Value of Preoperative Hemostasis Testing in Patients with Liver Disease for Perioperative Hemostatic Management

Preoperative coagulation tests: A narrative review of current guidelines

INTRODUCTION

Hemostasis tests are traditionally requested for all patients requiring any surgical act or invasive diagnostic-therapeutic procedure to prevent hemorrhagic complications. The aim of this study is to assess the necessity of requesting standard pre-procedure hemostasis tests.

METHODOLOGY

A narrative literature review was conducted using the PubMed data-base. Search terms included «Hemostasis» or «Blood coagulation» in combination with «Preoperative care», «Preoperative period», or «Preoperative procedure». Additionally, a targeted search was performed to find recommendations from international societies related to the topic.

RESULTS

A total of 233 articles were found, 17 were pre-selected, and after full-text evaluation, 14 relevant articles were identified. The targeted search yielded an additional 12 articles. The request for tests should be individualized according to the clinical history. Standardized screening questionnaires for hemostasis disorders are useful and complement the aforementioned approach. Factors such as age, ASA classification, bleeding potential-complexity of the procedure, and anesthetic technique may influence their request.

DISCUSSION

The incidence of hemostasis disorders in the general population is very low, and these can mostly be detected through clinical history. Thus, it is the clinical history that should guide the need for laboratory test requests.

CONCLUSIONS

Preoperative hemostasis tests should not be indiscriminately requested for all patients needing an intervention or invasive diagnostic-therapeutic procedure, but rather when there are doubts about their hemostatic competence or as advised by the nature of the procedure they are undergoing.

Risk Factors for Complications in Patients Undergoing Temporal Bone Resection and Neck Dissection: Insights From a National Database

BACKGROUND

Temporal bone resection (TBR) with or without neck dissection (ND) is performed for otologic malignancies with occult or clinical cervical lymph node metastases. To date, characterization of post-operative complications in single institution case series may be non-representative of real-world outcomes. Here, we used data from the National Inpatient Sample (NIS) to comprehensively assess the complications encountered, their frequencies, and to identify underlying risk factors to improve future outcomes.

METHODS

The population was patients undergoing TBR and ND derived from the NIS between the years of 2017 and 2019. We utilized ICD-10 diagnosis codes to identify patients with post-operative complications, those discharged to non-home facilities (DNHF), and those with increased length of stay (LOS). Multivariable regression was performed to identify significant variables related to the above outcomes.

RESULTS

Ninety of 277 patients that underwent LTBR with ND had postoperative complications. Wound complications were the most frequent complication, occurring in 11 (4%) of patients, followed by CSF leak (n = 6; 2.2%), with acute respiratory failure being the most common medical complication (n = 4; 1.4%). Sixteen percent (45/277) were discharged to a facility besides home. Dementia (OR = 7.96; CI95 3.62-17.48), anemia (OR = 2.39; CI95 1.15-4.99), congestive heart failure (OR = 5.31; CI95 1.82-15.45), COPD (OR = 3.70; CI95 1.35-10.16), and history of prior stroke (OR = 8.50; CI95 1.55-46.68) increased the odds of DNHF. When evaluating LOS (median = 5 days, IQR = 1, 9), anemia (OR = 5.49; CI95 2.86-10.52), and Medicaid insurance (OR = 3.07; CI95 1.06-10.52) were found to increase the LOS.

CONCLUSIONS

The vast majority of patients undergoing LTBR with ND have no complications and are discharged within a week. Liver disease is a risk factor for medical complications and increased charges. Patients with dementia or a prior stroke are at risk for DNHF, and those with prior anemia are at risk for a wound complication.

LAY SUMMARY

This study identified factors related to worse post-operative outcomes in patients undergoing temporal bone resection and neck dissection. Although safe for most patients, an existing diagnosis of liver disease, stroke, dementia, and anemia specifically are at risk for developing negative outcomes.

LEVEL OF EVIDENCE

3.

Acquired bleeding disorders

Acquired bleeding disorders can develop in previously healthy people irrespective of age or gender but are particularly common in patients with certain underlying conditions. Here, we review recent advances in the management of acquired haemophilia A (AHA), acquired von Willebrand syndrome (AVWS), and patients with hemostatic abnormalities due to chronic liver disease (CLD). Patients with AHA can now benefit from prophylaxis with emicizumab, a therapeutic antibody that mimics the function of activated coagulation factor VIII. The treatment of AVWS remains challenging in many situations and requires careful consideration of the underlying condition. Haemostatic abnormalities in CLD are often compensated by proportional reduction in pro and anti-haemostatic factors resulting in sustained or even increased thrombin generation. Consequently, bleeding in CLD is rarely caused by haemostatic failure and infusion of plasma or coagulation factor concentrates may not be effective.

