Principles, Interpretation, and Evidence-Based Role of Viscoelastic Point-of-Care Coagulation Assays in Cirrhosis and Liver Failure

Role of point-of-care ultrasound (POCUS) in clinical hepatology

Hospitalized patients with cirrhosis frequently require critical care management for sepsis, HE, respiratory failure, acute variceal bleeding, acute kidney injury (AKI), shock, and optimization for liver transplantation, while outpatients have unique care considerations. Point-of-care ultrasonography (POCUS) enhances bedside examination of the hepatobiliary system and relevant extrahepatic sites. POCUS includes cardiac US and is used to assess volume status and hemodynamic parameters like cardiac output, systemic vascular resistance, cardiac contractility, and pulmonary artery pressure, which aid in the early and accurate diagnosis of heart failure, cirrhotic cardiomyopathy, porto-pulmonary hypertension, hepatopulmonary syndrome, arrhythmia, and pulmonary embolism. This also helps in fluid management and vasopressor use in the resuscitation of patients with cirrhosis. Lung ultrasound (LUS) can help in differentiating pneumonia, effusion, and edema. Further, US guides interventions such as line placement, drainage of abdominal collections/abscesses, relief of tension pneumothorax, drainage of pleural and pericardial effusions, and biliary drainage in cholangitis. Additionally, its role is essential to assess liver masses foci of sepsis, for appropriate sites for paracentesis, and to assess for vascular disorders such as portal vein or hepatic vein thrombosis. Renal US can identify renal and postrenal causes of AKI and aid in diagnosis of prerenal AKI through volume assessment. In this review, we address the principles and methods of POCUS in hospitalized patients and in outpatients with cirrhosis and discuss the application of this diverse modality in clinical hepatology.

A machine learning-based model analysis for serum markers of liver fibrosis in chronic hepatitis B patients

Early assessment and accurate staging of liver fibrosis may be of great help for clinical diagnosis and treatment in patients with chronic hepatitis B (CHB). We aimed to identify serum markers and construct a machine learning (ML) model to reliably predict the stage of fibrosis in CHB patients. The clinical data of 618 CHB patients between February 2017 and September 2021 from Zhejiang Provincial People's Hospital were retrospectively analyzed, and these data as a training cohort to build the model. Six ML models were constructed based on logistic regression, support vector machine, Bayes, K-nearest neighbor, decision tree (DT) and random forest by using the maximum relevance minimum redundancy (mRMR) and gradient boosting decision tree (GBDT) dimensionality reduction selected features on the training cohort. Then, the resampling method was used to select the optimal ML model. In addition, a total of 571 patients from another hospital were used as an external validation cohort to verify the performance of the model. The DT model constructed based on five serological biomarkers included HBV-DNA, platelet, thrombin time, international normalized ratio and albumin, with the area under curve (AUC) values of the DT model for assessment of liver fibrosis stages (F0-1, F2, F3 and F4) in the training cohort were 0.898, 0.891, 0.907 and 0.944, respectively. The AUC values of the DT model for assessment of liver fibrosis stages (F0-1, F2, F3 and F4) in the external validation cohort were 0.906, 0.876, 0.931 and 0.933, respectively. The simulated risk classification based on the cutoff value showed that the classification performance of the DT model in distinguishing hepatic fibrosis stages can be accurately matched with pathological diagnosis results. ML model of five serum markers allows for accurate diagnosis of hepatic fibrosis stages, and beneficial for the clinical monitoring and treatment of CHB patients.

Critical care management of acute liver failure

The management of acute liver failure (ALF) in modern hepatology intensive care units (ICU) has improved patient outcomes. Critical care management of hepatic encephalopathy, cerebral edema, fluid and electrolytes; prevention of infections and organ support are central to improved outcomes of ALF. In particular, the pathogenesis of encephalopathy is multifactorial, with ammonia, elevated intra-cranial pressure and systemic inflammation playing a central role. Although ALF remains associated with high mortality, the availability of supportive care, including organ failure support such as plasma exchange, timely mechanical ventilation or continuous renal replacement therapy, either conservatively manages patients with ALF or offers bridging therapy until liver transplantation. Thus, appropriate critical care management has improved the likelihood of patient recovery in ALF. ICU care interventions such as monitoring of cerebral edema, fluid status assessment and interventions for sepsis prevention, nutritional support and management of electrolytes can salvage a substantial proportion of patients. In this review, we discuss the key aspects of critical care management of ALF.

