Review: The Perioperative Use of Thromboelastography for Liver Transplant Patients

Effect of clustered nursing on liver function indexes, nutrition, and emotional status of patients with severe liver failure

Liver failure is a metabolic disorder caused by a variety of mixed factors. For such diseases, adopting cluster care can effectively improve the relevant symptoms of patients. To explore the nursing effect of nutritional nursing combined with clustered nursing for patients with severe liver failure. A total of 129 patients with severe liver failure were selected as retrospective study subjects. Nine cases were due to an end event, such as death. The other patients were divided into control group and observation group according to different nursing methods. Among them, the control group adopted nutrition nursing, and the observation group implemented cluster nursing on this basis. The differences of liver function, anxiety and depression score, gastrointestinal recovery, nutritional status, and sleep quality were compared between the 2 groups before and after nursing. After nursing, the total bilirubin, albumin, and aspartate aminotransferase of the observation group were significantly higher than those of the control group (P < .05). The nursing staff used Self-Rating Anxiety Scale and Self-Rating Depression Scale of the observation group, which were slightly lower than those of the control group. The difference was statistically significant after testing (P < .05). After nursing, the observation group's upper arm circumference, brachial tri-scalp fold thickness, and hemoglobin were better than those of the control group. Statistics showed that the difference was statistically significant (P < .05). The depth of sleep, time to fall asleep, number of awakenings, time to fall asleep after awakening, overall sleep quality, and intensive care unit environmental noise intensity in the Richards-Campbell Sleep Questionnaire sleep scale after nursing in the 2 groups were significantly higher than those before nursing, and the scores of the observation group were significantly lower than those in the observation group. In the control group, this difference was statistically significant (P < .05). Nutritional nursing combined with clustered nursing can effectively promote the recovery of gastrointestinal function in patients with severe liver failure.

Thromboelastography characteristics in critically ill patients with liver disease

OBJECTIVE

The purpose of this study was to determine how thromboelastography (TEG) parameters differ by various clinical conditions that commonly occur in patients with cirrhosis, including sepsis, acute on chronic liver failure (ACLF), alcohol-associated hepatitis (AAH) and portal vein thrombosis (PVT).

BACKGROUND

TEG, a whole blood assay, is used to assess several parameters of coagulation and is becoming increasingly used in clinical practice.

STUDY

This study was a retrospective chart review of 155 patients admitted to the ICU with decompensated cirrhosis from 2017 to 2019.

RESULTS

The R time was significantly shorter in patients when they were septic compared to when they were not and longer in patients with vs. without ACLF grade 3. Alpha angle and maximum amplitude was decreased in patients with severe AAH compared to those without severe AAH; and maximum amplitude was increased in patients with acute PVT compared to those with chronic PVT. R time was positively correlated with Chronic Liver Failure Consortium Organ Failure and Chronic Liver Failure Consortium ACLF scores (rho = 0.22, P = 0.020), while alpha angle and maximum amplitude were negatively correlated with MELD-NA.

CONCLUSION

Findings suggest TEG parameters vary in several clinical conditions in patients with decompensated cirrhosis who are admitted to the ICU. Prospective research is needed to confirm our findings and to determine how this knowledge can be used to guide clinical practice, as well as blood product transfusions in the setting of bleeding or prior to invasive procedures.

Donation After Circulatory Death Liver Transplantation: Early Challenges, Clinical Improvement, and Future Directions

Donation after circulatory death (DCD) liver allografts remain a widely underutilized source of donor organs for transplantation. Although initially linked with inferior outcomes, DCD liver transplant can achieve excellent patient and graft survival with suitable matching of donor and recipient characteristics, rapid donor recovery and precise donor assessment, and appropriate perioperative management. The advent of clinical liver perfusion modalities promises to redefine the viability parameters for DCD liver allografts and hopefully will encourage more widespread usage of this growing source of donor livers.

User Perceptions of Visual Clot in a High-Fidelity Simulation Study: Mixed Qualitative-Quantitative Study

BACKGROUND

Viscoelastic hemostatic assays, such as rotational thromboelastometry (ROTEM) or thromboelastography, enable prompt diagnosis and accelerate targeted treatment. However, the complex interpretation of the results remains challenging. Visual Clot-a situation awareness-based visualization technology-was developed to assist clinicians in interpreting viscoelastic tests.

