tests of hemostasis in liver disease patients. This review provides a background on the most common VET POC tests (thromboelastography and rotational thromboelastometry) and discusses the current evidence for these tests in the prediction and management of bleeding and thrombosis in patients with chronic liver disease, and in liver resection and transplant. With the recent publication of several randomized controlled trials, there is growing evidence that VET POC tests may be used to improve bleeding risk assessment and reduce blood product use in liver disease patients outside of the transplant setting. However, consensus is still lacking regarding the VET POC tests' thresholds that should be used to trigger blood product transfusion. VET POC tests also show promise in predicting thrombosis in patients with liver disease, but further research is needed before they can be used to guide anticoagulant therapy.

Current perspective on fibrinogen concentrate in critical bleeding

INTRODUCTION

. Massive hemorrhage continues to be a treatable cause of death. Its management varies from prefixed ratio-driven administration of blood components to goal-directed therapy based on point-of-care testing and administration of coagulation factor concentrates.

AREAS COVERED

. We review the current role of fibrinogen concentrate (FC) for the management of massive hemorrhage, either administered without coagulation testing in life-threatening hemorrhage, or within an algorithm based on viscoelastic hemostatic assays and plasma fibrinogen level. We identified relevant guidelines, meta-analyzes, randomized controlled trials, and observational studies that included indications, dosage, and adverse effects of FC, especially thromboembolic events.

EXPERT OPINION

. Moderate- to high-grade evidence supports the use of FC for the treatment of severe hemorrhage in trauma and cardiac surgery; a lower grade of evidence is available for its use in postpartum hemorrhage and end-stage liver disease. Pre-emptive FC administration in non-bleeding patients is not recommended. FC should be administered early, in a goal-directed manner, guided by early amplitude of clot firmness parameters (A5- or A10-FIBTEM) or hypofibrinogenemia. Further investigation is required into the early use of FC, as well as its potential advantages over cryoprecipitate, and whether or not its administration at high doses leads to a greater risk of adverse events.

High D dimers and low global fibrinolysis coexist in COVID19 patients: what is going on in there?

BACKGROUD

COVID-19 coagulopathy linked to increased D-dimer levels has been associated with high mortality (Fei Z et al. in Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. Lancet (London, England) 395(10229):1054-62, 2020). While D-dimer is accepted as a disseminated intravascular coagulation marker, rotational thromboelastometry (ROTEM) also detects fibrinolysis (Wright FL et al. in Fibrinolysis shutdown correlates to thromboembolic events in severe COVID-19 infection. J Am Coll Surg (2020). Available from https://pubmed.ncbi.nlm.nih.gov/32422349/ [cited 14 Jun 2020]; Schmitt FCF et al. in Acute fibrinolysis shutdown occurs early in septic shock and is associated with increased morbidity and mortality: results of an observational pilot study. Ann Intensive Care 9(1):19, 2019). We describe the ROTEM profile in severely ill COVID-19 patients and compare it with the standard laboratory coagulation test.

METHODS

Adult patients diagnosed with COVID-19 admitted to the ICU were prospectively enrolled after Ethics Committee approval (HCB/2020/0371). All patients received venous thromboembolism prophylaxis; those on therapeutic anticoagulation were excluded. The standard laboratory coagulation test and ROTEM were performed simultaneously at 24-48 h after ICU admission. Sequential organ failure assessment (SOFA), disseminated intravascular coagulation (DIC) and sepsis-induced coagulopathy (SIC) scores were calculated at sample collection.

RESULTS

Nineteen patients were included with median SOFA-score of 4 (2-6), DIC-score of 1 (0-3) and SIC-score of 1.8 (0.9). Median fibrinogen, D-dimer levels and platelet count were 6.2 (4.8-7.6 g/L), 1000 (600-4200 ng/ml) and 236 (136-364 10⁹/L), respectively. Clot firmness was above the normal range in the EXTEM and FIBTEM tests while clot lysis was decreased. There was no significant correlation between ROTEM or D-dimer parameters and the SOFA score.