Anesthesia in patients with chronic liver disease: An updated review

Anesthesia in chronic liver disease patients can be challenging because of the medications given or interventions performed and their effects on liver physiology. Also, the effects of liver disease on coagulation and metabolism should be considered carefully. This review focuses on anesthesia in patients with different chronic liver disease stages. A literature search was performed for Scopus and PubMed databases for articles discussing different types of anesthesia in patients with chronic liver disease, their safety, usage, and risks. The choice of anesthesia is of crucial importance. Regional anesthesia, especially neuroaxial anesthesia, may benefit some patients with liver disease, but coagulopathy should be considered. Regional anesthesia provides optimum intraoperative relaxation and analgesia that extends to the postoperative period while avoiding the side effects of intravenous anesthetics and opioids. Pharmacodynamics and pharmacokinetics of anesthetic medications must guard against complications related to overdose or decreased metabolism. The choice of anesthesia in chronic liver disease patients is crucial and could be tailored according to the degree of liver compensation and the magnitude of the surgical procedure.

Risk Factors for Postoperative Bleeding Following Breast Cancer Surgery: A Nationwide Database Study of 477,108 Cases in Japan

BACKGROUND

Although postoperative bleeding is a common and serious complication in breast cancer surgery, the risk factors remain unclear. Therefore, we examined the risk factors using a Japanese nationwide database.

METHODS

Patients who underwent breast cancer surgery between July 2010 and March 2020 were identified from a Japanese nationwide database. Multivariable analyses for 47 candidate risk factors (4 patient characteristics, 32 comorbidities, 5 tumor characteristics, 3 preoperative drug uses, and 3 surgical procedures) were conducted to investigate risk factors associated with postoperative bleeding requiring reoperation. Two sensitivity analyses were conducted: an analysis for postoperative bleeding with or without reoperation and an analysis for patients who underwent total mastectomy without breast reconstruction.

RESULTS

Among the 477,108 patients included, 7048 (1.5%) developed postoperative bleeding and 2357 (0.5%) underwent reoperation for postoperative bleeding. Male sex, old age, body mass index ≥ 25.0 kg/m², several comorbidities (deficiency anemia, cardiac arrhythmias, hypertension, liver disease, psychoses, and valvular disease), preoperative heparin use, and several procedures were identified as risk factors. Deficiency anemia showed the highest odds ratio among the risk factors (4.41 [95% confidence interval, 3.63-5.36]). High odds ratios were also observed in total mastectomy (2.32 [2.10-2.56]), flap reconstruction (1.93 [1.55-2.40]), and preoperative heparin use (1.64 [1.26-2.14]). The results corresponded with the sensitivity analyses.

CONCLUSIONS

This study identified several risk factors for postoperative bleeding in breast cancer surgery, such as high body mass index, anemia, cardiovascular diseases, liver diseases, psychoses, preoperative heparin use, and surgical procedures.

Acquired bleeding disorders

Acquired bleeding disorders can accompany hematological, neoplastic, autoimmune, cardiovascular or liver diseases, but can sometimes also arise spontaneously. They can manifest as single factor deficiencies or as complex hemostatic abnormalities. This review addresses (a) acquired hemophilia A, an autoimmune disorder characterized by inhibitory autoantibodies against coagulation factor VIII; (b) acquired von Willebrand syndrome in patients with cardiovascular disorders, where shear stress abnormalities result in destruction of von Willebrand factor; and (c) liver function disorders that comprise complex changes in pro- and anti-hemostatic factors, whose clinical implications are often difficult to predict. The article provides an overview on the pathophysiology, diagnostic tests and state-of-the-art treatment strategies.

EASL Clinical Practice Guidelines on prevention and management of bleeding and thrombosis in patients with cirrhosis

The prevention and management of bleeding and thrombosis in patients with cirrhosis poses several difficult clinical questions. These Clinical Practice Guidelines have been developed to provide practical guidance on debated topics, including current views on haemostasis in liver disease, controversy regarding the need to correct thrombocytopenia and abnormalities in the coagulation system in patients undergoing invasive procedures, and the need for thromboprophylaxis in hospitalised patients with haemostatic abnormalities. Multiple recommendations in this document are based on interventions that the panel feels are not useful, even though widely applied in clinical practice.

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.

The concept of rebalanced hemostasis in patients with liver disease: Communication from the ISTH SSC working group on hemostatic management of patients with liver disease

Patients with liver diseases acquire complex alterations in their hemostatic system that may lead to abnormalities in routine diagnostic test of hemostasis. Thrombocytopenia, prolongations in the prothrombin time and activated partial thromboplastin time, and decreased plasma fibrinogen are common in patients with advanced liver disease. Historically, liver diseases therefore have been classified as an acquired bleeding disorder. Laboratory and clinical observations have demonstrated that although routine diagnostic tests of hemostasis suggest a hypocoagulable state, patients with liver disease also tend to develop thrombotic events. Overall, patients have commensurate changes in both pro- and antihemostatic pathways. This new hemostatic balance, however, appears much more fragile than the hemostatic balance in individuals with normal liver function, and patients with liver disease can readily experience both hemostasis-related bleeding and thrombotic events. These insights into the hemostatic balance in patients with liver disease have led to revised recommendations for clinical management of hemostasis. In 2020, an SSC working group within the ISTH has been founded with the aim to disseminate new concepts on prevention and treatment of bleeding and thrombosis in patients with liver disease. The current document will outline the hemostatic changes in patients with liver disease, the limitations of routine diagnostic tests of hemostasis, and the concept of rebalanced hemostasis.

