Decoding the Clavien-Dindo Classification: Artificial Intelligence (AI) as a Novel Tool to Grade Postoperative Complications.

OBJECTIVE: To assess ChatGPT's capability of grading postoperative complications using the Clavien-Dindo classification (CDC) via Artificial Intelligence (AI) with Natural Language Processing (NLP). BACKGROUND: The CDC standardizes grading of postoperative complications. However, consistent, and precise application in dynamic clinical settings is challenging. AI offers a potential solution for efficient automated grading. METHODS: ChatGPT's accuracy in defining the CDC, generating clinical examples, grading complications from existing scenarios, and interpreting complications from fictional clinical summaries, was tested. RESULTS: ChatGPT 4 precisely mirrored the CDC, outperforming version 3.5. In generating clinical examples, ChatGPT 4 showcased 99% agreement with minor errors in urinary catheterization. For single complications, it achieved 97% accuracy. ChatGPT was able to accurately extract, grade, and analyze complications from free text fictional discharge summaries. It demonstrated near perfect performance when confronted with real-world discharge summaries: comparison between the human and ChatGPT4 grading showed a κ value of 0.92 (95% CI 0.82-1) (P<0.001). CONCLUSIONS: ChatGPT 4 demonstrates promising proficiency and accuracy in applying the CDC. In the future, AI has the potential to become the mainstay tool to accurately capture, extract, and analyze CDC data from clinical datasets.

An international, multicenter, survey-based analysis of practice and management of acute liver failure.

Acute liver failure (ALF) is an acute liver dysfunction with coagulopathy and HE in a patient with no known liver disease. As ALF is rare and large clinical trials are lacking, the level of evidence regarding its management is low-moderate, favoring heterogeneous clinical practice. In this international multicenter survey study, we aimed to investigate the current practice and management of patients with ALF. An online survey targeting physicians who care for patients with ALF was developed by the International Liver Transplantation Society ALF Special-Interest Group. The survey focused on the management and liver transplantation (LT) practices of ALF. Survey questions were summarized overall and by geographic region. A total of 267 physicians completed the survey, with a survey response rate of 21.36%. Centers from all continents were represented. More than 90% of physicians specialized in either transplant hepatology/surgery or anesthesiology/critical care. Two hundred fifty-two (94.4%) respondents' institutions offered LT. A total of 76.8% of respondents' centers had a dedicated liver-intensive or transplant-intensive care unit ( p < 0.001). The median time to LT was within 48 hours in 12.7% of respondents' centers, 72 hours in 35.6%, 1 week in 37.6%, and more than 1 week in 9.6% ( p < 0.001). Deceased donor liver graft (49.6%) was the most common type of graft offered. For consideration of LT, 84.8% of physicians used King's College Criteria, and 41.6% used Clichy Criteria. Significant differences were observed between Asia, Europe, and North America for offering LT, number of LTs performed, volume of patients with ALF, admission to a dedicated intensive care unit, median time to LT, type of liver graft, monitoring HE and intracranial pressure, management of coagulopathy, and utilization of different criteria for LT. In our study, we observed significant geographic differences in the practice and management of ALF. As ALF is rare, multicenter studies are valuable for identifying global practice.

Diagnostic accuracy of coronary computed tomography angiography-derived fractional flow reserve (CT-FFR) in patients before liver transplantation using CT-FFR machine learning algorithm.

OBJECTIVES: Liver transplantation (LT) is associated with high stress on the cardiovascular system. Ruling out coronary artery disease (CAD) is an important part of evaluation for LT. The aim of our study was to assess whether CT-derived fractional flow reserve (CT-FFR) allows for differentiation of hemodynamically significant and non-significant coronary stenosis in patients evaluated for LT. METHODS: In total, 201 patients undergoing LT evaluation were included in the study. The patients received coronary computed tomography angiography (CCTA) to rule out CAD and invasive coronary angiography (ICA) to further evaluate coronary lesions found in CCTA if a significant (≥ 50 % on CCTA) stenosis was suspected. CT-FFR was computed from CCTA datasets using a machine learning-based algorithm and compared to ICA as a standard of reference. Coronary lesions with CT-FFR ≤ 0.80 were defined as hemodynamically significant. RESULTS: In 127 of 201 patients (63%), an obstructive CAD was ruled out by CCTA. In the remaining 74 patients (37%), at least one significant stenosis was suspected in CCTA. Compared to ICA, sensitivity, specificity, PPV, and NPV of the CT-FFR measurements were 71% (49-92%), 90% (82-98%), 67% (45-88%), and 91% (84-99%), respectively. The diagnostic accuracy was 85% (85-86%). In 69% of cases (52 of 75 lesions), additional analysis by CT-FFR correctly excluded the hemodynamic significance of the stenosis. CONCLUSIONS: Machine learning-based CT-FFR seems to be a very promising noninvasive approach for exclusion of hemodynamic significant coronary stenoses in patients undergoing evaluation for LT and could help to reduce the rate of invasive coronary angiography in this high-risk population. KEY POINTS: • Machine learning-based computed tomography-derived fractional flow reserve (CT-FFR) seems to be a very promising noninvasive approach for exclusion of hemodynamic significance of coronary stenoses in patients undergoing evaluation for liver transplantation and could help to reduce the rate of invasive coronary angiography in this high-risk population.

