Comparative Analysis of Artificial Intelligence (AI) Languages in Predicting Sequential Organ Failure Assessment (SOFA) Scores.

PURPOSE: The Sequential Organ Failure Assessment (SOFA) score plays a crucial role in intensive care units (ICUs) by providing a reliable measure of a patient's organ function or extent of failure. However, the precise assessment is time-consuming, and daily assessment in clinical practice in the ICU can be challenging. METHODS: Realistic scenarios in an ICU setting were created, and the data mining precision of ChatGPT 4.0 Plus, Bard, and Perplexity AI were assessed using Spearman's as well as the intraclass correlation coefficients regarding the accuracy in determining the SOFA score. RESULTS: The strongest correlation was observed between the actual SOFA score and the score calculated by ChatGPT 4.0 Plus (r correlation coefficient 0.92) (p<0.001). In contrast, the correlation between the actual SOFA and that calculated by Bard was moderate (r=0.59, p=0.070), while the correlation with Perplexity AI was substantial, at 0.89, with a p<0.001. The interclass correlation coefficient analysis of SOFA with those of ChatGPT 4.0 Plus, Bard, and Perplexity AI was ICC=0.94. CONCLUSION: Artificial intelligence (AI) tools, particularly ChatGPT 4.0 Plus, show significant promise in assisting with automated SOFA score calculations via AI data mining in ICU settings. They offer a pathway to reduce the manual workload and increase the efficiency of continuous patient monitoring and assessment. However, further development and validation are necessary to ensure accuracy and reliability in a critical care environment.

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.

INTRODUCTION: Acute liver failure (ALF) is an acute liver dysfunction with coagulopathy and hepatic encephalopathy 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. METHODS: 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 management and liver transplantation (LT) practices of ALF. Survey questions were summarized overall and by geographic region. RESULTS: 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 were specialized in either transplant hepatology/surgery or anesthesiology/critical care. Two hundred and fifty-two (94.4%) respondents' institutions offered LT. A total of 76.8% of respondents' centers had a dedicated liver- or transplant- intensive care unit (p<0.001). Median time to LT was within 48 hours in 12.7% of respondents' centers, 72 hours in 35.6%, one week in 37.6%, and more than one 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 ALF patients, admission to a dedicated intensive care unit, median time to LT, type of liver graft, monitoring hepatic encephalopathy and intracranial pressure, management of coagulopathy, and utilization of different criteria for LT. DISCUSSION: In our study, we observed significant geographic differences in the practice and management of ALF. As ALF is rare multicenter studies are valuable to identify global practice.

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Risk Factor Analysis for Developing Major Complications Following Esophageal Surgery-A Two-Center Study.

BACKGROUND: Esophagectomy carries a high risk of morbidity and mortality compared to other major surgeries. With the aim of creating an easy-to-use clinical preoperative risk assessment tool and to validate previously described risk factors for major complications following surgery, esophagectomies at two tertiary medical centers were analyzed. METHODS: A total of 450 patients who underwent esophagectomy for esophageal carcinoma at the University Medical Centre, Hamburg, or at the Medical Center University Duisburg-Essen, Germany (January 2008 to January 2020) were retrospectively analyzed. Epidemiological and perioperative data were analyzed to identify the risk factors that impact major complication rates. The primary endpoint of this study was to determine the incidence of major complications. RESULTS: The mean age of the patients was 63 years with a bimodal distribution. There was a male predominance across the cohort (81% vs. 19%, respectively). Alcohol abuse (p = 0.0341), chronic obstructive pulmonary disease (p = 0.0264), and cardiac comorbidity (p = 0.0367) were associated with a significantly higher risk of major complications in the multivariate analysis. Neoadjuvant chemotherapy significantly reduced the risk of major postoperative complications (p < 0.0001). CONCLUSIONS: Various patient-related risk factors increased the rate of major complications following esophagectomy. Patient-tailored prehabilitation programs before esophagectomy that focus on minimizing these risk factors may lead to better surgical outcomes and should be analyzed in further studies.

Navigating the Labyrinth: Intensive Care Challenges for Patients with Acute-on-Chronic Liver Failure.

Acute-on-chronic liver failure (ACLF) refers to the deterioration of liver function in individuals who already have chronic liver disease. In the setting of ACLF, liver damage leads to the failure of other organs and is associated with increased short-term mortality. Optimal medical management of patients with ACLF requires implementing complex treatment strategies, often in an intensive care unit (ICU). Failure of organs other than the liver distinguishes ACLF from other critical illnesses. Although there is growing evidence supporting the current approach to ACLF management, the mortality associated with this condition remains unacceptably high. In this review, we discuss considerations for ICU care of patients with ACLF and highlight areas for further research.