ROTEM in the setting of liver transplant surgery reduces frozen plasma transfusion

BACKGROUND

INR is traditionally used as a marker of clinical coagulopathy, but is suboptimal in liver disease patients due to rebalanced hemostasis and its ineffectiveness to predict bleeding. Rotational thromboelastometry (ROTEM) testing evaluates whole blood hemostasis, which may provide more accurate assessments with the EXTEM CT parameter than INR. Thus, in end-stage liver disease (ESLD) patients, we hypothesized that elevated INRs are associated with normal EXTEM CT values.

METHODS

A retrospective study assessing adult (>18) patients with ESLD and elevated INRs undergoing liver transplantation, was performed to assess correlations between INR and EXTEM CT. This included patients post-ROTEM implementation where all had pre-operative ROTEM testing; and patients up to one year pre-ROTEM implementation to compare transfusion utilization. Data abstracted also included patient demographics, coagulation testing results, liver disease etiology, and MELD score.

RESULTS

The study included 138 patients in the post-ROTEM group and 59 patients in the pre-ROTEM group. Normal EXTEM CT was observed in 95.3 % and 93 % of patients with INR of 1.3-1.8 and up to 3 respectively. There was no correlation between INR of 1.3-1.8 and EXTEM CT (⍴ = 0.239), and only moderate correlation was observed with higher INRs (⍴ = 0.617 with INRs >1.8). ROTEM-guided transfusion in liver transplant surgeries was associated with reduced plasma transfusion (OR 0.27, 95 % CI 0.12-0.58, p = 0.001) after adjusting for red cell utilization and coagulation testing.

CONCLUSION

Our study suggests ROTEM may be advantageous for evaluating coagulopathy in patients with liver disease and ROTEM-guided transfusion reduces plasma transfusion.

Prophylactic fresh frozen plasma and platelet transfusion have a prothrombotic effect in patients with liver disease

BACKGROUND AND AIMS

Patients with liver disease acquire complex changes in their hemostatic system, resulting in prolongation of the international normalized ratio and thrombocytopenia. Abnormalities in these tests are commonly corrected with fresh frozen plasma (FFP) or platelet transfusions before invasive procedures. Whether these prophylactic transfusions are beneficial and truly indicated is increasingly debated. In this study, we studied ex vivo effects of FFP and platelet transfusions in patients with liver disease-associated hemostatic changes in a real-life clinical setting.

METHODS

We included 19 patients who were deemed to require prophylactic FFP transfusion by their treating physician and 13 that were prescribed platelet transfusion before a procedure. Hemostatic status was assessed in blood samples taken before and after transfusion and compared with healthy controls (n = 20).

RESULTS

Ex vivo thrombin generation was preserved in patients with liver disease before FFP transfusion. Following FFP transfusion, both in and ex vivo thrombin generation significantly increased, as evidenced by a 92% and 38% increase in thrombin-antithrombin and prothrombin fragment 1 + 2 levels, respectively, and a 20% increase in endogenous thrombin potential. Platelet counts increased from 28 [21-41] × 109 /L before to 43 [39-64] × 109 /L after platelet transfusion (P < .01), and was accompanied by increases in in vivo markers of hemostatic activation.

CONCLUSIONS

FFP and platelet transfusion resulted in increased thrombin generation and platelet counts in patients with liver disease, indicating a prothrombotic effect. However, whether all transfusions were truly indicated and had a clinically relevant effect is questionable.

Pediatric liver transplantation in Australia and New Zealand: The case for a collaborative anesthetic database

BACKGROUND

Liver transplantation is conducted with strict oversight of organizational structure and clinical practice. However, specific regulations pertaining to the delivery of anesthetic services are lacking and consideration of departmental structure and mechanisms for quality control must occur at a local level. Busy centers collect and process sufficient data to guide this process but those with low case loads may not generate enough data for useful analysis. In Australia and New Zealand, pediatric liver transplants are performed at only four locations. As these operations are not equally distributed geographically or temporally there are periods of low activity at some centers. As anesthesia affects patient outcome, quality assurance activities are important in this setting.

AIMS

Provide a global overview of the structure and function of liver transplantation networks. Identify issues related to provision of pediatric anesthetic services with specific reference to Australasia. Examine anesthetic data from a single pediatric center to illustrate benefits and limitations of such activity.

METHODS

Pediatric liver transplant centers from Australia and New Zealand were surveyed to determine the organizational and logistical issues related to a liver transplant service. An audit of 15 years of liver transplants from a single center was conducted for benchmarking purposes and to identify changes in anesthetic practice over time.