CONCLUSION

In COVID-19 patients, the ROTEM pattern was characterized by a hypercoagulable state with decreased fibrinolytic capacity despite a paradoxical increase in D-dimer levels. We suggest that, in COVID-19 patients, the lungs could be the main source of D-dimer, while a systemic hypofibrinolytic state coexists. This hypothesis should be confirmed by future studies.

How Much Is the Inevitable Loss of Different Coagulation Factors During Blood Product-Free Liver Transplantations?

BACKGROUND

Bloodless liver transplantations (LT) have already been reported, but special characteristics of hemostatic changes remain less defined. The aim of this study was to evaluate the "inevitable" loss of coagulation factors (CF) in blood product-free LT.

METHODS

Blood product and CF concentrate-free LT patient data were analyzed in terms of the first 2 days of perioperative hemostasis kinetics (N = 59). CF levels (FI, II, V, VII, X, and XIII), platelet (PLT) levels, and hemoglobin levels were measured before LT (T1), on arrival at the intensive care unit (T2), and 12, 24, and 48 hours after LT (T3, T4, and T5, respectively). Thromboelastographic (TEG) parameters were determined before and at the end of LT (T1-T2).

RESULTS

Fibrinogen levels decreased by 1.2 ± 0.6 g/L, prothrombin levels by 26% ± 14%, factor V levels by 40% ± 23%, VII levels by 29% ± 19%, and X levels by 39% ± 22% (P < .001). From T2 to T4 fibrinogen increased by 0.9 ± 0.6g/L for 24 hours (P < .001). Factor II, V, and VII levels increased by 20% ± 16%, 31% ± 32%, and 12% ± 27%, respectively, between T3 and T5 (P < .001). However, factor X reached only half of the T1 level (T3-T5, P < .001). Platelet count increased in 34 (58%) patients at T2 (P < .001). The TEG parameters remained in the normal range during LT (T1-T2).

CONCLUSION

The major findings of this study advocate that "inevitable" levels of CF decrease during LT by an average of 1.2 g/L in terms of fibrinogen and 23% to 40% regarding factors II, V, VII, and X. The authors suggest that knowing the "magic numbers" and comparing them against baseline laboratory results might predict the possibility of blood product-free transplant, providing confidence and safety to the surgeon and the anesthetist.

Thromboelastography and rotational thromboelastometry for the surgical intensivist: A narrative review

BACKGROUND

Viscoelastic tests (VETs), specifically thromboelastography (TEG) and rotational thromboelastometry (ROTEM), are gaining popularity in the management of critically ill surgical patients with hemorrhage or thrombosis due to their comprehensive characterization of the coagulation process and point-of-care availability in comparison to conventional coagulation tests (CCTs). We review current evidence for VET use in patients in the surgical intensive care unit (SICU).

METHODS

We searched PUBMED, EMBASE and the Cochrane Library through May 30, 2018 for articles that evaluated the use of VETs in patient populations and clinical scenarios germane to the surgical intensivist. Individual articles were critically evaluated for relevance and appropriate methodology using a structured technique. Information on patient characteristics, timing and methods of CCTs/VETs, and outcomes was collected and summarized in narrative form.

RESULTS

Of 2,589 identified articles, 36 were included. Five (14%) were interventional studies and 31 (86%) were observational. Twenty-five (69%) evaluated TEG, 11 (31%) ROTEM and 18 (50%) CCTs. Investigated outcomes included quantitative blood loss (13 (36%)), blood product transfusion (9 (25%)), thromboembolic events (9 (25%)) and mortality (6 (17%)). We identified 12 clinical scenarios with sufficient available evidence, much of which was of limited quantity and poor methodological quality. Nonetheless, research supports the use of VETs for guiding early blood product administration in severe traumatic hemorrhage and for the prediction of abstract excess bleeding following routine cardiac surgery. In contrast, evidence suggests VET-based heparin dosing strategies for venous thromboembolism prophylaxis are not superior to standard dosing in SICU patients.