A combination of clot formation abnormalities in thromboelastometry has a high prognostic value in patients with acute-on-chronic liver failure

BACKGROUND

Global coagulation tests offer a better tool to assess procoagulant and anticoagulant pathways, fibrinolysis and clot firmness and evaluate more accurately coagulation defects compared to conventional coagulation tests. Their prognostic role in acute-on-chronic liver disease (ACLF) or acute decompensation (AD) has not been well established.

AIMS

To assess the properties and prognostic value of the coagulation profile measured by rotational thromboelastometry (ROTEM) in ACLF and AD.

METHODS

84 consecutive patients (35 ACLF and 49 AD) were prospectively studied. Twenty healthy persons matched for age and gender were used as controls. 'Hypocoagulable' or 'hypercoagulable' profiles on admission were assessed based on nine ROTEM parameters and mortality was recorded at 30 and 90 days.

RESULTS

Individual ROTEM parameters denoted significantly more hypocoagulability in patients compared to controls. 'Hypocoagulable' profile (defined as a composite of 4 or more ROTEM parameters outside the range) was associated with more severe liver disease assessed either as MELD or Child-Pugh scores ( P  < 0.001 for both) and higher 30-day mortality (Log-rank P  = 0.012). 'Hypocoagulable' profile (HR 3.160, 95% CI 1.003-9.957, P  = 0.049) and ACLF status (HR 23.786, 95% CI 3.115-181.614, P  = 0.002) were independent predictors of 30-day mortality, in multivariate model. A higher early mortality rate was shown in ACLF patients with 'hypocoagulable' phenotype compared to those without (Log-rank P  = 0.017). 'Hypocoagulable' profile was not associated with mortality in AD.

CONCLUSION

'Hypocoagulable' profile was associated with more advanced liver disease and higher short-term mortality in patients with ACLF.

Serial rotational thromboelastometry measurements show worsening hypocoagulability in acute-on-chronic liver failure and are associated with the severity of liver disease

Background

Viscoelastic tests are used to better understand the complex picture of hemostasis in cirrhosis. Limited data exist regarding the clinical relevance of rotational thromboelastometry (ROTEM) in acute-on-chronic liver failure (ACLF) or acute decompensation (AD). We examined the pattern and role of sequential observations of 9 ROTEM components in both ACLF and AD groups.

Method

ROTEM measurements were compared within and between groups at 3 time points: on admission (T1), at 24 h (T2) and 48 h post-admission (T3).

Results

Forty-two consecutive patients (22 ACLF, 20 AD) were included. ROTEM determinants exhibited significant hypocoagulable deterioration in ACLF but not in AD over the 3 time points in clot formation time (CFT)EXTEM (P=0.01), maximum clot firmnessEXTEM (P=0.014), CFTINTEM (P<0.001), and alphaINTEM (P=0.028). The sum of hypocoagulable determinants increased from T1 to T3 in ACLF (P=0.029), but remained stable in AD. Five ROTEM variables showed significant differences towards hypocoagulability in ACLF compared to AD at T3. A "hypocoagulable" profile was associated with more severe liver disease (P<0.001 for model for end-stage liver disease [MELD] or Child-Pugh scores) and higher 30- and 90-day mortality (log-rank P=0.001 and P=0.013, respectively) but no more bleeding episodes or transfusions. Two ROTEM variables displayed strong correlations with MELD at T1 and 7 at T3 (|r coefficient|>0.5).

Conclusions

ROTEM measurements indicated worsening hypocoagulability shortly post-admission compared to baseline in ACLF, but remained stable in AD. The hypocoagulable derangement was mostly correlated with the severity of liver disease and higher short-term mortality, but not more bleeding episodes.

Clinical Application of Thromboelastography in Patients With Cirrhosis: A Single Center Experience

INTRODUCTION

Thromboelastography (TEG) is a functional test of coagulation used to guide transfusions. Despite literature supporting its utility, its use remains limited to select populations. In patients with cirrhosis, conventional coagulation tests are notoriously inaccurate, and TEG may be a better measure of coagulopathy. We aimed to assess the utilization of TEG in patients with cirrhosis to steward blood transfusions in this high-risk group.

METHODS

A single-center retrospective chart review of all patients ≥18 y old with a diagnosis of liver cirrhosis who had TEG results documented in the electronic medical record from January 1 to November 1, 2021.