RESULTS

Pediatric liver transplants performed in Queensland from January 2005 to December 2019 were reviewed. Changes in transfusion practice reflected international trends. Morbidity and mortality were comparable to international data. Important complications such as hepatic artery and portal vein thrombosis were uncommon and did not generate enough data for further analysis.

CONCLUSIONS

Combining the anesthetic liver transplant data from all sites in a single registry would expand data collection and generate broadly applicable findings. We propose the establishment of an Australasian pediatric anesthetic liver transplant database.

CIRSE Standards of Practice on Peri-operative Anticoagulation Management During Interventional Radiology Procedures

This CIRSE Standards of Practice document is aimed at interventional radiologists and provides best practices for peri-operative anticoagulation management during interventional radiology procedures.

Spontaneous hemorrhage after external ventricular drain placement in the setting of low factor VII secondary to liver cirrhosis

BACKGROUND

Alterations in normal coagulation and hemostasis are critical issues that require special attention in the neurosurgical patient. These disorders pose unique challenges in the management of these patients who often have concurrent acute ischemic and hemorrhagic injuries. Although neurosurgical intervention in such cases may be unavoidable and potentially life-saving, these patients should be closely observed after instrumentation.

CASE DESCRIPTION

A 57-year-old male with liver cirrhosis secondary to amyloid light-chain amyloidosis was admitted to the intensive care unit for the management of delayed hydrocephalus. An external ventricular drain (EVD) was placed for the treatment and monitoring of hydrocephalus. Five days after EVD placement, a head computed tomography scan revealed a tract hemorrhage. However, on repeated imaging, the size of the hemorrhage continued to increase despite aggressive blood pressure control and several doses of phytonadione. Extensive coagulopathy workup was remarkable for low factor VII levels. In that setting, recombinant activated factor VII was administered to normalize factor VII levels, and the tract hemorrhage stabilized.

CONCLUSION

To the best of our knowledge, this is the first case of spontaneous hemorrhage after EVD placement in the setting of liver cirrhosis-associated factor VII deficiency. Our case highlights the importance of identifying coagulation disorders in neurosurgical patients at high risk for coagulopathy and closely monitoring them postoperatively.

Efficacy of pro- and anticoagulant strategies in plasma of patients undergoing hepatobiliary surgery

BACKGROUND

In vitro efficacy of pro- and antihemostatic drugs is profoundly different in patients with compensated cirrhosis and in those who have cirrhosis and are critically ill.

OBJECTIVES

Here we assessed the efficacy of pro- and anticoagulant drugs in plasma of patients undergoing hepato-pancreato-biliary (HPB) surgery, which is associated with unique hemostatic changes.

METHODS

We performed in vitro analyses on blood samples of 60 patients undergoing HPB surgery and liver transplantation: 20 orthotopic liver transplantations, 20 partial hepatectomies, and 20 pylorus-preserving pancreaticoduodenectomies. We performed thrombin generation experiments before and after in vitro addition of fresh frozen plasma (FFP), prothrombin complex concentrate (PCC), recombinant factor VIIa (rFVIIa), low molecular weight heparin (LMWH), unfractionated heparin, dabigatran, and rivaroxaban.

RESULTS

We showed that patients undergoing HPB surgery are in a hypercoagulable state by thrombin generation testing. FFP and rFVIIa had minimal effects on thrombin generation, whereas PCC had a more pronounced procoagulant effect in patients compared with controls. Dabigatran showed a more pronounced anticoagulant effect in patients compared with controls, whereas rivaroxaban and LMWH had a decreased anticoagulant effect in patients.

CONCLUSION

We demonstrate profoundly altered in vitro efficacy of commonly used anticoagulants, in patients undergoing HPB surgery compared with healthy controls, which may have implications for anticoagulant dosing in the early postoperative period. In the correction of perioperative bleeding complications, PCCs appear much more potent than FFP or rFVIIa, and PCCs may require conservative dosing and caution in use in patients undergoing HPB surgery.

Viscoelastic testing in liver transplantation

Despite the lack of large randomized clinical studies, viscoelastic tests (VETs) have been a critical armamentarium for hemostatic control in liver transplantation (LT) since the 1960s. Many transplant institutions have adopted VETs in their clinical practice. Several small-size randomized clinical trials on LT patients have suggested that VET-guided hemostatic treatment algorithms have led to decreased indications for and amounts of transfused blood products, especially fresh-frozen plasma, compared to standard laboratory-based hemostatic management. VETs have also been reported to offer insight into the diagnosis and prediction of LT patients' development of hypercoagulability-related morbidity and mortality. There is still a need for VET device-specific hemostatic algorithms in LT, and clinicians must take into account the tendency to underestimate the coagulation capacity of VETs in patients with end-stage liver disease where hemostasis is rebalanced.