A brief history of liver transplantation and transplant anesthesia.

In this review, we describe the major milestones in the development of organ transplantation with a specific focus on hepatic transplantation. For many years, the barriers preventing successful organ transplantation in humans seemed insurmountable. Although advances in surgical technique provided the technical ability to perform organ transplantation, limited understanding of immunology prevented successful organ transplantation. The breakthrough to success was the result of several significant discoveries between 1950 and 1980 involving improved surgical techniques, the development of effective preservative solutions, and the suppression of cellular immunity to prevent graft rejection. After that, technical innovations and laboratory and clinical research developed rapidly. However, these advances alone could not have led to improved transplant outcomes without parallel advances in anesthesia and critical care. With increasing organ demand, it proved necessary to expand the donor pool, which has been achieved with the use of living donors, split grafts, extended criteria organs, and organs obtained through donation after cardiac death. Given this increased access to organs and organ resources, the number of transplantations performed every year has increased dramatically. New regulatory organizations and transplant societies provide critical oversight to ensure equitable organ distribution and a high standard of care and also perform outcome analyses. Establishing dedicated transplant anesthesia teams results in improved organ transplantation outcomes and provides a foundation for developing new standards for other subspecialties in anesthesiology, critical care, and medicine overall. Through a century of discovery, the success we enjoy at the present time is the result of the work of well-organized multidisciplinary teams following standardized protocols and thereby saving thousands of lives worldwide each year. With continuing innovation, the future is bright.

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.

Intensive care management of acute-on-chronic liver failure.

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

Analysis of Ascites-Challenged Blood in Patients with Liver Cirrhosis Using Rotational Thromboelastometry: How Robust Is the Evidence on Ascites-Attributed Fibrinolysis?

INTRODUCTION: For over 30 years, ascites has been postulated to facilitate fibrinolysis in patients with liver cirrhosis. In contrast to previous research employing conventional coagulation tests, this study aimed to characterize hemostatic interactions between blood and ascites using the rotational thromboelastometry (ROTEM). METHODS: Blood samples - pure or mixed with ascites in a ratio of 1:1 - from cirrhotic patients (n = 10) were subjected to ROTEM analysis. In addition, a negative control group was built with cirrhotic patients (n = 10) whose blood was mixed with physiologic sodium chloride (0.9% NaCl) solution in a ratio of 1:1. Subsequently, ROTEM measurements were subjected to statistical analysis. RESULTS: During ascites challenge, clotting time (CT, measured in seconds) was significantly prolonged in EXTEM (blood: 70.40 ± 20.40 vs. ascites/blood: 109.8 ± 47.7) and APTEM (blood: 66.50 ± 14.55 vs. ascites/blood: 138.7 ± 105.8), likely reflecting a dilution effect. However, CT in INTEM remained unchanged, suggesting a sustained intrinsic pathway function. Maximal clot firmness (measured in millimeters) in FIBTEM decreased significantly (blood: 14.70 ± 9.55 vs. ascites/blood: 6.00 ± 5.66), thus indicating depletion of fibrinogen in ascites. Strikingly, maximum lysis (measured in %) significantly decreased in EXTEM (blood: 9.30 ± 2.79 vs. ascites/blood: 5.50 ± 2.84), APTEM (blood: 8.50 ± 3.10 vs. ascites/blood: 5.60 ± 2.88), and INTEM (blood: 7.50 ± 2.27 vs. ascites/blood: 5.10 ± 3.48). CONCLUSIONS: ROTEM provided new evidence that ascites may not primarily induce fibrinolysis in cirrhotic patients. This finding seems to be of significant importance for the clinical management of cirrhotic patients experiencing complications, for example, abdominal hemorrhage after liver biopsy or paracentesis; here, replacement of prothrombin complex concentrates and/or fibrinogen concentrates may prove more beneficial than the use of fresh frozen plasma or antifibrinolytic drugs.

