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

The Role of Viscoelastic Testing in Assessing Hemostasis: A Challenge to Standard Laboratory Assays?

Viscoelastic testing is increasingly being used in clinical and research settings to assess hemostasis. Indeed, there are potential situations in which viscoelastic testing is reportedly superior to standard routine laboratory testing for hemostasis. We report the current testing platforms and terminology, as well as providing a concise narrative review of the published evidence to guide its use in various clinical settings. Notably, there is increasing evidence of the potential utility of viscoelastic testing for assessment of direct oral anticoagulants, and bleeding associated with chronic liver disease, orthotopic liver transplantation, cardiac surgery, trauma, obstetrics and pediatrics.

Surgical risk stratification in patients with cirrhosis

Individuals with cirrhosis experience higher morbidity and mortality rates than the general population, irrespective of the type or scope of surgery. This increased risk is attributed to adverse effects of liver disease, encompassing coagulation dysfunction, altered metabolism of anesthesia and sedatives, immunologic dysfunction, hemorrhage related to varices, malnutrition and frailty, impaired wound healing, as well as diminished portal blood flow, overall hepatic circulation, and hepatic oxygen supply during surgical procedures. Therefore, a frequent clinical dilemma is whether surgical interventions should be pursued in patients with cirrhosis. Several risk scores are widely used to aid in the decision-making process, each with specific advantages and limitations. This review aims to discuss the preoperative risk factors in patients with cirrhosis, describe and compare surgical risk assessment models used in everyday practice, provide insights into the surgical risk according to the type of surgery and present recommendations for optimizing those with cirrhosis for surgical procedures. As the primary focus is on currently available risk models, the review describes the predictive value of each model, highlighting its specific advantages and limitations. Furthermore, for models that do not account for the type of surgical procedure to be performed, the review suggests incorporating both patient-related and surgery-related risks into the decision-making process. Finally, we provide an algorithm for the preoperative assessment of patients with cirrhosis before elective surgery as well as guidance perioperative management.

Clinical Characteristics and Survival of Hepatocellular Carcinoma: Insights from Single-Centre Experience in Saudi Arabia

Background Hepatocellular carcinoma (HCC) represents the most common primary liver malignancy, with a high fatality rate. Relatively, Saudi Arabia has a high incidence of HCC, which is detected in later stages with a poor prognosis. This study aims to investigate the patterns, outcomes, and mortality predictors of HCC in Saudi Arabia. Method A retrospective study from April 2018 to June 2022 included patients with HCC who were diagnosed and managed at the Najran Oncology Center, Saudi Arabia. Through our cancer registry, the patients' clinical, laboratory, radiological, and survival profiles were extracted and analyzed to assess factors associated with mortality using a univariate analysis. The overall survival was calculated by the Kaplan-Meier method. Results The study involved 52 patients with an average age of 74.6 years, predominantly male (the male-to-female ratio is 2.25:1). Viral infections were the primary cause of liver disease in 40.3% (n=21) of patients. At diagnosis, the Child-Pugh class distribution included 23.1% (n=12) patients in class A, 36.5% (n=19) patients in class B, and 40.4% (n=21) patients in class C. Uninodular tumors with ≤50% liver extension were observed in 65.4% (n=34) of cases, and 30.8% (n=16) had portal vein thrombosis. Elevated alpha-fetoprotein (AFP) levels were noted in 48.1% (n=25) of patients, with 23.1% (n=12) exceeding 400 ng/mL. Curative resection was performed in 32.7% (n=17) of patients. The mean survival time was 23±11.8 months (median of 22.5 months, minimum of six, and maximum of 49 months). Relapse occurred in seven (13.5%) cases, while new metastasis occurred in 20 (38.5%) cases. During the study period, 26 (50.0%) patients died. The main cause of death was disease progression in 15 (28.8%) patients. Univariate analysis showed that AFP>400 ng/mL (OR: 4.68; 95% CI: 1.87-11.66, p=0.001), presence of relapse (OR: 0.16; 95% CI: 0.03-0.78, p=0.023), abdominal ascites (OR: 3.38; 95% CI: 1.25-9.14, p=0.016), advanced the Cancer of the Liver Italian Program (CLIP) score (OR: 0.60; 95% CI: 0.41-0.88, p=0.009) were associated with higher mortality rate and were statistically significant. Conclusion Most cases of HCC in our patients were attributed to viral hepatitis, with the majority having liver cirrhosis. Higher AFP (>400 ng/mL), relapse, abdominal ascites, and a higher cancer CLIP score were associated with poorer outcomes. Targeted screening and health education should be advocated; in addition, social determinants should be proactively addressed.