CONCLUSION

While VETs have the potential to impact the care of critically ill surgical patients in many ways, current evidence for their use is limited, mainly because of poor methodological quality of most available studies. Further high-quality research, including several ongoing randomized controlled trials, is needed to elucidate the role of TEG/ROTEM in the SICU population.

LEVEL OF EVIDENCE

Systematic review, level IV.

Coagulation abnormalities, bleeding, thrombosis, and management of patients with acute liver failure in Australia and New Zealand

BACKGROUND AND AIM

To study the management of coagulation and hematological derangements among severe acute liver failure (ALF) patients in Australia and New Zealand liver transplant intensive care units (ICUs).

METHODS

Analysis of key baseline characteristics, etiology, coagulation and hematological tests, use of blood products, thrombotic complications, and clinical outcomes during the first ICU week.

RESULTS

We studied 62 ALF patients. The first day median peak international normalized ratio was 5.5 (inter-quartile range [IQR] 3.8-8.7), median longest activated partial thromboplastin time was 62 s (IQR 44-87), and median lowest fibrinogen was 1.1 (IQR 0.8-1.6) g/L. Fibrinogen was only measured in 85% of patients, which was less than other tests (P < 0.0001). Median initial lowest platelet count was 83 (IQR 41-122) × 10⁹ /L. Overall, 58% of patients received fresh frozen plasma, 40% cryoprecipitate, 35% platelets, and 15% prothrombin complex concentrate. Patients with bleeding complications (19%) had more severe overall hypofibrinogenemia and thrombocytopenia. Thrombotic complications were less common (10% of patients), were not associated with consistent patterns of abnormal hemostasis, and were not immediately preceded by clotting factor administration and half occurred only after liver transplantation surgery.

CONCLUSION

In ALF patients admitted to dedicated Australia and New Zealand ICUs, fibrinogen was measured less frequently than other coagulation parameters but, together with platelets, appeared more relevant to bleeding risk. Blood products and procoagulant factors were administered to most patients at variable levels of hemostatic derangement, and bleeding complications were more common than thrombotic complications. This epidemiologic information and practice variability provide baseline data for the design and powering of interventional studies.

Viscoelastic coagulation test for liver transplantation

Coagulation and transfusion management in patients undergoing liver transplantation is challenging. Proper perioperative monitoring of hemostasis is essential to predict the risk of bleeding during surgery, to detect potential causes of hemorrhage in time, and to guide hemostatic therapy. The value of conventional coagulation test is questionable in the acute perioperative setting due to their long turnaround time and the inability to adequately reflect the complex changes in hemostasis in patients with liver disease. Viscoelastic coagulation tests provide simultaneous measurement of multiple aspects of whole-blood coagulation including plasmatic coagulation and fibrinolytic factors and inhibitors that reflect most aspects of hemostasis. Coagulation initiation, mechanical clot stability, and fibrinolysis can be estimated immediately using point-of-care techniques. Therefore, viscoelastic coagulation tests including ROTEM & TEG would be useful to guide patient blood management strategy during liver transplantation.

Assessment and management of coagulopathy in critically-ill patients with liver failure

PURPOSE OF REVIEW

This review provides insight into our current understanding of the pathophysiology and treatment of coagulopathy associated with liver failure, and bleeding risk assessment.

RECENT FINDINGS

Patients with end-stage liver disease (ESLD) have a rebalanced coagulation profile and are at risk for both excessive clotting and bleeding. Hypercoagulability is associated with profound endothelial dysfunction and an increased concentration of liver-independent coagulation factors. Because of this rebalanced coagulation profile, standard laboratory tests have been demonstrated to be ineffective in either predicting and/or guiding the management of coagulopathy. Viscoelastic testing, however, is able to provide a dynamic assessment of clot formation in whole blood and has been demonstrated to be invaluable in both monitoring and management of coagulation problems associated with liver failure. More recently, there is increasing interest in thrombin generation tests to monitor coagulation in patients with ESLD.Multiple institutional protocols for prophylaxis and treatment of ESLD-related thromboses have been developed. High-quality studies evaluating these approaches are lacking.

