Use of Transesophageal Echocardiography for Liver Transplantation: A Global Comparison of Practice From the ILTS, SATA, and LICAGE

BACKGROUND

Anesthesiologists frequently use intraoperative transesophageal echocardiography (TEE) to aid in the diagnosis and management of hemodynamic problems during liver transplantation (LT). Although the use of TEE in US centers continues to increase, data regarding international use are lacking.

METHODS

This prospective, global, survey-based study evaluates international experience with TEE for LT. Responses from 252 LT (105 US and 147 non-US) centers representing 1789 anesthesiologists were analyzed.

RESULTS

Routine use of TEE in the United States has increased in the last 5 y (from 37% to 47%), but only 21% of non-US LT anesthesiologists use TEE routinely. Lack of training (44% US versus 70% non-US) and equipment (9% non-US, versus 34% US) were cited as obstacles. Most survey participants preferred not to perform a complete cardiac examination but rather use only 6 of 11 basic views. Although non-US LT anesthesiologists more frequently had additional clinical training than their US counterparts, they had less TEE experience (13% versus 44%) and less frequently, TEE certification (22% versus 35%). Most LT anesthesiologists agreed that TEE certification is essential for proficiency. Of all respondents, 89% agreed or strongly agreed that TEE provides valuable information needed for immediate clinical decision-making, and >86% agreed or strongly agreed that that information could not be derived from other sources.

CONCLUSIONS

The use of TEE for LT surgery in the US LT centers is currently higher compared with non-US LT centers. This may become a standard monitoring modality during LT in the near future.

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.

Liver Transplant Outcomes in Young Adults with Cirrhosis Related to Nonalcoholic Fatty Liver Disease

BACKGROUND

The prevalence of nonalcoholic fatty liver disease (NASH) and cryptogenic cirrhosis (CC) is constantly increasing in adolescents and young adults (AYAs).

METHODS

In a retrospective UNOS database evaluation, we analyzed postoperative outcomes of AYAs with nonalcoholic NASH/CC undergoing LT between January 1st, 2003 and March 5th, 2021. After exclusions, 85,970 LT recipients, 393 (47.1%) AYAs with NASH/CC and 441 (52.9%) AYAs with other metabolic conditions, were analyzed.

RESULTS

During the study period, the number of LTs performed for AYAs with NASH/CC increased from 4%-7% but decreased from 6.6%-5.3% compared to LTs performed for NASH/CC in all ages. In comparison to AYAs with other metabolic conditions, AYA LT recipients with NASH/CC had a higher prevalence of metabolic syndrome (MetS) components, including diabetes and increased body mass index (P < .0001 for both). Patient and graft survival in AYAs with NASH/CC were significantly lower in comparison to AYAs transplanted for other metabolic conditions (P < .0001) (Hazard Ratio = 1.93, P < .001). Patient survival in AYAs with NASH/CC was significantly better in comparison to older (40-65-year-old) patients with the same diagnosis (P = .01).

CONCLUSIONS

Our study found that the overall number of LTs in AYAs with NASH increased significantly, but to a lesser degree compared to the older population with the same diagnosis. Outcomes after LT in AYAs with NASH/CC were worse compared to LT for other metabolic conditions, but significantly better in comparison to older patients. The prevalence of LT for NASH/CC in AYAs is growing. MetS may contribute to worse outcomes in AYAs.

Anesthesia and Critical Care for the Prediction and Prevention for Small-for-size Syndrome: Guidelines from the ILTS-iLDLT-LTSI Consensus Conference

BACKGROUND

During the perioperative period of living donor liver transplantation, anesthesiologists and intensivists may encounter patients in receipt of small grafts that puts them at risk of developing small for size syndrome (SFSS).

METHODS

A scientific committee (106 members from 21 countries) performed an extensive literature review on aspects of SFSS with proposed recommendations. Recommendations underwent a blinded review by an independent expert panel and discussion/voting on the recommendations occurred at a consensus conference organized by the International Liver Transplantation Society, International Living Donor Liver Transplantation Group, and Liver Transplantation Society of India.