Thromboelastographic results and hypercoagulability in dogs with surgically treated hepatocellular adenoma and carcinoma: A Veterinary Society of Surgical Oncology prospective study

BACKGROUND

The most common haemostatic abnormality in dogs with cancer is hypercoagulability. A transient hypercoagulability has been documented in people with hepatocellular carcinoma (HCC) that resolves within weeks following hepatic tumour resection.

OBJECTIVE

The objective was to compare the haemostatic status of dogs with liver tumours and healthy control dogs, by comparing coagulation and thromboelastography (TEG) measurements at three time points.

METHODS

Liver tumour and healthy control dogs receiving surgery for liver lobectomy and ovariohysterectomy, respectively, were prospectively enrolled. All dogs had blood collected at three time points: pre-operative, 24 h post-operative and ~2 weeks post-operative. Haematological and haemostatic values were compared across time points in each group using repeated measures ANOVA tests.

RESULTS

Ten and eight dogs were enrolled for the liver and control groups, respectively. Platelet count was significantly higher in the liver group than the control group at all time points, but within the normal range (pre-operative: 438.7 vs. 300.9 × 109 /L, p = .0078; 24 h post-operative: 416.2 vs. 283.9 × 109 /L, p = .0123; 10-14 days post-operative: 524.6 vs. 317.3 × 109 /L, p = .0072). The measure of the overall coagulant state (G-value) was significantly increased for the liver group compared to the control group at all time points (pre-operative: 15.6 vs. 8.6 d/sc, p = .0003; 24 h post-operative: 18.3 vs. 11.2 d/sc, p = .039; 10-14 days post-operative: 15.1 vs. 9.6 d/sc, p = .015).

CONCLUSION

The liver group was hypercoagulable based on elevated G-values at all time points compared to the control group. This hypercoagulability was attributed to the effect of hepatic tumours alone, and not secondary to surgery and anaesthesia.

The Effect of Antiplatelet Agents on Thromboelastography

BACKGROUND

Thomboelastography (TEG) is a point of care viscoelastic test that provides an assessment of clot formation and kinetics. Antiplatelet agents are commonly used but there is limited literature evaluating their possible effects on overall clot kinetics. We aimed to evaluate the relationship between antiplatelet agents and clot kinetics as defined by TEG.

METHODS

This is a retrospective study of adult patients who underwent TEG from February 2018 to July 2020. Patients who received anticoagulants or blood transfusions within 72 hours, had an incomplete TEG, were diagnosed with COVID-19, or had liver failure were excluded. Patients were stratified based on antiplatelet status.

RESULTS

Of 1060 patients, 119 were included (50 controls, 69 antiplatelet agents-37 aspirin monotherapy, 26 dual antiplatelet therapy). Between the control and antiplatelet therapy groups, there was no significant difference in clot time, maximal clot strength, or fibrinogen level. When compared to control patients, patients on dual antiplatelets had significantly higher fibrinogen levels (408.1 mg/dL vs 481.5 mg/dL, P = .013) but no significant differences in clot time or maximal clot strength. In our subgroup analysis, patients on dual antiplatelets had increased maximal clot strength (58.8° vs 63°, P = .005) and fibrinogen levels (384.1 mg/dL vs 481.5 mg/dL, P = .005) compared to those on aspirin alone.

DISCUSSION

Compared to control patients and those on aspirin alone, patients on dual antiplatelets have increased maximal clot strength and increased fibrinogen levels. These results can help physicians better target product resuscitation in patients who are on antiplatelet agents.

Approach to thromboelastography-based transfusion in cirrhosis: An alternative perspective on coagulation disorders

Viscoelastic tests, specifically thromboelastography and rotational thromboelastometry, are increasingly being used in the management of postoperative bleeding in surgical intensive care units (ICUs). However, life-threatening bleeds may complicate the clinical course of many patients admitted to medical ICUs, especially those with underlying liver dysfunction. Patients with cirrhosis have multiple coagulation abnormalities that can lead to bleeding or thrombotic complications. Compared to conventional coagulation tests, a comprehensive depiction of the coagulation process and point-of-care availability are advantages favoring these devices, which may aid physicians in making a rapid diagnosis and instituting early interventions. These tests may help predict bleeding and rationalize the use of blood products in these patients.

Elevated levels of soluble glycoprotein V - The plasma marker of platelet activation by thrombin in patients with early stage primary biliary cholangitis (PBC)

PURPOSE

There is a growing body of evidence for a prothrombotic tendency in patients with primary biliary cholangitis (PBC). The aim of the study was to evaluate coagulation disorders in patients with early stage PBC compared to healthy controls and evaluation of their relationship with clinical data, with particular emphasis on minimal hepatic encephalopathy (MHE).