OBJECTIVE

Following a previous high-fidelity simulation study, we analyzed users' perceptions of the technology, to identify its strengths and limitations from clinicians' perspectives.

METHODS

This is a mixed qualitative-quantitative study consisting of interviews and a survey. After solving coagulation scenarios using Visual Clot in high-fidelity simulations, we interviewed anesthesia personnel about the perceived advantages and disadvantages of the new tool. We used a template approach to identify dominant themes in interview responses. From these themes, we defined 5 statements, which were then rated on Likert scales in a questionnaire.

RESULTS

We interviewed 77 participants and 23 completed the survey. We identified 9 frequently mentioned topics by analyzing the interview responses. The most common themes were "positive design features," "intuitive and easy to learn," and "lack of a quantitative component." In the survey, 21 respondents agreed that Visual Clot is easy to learn and 16 respondents stated that a combination of Visual Clot and ROTEM would help them manage complex hemostatic situations.

CONCLUSIONS

A group of anesthesia care providers found Visual Clot well-designed, intuitive, and easy to learn. Participants highlighted its usefulness in emergencies, especially for clinicians inexperienced in coagulation management. However, the lack of quantitative information is an area for improvement.

Guidelines for the management of coagulation disorders in patients with cirrhosis

Coagulation management in the patient with cirrhosis has undergone a significant transformation since the beginning of this century, with the concept of a rebalancing between procoagulant and anticoagulant factors. The paradigm that patients with cirrhosis have a greater bleeding tendency has changed, as a result of this rebalancing. In addition, it has brought to light the presence of complications related to thrombotic events in this group of patients. These guidelines detail aspects related to pathophysiologic mechanisms that intervene in the maintenance of hemostasis in the patient with cirrhosis, the relevance of portal hypertension, mechanical factors for the development of bleeding, modifications in the hepatic synthesis of coagulation factors, and the changes in the reticuloendothelial system in acute hepatic decompensation and acute-on-chronic liver failure. They address new aspects related to the hemorrhagic complications in patients with cirrhosis, considering the risk for bleeding during diagnostic or therapeutic procedures, as well as the usefulness of different tools for diagnosing coagulation and recommendations on the pharmacologic treatment and blood-product transfusion in the context of hemorrhage. These guidelines also update the knowledge regarding hypercoagulability in the patient with cirrhosis, as well as the efficacy and safety of treatment with the different anticoagulation regimens. Lastly, they provide recommendations on coagulation management in the context of acute-on-chronic liver failure, acute liver decompensation, and specific aspects related to the patient undergoing liver transplantation.

Postoperative fibrinolytic resistance is associated with early allograft dysfunction in liver transplantation: A prospective observational study

Perioperative dysfunction of the fibrinolytic system may play a role in adverse outcomes for liver transplant recipients. There is a paucity of data describing the potential impact of the postoperative fibrinolytic system on these outcomes. Our objective was to determine whether fibrinolysis resistance (FR), on postoperative day one (POD-1), was associated with early allograft dysfunction (EAD). We hypothesized that FR, quantified by tissue plasminogen activator thrombelastography, is associated with EAD. Tissue plasminogen activator thrombelastography was performed on POD-1 for 184 liver transplant recipients at a single institution. A tissue plasminogen activator thrombelastography clot lysis at 30 minutes of 0.0% was identified as the cutoff for FR on POD-1. EAD occurred in 32% of the total population. Fifty-nine percent (n=108) of patients were categorized with FR. The rate of EAD was 42% versus 17%, p <0.001 in patients with FR compared with those without, respectively. The association between FR and EAD risk was assessed using multivariable logistic regression after controlling for known risk factors. The odds of having EAD were 2.43 times (95% CI, 1.07-5.50, p =0.03) higher in recipients with FR [model C statistic: 0.76 (95% CI, 0.64-0.83, p <0.001]. An additive effect of receiving a donation after circulatory determination of death graft and having FR in the rate of EAD was observed. Finally, compared with those without FR, recipients with FR had significantly shorter graft survival time ( p =0.03). In conclusion, FR on POD-1 is associated with EAD and decreased graft survival time. Postoperative viscoelastic testing may provide clinical utility in identifying patients at risk for developing EAD, especially for recipients receiving donation after circulatory determination of death grafts.