Fibrinogen Supplementation and Its Indications.

Adequate plasma levels of fibrinogen are essential for clot formation, and in severe bleeding, fibrinogen reaches a critically low plasma concentration earlier than other coagulation factors. Although the critical minimum concentration of fibrinogen to maintain hemostasis is a matter of debate, many patients with coagulopathic bleeding require fibrinogen supplementation. Among the treatment options for fibrinogen supplementation, fibrinogen concentrate may be viewed by some as preferable to fresh frozen plasma or cryoprecipitate. The authors review major studies that have assessed fibrinogen treatment in trauma, cardiac surgery, end-stage liver disease, postpartum hemorrhage, and pediatric patients. Some but not all randomized controlled trials have shown that fibrinogen concentrate can be beneficial in these settings. The use of fibrinogen as part of coagulation factor concentrate based therapy guided by point-of-care viscoelastic coagulation monitoring (ROTEM [rotational thromboelastometry] or TEG [thromboelastography]) appears promising. In addition to reducing patients' exposure to allogeneic blood products, this strategy may reduce the risk of complications such as transfusion-associated circulatory overload, transfusion-related acute lung injury, and thromboembolic adverse events. Randomized controlled trials are challenging to perform in patients with critical bleeding, and more evidence is needed in this setting. However, current scientific rationale and clinical data support fibrinogen repletion in patients with ongoing bleeding and confirmed fibrinogen deficiency.

The Effect of Immunosuppression on Coagulation After Liver Transplantation.

Everolimus (EVR) is a mammalian target of rapamycin (mTOR) inhibitor commonly used for immunosuppression (IS) after liver transplantation (LT). However, there are concerns about whether mTOR inhibitors may move the hemostatic balance toward a higher likelihood of thrombosis. The present study aimed to investigate potential coagulation disorders after the administration of EVR. We evaluated 54 patients after conversion to an EVR-based IS regimen (n = 26) and compared those patients with patients who were switched to extended-release tacrolimus (TAC) but had never received EVR (n = 28). At baseline and again at 1 month and 6 months after conversion, we measured international normalized ratio, activated partial thromboplastin time, and anticoagulation and fibrinolysis factors, and we performed rotational thromboelastometry (ROTEM). Data were analyzed with a Mann-Whitney U test, a repeated-measure analysis of variance, and a Fisher's exact test. Statistical significance was set at the level of P ≤ 0.05. Plasma levels of von Willebrand factor, fibrinogen, and factor VIII were significantly higher than baseline levels at 1 month and 6 months after conversion of IS to EVR (P < 0.001); plasma levels of protein C, protein S, and plasminogen also increased significantly (P < 0.001). ROTEM confirmed a significant increase in maximum clot firmness in EXTEM, INTEM, and FIBTEM assays (P < 0.001). In all assays, maximum lysis was significantly lower than baseline levels at 1 month and 6 months after conversion to EVR. Patients converted to IS with extended-release TAC exhibited no significant changes in coagulation variables. Retrospective analysis showed a significantly higher incidence of thromboembolic complications among patients treated with EVR-based IS than among those treated with extended-release TAC (P < 0.01). In conclusion, the administration of EVR after LT seems to modify hemostasis to a procoagulant state. Thrombophilia screening before conversion may determine which patients will benefit from conversion to EVR-based IS.