Systematic review with meta-analysis: abnormalities in the international normalised ratio do not correlate with periprocedural bleeding events among patients with cirrhosis

BACKGROUND

Cirrhotic coagulopathy is a delicate interplay comprising deficiencies of both procoagulant and anticoagulant factors.

AIM

To identify the relationship between international normalised ratio [INR] with periprocedural bleeding risk among patients with cirrhosis.

METHODS

Following a thorough database search of the primary literature, 29 studies were targeted for analysis, including 13 276 patients with cirrhosis undergoing indicated procedures.

RESULTS

There was no significant association between periprocedural bleeding events and pre-procedural INR [pooled odds ratio 1.52; 95% CI 0.99, 2.33; P = 0.06]. Furthermore, there was no significant difference in mean INR [pooled mean difference 0.05; 95% CI -0.03, 0.13; P = 0.23] upon comparison of patients who either did or did not experience a periprocedural bleeding event. Significant heterogeneity among some studies was primarily fuelled by significant subgroup effects of both specific procedure types performed. Additionally, there were markedly inconsistent transfusion practices across studies.

CONCLUSIONS

INR fails to serve as a significant correlate for periprocedural bleeding events among patients with cirrhosis. Ideally, these new findings will help serve as a springboard for future studies, as well as to minimize transfusion of blood products, which command a myriad of adverse effects among patients with cirrhosis.

In Vitro Evaluation of Pro- and Anticoagulant Drugs in Children with End-Stage Liver Disease Undergoing Liver Transplantation

Background Pro- and anticoagulant drugs are commonly used in pediatric liver transplantation to prevent and treat thrombotic and bleeding complications. However, the combination of baseline hemostatic changes in children with liver disease and additional changes induced by transplantation makes this very challenging. This study aimed to analyze the efficacy of clinically available pro- and anticoagulant drugs in plasma from children undergoing liver transplantation.

Methods In vitro effects of pro- and anticoagulant drugs on thrombin generation capacity were tested in plasma samples of 20 children (≤ 16 years) with end-stage liver disease undergoing liver transplantation, and compared with 30 age-matched healthy controls.

Results Addition of pooled normal plasma had no effect in patients or controls, while 4-factor prothrombin complex concentrate increased thrombin generation in both patients and controls, with enhanced activity in patients. At start of transplantation, dabigatran and unfractionated heparin had a higher anticoagulant potency in patients, whereas 30 days after transplantation low molecular weight heparin was slightly less effective in patients. Effects of rivaroxaban were comparable between patients and controls.

Conclusion This study revealed important differences in efficacy of commonly used pro- and anticoagulant drugs in children with end-stage liver disease undergoing liver transplantation. Therefore, dose adjustments of these drugs may be required. The results of this study may be helpful in the development of urgently needed protocols for strategies to prevent and treat bleeding and thrombotic complications in pediatric liver transplantation.

Acquired bleeding disorders

Acquired bleeding disorders can accompany hematological, neoplastic, autoimmune, cardiovascular or liver diseases, but can sometimes also arise spontaneously. They can manifest as single factor deficiencies or as complex hemostatic abnormalities. This review addresses (a) acquired hemophilia A, an autoimmune disorder characterized by inhibitory autoantibodies against coagulation factor VIII; (b) acquired von Willebrand syndrome in patients with cardiovascular disorders, where shear stress abnormalities result in destruction of von Willebrand factor; and (c) liver function disorders that comprise complex changes in pro- and anti-hemostatic factors, whose clinical implications are often difficult to predict. The article provides an overview on the pathophysiology, diagnostic tests and state-of-the-art treatment strategies.

The spatial distribution of the normal reference values of the activated partial thromboplastin time based on ArcGIS and GeoDA

We explored the variation and spatial distribution of the activated partial thromboplastin time (APTT) reference values of healthy people at different altitudes in China in order to develop a scientific basis for a unified standard. The APTT reference values of 49,020 healthy males (41-75 years old) and 32,447 healthy females (41-75 years old) were collected from 601 work units and 546 work units in China, respectively. The relationship between the APTT reference values and altitude was tested by correlation analysis. Linear regression analysis and curve analysis were employed to predict the APTT reference values in the whole country. Trend surface analysis, the variation function, kriging interpolation, and Getis-Ord Gi* statistic were utilized to reveal the spatial characteristics of the values. The result showed a significant positive correlation between the APTT reference values and altitude. The APTT values for females were prolonged for a greater amount of time than the males in several same areas in China. The spatial contact forms of the APTT reference values of healthy Chinese were mainly "high-high" and "low-low," which was in accord with the first law of geography. The APTT reference values still showed spatial autocorrelation and regional variation. The values were higher in the western and northern areas than in the eastern and southern areas of China. The APTT reference values of people aged 41-75 in China showed regional differences. The APTT reference values in one area can be estimated by using the best prediction model or can be obtained by the geographical distribution.