PATIENTS AND METHODS

Fifty-one participants (PBC group - 38 patients, all patients but one Child-Pugh A; control group - 13 healthy controls) were included in our prospective, single center study. We assessed the plasma levels of sGPV, plasma procoagulant phospholipids (PPL) and rotational thromboelastometry (ROTEM) profiles in all study participants. Porto-systemic encephalopathy syndrome test was used to assess MHE.

RESULTS

The sGPV levels were higher in the PBC group compared to the controls: 36.07 ​± ​11.32 ​ng/mL vs 27.04 ​± ​11.72 ​ng/mL, p ​= ​0.031. The PPL level was lower in the PBC group compared to controls resulting in increased clotting time in a factor Xa-based coagulation assay: 54.65 (47.83-58.83) sec. vs 45.90 (43.3-50.5) sec., p ​= ​0.0065. PPL levels were correlated with platelet count (rho ​= ​-0.46, p ​= ​0.001). ROTEM parameters did not differ significantly between groups. Coagulation parameters did not differ significantly between patients with and without MHE.

CONCLUSIONS

We have showed increased levels of sGPV - a plasma marker of platelet activation by thrombin in patients with early stage PBC compared to healthy controls. We found no relationship between the coagulation disorders and the occurrence of MHE. The PPL level was lower in the PBC group.

The effect of thromboelastogram-guided transfusion on postoperative complications and transfusion requirement in the post-reperfusion period in liver transplantation surgery

Background/Aim: Liver transplantation surgery is one of the most common abdominal surgeries requiring blood transfusion. Coagulation parameters vary during the perioperative period because of the patient profile. Blood transfusion management should be carefully controlled to avoid causing dysfunction in the newly transplanted organ. Various laboratory parameters are used to achieve this. This study aimed to investigate the effect of transfusion managed by conventional coagulation tests or thromboelastogram (TEG) on blood product consumption and postoperative outcomes in the post-reperfusion period. Methods: The records of 90 recipients who underwent transplantation between January 1, 2012, and November 30, 2022, were retrospectively analyzed. Twenty patients who were administered blood transfusion under TEG guidance in the post-reperfusion period constituted the case group, while 20 patients non-consecutive randomly selected among other patients who were administered blood transfusion with conventional coagulation tests constituted the control group. In conclusion, 40 patients were included in this retrospective case-control study. We retrospectively analyzed demographic data, surgical data, perioperative laboratory parameters, intraoperative total and post-reperfusion blood and blood product transfusions, TEG parameters, and postoperative complications. Results: No difference was found between the groups regarding demographic data, etiological factors, surgical data, and preoperative laboratory parameters (P>0.05). There was a significant decrease in the amount of fresh frozen plasma (FFP) transfused in the case group compared to the control group in the intraoperative total and post-reperfusion period (P=0.011, P=0.003). There was no difference between the groups regarding other blood product transfusions and postoperative complications (P>0.05). Regarding the effects of intraoperative total and post-reperfusion blood and blood products on ventilator stay, intensive care unit stay, length of stay (LOS), hepatic artery thrombosis, graft rejection, postoperative kidney damage, and first 28-day mortality, only a weak negative correlation was found between intraoperative total and postreperfusion fibrinogen use and LOS (r=-0.325/P=0.041, r=-0.354/P=0.025). Conclusion: TEG-guided transfusion in the post-reperfusion period reduced total blood product consumption. Besides, the increase in the use of fibrin has led to a decrease in LOS. However, using TEG has no significant effect on postoperative mortality and morbidity. TEG and an objective assessment of patient clinical status may be an ideal guide for transfusion strategy.

Lights and Shadows of Paracentesis: Is an Ultrasound Guided Approach Enough to Prevent Bleeding Complications?

Paracentesis is a validated procedure for diagnosing and managing ascites. Although paracentesis is a safe procedure with a 1–2% risk of complications such as bleeding, it is necessary to inform the patient about the possible adverse events. We would like to share our experience with two cases of bleeding after paracentesis. In our unit, two major hemorrhagic complications occurred in 162 procedures performed over the year 2020 (frequency of bleeding complications: 1.2%). We report two clinical cases of post-paracentesis abdominal wall hematomas. Despite a similar clinical presentation, the management approach was different: in the first case, embolization of the epigastric artery supplying the hematoma was performed. In the second case, conservative treatment was adopted. Our report aims to provide food for thought about a potentially challenging hemorrhagic complication, even with the risk of adverse outcomes.