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

PURPOSE OF REVIEW: This review provides insight into our current understanding of the pathophysiology and treatment of coagulopathy associated with liver failure, and bleeding risk assessment. RECENT FINDINGS: Patients with end-stage liver disease (ESLD) have a rebalanced coagulation profile and are at risk for both excessive clotting and bleeding. Hypercoagulability is associated with profound endothelial dysfunction and an increased concentration of liver-independent coagulation factors. Because of this rebalanced coagulation profile, standard laboratory tests have been demonstrated to be ineffective in either predicting and/or guiding the management of coagulopathy. Viscoelastic testing, however, is able to provide a dynamic assessment of clot formation in whole blood and has been demonstrated to be invaluable in both monitoring and management of coagulation problems associated with liver failure. More recently, there is increasing interest in thrombin generation tests to monitor coagulation in patients with ESLD.Multiple institutional protocols for prophylaxis and treatment of ESLD-related thromboses have been developed. High-quality studies evaluating these approaches are lacking. SUMMARY: Patients with ESLD are at risk for excessive bleeding and clotting. Treatment of any significant coagulopathy should not be based solely on standard laboratory tests. Thrombosis prophylaxis has to be considered in susceptible populations.

Safety of coagulation factor concentrates guided by ROTEM™-analyses in liver transplantation: results from 372 procedures.

BACKGROUND: Most centres use fresh frozen plasma (FFP) based protocols to prevent or treat haemostatic disturbances during liver transplantation. In the present study, we used a rotational thrombelastometry (ROTEM™, TEM, Munich, Germany) guided haemostasis management with fibrinogen concentrates, prothrombin complex concentrates (PCC), platelet concentrates and tranexamic acid without FFP usage and determined the effect on 30 day mortality. METHODS: Retrospective data analysis with 372 consecutive adult liver transplant patients performed between 2007 and 2011. RESULTS: Thrombelastometry guided coagulation management resulted in a transfusion rate for fibrinogen concentrates in 50.2%, PCC in 18.8%, platelet concentrates in 21.2%, tranexamic acid in 4.5%, and red blood cell concentrates in 59.4%. 30 day mortality for the whole cohort was 14.2%. The univariate analyses indicated that nonsurvivors received significantly more fibrinogen concentrates, PCC, red blood cell concentrates, platelet concentrates, and infusion volume, and had a higher MELD score. However, association with mortality was weak as evidenced by receiver operating characteristic curve analyses. Further univariate analyses demonstrated, that up to 8 g of fibrinogen did not increase mortality compared to patients not receiving the coagulation factor. Multivariate analysis demonstrated that platelet concentrates (p = 0.0002, OR 1.87 per unit), infused volume (p = 0.0004, OR = 1.13 per litre), and MELD score (p = 0.024; OR 1.039) are independent predictors for mortality. Fibrinogen concentrates, PCC, and red blood cell concentrates were ruled out as independent risk factors. CONCLUSIONS: ROTEM™ guided substitution with fibrinogen concentrates and PCC does not negatively affect mortality after liver transplantation, while the well-known deleterious effect associated with platelet concentrates was confirmed.

Perioperative thrombotic complications associated with pediatric liver transplantation: a UNOS database evaluation.

BACKGROUND: This retrospective UNOS database evaluation analyzes the prevalence of preoperative portal vein thromboses (PVT), and postoperative thromboses leading to graft failure in pediatric patients undergoing liver transplantation (LT). METHODS: The evaluation was performed in three age groups: I (0-5), II (6-11), III (12-18) years old. Factors predictive of pre- and postoperative thromboses were analyzed. RESULTS: Between 2000 and 2015, 8982 pediatric LT were performed in the US. Of those, 390 patients had preoperative PVT (4.3%), and 396 (4.4%) had postoperative thromboses. The prevalence of both types of thromboses was less in Group III than in the other two groups (3.20% vs 4.65%, p = 0.007 and 1.73% vs. 5.13%, p < 0.001, respectively). The prevalence of postoperative thromboses was significantly higher in Group I than in the other two groups (5.49% vs. 2.51%, p < 0.001). Preoperative PVT was independently associated with postoperative thromboses (OR = 1.7, p = 0.02). Children less than 5 years of age were more likely to develop postoperative thromboses leading to graft failure (OR = 2.9, p < 0.001). CONCLUSION: Younger children undergoing LT are prone to pre-and postoperative thrombotic complications. Preoperative PVT at the time of transplantation was independently associated with postoperative thromboses. Perioperative antithrombotic therapy should be considered in pediatric patients undergoing LT.

Donor Leucocytosis Predicts Bacterial and Fungal Contamination of the Preservation Solution in Visceral Organ Transplantation.