Evidence for a rebalanced hemostatic system in pediatric liver transplantation: A prospective cohort study

In adults with end-stage liver disease concurrent changes in pro- and antihemostatic pathways result in a rebalanced hemostasis. Children though, have a developing hemostatic system, different disease etiologies, and increased risk of thrombosis. This study aimed to assess the hemostatic state of children during and after liver transplantation. Serial blood samples were obtained from 20 children (≤16 years) undergoing primary liver transplantation (September 2017-October 2018). Routine hemostasis tests, thrombomodulin-modified thrombin generation, clot lysis times, and hemostatic proteins were measured. Reference values were established using an age-matched control group of 30 children. Thrombocytopenia was present in study patients. Von Willebrand factors were doubled and ADAMTS13 levels decreased during and after transplantation up until day 30, when platelet count had normalized. Whereas prothrombin time and activated partial thromboplastin time were prolonged during transplantation, thrombin generation was within normal ranges, except during perioperative heparin administration. Fibrinogen, factor VIII levels, and clot lysis time were elevated up until day 30. In conclusion, children with end-stage liver disease are in tight hemostatic balance. During transplantation a temporary heparin-dependent hypocoagulable state is present, which rapidly converts to a hemostatic balance with distinct hypercoagulable features that persist until at least day 30. This hypercoagulable state may contribute to the risk of posttransplant thrombosis.

[Anesthesiological aspects of liver transplantation]

Liver transplantation (LTPL) is the only curative option for patients with end stage liver disease (ESLD) or with hepatocellular carcinoma (HCC). Eurotransplant in Leiden, the Netherlands, is responsible for organ allocation. The model of end stage liver disease (MELD) score, which describes the severity of the liver disease, is decisive for organ allocation. The heterogeneous patient collective and hepatic-related comorbidities and their dynamics represent challenges. The anesthesiologist is responsible for evaluating the overall prognosis, whereby cardiac, pulmonary, renal and neurological comorbidities must be taken into consideration. During LTPL surgery is divided into several stages. Besides volume management, heat preservation and coagulation management, major challenges for the anesthesiologist are hemodynamic stabilization and regulation of the acid-base balance.

Perioperative hemostatic management in the cirrhotic patient: a position paper on behalf of the Liver Intensive Care Group of Europe (LICAGE)

Recent data demonstrated that amongst patients undergoing elective surgery the prevalence of cirrhosis is 0.8% equating to approximately 25 million cirrhotic patients undergoing surgery each year worldwide. Overall, the presence of cirrhosis is independently associated with 47% increased risk of postoperative complications and over two and a half-increased risk of in-hospital mortality in patients undergoing elective surgery. In particular, perioperative patients with chronic liver disease have long been assumed to have a major bleeding risk on the basis of abnormal results for standard tests of hemostasis. However, recent evidence outlined significant changes to traditional knowledge and beliefs and, nowadays, with more sophisticated laboratory tests, it has been shown that patients with chronic liver disease may be in hemostatic balance as a result of concomitant changes in both pro- and antihemostatic pathways. The aim of this paper endorsed by the Liver Intensive Care Group of Europe was to provide an up-to-date overview of coagulation management in perioperative patients with chronic liver disease focusing on patient blood management, monitoring of hemostasis, and current role of hemostatic agents.

Management of haemostatic alterations and associated disorders in cirrhosis in Spain: A national survey

BACKGROUND

Knowledge of haematological abnormalities in cirrhosis has greatly improved in recent years.

AIMS

To evaluate how Spanish Digestive Disease specialists manage haemostatic alterations and associated disorders in patients with cirrhosis.

METHODS

All members of the Spanish Association for the Study of the Liver and Spanish Society of Digestive Pathology were invited to fill in a web-based questionnaire.

RESULTS

135 professionals, 93 hepatologists and 42 non-hepatologists responded to the survey. The concept of rebalanced haemostasis was known by 74.8% of them. Most specialists corrected the INR and thrombocytopenia before invasive procedures with moderate risk of bleeding or major surgery and in severe gastrointestinal bleeding. The threshold of platelets and, especially, INR used to administer blood products varied greatly. Pharmacological prophylaxis of venous thromboembolism prevailed, but it was highly dependent on the INR and platelet figures. Most participants initiated anticoagulation regardless of the degree of portal vein thrombosis, even in patients ineligible for transplantation. In potential candidates, only 56% maintained it indefinitely or until liver transplantation. No major differences between hepatologists and non-hepatologists were found.

CONCLUSIONS

A significant variability and certain deviation from current guidelines was observed among Spanish Digestive Disease specialists regarding management of haemostatic alterations and associated disorders in cirrhosis.

Reversal of hypercoagulability in patients with HCV-related cirrhosis after treatment with direct-acting antivirals

BACKGROUND & AIMS

The long-term impact of sustained virological response (SVR) after direct-acting antivirals (DAAs) on the hypercoagulability associated with HCV cirrhosis is unknown. We longitudinally evaluated the effect of DAAs treatment on cirrhotic coagulopathy.