RESULTS

There were 277 TEG results on 89 patients with cirrhosis. Overall, 91% of the TEGs performed were associated with a clinical indication for transfusion. However, of the patients who were transfused, abnormal TEG values, including elevated R time and reduced maximum amplitude, did not correspond to transfusion of indicated blood products (fresh frozen plasma and platelets). A reduction in alpha angle showed a statistically significant association with transfusion of cryoprecipitate (P < 0.05). When assessing conventional coagulation tests, abnormal values were not significantly associated with transfusion (P = 0.07).

CONCLUSIONS

Despite TEG suggesting that transfusions could be avoided in many cirrhotic patients, patients are still being transfused platelets and fresh frozen plasma in the absence of evidence of coagulopathy on TEG. Our finding suggests the need for education about appropriate utilization of TEG. More research is needed to understand the role of these tests to guide transfusion practices in patients with cirrhosis.

Association of Heparin-Like Effect, Factor VII/XIII Deficiency and Fibrinolysis with Rebleeding Risk in Cirrhosis with Acute Variceal Bleeding

BACKGROUND

Hyperfibrinolysis and coagulation dysfunction may occur in cirrhotic patients with acute variceal bleed (AVB) despite successful endotherapy.

AIMS

To prospectively study the association of endogenous heparinoids and coagulation dysfunction with variceal rebleeding and outcome in cirrhosis.

METHODS

Consecutive patients were assessed with conventional coagulation tests, SONOCLOT™ [(global(gb) and heparinase(h) treated] and factors VII, VIII, XIII, X, tissue plasminogen activator, and plasminogen activator inhibitor ELISA assays in a university hospital. Heparin-like-effect (HLE) was defined as ≥ 20% difference in paired gb/h-SONOCLOT™ traces for activated clotting time (ACT).

RESULTS

Of 143 patients screened, 90 (46.4 ± 11.7 years, males 82.2%, ethanol-related 58.8%) were recruited, who bled from esophageal varices (81,90.0%), gastric varices (6,6.6%), or esophageal varices with portal hypertensive gastropathy (3,3.3%). Twenty (21.7%) had early rebleeding, mainly post-variceal ligation ulcer related (70%). Patients who rebled had low Factor XIII [1.6 (1.2-2.1) vs 2.4 ng/ml (2.0-2.8) P = 0.035] and Factor VII (94.1 ± 46.9 vs. 124.0 ± 50.4, P = 0.023). On receiver operating curve analysis, the gbACT > 252 s (sensitivity 86.8%, specificity 76.9%, P < 0.001), hACT > 215 s (sensitivity 71.1%, specificity 70.3%, P < 0.001), and HLE > 50% (sensitivity 69.5%, specificity 70.3%, P = 0.006) predicted rebleeding. Baseline Factor VIII (HR 1.26; 95% CI 1.17-1.34, P < 0.001), low factor VII (HR 0.89; 95% CI 0.76-0.98, P = 0.035), and lysis (HR 1.25, 95% CI 1.17-1.33, P < 0.001) predicted mortality. Endogenous heparinoids at baseline predicted sepsis (HR 1.8; 95% CI 1.4-6.5; P = 0.022), rebleeding events (HR 1.2; 95% CI 1.1-6.3; P = 0.030), and mortality (HR 1.1; 95% CI 1.0-4.6; P = 0.030).

CONCLUSIONS

Hyperfibrinolysis, Factor VII/XIII deficiency, and HLE are associated with rebleeding after AVB. Trial Registration NCT04111120 available from https://clinicaltrials.gov/ct2/show/NCT04111120 .

Fresh Frozen Plasma in Cases of Acute Upper Gastrointestinal Bleeding Does Not Improve Outcomes

Background

Blood products are commonly transfused in patients with acute upper gastrointestinal bleeding (UGIB). There exists considerable practice variation and less evidence to guide fresh frozen plasma transfusion in patients with UGIB. The aim of this study was to explore any association between fresh frozen plasma transfusion following acute UGIB and clinical outcomes.

Methods

This was a prospective, observational, multicenter study conducted at 20 tertiary hospitals in China. Patients with acute UGIB with an international normalized ratio ≤ 2.0 at emergency department admission were included. Multivariate logistic regression models were used to examine and quantify any clinical associations.