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.

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.

Viscoelastic Testing Prior to Non-surgical Procedures Reduces Blood Product Use Without Increasing Bleeding Risk in Cirrhosis

BACKGROUND/AIMS

Thromboelastography (TEG) and Rotational Thromboelastometry (ROTEM) analyze hemostatic function in patients with coagulopathy. We sought to quantify the impact of TEG and ROTEM-guided transfusion algorithms on blood product utilization in patients with cirrhosis undergoing non-surgical procedures.

METHODS

We performed a systematic review and meta-analysis on the utility of viscoelastic testing prior to non-surgical procedures to determine their impact on pre-procedural blood product use and post-procedural bleeding events. Studies comparing TEG or ROTEM-guided transfusions with standard-of-care (SOC) prior to non-surgical procedures in adult patients with cirrhosis were included. Primary outcomes were fresh frozen plasma (FFP) and platelet transfusion and secondary outcomes of post-procedure bleeding, transfusion-related complications, and mortality; and were reported as standardized mean differences (SMD) and risk ratios (RR).

RESULTS

Six studies (five randomized controlled trials and one cohort study) involving 367 patients met inclusion criteria. Compared with SOC, TEG/ROTEM-guided transfusions led to an overall decreased number of patients who received FFP transfusions (SMD = -0.93, 95% CI [-1.54, -0.33], p < 0.001) and platelets transfusions (SMD = -1.50, CI [-1.85, -1.15], p < 0.001). Total amount of FFP (SMD-0.86, p < 0.001) and platelet (SMD = -0.99, p < 0.001) transfused in the TEG/ROTEM group were also lower. Decreased pre-procedure transfusion in the TEG/ROTEM group did not result in increased post-procedure bleeding (RR = 0.61, p = 0.09) or in mortality (RR = 0.91, p = 0.93).

CONCLUSION

In patients with cirrhosis, TEG or ROTEM significantly reduces blood product utilization prior to non-surgical procedures, with no increase in post-procedure bleeding or mortality. TEG and ROTEM utilization can promote high-value care and improve transfusion stewardship in this population.

Refractory thrombocytopenia during liver transplantation requiring splenectomy

Although thrombocytopenia is common in end-stage liver disease, severe, refractory thrombocytopenia during liver transplantation is rare, and if immune based, usually presents months or years later. This case describes an adult woman in whom preoperative evaluation had not determined an immune-related cause of thrombocytopenia. Clot strength was dramatically impaired as measured by thrombelastography during the transplant. Following a lack of response to repeat platelet transfusions, splenectomy was performed after graft reperfusion with rapid temporal restoration of clot strength. This case shows a severe manifestation of perioperative thrombocytopenia during liver transplantation and clinically guided management when measured clot strength is too low for accurate determination.

Faster Time to Treatment Decision of Viscoelastic Coagulation Test Results through Improved Perception with the Animated Visual Clot: A Multicenter Comparative Eye-Tracking Study