METHODS

Pro- and anticoagulant factor levels and thrombin generation were assessed in patients with HCV-related cirrhosis at baseline, end of therapy (EOT), at 12, 24 and 48 weeks (W) after EOT.

RESULTS

Fifty-eight patients were enrolled (86% Child's A). SVR was 100%. Median factor VIII activity significantly decreased at EOT, 12 weeks and 24 weeks compared with baseline, whereas protein C significantly increased at 24 weeks and 48 weeks. Cirrhotic patients showed a slight but sustained increase in endogenous thrombin potential (ETP) with a statistically significant difference at EOT, 12 weeks, 24 weeks and 48 weeks compared with baseline. Conversely, thrombomodulin-modified ETP was elevated before treatment and decreased over time to normal levels at 24 weeks and 48 weeks. The ETP ratio decreased slowly at EOT and 12 weeks, and was significantly decreased at 24 weeks and 48 weeks compared with baseline (P < .001 for both comparisons), being not statistically different from ETP ratio measured in healthy controls. Child's B patients showed a significantly higher ETP ratio compared to Child's A at baseline and did not show any significant improvement in ETP ratio through 12 weeks. Two Child's B patients developed PVT with an incidence rate of 1.1% p-yrs (95%CI, 0.18 to 3.58).

CONCLUSIONS

DAAs therapy in HCV-related cirrhotic patients is associated with significant changes in thrombin generation suggesting a reversal of hypercoagulability particularly in Child's A patients.

Anesthetic Care of 2 Siblings With Neonatal Ichthyosis and Sclerosing Cholangitis Syndrome: Case Reports

We report for the first time the anesthetic management of 2 sisters suffering from neonatal ichthyosis and sclerosing cholangitis syndrome. They both presented with neonatal cholestatic jaundice and ichthyosis. The first was admitted for orthotopic liver transplantation at the age of 1 year, and the second patient underwent open pyeloplasty for a pyeloureteric junction syndrome at the age of 4 years. These 2 case reports highlight that, except for the potential difficulties with securing the catheters, dressings and endotracheal tube to the skin, the anesthetic implications of neonatal ichthyosis and sclerosing cholangitis syndrome are mainly related to the liver disease: cirrhosis and portal hypertension.

Correction of Severe Coagulopathy and Hyperfibrinolysis by Tranexamic Acid and Recombinant Factor VIIa in a Cirrhotic Patient After Trauma: A Case Report

Coagulopathy induced by trauma or cirrhosis is a well-recognized entity. Viscoelastic testing has been used in either condition for goal-directed transfusion and detection of fibrinolysis since conventional coagulation tests do not correlate with clinical risk of bleeding. Hemostatic resuscitation may not be adequate for a trauma patient with liver disease due to complex alterations in coagulation systems and occasionally require adjuvant therapy. We report a case of trauma-induced coagulopathy presenting as severe hyperfibrinolysis in a cirrhotic patient who was refractory to hemostatic resuscitation but was rapidly corrected by the administration of tranexamic acid and recombinant Factor VIIa.

The Coagulation Profile of End-Stage Liver Disease and Considerations for Intraoperative Management

The coagulopathy of end-stage liver disease results from a complex derangement in both anticoagulant and procoagulant processes. With even minor insults, cirrhotic patients experience either inappropriate bleeding or clotting, or even both simultaneously. The various phases of liver transplantation along with fluid and blood product administration may contribute to additional disturbances in coagulation. Thus, anesthetic management of patients undergoing liver transplantation to improve hemostasis and avoid inappropriate thrombosis in the perioperative environment can be challenging. To add to this challenge, traditional laboratory tests of coagulation are difficult to interpret in patients with end-stage liver disease. Viscoelastic coagulation tests such as thromboelastography (Haemonetics Corporation, Braintree, MA) and rotational thromboelastometry (TEM International, Munich, Germany) have helped to reduce transfusion of allogeneic blood products, especially fresh frozen plasma, but have also lead to the increased use of fibrinogen-containing products. In general, advancements in surgical techniques and anesthetic management have led to significant reduction in blood transfusion requirements during liver transplantation. Targeted transfusion protocols and pharmacologic prevention of fibrinolysis may further aid in the management of the complex coagulopathy of end-stage liver disease.

Viscoelastic Monitoring to Guide Hemostatic Resuscitation in Liver Transplantation Surgery

Coagulopathic bleeding must be anticipated during liver transplantation (LT) surgery. Patients with end-stage liver disease (ESLD) often present with disease-related hematologic disturbances, including the loss of hepatic procoagulant and anticoagulant clotting factors and thrombocytopenia. Transplantation surgery itself presents additional hemostatic changes, including hyperfibrinolysis. Viscoelastic monitoring (VEM) is often used to provide targeted, personalized hemostatic therapies for complex bleeding states including cardiac surgery and major trauma. The use in these coagulopathic conditions led to its application to LT, although the mechanisms of coagulopathy in these patients are quite different. While VEM is often used during transplant surgeries in Europe and North America, evidence supporting its use is limited to a few small clinical studies. The theoretical and clinical applications of the standard and specialized VEM assays are discussed in the setting of LT and ESLD.