Results

A total of 976 patients (61.57 ± 15.79 years old, 73.05% male) were included, of whom 17.42% received fresh frozen plasma transfusion. The overall 90-day mortality and rebleeding rates were 10.20 and 12.19%, respectively. After adjusting for confounding factors, transfusion of fresh frozen plasma during hospitalization was associated with higher 90-day mortality [odd ratio (OR), 2.36; 95% confidence interval (CI), 1.36–4.09; p = 0.002] but not rebleeding (OR, 1.5; 95% CI; 0.94-2.54; p = 0.085). In a subgroup analysis, patients with an international normalized ratio <1.5 who were treated with fresh frozen plasma were associated with both significantly higher 90-day mortality (OR, 2.78; 95% CI, 1.49–5.21; p = 0.001) and rebleeding (OR, 2.02; 95% CI, 1.16–3.52; p = 0.013), whereas in patients with an international normalized ratio between 1.5 and 2, we did not find any significant correlation.

Conclusion

This study found an association between fresh frozen plasma transfusion following acute UGIB and elevated 90-day mortality. Both 90-day mortality and rebleeding risk were significantly higher in patients with an international normalized ratio < 1.5. Fresh frozen plasma transfusion in acute UGIB does not improve the poor outcomes (Chinese Clinical Trial registry, Number ChiCTR1900028676).

Development of Machine Learning Models Predicting Estimated Blood Loss during Liver Transplant Surgery

The incidence of major hemorrhage and transfusion during liver transplantation has decreased significantly over the past decade, but major bleeding remains a common expectation. Massive intraoperative hemorrhage during liver transplantation can lead to mortality or reoperation. This study aimed to develop machine learning models for the prediction of massive hemorrhage and a scoring system which is applicable to new patients. Data were retrospectively collected from patients aged >18 years who had undergone liver transplantation. These data included emergency information, donor information, demographic data, preoperative laboratory data, the etiology of hepatic failure, the Model for End-stage Liver Disease (MELD) score, surgical history, antiplatelet therapy, continuous renal replacement therapy (CRRT), the preoperative dose of vasopressor, and the estimated blood loss (EBL) during surgery. The logistic regression model was one of the best-performing machine learning models. The most important factors for the prediction of massive hemorrhage were the disease etiology, activated partial thromboplastin time (aPTT), operation duration, body temperature, MELD score, mean arterial pressure, serum creatinine, and pulse pressure. The risk-scoring system was developed using the odds ratios of these factors from the logistic model. The risk-scoring system showed good prediction performance and calibration (AUROC: 0.775, AUPR: 0.753).

Overview of Complications in Cirrhosis

BACKGROUND

Cirrhosis is the outcome of chronic liver disease of any etiology due to progressive liver injury and fibrosis. Consequently, cirrhosis leads to portal hypertension and liver dysfunction, progressing to complications like ascites, variceal bleeding, hepatic encephalopathy, hepatorenal syndrome, hepatopulmonary syndrome, cirrhotic cardiomyopathy, sarcopenia, hepatocellular carcinoma, and coagulation disorders. End-stage liver disease leads to an impaired quality of life, loss of social and economic productivity, and reduced survival.

METHODS

This narrative review explains the pathophysiology of complications of cirrhosis, the diagnostic approach and innovative management, with focus on data from India. A comprehensive literature search of the published data was performed in regard with the spectrum, diagnosis, and management of cirrhosis and its complications.

RESULTS

There is a change in the epidemiology of metabolic syndrome, lifestyle diseases, alcohol consumption and the spectrum of etiological diagnosis in patients with cirrhosis. With the advent of universal vaccination and efficacious long-term viral suppression agents for chronic hepatitis B, availability of direct-acting antiviral agents for chronic hepatitis C, and a booming liver transplantation programme across the country, the management of complications is essential. There are several updates in the standard of care in the management of complications of cirrhosis, such as hepatorenal syndrome, hepatocellular carcinoma, and hepatic encephalopathy, and new therapies that address supportive and palliative care in advanced cirrhosis.

CONCLUSION

Prevention, early diagnosis, appropriate management of complications, timely transplantation are cornerstones in the management protocol of cirrhosis and portal hypertension. India needs improved access to care, outreach of public health programmes for viral hepatitis care, health infrastructure, and disease registries for improved healthcare outcomes. Low-cost initiatives like immunization, alcohol cessation, awareness about liver diseases, viral hepatitis elimination, and patient focused decision-making algorithms are essential to manage liver disease in India.