As the interpretation of viscoelastic coagulation test results remains challenging, we created Visual Clot, an animated blood clot aiming to facilitate raw rotational thromboelastometry (ROTEM) parameters. This study investigated anesthesia personnel’s cognitive processing in managing simulated bleeding scenarios using eye-tracking technology. This multicenter, international, computer-based study across five large, central European hospitals included 35 participants with minimal to no prior experience interpreting viscoelastic test results. Using eye-tracking technology and an iPad tagged with quick response codes, we defined the time to treatment decision and the time on screen surface in seconds of correctly solved scenarios as our outcomes. The median time to treatment decision was 52 s for Visual Clot and 205 s for ROTEM (p < 0.0001). The probability of solving the scenario correctly was more than 8 times higher when using Visual Clot than when using ROTEM (Hazard ratio [HR] 8.54, 95% CI from 6.5 to 11.21; p < 0.0001). Out of 194 correctly answered scenarios of participants with the eye-tracker, 154 (79.4%) were solved with Visual Clot and 40 (20.6%) with ROTEM. Participants spent on average 30 s less looking at the screen surface with Visual Clot compared to ROTEM (Coefficient −30.74 s, 95% CI from −39.27 to −22.27; p < 0.0001). For a comparison of the two modalities in terms of information transfer, we calculated the percentage of time on the screen surface of the overall time to treatment decision, which with Visual Clot was 14 percentage points shorter than with ROTEM (Coefficient −14.55, 95% CI from −20.05 to −9.12; p < 0.0001). Visual Clot seems to improve perception and detection of coagulopathies and leads to earlier initiation of the appropriate treatment. In a high-pressure working environment such as the operating and the resuscitation room, correct and timely decisions regarding bleeding management may have a relevant impact on patients’ outcomes.

Hyponatremia and Liver Transplantation: A Narrative Review

Hyponatremia is a common electrolyte disorder in patients with end-stage liver disease (ESLD) and is associated with increased mortality on the liver transplantation (LT) waiting list. The impact of hyponatremia on outcomes after LT is unclear. Ninety-day and one-year mortality may be increased, but the data are conflicting. Hyponatremic patients have an increased rate of complications and longer hospital stays after transplant. Although rare, osmotic demyelination syndrome (ODS) is a feared complication after LT in the hyponatremic patient. The condition may occur when the serum sodium (sNa) concentration increases excessively during or after LT. This increase in sNa concentration correlates with the degree of preoperative hyponatremia, the amount of intraoperative blood loss, and the volume of intravenous fluid administration. The risk of developing ODS after LT can be mitigated by avoiding large perioperative increases in sNa concentration . This can be achieved through measures such as carefully increasing the sNa pretransplant, and by limiting the intravenous intra- and postoperative amounts of sodium infused. SNa concentrations should be monitored regularly throughout the entire perioperative period.

Point-of-care blood coagulation assay enabled by printed circuit board-based digital microfluidics

The monitoring of coagulation function has great implications in many clinical settings. However, existing coagulation assays are simplex, sample-consuming, and slow in turnaround, making them less suitable for point-of-care testing. In this work, we developed a novel blood coagulation assay that simultaneously assesses both the tendency of clotting and the stiffness of the resultant clot using printed circuit board (PCB)-based digital microfluidics. A drop of blood was actuated to move back and forth on the PCB electrode array, until the motion winded down as the blood coagulated and became thicker. The velocity tracing and the deformation of the clot were calculated via image analysis to reflect the coagulation progression and the clot stiffness, respectively. We investigated the effect of different hardware and biochemical settings on the assay results. To validate the assay, we performed assays on blood samples with hypo- and hyper-coagulability, and the results confirmed the assay's capability in distinguishing different blood samples. We then examined the correlation between the measured metrics in our assays and standard coagulation assays, namely prothrombin time and fibrinogen level, and the high correlation supported the clinical relevance of our assay. We envision that this method would serve as a powerful point-of-care coagulation testing method.

Clinical Implications, Evaluation, and Management of Hyponatremia in Cirrhosis

Hyponatremia is the most common electrolyte abnormality in patients with decompensated cirrhosis on Liver Transplantation (LT) waiting list. Most of these patients have dilutional or hypervolemic hyponatremia secondary to splanchnic vasodilatation. Excessive secretion of the antidiuretic hormone also plays an important role. Hypervolemic hyponatremia is commonly associated with refractory ascites, spontaneous bacterial peritonitis, and hepatic encephalopathy. Although uncommon, the use of diuretics and laxatives can cause hypovolemic hyponatremia that is characterized by the striking absence of ascites or pedal edema. Clinical features are often nonspecific and depend on the acuity of onset rather than the absolute value of serum sodium. Symptoms may be subtle, including nausea, lethargy, weakness, or anorexia. However, rarely patients may present with confusion, seizures, psychosis, or coma. Treatment includes discontinuation of diuretics, beta-blockers, and albumin infusion. Hypertonic saline (3%) infusion may be used in patients with very low serum sodium (<110 mmol/L) or when patients present with seizures or coma. Short-term use of Vasopressin (V₂) receptor antagonists may also be used to normalize sodium levels prior to LT. However, all these measures may be futile, and LT remains the definite treatment in these patients to improve survival. In this review, we describe the classification, pathogenesis of hyponatremia, and its clinical implications in patients with cirrhosis. Approach to these patients along with management will also be discussed briefly.