A Comprehensive Review of the Diagnosis and Management of Acute Liver Failure.

Acute liver failure (ALF) is a rare and specific form of severe hepatic dysfunction characterized by coagulopathy and hepatic encephalopathy in a patient with no known liver disease. ALF carries a high morbidity and mortality. Careful attention should be given to hemodynamics and metabolic parameters along with the active surveillance of infections. Timely transfer and supportive management are important in an intensive care unit in a liver transplant center. Identifying patients who will and will not improve with medical management and may need emergent liver transplantation is critical. In this review, we provide a comprehensive update on the etiology, diagnosis, and management of ALF.

The Yin and the Yang of Hemostasis in End-Stage Liver Disease.

Patients with end-stage liver disease (ESLD) undergoing liver transplantation (LT) are prone to thromboses both while on the waiting list and in the perioperative period. This hypercoagulability is associated with significant endothelial dysfunction (ED) due to nitric oxide dysregulation. ED and increased thrombin generation are the main factors responsible for this hypercoagulability. Sepsis alone can significantly alter a patient's coagulation profile. In combination with ESLD, however, sepsis or septic shock are responsible for very complex changes. This makes both the assessment and management of coagulation in septic patients with ESLD very challenging. Viscoelastic testing (VET) is the preferred method of coagulation management in patients with cirrhosis because, as with standard laboratory testing, VET can assess the entire coagulation system including the interaction between both pro- and anticoagulants and platelets.

Lymph Node Staging in Perihilar Cholangiocarcinoma: The Key to the Big Picture.

Klatskin tumors have a bad prognosis despite aggressive therapy. The role and extent of lymph node dissection during surgery is a matter of discussion. This retrospective study analyzes our current experience of surgical treatments in the last decade. Patients and Methods: A retrospective single-center analysis of patients (n = 317) who underwent surgical treatment for Klatskin tumors. Univariable and multivariable logistic regression and Cox proportional analysis were performed. The primary endpoint was to investigate the role of lymph node metastasis for patient survival after complete tumor resection. The secondary endpoint was the prediction of lymph node status and long-term survival from preoperatively available parameters. Results: In patients with negative resection margins, a negative lymph node status was the prognosis-determining factor with a 1-, 3-, and 5-year survival rate of 87.7%, 37%, and 26.4% compared with 69.5%, 13.9%, and 9.3% for lymph-node-positive patients, respectively. Multivariable logistic regression for complete resection and negative lymph node status demonstrated only Bismuth type 4 (p = 0.01) and tumor grading (p = 0.002) as independent predictors. In multivariate Cox regression analysis, independent predictors of survival after surgery were the preoperative bilirubin level (p = 0.03), intraoperative transfusion (p = 0.002), and tumor grading (G) (p = 0.001). Conclusion: Lymph node dissection is of utmost importance for adequate staging in patients undergoing surgery for perihilar cholangiocarcinoma. In spite of extensive surgery, long-term survival is clearly associated with the aggressiveness of the disease.

Transplantation for Primary Sclerosing Cholangitis: Outcomes and Recurrence.

Primary sclerosing cholangitis (PSC) is characterized by inflammation of the whole bile duct system. Liver transplantation is only approved as a curative treatment when it comes to end-stage liver disease. The aim of our study was to assess morbidity, survival rates and PSC recurrence and the impact of donor characteristics in long-term follow-up. This was an IRB-approved retrospective study. A total of 82 patients were identified who were transplanted between January 2010 and December 2021 for PSC. Among these patients, 76 adult liver transplant PSC patients and their corresponding donors were analyzed. Three pediatric cases and three adult patients with a follow-up within <1 year were excluded from further analysis. Median (range) age was 47 years (18-70) with a median (range) lab-MELD of 16 (7-40). Median (range) ICU and hospital stays were 4.6 days (0-147) and 21 days (1-176), respectively. The majority of patients suffered from Crohn's disease or ulcerative colitis as a concomitant comorbidity (65.8%). The ten-year survival rate was 74.6%. A significantly lower lab-MELD score was identified in patients surviving for > 10 years (15 vs. 22, p = 0.004). Most patients (65%) passed in the first year following transplantation, with primary non-function (PNF), sepsis and arterial thrombosis being the most common causes of death. Donor characteristics did not affect patient survival. Patients with PSC show excellent 10-year survival rates. While the lab-MELD score significantly affected long term outcomes, donor characteristics did not affect survival rates.