SUMMARY

Patients with ESLD are at risk for excessive bleeding and clotting. Treatment of any significant coagulopathy should not be based solely on standard laboratory tests. Thrombosis prophylaxis has to be considered in susceptible populations.

Relationship of thromboelastography and conventional clotting test values with severe bleeding in critically ill patients with coagulopathy: A prospective study

INTRODUCTION

This study aimed to ascertain the associations of thromboelastography (TEG^® ) and standard laboratory test (SLTs) values with the presence of bleeding in critically ill patients with known coagulopathy.

METHODS

Three groups of coagulopathic patients with (a) hepatic failure, (b) postoperative period after prolonged cardiac surgery, and (c) complex abdominal surgery with sepsis were prospectively included in this study. On intensive care unit (ICU) admission, patients were stratified into two groups according to whether they had major bleeding (MB) (evident overt bleeding, important bleeding apparent on imaging studies, and/or need for moderate-massive blood transfusion and hemodynamic instability). Blood samples were drawn for the SLTs (international normalized ratio [INR], activated partial thromboplastin time [aPTT], platelet count, and fibrinogen level [Clauss]) and TEG whole blood coagulation assays. Receiver operating characteristic (ROC) curves were generated to determine the efficiency of TEG and SLTs for detecting bleeding. The correlations between SLTs and TEG parameters with similar coagulation profiles were evaluated by Spearman rank-order analysis.

RESULTS

Eighty-three patients were included, and bleeding was confirmed in 45 (54%). The fibrinogen level demonstrated the best accuracy for detecting bleeding with an area under the curve and 95% confidence intervals [AUC (95% CI)] of 0.74 (0.63-0.85) with the best cutoff value of ≤ 2 g/L. Regarding TEG-MA, the AUC (CI) obtained with the optimal cutoff value of ≤ 51 mm was 0.68 (0.56-0.80).

CONCLUSIONS

Both conventional clotting tests and TEG values were poorly associated with bleeding in this critically ill cohort of patients with coagulopathy.

Efficacy of IgM-enriched Immunoglobulin for Vasopressor-resistant Vasoplegic Shock After Liver Transplantation

BACKGROUND

Vasoplegia is a clinical condition typically manifested by cardiovascular instability unresponsive to the usual doses of inotropes or vasopressors. It can occur in a variety of clinical settings including liver transplantation (LT). Immunoglobulins have been used to treat sepsis-related vasoplegia. We performed a retrospective study to evaluate the efficacy of IgM-enriched immunoglobulin (IgMIg) on 30-day mortality and its ability to reverse vasoplegia in patients undergoing LT.

METHODS

Between May 2013 and November 2017, 473 LT were performed at our institution. We identified 21 patients who received IgMIg for 3 days to treat vasoplegia. Patients included in the study met the criteria for having vasoplegia and required noradrenaline administration greater than 1 μg·kg·min for more than 24 hours to maintain a mean arterial pressure of 70 mm Hg or greater. Procalcitonin and interleukin-6 (IL-6) levels were used as surrogate markers for inflammation and were measured at the beginning and end of IgM treatment.

RESULTS

After IgMIg administration, median noradrenaline infusion rates could be significantly reduced from 1.6 μg·kg·min (1.3-2 μg·kg·min) to 0.16 μg·kg·min (0.08-0.34 μg·kg·min) (P < 0.001). In addition, after treatment, procalcitonin levels decreased significantly from 44 ng/mL (24-158) to 26.1 ng/mL (10.9-48.7) (P < 0.001) and IL-6 levels decreased significantly from 63 pg/mL (29-102) to 20 pg/mL (11-20) (P < 0.001). Thirty-day morality was 14.3%.

CONCLUSIONS

The administration of IgMIg in patients with vasoplegia after LT is associated with a return of hemodynamic stability. Despite a predicted mortality of over 90% by Sepsis-Related Organ Failure Assessment score, the mortality rate of patients receiving IgMIg in our study was less than 20%.

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.