INTRODUCTION: Contamination of the preservation solution may contribute to septic complications that can occur after transplantation and cause higher morbidity and mortality among recipients. The aim of this study was to determine potential donor-related predictors of positive microbiological findings in the preservation solution. DESIGN: We retrospectively studied 16 donor parameters on data from our center for microbiological findings in the preservation solution used in solid-organ recovery. From January 2008 through December 2011, 976 solid organs were transplanted, and in 167, the solution was positive for contaminants. RESULTS: The most frequently detected contaminant was coagulase-negative staphylococci. Only the donor leucocyte count (cutoff at 9.1 × 109/L) predicted positive microbiological findings in the preservation solution ( P = .0024). Multivariable regression analysis found that donor age, donor sex, intensive care unit stay, total number of organs recovered, and leucocyte count differentiated various categories of potentially pathogenic bacteria. CONCLUSION: Donor leucocyte count higher than 9.1 × 109/L predicts contamination of preservation solution.

Rotational thromboelastometry can detect factor XIII deficiency and bleeding diathesis in patients with cirrhosis.

BACKGROUND & AIMS: Patients with progressive liver disease exhibit complex coagulation disorders. Factor XIII plays a crucial role in the last steps of haemostasis, and its deficiency is associated with an increased incidence of bleeding diathesis. However, current conventional coagulation tests cannot detect factor XIII deficiency. In this study, we examined factor XIII activity and the ability of rotational thromboelastometry to detect factor XIII deficiency and bleeding diathesis in patients with cirrhosis. METHODS: We retrospectively studied 74 patients with cirrhosis, comparing the results of conventional coagulation tests (international normalized ratio, activated partial thromboplastin time, platelet count, fibrinogen level), rotational thromboelastometry, factor XIII activity and clinical scores. RESULTS: Patients with cirrhosis exhibited reduced factor XIII activity. Factor XIII activity was positively correlated with conventional coagulation parameters and rotational thromboelastometry values, such as maximum clot formation (MCF)extem (r=.48, P<.0001) and MCFfibtem (r=.60, P<.0001). However, maximum lysis (ML)extem and MLaptem were not correlated with factor XIII activity. Three-month mortality rates (P=.0469) and bleeding complications (P<.0001) were significantly associated with lower factor XIII activity. Patients with haemorrhage exhibited significantly altered rotational thromboelastometry values. CONCLUSIONS: Reduced levels of MCFextem and MCFfibtem but not high levels of MLextem and MLaptem are associated with factor XIII deficiency in patients with liver disease. Therefore, substituting factor XIII should be considered for such patients to strengthen clot formation in patients experiencing haemorrhage or those who have undergone interventions.

Low transferrin and high ferritin concentrations are associated with worse outcome in acute liver failure.

BACKGROUND & AIMS: Serum ferritin and transferrin have been identified as prognostic markers in patients with chronic diseases. In this study, we investigated if these parameters can predict outcome in patients with acute liver failure. METHODS: A total of 102 consecutive patients with acute liver failure were retrospectively analysed. The patients were grouped by outcome: spontaneous recovery vs liver transplantation and/or death or survival vs death. Routine laboratory parameters, transferrin and ferritin concentrations in serum, and anthropomorphic data collected on admission were analysed. RESULTS: Non-spontaneously recovering patients had higher ferritin (12 252±25 791 vs 4434.4±9027.2 µg/L; P<.05) and lower transferrin levels (140.4±66.7 vs 206.9±65.8 mg/dL; P<.05) than spontaneously recovering patients. Similarly non-survivors exhibited higher serum ferritin and lower transferrin than non-transplanted survivors. Patients with severe hepatic inflammation (A3) had higher ferritin levels compared to patients with mild-moderate inflammation (A1-2) (5280±5094 vs 2361±2737 µg/L; P=.025). ROC analysis of single parameters was performed in non-transplanted patients, resulting in an area under the curve, sensitivity and specificity of 0.812%, 83.3%, and 77.1% for age, 0.871%, 84.1% and 75% for transferrin and 0.802%, 91.7% and 62.9% for ferritin. A model incorporating age, MELD and transferrin had the best predictive value with an area under the curve of 0.947, a sensitivity of 100% and corresponding specificity of 77.8%. CONCLUSIONS: High ferritin and low transferrin levels are associated with worse outcome in patients with acute liver failure. A model incorporating age, MELD score and transferrin outperformed MELD score for 90-day overall survival of non-transplanted patients.

Hepatic artery and biliary complications in liver transplant recipients with radioembolization bridging treatment for hepatocellular carcinoma.