Use or Misuse of Albumin in Critical Ill Patients.

Since 1940 albumin has been used worldwide and is widely available commercially since this time. However, a meta-analysis in 1998 challenged the use of albumin and identified a trend toward higher mortality in critically ill patients who had received albumin. Since then, many studies including multicenter randomized controlled trials have been carried out investigating the safety and efficacy of albumin treatment in different patient cohorts. In this context, patient cohorts that benefit from albumin were identified. However, particularly in non-liver patients, the use of albumin remains controversial. In our comprehensive review, we would like to highlight the most important studies in the recent 20 years and therefore offer an evidence-based outlook for the use of albumin for patients treated in the ICU.

International Liver Transplantation Society/Society for Advancement of Transplant Anesthesia Consensus Statement on Essential Attributes of a Liver Transplant Anesthesiologist.

BACKGROUND: We sought to establish consensus on the essential skills, knowledge, and attributes that a liver transplant (LT) anesthesiologist should possess in a bid to help guide the further training process. METHODS: Consensus was achieved via a modified Delphi methodology, surveying 15 identified international experts in the fields of LT anesthesia and critical care. RESULTS: Key competencies were identified in preoperative management and optimization of a potential LT recipient; intraoperative management, including hemodynamic monitoring; coagulation and potential crisis management; and postoperative intensive and enhanced recovery care. CONCLUSIONS: This article provides an essential guide to competency-based training of an LT anesthesiologist.

Platelet Aggregation Inhibitors and Anticoagulants in Gastroenterological and Visceral Surgical Procedures.

BACKGROUND: The proper management of patients being treated with platelet aggregation inhibitors or anticoagulant drugs is a common clinical problem for both elective and emergency procedures in gastroenterology and visceral surgery. The essential matters that must be kept in mind in this situation are the hemorrhagic risk of the procedure, the indication for anticoagulation, and the pharmacology of anticoagulant drugs and platelet aggregation inhibitors. METHODS: This review is based on publications retrieved by a selective search in PubMed and on the guidelines of the relevant specialist societies. RESULTS: Nearly all procedures in gastroenterology and visceral surgery can be performed under monotherapy with acetyl - salicylic acid. Other platelet aggregation inhibitors, such as clopidogrel or prasugrel, or anticoagulant drugs generally do not need to paused before diagnostic endoscopic procedures with a low risk of bleeding (<1.5%), but they must be paused before procedures in gastroenterology and visceral surgery where the risk of bleeding is high (≥ 1.5%). Bridging with heparin is reserved for patients with a very high risk of thromboembolism ( ≥ 5%). CONCLUSION: Knowledge of the current recommendations on the management of anticoagulants before gastroenterological and visceral surgical procedures gives the clinician a well-founded means of dealing with this complex and common clinical situation.

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.

Controlled oxygenated rewarming as novel end-ischemic therapy for cold stored liver grafts. A randomized controlled trial.

Abrupt return to normothermia has been shown a genuine factor contributing to graft dysfunction after transplantation. This study tested the concept to mitigate reperfusion injury of liver grafts by gentle warming-up using ex vivo machine perfusion prior to reperfusion. In a single center randomized controlled study, livers were assigned to conventional static cold storage (SCS) alone or to SCS followed by 90 min of ex vivo machine perfusion including controlled oxygenated rewarming (COR) by gentle and protracted elevation of the perfusate temperature from 10°C to 20°C. Primary outcome mean peak aspartate aminotransferase (AST) was 1371 U/L (SD 2871) after SCS versus 767 U/L (SD 1157) after COR (p = 0.273). Liver function test (LiMAx) on postoperative day 1 yielded 187 µg/kg/h (SD 121) after SCS, but rose to 294 µg/kg/h (SD 106) after COR (p = 0.006). Likewise, hepatic synthesis of coagulation factor V was significantly accelerated in the COR group immediately after transplantation (103% [SD 34] vs. 66% [SD 26]; p = 0.001). Fewer severe complications (Clavien-Dindo grade ≥3b) were reported in the COR group (8) than in the SCS group (15). Rewarming/reperfusion injury of liver grafts can be safely and effectively mitigated by controlling of the rewarming kinetics prior to blood reperfusion using end-ischemic ex vivo machine perfusion after cold storage.

Elevated Pre- and Postoperative ROTEM™ Clot Lysis Indices Indicate Reduced Clot Retraction and Increased Mortality in Patients Undergoing Liver Transplantation.