The Use of Methylene Blue during Liver Transplantation for Vasoplegia

The use of methylene blue for vasoplegia in cardiac cases with cardiopulmonary bypass, septic shock, and acute liver failure is well documented. Use of MB for liver transplantation has been largely limited to case reports. We describe three separate liver transplantation patients with significant hypotension following reperfusion. Administration of methylene blue to each patient resulted in a significant decrease in vasopressor medication and two patients weaned completely. We argue that the use of MB should be considered as a treatment option for refractory hypotension.

Working towards an ERAS Protocol for Pancreatic Transplantation: A Narrative Review

Enhanced recovery after surgery (ERAS) initially started in the early 2000s as a series of protocols to improve the perioperative care of surgical patients. They aimed to increase patient satisfaction while reducing postoperative complications and postoperative length of stay. Despite these protocols being widely adopted in many fields of surgery, they are yet to be adopted in pancreatic transplantation: a high-risk surgery with often prolonged length of postoperative stay and high rate of complications. We have analysed the literature in pancreatic and transplantation surgery to identify the necessary preoperative, intra-operative and postoperative components of an ERAS pathway in pancreas transplantation.

Clinical Considerations of Coagulopathy in Acute Liver Failure

Acute liver failure (ALF) is the rapid onset of severe liver dysfunction, defined by the presence of hepatic encephalopathy and impaired synthetic function (international normalized ratio of ≥1.5) in the absence of underlying liver disease. The elevated international normalized ratio value in ALF is often misinterpreted as an increased hemorrhagic tendency, which can lead to inappropriate, prophylactic transfusions of blood products. However, global assessments of coagulopathy via viscoelastic tests or thrombin generation assay suggest a reestablished hemostatic, or even hypercoagulable, status in patients with ALF. Although the current versions of global assays are not perfect, they can provide more nuanced insights into the hemostatic system in ALF than the conventional measures of coagulopathy.

Use of direct-acting oral anticoagulants in solid organ transplantation: A systematic review

The use of direct-acting oral anticoagulants (DOACs) has increased secondary to the mounting evidence for comparable efficacy and potentially superior safety to vitamin K antagonists (VKAs) in the general population. However, insufficient data regarding DOAC use in solid organ transplant (SOT) recipients and numerous pharmacokinetic and pharmacodynamic considerations limit their use in this highly selected patient population. A systematic review of recent clinical evidence on the safety and efficacy of DOACs compared to VKAs in SOT recipients was conducted. Additional considerations including transplant-specific strategies for DOAC reversal and common pharmacokinetic/pharmacodynamic concerns were also reviewed. Although current evidence is limited to single-center retrospective analyses, DOACs, especially apixaban, appear to be a safe and effective alternative to VKAs for SOT recipients with stable graft function and without drug-drug interactions. Reliable data on DOAC reversal at the time of transplant surgery are lacking, and clinicians should consider idarucizumab, andexanet alfa, and other non-specific reversal agents on an individual patient basis. There is no evidence supporting deviations from the Food and Drug Administration labeling recommendations for DOAC dosing in the setting of drug-drug interactions, obesity, and renal function, especially in patients on hemodialysis.

Thromboelastometry-guided anticoagulation reversal in a patient with ventricular assist device with intracranial hemorrhage

Intracranial hemorrhage (ICH) is a known complication in patients with ventricular assist devices (VAD). We present a case of a 42-year-old male with a VAD and on warfarin who presented to the emergency department with ICH necessitating anticoagulant reversal. An attenuated dose of 15 units/kg of 4-factor prothrombin complex-concentrates (4F-PCC) was given and the patient's coagulation profile was subsequently assessed using rotational thromboelastometry (ROTEM®) to determine appropriateness of reversal. ROTEM® analysis showed adequate reversal at the time of assessment and the patient ultimately returned home without further functional deficits, highlighting the role of ROTEM® to guide anticoagulation reversal in the VAD patient population.