New Aspects of Lung Transplantation: A Narrative Overview Covering Important Aspects of Perioperative Management

The management of lung transplant patients has continued to evolve in recent years. The year 2021 was marked by the publication of the International Consensus Recommendations for Anesthetic and Intensive Care Management of Lung Transplantation. There have been major changes in lung transplant programs over the last few years. This review will summarize the knowledge in anesthesia management of lung transplantation with the most recent data. It will highlight the following aspects which concern anesthesiologists more specifically: (1) impact of COVID-19, (2) future of transplantation for cystic fibrosis patients, (3) hemostasis management, (4) extracorporeal membrane oxygenation management, (5) early prediction of primary graft dysfunction, and (6) pain management.

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.

Portal vein thrombosis associates with high platelet-fibrin clot strength and platelet activation in decompensated cirrhosis: A retrospective study

BACKGROUND AND AIMS

Alteration of platelet status associates with decompensation and death in cirrhosis, while its effect on portal vein thrombosis (PVT) remains unclear. We aimed to retrospectively investigate whether PVT associates with platelet-fibrin clot strength and platelet activation in decompensated cirrhosis.

METHODS

Platelet-fibrin clot strength (G) was measured by thromboelastography (TEG). Platelet activation was reflected by plasma concentrations of soluble p-selectin (sPs) and a platelet aggregation test adjusted for platelet counts.

RESULTS

Among 166 patients, 45 had PVT. The platelet count was significantly lower in PVT. While the G value was positively correlated with platelet count (ρ = 0.74, P < 0.01), increased G was associated with PVT after adjusting for platelet count in the logistic regression (P = 0.04). The normalized G value according to the linear relation with platelet count was calculated as follows: G_platelet = [(G - 2622)/platelet count]. This coefficient had no correlation with platelet count and was an independent risk factor of PVT (OR = 1.03, CI_95%: 1.01-1.05, P = 0.012). In two subanalyses, the collagen-induced platelet aggregation (n = 37, P = 0.029) and plasma concentration of sPs (n = 56, P = 0.001) adjusted for platelet count were significantly higher in PVT.

CONCLUSION

This study showed a positive correlation of high platelet-fibrin clot strength detected via TEG and platelet activation with PVT in decompensated cirrhosis.

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).

Transfusion Strategies for Hemostatic Blood Products in Critically Ill Children: A Narrative Review and Update on Expert Consensus Guidelines

Critically ill children commonly receive coagulant products (plasma and/or platelet transfusions) to prevent or treat hemorrhage or correct coagulopathy. Unique aspects of pediatric developmental physiology, and the complex pathophysiology of critical illness must be considered and balanced against known transfusion risks. Transfusion practices vary greatly within and across institutions, and high-quality evidence is needed to support transfusion decision-making. We present recent recommendations and expert consensus statements to direct clinicians in the decision to transfuse or not to transfuse hemostatic blood products, including plasma, platelets, cryoprecipitate, and recombinant products to critically ill children.

Clinical correlation between coagulation disorders and sepsis in patients with liver failure

OBJECTIVE

This study aimed to explore the clinical detection and prognosis of coagulation function in patients with liver failure and sepsis.

METHODS

The plasma fibrinogen (FIB), factor II, factor VII, factor V, factor IV, antithrombin III (ATIII), platelet (PLT), mean PLT volume (MPV), D-dimer, prothrombin activity (PTA), and fibrin degradation product (FDP) levels and thromboelastogram values were detected in patients with liver failure complicated with sepsis and compared with those in the liver failure and liver cirrhosis groups. The patients with liver failure complicated with sepsis were analyzed by univariate and multivariate logistic regression, and the regression equation was established.

RESULTS

The levels of FIB, factor II, factor VII, factor V, ATIII, PLT, MPV, D-dimer, and FDP in the patients with liver failure complicated with sepsis were compared with those in the control group patients, and the differences were statistically significant (p <  0.05). Among the thromboelastography parameters in the patients with liver failure and sepsis, the differences in the K-value, R-value, angle, maximum amplitude, and coagulation index values compared with those of the control group were statistically significant (p <  0.05). The logistic regression model obtained was as follows: p = 1/(1 + e [-0.128×X1-0.058×X2 + 0.211×X3 + 0.2×X4 + 0.25]). The specificity, sensitivity, and accuracy values of the regression equation in determining the prognosis were 92%, 93.9%, and 92.8%, respectively. Among the 11 factors, factor VII, PLT, FDP, and D-dimer were included in the regression equation.

CONCLUSION

Coagulation disorder is exacerbated in patients with liver failure and sepsis. Among the 11 coagulation-related factors, factor VII, PLT, FDP, and D-dimer may be the independent factors influencing the prognosis of patients with acute liver failure and sepsis.