Thromboelastography and Thromboelastometry in Assessment of Fibrinogen Deficiency and Prediction for Transfusion Requirement: A Descriptive Review

Fibrinogen is crucial for the formation of blood clot and clinical outcomes in major bleeding. Both Thromboelastography (TEG) and Rotational Thromboelastometry (ROTEM) have been increasingly used to diagnose fibrinogen deficiency and guide fibrinogen transfusion in trauma and surgical bleeding patients. We conducted a comprehensive and comparative review on the technologies and clinical applications of two typical functional fibrinogen assays using TEG (FF TEG) and ROTEM (FIBTEM) for assessment of fibrinogen level and deficiency, and prediction of transfusion requirement. Clot strength and firmness of FF TEG and ROTEM FIBTEM were the most used parameters, and their associations with fibrinogen levels as measured by Clauss method ranged from 0 to 0.9 for FF TEG and 0.27 to 0.94 for FIBTEM. A comparison of the interchangeability and clinical performance of the functional fibrinogen assays using the two systems showed that the results were correlated, but are not interchangeable between the two systems. It appears that ROTEM FIBTEM showed better associations with the Clauss method and more clinical use for monitoring fibrinogen deficiency and predicting transfusion requirements including fibrinogen replacement than FF TEG. TEG and ROTEM functional fibrinogen tests play important roles in the diagnosis of fibrinogen-related coagulopathy and guidance of transfusion requirements. Despite the fact that high-quality evidence is still needed, the two systems are likely to remain popular for the hemostatic management of bleeding patients.

Hypocoagulability and Platelet Dysfunction Are Exacerbated by Synthetic Colloids in a Canine Hemorrhagic Shock Model

Background: Hemorrhagic shock and volume replacement can alter coagulation. Synthetic colloids, hydroxyethyl starch (HES), and gelatin, may enhance hypocoagulability. Our primary objective was to describe the effect of four fluid products on coagulation in canine hemorrhagic shock. Our secondary objective was to compare measurements of coagulation during shock to baseline in all dogs.

Methods: Anesthetized greyhounds subjected to atraumatic hemorrhage for 60 min were administered 20 mL kg⁻¹ of either fresh whole blood (FWB), 6% HES 130/0.4, 4% succinylated gelatin (GELO), or 80 mL kg⁻¹ of isotonic crystalloid over 20 min (n = 6 per group). Platelet closure time (PCT), rotational thromboelastometry (ROTEM) and plasma coagulation assays were measured at baseline, end of hemorrhage (shock), and 40 (T60), and 160 (T180) min after study fluid. ROTEM parameters included clotting time (CT), clot formation time (CFT), alpha angle, maximum clot firmness (MCF), lysis index at 60 min (LI60), and thrombodynamic potential index (TPI) for INTEM, EXTEM, FIBTEM (MCF only), and APTEM (LI60 only) profiles. Plasma coagulation assays included prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen concentration and activities of factor VII (FVII), factor VIII (FVIII), and von Willebrand Factor antigen (vWF). Between-group differences were tested using linear mixed models with post-hoc between-group comparisons (Bonferroni-Holm corrected). Differences between baseline and shock were tested using paired t-tests. Significance was set at P < 0.05.

Results: GELO showed longer PCT at T60, compared with FWB and CRYST, and at T180, compared with all other groups. HES showed longer EXTEM CT at T60, compared with all other groups. HES showed lower INTEM and EXTEM MCF at T60 and lower INTEM MCF at T180, compared with FWB. Some plasma coagulation assays showed greater hypocoagulability with HES. Comparing shock to baseline, EXTEM CT, INTEM CFT, EXTEM CFT, PT, and FVIII significantly increased and PCT, INTEM CT, INTEM MCF, EXTEM MCF, EXTEM LI60, EXTEM TPI, FIBTEM MCF, APTT, fibrinogen, FVII, and vWF significantly decreased.

Conclusions: In dogs with hemorrhagic shock, volume replacement with GELO caused mild platelet dysfunction and HES was associated with coagulation changes consistent with hypocoagulability, beyond effects of hemodilution. Shock alone produced some evidence of hypocoagulability.

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.