New Uses for Thromboelastography and Other Forms of Viscoelastic Monitoring in the Emergency Department: A Narrative Review

Patients frequently visit the emergency department with conditions that place them at risk of worse outcomes when accompanied by coagulopathy. Routine tests of coagulation-prothrombin time, partial thromboplastin time, platelets, and fibrinogen-have shortcomings that limit their use in providing emergency care. One alternative is to investigate coagulation disturbance with viscoelastic monitoring (VEM), a coagulation test that measures the timing and strength of blood clot development in real time. VEM is widely used and studied in cardiac surgery, liver transplant surgery, anesthesia, and trauma. In this article, we review the technique of VEM and the biologic rationale of using it in addition to routine tests of coagulation in emergency clinical situations. Then, we review the evidence (or lack thereof) for using VEM in the diagnosis and treatment of specific conditions. Finally, we describe the limitations of the test and future directions for clinical use and research in emergency medicine.

The use of thromboelastography to assess post-operative changes in coagulation and predict graft function in renal transplantation

BACKGROUND

End stage renal disease (ESRD) is associated with elevated fibrinogen levels and fibrinolysis inhibition. However, there is a paucity of data on how renal transplantation impacts coagulation. we hypothesize that renal transplantation recipients with good functioning grafts will have improved fibrinolytic activity following surgery.

METHODS

Kidney recipients were analyzed pre-operatively and on post-operative day 1(POD1) using three different TEG assays with and without two concentration of tissue-plasminogen activator (t-PA). TEG indices and percent reduction in creatinine from pre-op to POD1 were measured, with >50% defining "good" graft function. Follow up was done at 6, 12, and 24 months.

RESULTS

Percent lysis(LY30) on POD1 the t-PA TEG was significantly correlated to change creatinine from pre-op to POD-1(p = 0.006). A LY30 ≥ 23% was associated with good early graft function, and lower creatinine at 24-months(p = 0.028) compared to recipients with low POD1 LY30.

CONCLUSIONS

Post-operative tPA-TEG LY30 is associated with favorable early and late outcomes in kidney transplant.

A clinical coagulopathy score concurrent with viscoelastic testing defines opportunities to improve hemostatic resuscitation and enhance blood product utilization during liver transplantation

BACKGROUND

An NIH clinical coagulopathy score has been devised for trauma patients, but no such clinical score exists in transplantation surgery. We hypothesize that that this coagulopathy score can effectively identify laboratory defined coagulopathy during liver transplantation and correlates to blood product utilization.

METHODS

TEGs were performed and coagulopathy scores (1, normal bleeding - 5, diffuse coagulopathic bleeding) were assigned by the surgeons at 5 intra-operative time points. Blood products used during the case were recorded between time points. Statistical analyses were performed to identify correlations between coagulopathy scores, TEG-detected abnormalities, and blood product utilization.

RESULT

Transfusions rarely correlated with the appropriate TEG measurements of coagulation dysfunction. Coagulopathy score had significant correlation to various transfusions and TEG-detected coagulopathies at multiple points during the case. High aggregate coagulopathy scores identified patients receiving more transfusions, re-operations, and longer hospital stays CONCLUSION: The combination of viscoelastic testing and a standardized clinical coagulopathy score has the potential to optimize transfusions if used in tandem as well as standardize communication between surgery and anesthesia teams about clinically evident coagulopathy.