Background: The ROTEM™ clot lysis index, describing the decrease in firmness of a clot with time, predicts mortality in various settings. The variability of the clot lysis index in surgical procedures and the involved pathophysiological mechanisms are unknown. We therefore compared pre- and postoperative clot lysis indices in liver transplantation (LTX) procedures, determined the eventual association with mortality, and investigated the mechanisms underlying decreased clot lysis index using inhibitors of fibrinolysis and clot retraction, respectively. Methods: In this retrospective cohort study, data on pre- and post-transplant ROTEM™ findings as obtained with EXTEM (tissue factor activation), INTEM (intrinsic system activation), FIBTEM (extrinsic system activation and inhibition of clot retraction), APTEM (extrinsic system activation and fibrinolysis inhibition), conventional laboratory coagulation tests, blood loss, transfusion of blood products, and outcome were registered. Results: Pre-transplant clot lysis indices showed a broad distribution ranging from 75% to 99% independent of the activator used (EXTEM, INTEM). During the surgical procedure, median clot lysis index values markedly increased from 92% to 97% (EXTEM) and 93% to 98% (INTEM), respectively (p < 0.0001 each). Aprotinin had no effect on either pre- or postsurgical clot lysis indices. Inhibition of platelet clot retraction with cytochalasin D (FIBTEM) markedly increased the preoperative clot lysis index. High pre- and post-transplantation clot lysis indices were associated with increased mortality irrespective of the activator used (EXTEM, INTEM) and the inhibition of fibrinolysis (APTEM). Inhibition of clot retraction (FIBTEM) abolished the association of clot lysis index with mortality in both pre- and post-transplantation samples. Conclusion: Both pre- and postoperative ROTEM™ clot lysis indices predict mortality in patients following liver transplantation. Inhibitor experiments reveal that the clot lysis index is not an indicator of fibrinolysis, but indicates platelet clot retraction. The marked increase of clot lysis index during liver transplantation is caused by a decrease in clot retraction with eventual consequences for clot stability, retraction of wound margins, and reperfusion of vessels in case of thrombosis.

The Edge of Unknown: Postoperative Critical Care in Liver Transplantation.

Perioperative care of patients undergoing liver transplantation (LT) is very complex. Metabolic derangements, hypothermia, coagulopathy and thromboses, severe infections, and graft dysfunction can affect outcomes. In this manuscript, we discuss several perioperative problems that can be encountered in LT recipients. The authors present the most up-to-date information regarding predicting and treating hemodynamic instability, coagulation monitoring and management, postoperative ventilation strategies and early extubation, management of infections, and ESLD-related pulmonary complications. In addition, early post-transplant allograft dysfunction will be discussed.

Effect of norepinephrine on blood volume, cardiac output, and systemic filling pressure in patients undergoing liver transplantation.

BACKGROUND: Patients with liver cirrhosis develop symptoms comparable to those of patients with sepsis, who have increased total vascular compliance, which may cause blood pooling in the venous pool. No previous studies have evaluated the effect of using norepinephrine on the intravascular blood volume. We investigated the norepinephrine infusion's effect on the mean systemic filling pressure, venous return, and cardiac preload in patients undergoing liver transplantation. METHODS: Overall, 33 patients who underwent living donor liver transplantation were included in this study. Cardiac output (CO) was measured using a PiCCO device (Pulsion Medical Systems, Munich, Germany). The mean systemic filling pressure was calculated using the inspiratory hold maneuver at four time intervals - at baseline, 10 min after the norepinephrine infusion, 5 min after norepinephrine discontinuation, and after infusion of 500 cc of 5% albumin. Other hemodynamic parameters, including the mean arterial pressure (MAP), pulse pressure variation, stroke volume variation, global end-diastolic volume, and mitral inflow velocity (E wave), were also evaluated. RESULTS: The norepinephrine infusion increased MAP and systemic vascular resistance in all patients. Moreover, it increased CO, mean systemic filling pressure, and global end-diastolic volume in 20 patients (60%), whereas there were no changes in these variables in 13 patients (40%). In all patients, norepinephrine infusion discontinuation caused a significant decrease in MAP, CO, resistance to venous return, and mean systemic filling pressure. Infusion of 500 cc colloid increased CO; however, interestingly, it was associated with a significant decrease in systemic vascular resistance; hence, MAP and mean systemic filling pressure showed no changes. CONCLUSIONS: The norepinephrine infusion at 0.1 µg-1 kg-1 min-1 was associated with an increase in CO in patients with liver cirrhosis undergoing liver transplantation. Norepinephrine's effect on CO was primarily attributable to an increase in venous return due to an increase in mean systemic filling pressure.

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.