Coagulation Management During Liver Transplantation: Use of Fibrinogen Concentrate, Recombinant Activated Factor VII, Prothrombin Complex Concentrate, and Antifibrinolytics

Coagulation management, and transfusion practice in liver transplantation (LT) have been evolving in the recent years due to better understanding of coagulation abnormalities in end-stage liver disease, and clinical management of LT patients. Avoidance of allogeneic blood components is feasible in some patients, but multi-modal coagulation therapies may be necessary in others who develop complex coagulopathy due to hemorrhage, hemodilution, hypothermia, and acid-base disturbances. Transfusions of plasma and cryoprecipitate remain to be the mainstay therapy for procoagulant factor replacement during LT. Clinical efficacy and safety of these products are limited by logistic issues (eg, thawing), and mostly noninfectious complications. Considering potential alternatives to conventional transfusion is thus important to improve hemostatic resuscitation in complex LT cases. The present review is mainly focused on procoagulant properties of plasma and platelet transfusion, and currently available plasma-derived and recombinant factor concentrates, and antifibrinolytic agents in LT patients. The role of viscoelastic coagulation tests to guide specific component therapies will be also discussed.

Development of a Predictive Model for Blood Transfusions and Bleeding During Liver Transplantation: An Observational Cohort Study

OBJECTIVE

Orthotopic liver transplantation (OLT) frequently is associated with major blood loss and considerable transfusion requirements. The goal of this study was to define the risk factors for multiple transfusions and major bleeding during OLT and to help identify higher risk patients that could benefit from targeted interventions.

DESIGN

OLTs were studied for this observational cohort study.

SETTING

Community hospital.

PARTICIPANTS

A total of 800 consecutive OLTs were studied.

INTERVENTION

No intervention.

MEASUREMENTS AND MAIN RESULTS

Baseline and intraoperative data were gathered. Multivariate logistic regression analyses were performed to find variables associated with 2 outcomes: transfusion of more than 2 units of red blood cells (RBC) and bleeding ≥900 mL. Two nomograms were developed to predict individual risks. The overall intraoperative RBC transfusion was 0.6 ± 1.4 units on average, and 61 surgeries (7.6%) received more than 2 units of RBC (4.5 ± 1.9). Some variables were associated with the outcomes: 5 were associated with transfusion of more than 2 units of RBC (patient's height, starting hemoglobin concentration, starting bilirubin value, the use of a phlebotomy, and central venous pressure [CVP] at the time of vena cava clamping) and 3 with blood loss of ≥900 mL (starting hemoglobin value, Child-Turcotte-Pugh score, and CVP at the time of vena cava clamping). Preclamping CVP showed the strongest association with both outcomes. Nomograms were developed to predict the individual OLT recipients' risk of requiring more than 2 units RBC and suffering from major bleeding. Among the variables associated with multiple RBC transfusions and major bleeding, 3 can lead to interventions: baseline hemoglobin value, the use of a phlebotomy, and the preclamping CVP.

CONCLUSION

Some variables were able to predict the risk of multiple transfusions and major bleeding in this low bleeding liver transplantation population. Further studies based on these variables should be done to better define the role of targeted interventions in higher risk liver transplant recipients.

Incidence and predictors of massive bleeding in children undergoing liver transplantation: A single-center retrospective analysis

BACKGROUND

Liver transplantation represents a major surgery involving a highly vascular organ. Reports defining the scope of bleeding in pediatric liver transplants are few.

AIMS

We conducted a retrospective analysis of liver transplants performed at our pediatric tertiary care center to quantify blood loss, blood product utilization, and to determine predictors for massive intraoperative bleeding.

METHODS

Pediatric patients who underwent isolated liver transplantation at Boston Children's Hospital between 2011 and 2016 were included. The amount of blood product transfused in the perioperative period and the incidence of postoperative complications were reported. Univariable and multivariable logistic regressions were used to determine predictors for massive bleeding, defined as estimated blood loss exceeding one circulating blood volume within 24 hours.

RESULTS

Sixty-eight children underwent liver transplantation during the study period and were included in the analysis. Multivariable logistic regression analysis identified the following independent predictors of massive bleeding: preoperative hemoglobin level <8.5 g/dL (OR 11.09, 95% CI 1.87-65.76), INR >1.5 (OR 11.62, 95% CI 2.36-57.26), platelet count <100 10⁹ /L (OR 7.92, 95% CI 1.46-43.05), and surgery duration >600 minutes (OR 6.97, 95% CI 0.99-48.92).

CONCLUSIONS

Pediatric liver transplantation is associated with substantial blood loss and a significant blood product transfusion burden. A 43% incidence of massive bleeding is reported. Further efforts are needed to improve bleeding management in this high-risk population.