Thromboelastography maximum amplitude predicts short-term mortality in patients with hepatitis B virus-related acute-on-chronic liver failure

Patients with hepatitis B virus (HBV)-related acute-on-chronic liver failure (ACLF) exhibit complex hemostatic defects. Thromboelastography (TEG) can be used to reveal global hemostasis in patients with liver disease; however, little is known about the association between TEG and the outcome of patients with HBV-related ACLF. The present study aimed to investigate the value of TEG for predicting 90 day mortality in patients with HBV-related ACLF. A total of 51 patients with HBV-related ACLF, 26 patients with chronic hepatitis B (CHB) and 26 healthy controls (HC) were enrolled in the present study. TEG, standard coagulation tests, routine blood tests, biochemical markers and demographic variables were recorded and assessed for prognostic value. The results indicated that a prolonged reaction and kinetics (K) time, a shortened α angle and a decreased maximum amplitude (MA) and coagulation index (CI) were observed in patients with HBV-related ACLF, compared with CHB and HC subjects. Patients with HBV-related ACLF in the mortality group exhibited a decrease in α angle, MA, lysis at 30 min, CI, fibrinogen and platelet count, and an increase in K time, international normalized ratio (INR) and the model for end-stage liver disease (MELD) score in comparison with the survival group. MA and INR were two independent predictors of 90 day mortality in patients with HBV-related ACLF, with hazard ratios of 0.918 (95% CI, 0.867-0.971; P=0.003) and 3.141 (95% CI, 1.843-5.354; P<0.001) respectively. When predicting 90 day mortality, MA + INR exhibited the highest area under the receiver operating characteristic curve, followed by INR, MELD score and MA. Patients with ACLF and MA ≤51.5 mm exhibited a poorer outcome than those with MA >51.5 mm, as revealed via the Kaplan-Meier analysis. In summary, the findings of the present study suggested that TEG MA was associated with 90 day mortality in patients with HBV-related ACLF, and a combination of MA and INR was superior to MA, INR and MELD score in terms of prognostic value.

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.

Tracing the Lines: A Review of Viscoelastography for Emergency Medicine Clinicians

BACKGROUND

Viscoelastography (VE) is an established method to identify coagulopathies in various disease processes. Clinical decisions can be made with real-time tracings and quantitative values at the bedside. Thromboelastography (TEG®) and rotational thromboelastometry (ROTEM®) have been utilized in several disease states with clinical varying success.

OBJECTIVES

This review will summarize the literature and provide recommendations pertaining to major disease processes where VE may be beneficial, including trauma, anticoagulation reversal, liver disease, acute ischemic stroke, and acquired brain injuries.

DISCUSSION

VE has a role in many emergency medicine patients encountered by clinicians. Reduced mortality, decreased blood product utilization, and prognostication ability makes VE an intriguing tool that can be utilized by providers to improve patient care.

CONCLUSION

This review serves as a way for emergency medicine clinicians to utilize VE in their practice and provides an insightful literature overview.

Eliminating international normalized ratio threshold for transfusion in pediatric patients with acute liver failure

INTRODUCTION

Transfusion protocols are not well-studied for pediatric patients with acute liver failure (ALF). This study evaluates the utility of an international normalized ratio (INR)-based transfusion threshold for these patients.

METHODS

Forty-four ALF pediatric patients from 2009 to 2018 were reviewed and divided into two groups: (a) a threshold group including patients between 2009 and 2015 who were transfused for an INR above 3.0, per institutional policy (n = 30), and (b) a post-threshold group including patients after 2015 through 2018 who were transfused based on clinical judgment (n = 14). Preoperative INRs, preoperative transfusions, intraoperative transfusions, early reoperation, renal function, graft function and deaths were compared.

RESULTS

Liver failure severity was similar between threshold and post-threshold groups. Threshold patients had a lower average INR prior to transplantation, 2.8 (range 1.8-3.8) vs 4.4 (range 2.1-9.0), respectively (P = .01). Twenty-six threshold patients (87%) received preoperative FFP compared with seven post-threshold patients (50%, P = .0088). Two threshold patients (7%) received preoperative cryoprecipitate compared with five post-threshold patients (36%, P = .014). The incidence of pre-transplant bleeding, operative transfusions, and 1-year patient and graft survival did not differ significantly.

CONCLUSION

Clinical judgment vs an INR-based threshold for transfusions did not increase perioperative complications in children with ALF.