BACKGROUND: Locoregional bridging treatments are commonly applied in patients with hepatocellular carcinoma (HCC) prior to liver transplantation to prevent tumor progression during waiting time. It remains unknown whether pre-transplant radioembolization treatment may increase the prevalence of hepatic artery and biliary complications post-transplant. METHODS: We performed a retrospective review of 173 consecutive patients with HCC who underwent liver transplantation at our transplant center between January 2007 and December 2016. RESULTS: Radioembolization bridging treatment was applied in 42 patients while 131 patients received other or no forms of bridging treatment. The overall prevalence of intra-operative and early post-operative hepatic artery complications was 9.5% in the radioembolization group and 9.2% in the control group (P = 1.000). Biliary complications were significantly less frequent in the radioembolization group (4.8% vs 17.6%, P = .0442). In multivariable analysis, radioembolization was not significantly associated with an increased risk of arterial complications. Considering biliary complications, radioembolization bridging treatment was the only factor significantly associated with decreased odds (OR 0.187 (0.039, 0.892), P = .036). CONCLUSIONS: Radioembolization is not associated with higher odds of hepatic artery complications following liver transplantation. There may even be a protective effect regarding biliary complications. Radioembolization as a bridge to transplantation may effectively be applied without compromising successful liver transplantation.

Citrate shows protective effects on cardiovascular and renal function in ischemia-induced acute kidney injury.

BACKGROUND: Ischemia and reperfusion (I/R) is one of the major causes of acute kidney injury (AKI). Citrate reduces hypoxia-induced mitochondrial energetic deficits in isolated proximal tubules. Moreover, citrate anticoagulation is now frequently used in renal replacement therapy. In the present study a rat model of I/R-induced AKI was utilized to examine renal protection by citrate in vivo. METHODS: AKI was induced by bilateral renal clamping (40 min) followed by reperfusion (3 h). Citrate was infused at three different concentrations (0.3 mmol/kg/h; 0.6 mmol/kg/h and 1.0 mmol/kg/h) continuously for 60 min before and 45 min after ischemia. Plasma calcium concentrations were kept stable by infusion of calcium gluconate. The effect of citrate was evaluated by biomonitoring, blood and plasma parameters, histopathology and tissue ATP content. RESULTS: In comparison to the normoxic control group bilateral renal ischemia led to an increase of creatinine and lactate dehydrogenase activity and a decrease in tissue ATP content and was accompanied by a drop in mean arterial blood pressure. Infusion of 1.0 mmol/kg/h citrate led to lower creatinine and reduced LDH activity compared to the I/R control group and a tendency for higher tissue ATP content. Pre-ischemic infusion of 1.0 mmol/kg/h citrate stabilized blood pressure during ischemia. CONCLUSIONS: Citrate has a protective effect during I/R-induced AKI, possibly by limiting the mitochondrial deficit as well as by beneficial cardiovascular effects. This strengthens the rationale of using citrate in continuous renal replacement therapy and encourages consideration of citrate infusion as a therapeutic treatment for AKI in humans.

African Americans have a lower prevalence of portal vein thrombosis at the time of liver transplantation.

BACKGROUND: Perioperative vascular thrombotic events in patients undergoing liver transplantation (LT) are associated with significant morbidity and mortality. METHODS: In this retrospective UNOS database analysis, we evaluated the prevalence of portal vein thrombosis (PVT) and factors contributing to PVT development in different ethnic groups. RESULTS: Of the 47 953 LT performed between 2002 and 2015, we identified 3642 cases of PVT. African Americans (AA) had a significantly lower prevalence of PVT compared to other ethnic groups (p = 0.0001). Multivariable regression analysis confirmed that AA were less likely than other ethnicities to have PVT (OR = 0.6). AA cohort was more likely to have infectious or autoimmune causes of liver failure (OR = 1.6, 1.7 respectively) as well as higher creatinine and INR compared to other groups (OR = 1.6, 1.3 respectively). AA's were less likely to have encephalopathy, ascites, or variceal bleeding, which might indicate lower portal pressures. AA's were listed for LT later than other ethnicities and had both a lower functional status and higher MELD score at the time of registration. DISCUSSION: AA's had a significantly lower prevalence of preoperative PVT despite having a greater number of factors predisposing to thrombosis. This predisposition should be considered before instituting perioperative antithrombotic therapy.