Establishment of thromboelastography reference intervals by indirect method and relevant factor analyses

Thromboelastography (TEG) as a global coagulation test has been continuously developed for many decades in either research or clinical practice. The versatility of TEG test leads to difficulty in standardization and result interpretation. Reference intervals (RIs) of TEG may be one of the most controversial factors that influence its wide applications. RIs establishment with the traditional method is time‐consuming and laborious as well as beyond general laboratory capability. Indirect method using stored data and with statistical calculation and small cost is emerging as an alternative approach for RIs determination. Gender, age, or both affect RIs and must be taken into account before RIs estimation. The present study retrospectively collected a total of 930 TEG results as subjects and established RIs with indirect method for Kaolin‐activated TEG, including the parameters of R, K, αAngle, MA, and CI. Furthermore, gender, age, and gender‐dependent age subsets analyses were performed to determine their effects on RIs of TEG. In this study, we found that TEG parameters showed more hypercoagulability in female than male, most of the measured TEG variables were significantly associated with aging, but only in male statistical significance was found among different age stratification and 60‐year‐old could be considered as cutting point to differentiate coagulation ability in male. In addition, RIs of TEG were estimated by indirect method suitably and verified to be valid in our study. Finally, the RIs of TEG by indirect method were basically significantly different to the RIs recommended by manufacturer, but the consistent percentage is relatively high in the most of measured parameters. In conclusion, it is suggestive that the indirect method for RIs establishment is feasible, but relevant factors, such as gender and age, specifically gender‐dependent age effect, should be considered before RIs determinations.

Liver Transplantation

The field of liver transplantation has changed since the MELD scoring system became the most widely used donor allocation tool. Due to the MELD-based allocation system, sicker patients with higher MELD scores are being transplanted. Persistent organ donor shortages remain a challenging issue, and as a result, the wait-list mortality is a persistent problem for most of the regions. This chapter focuses on deceased donor and live donor liver transplantation in patients with complications of portal hypertension. Special attention will also be placed on donor-recipient matching, perioperative management of transplant patients, and the impact of hepatic hemodynamics on transplantation.

Application of thromboelastography to evaluate the effect of different routes administration of tranexamic acid on coagulation function in total hip arthroplasty

Background

Tranexamic acid (TXA) is widely used to reduce blood loss and transfusion rates in total hip arthroplasty(THA). Thromboelastography, which can monitor coagulation changes from clotting to fibrinolysis dynamically. In this study, thromboelastography was used to assess the dynamic changes in the coagulation of patients who underwent THA with the administration of TXA.

Methods

This randomized controlled trial consisted of 207 consecutive patients who underwent primary total hip arthroplasty. Patients were randomized into three groups: topical-TXA group received a topical application of TXA, IV-TXA group received an intravenous injection of TXA, and control group. Thromboelastography was performed 1 day before surgery and first, fourth, seventh days after surgery. The primary outcomes were thromboelastography parameters, the rates of deep vein thrombosis(DVT), and pulmonary embolism(PE). Secondary outcomes included perioperative blood loss, transfusion rates, and other perioperative complications.

Results

The mean calculated total blood loss in the Topical-TXA group were 832.7 ± 279.84 ml and 834.8 ± 322.94 ml in the IV-TXA group, which were significantly reduced (p < 0.05) compared with control groups at 1093.3 ± 379.7 ml. There were no significant differences between topical-TXA and IV-TXA groups in total blood loss or transfusion rates. K and R have reached a nadir from preoperative levels to 4th day postoperatively and then began to increase.α angle and CI peaked from preoperative levels to the fourth day postoperatively and then began to decline.IV-TXA significantly (p < 0.05) promoted coagulation levels compared with topical-TXA and control groups in the early postoperative period. Almost no significant differences were observed between topical-TXA and control groups in thromboelastography parameters.No significant differences were observed in the incidence of thromboembolic complications and other perioperative complications.

Conclusions

The topical administration of TXA had the same hemostatic effect as intravenous injection tranexamic acid. Coagulation function peaked on 4th day postoperatively and then began to decline. IV-TXA was more enhanced coagulation functions compared with topical-TXA.