RESULTS

It was determined that centers with experience in living donor liver transplantation should utilize potential small for size grafts. Higher risk recipients with sarcopenia, cardiopulmonary, and renal dysfunction should receive small for size grafts with caution. In the intraoperative phase, a restrictive fluid strategy should be considered along with routine use of cardiac output monitoring, as well as use of pharmacologic portal flow modulation when appropriate. Postoperatively, these patients can be considered for enhanced recovery and should receive proactive monitoring for SFSS, nutrition optimization, infection prevention, and consideration for early renal replacement therapy for avoidance of graft congestion.

CONCLUSIONS

Our recommendations provide a framework for the optimal anesthetic and critical care management in the perioperative period for patients with grafts that put them at risk of developing SFSS. There is a significant limitation in the level of evidence for most recommendations. This statement aims to provide guidance for future research in the perioperative management of SFSS.

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.

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.

Enhanced recovery for liver transplantation: recommendations from the 2022 International Liver Transplantation Society consensus conference

There is much controversy regarding enhanced recovery for recipients of liver transplants from deceased and living donors. The objectives of this Review were to summarise current knowledge on individual enhanced recovery elements on short-term outcomes, identify key components for comprehensive pathways, and create internationally accepted guidelines on enhanced recovery for liver-transplant recipients. The ERAS4OLT.org collaborative partnered by the International Liver Transplantation Society performed systematic literature reviews on the effect of 32 relevant enhanced perioperative recovery elements on short-term outcomes, and global specialists prepared expert statements on deceased and living donor liver transplantation. The Grading Recommendations, Assessment, Development and Evaluations approach was used for rating of quality of evidence and grading of recommendations. A virtual international consensus conference was held in January, 2022, in which results were presented, voted on by the audience, and discussed by an independent international jury of eight members, applying the Danish model of consensus. 273 liver transplantation specialists from 30 countries prepared expert statements on elements of enhanced recovery for liver transplantation based on the systematic literature reviews. The consensus conference yielded 80 final recommendations, covering aspects of enhanced recovery for preoperative assessment and optimisation, intraoperative surgical and anaesthetic conduct, and postoperative management for the recipients of liver transplants from both deceased and living donors, and for the living donor. The recommendations represent a comprehensive overview of the relevant elements and areas of enhanced recovery for liver transplantation. These internationally established guidelines could direct the development of enhanced recovery programmes worldwide, allowing adjustments according to local resources and practices.

Decline in Functional Status While on the Waiting List Predicts Worse Survival After Lung Transplantation

OBJECTIVES

To determine if decreases in the Karnofsky Performance Score (KPS) while on the waitlist predict decreased survival after lung transplantation (LTx).

DESIGN

A retrospective evaluation of the United Network for Organ Sharing database. The KPS was evaluated at the time of listing for transplant and at the time of transplantation. Group I consisted of patients having a decrease in KPS during the time on the waiting list (from the time of listing to the time of transplant), and Group II consisted of patients whose KPS stayed the same or increased during the same period. The authors used propensity-score weighting for comparisons of these groups.

SETTING

Retrospective observational database review.

PARTICIPANTS

Adult patients undergoing lung transplantation.

INTERVENTIONS

None. Patients were stratified according to a change in their KPS.

MEASUREMENTS AND MAIN RESULTS

Patient and graft survival of patients with decreasing or not decreasing KPS were compared. Of the 27,558 subjects included in the analysis, 17,986 (65%) had worsening KPS, which was associated with worse graft (p = 0.0003) and patient (p = 0.0019) survival after LTx. Using multivariate regression, a decrease in KPS of ≥40 was associated with decreased survival, and an increase of ≥40 was associated with improved survival (HR = 1.245, 95% CI [1.181-1.312], p < 0.0001 and HR = 0.866, 95% CI [0.785, 0.955], respectively). Among patients with a KPS <40 at the time of transplant, those with a decrease in KPS of ≥40 had decreased graft and patient survival compared with those with a smaller decrease (p = 0.0002 and p = 0.0021, respectively).

CONCLUSIONS

Deterioration of KPS on the waiting list for LTx is associated with significantly greater postoperative mortality in patients after LTx. These results should be taken into consideration when allocating organs. Strategies to increase or to prevent a decrease in KPS before LTx should be evaluated.

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.

Intraoperative transfusion management, antifibrinolytic therapy, coagulation monitoring and the impact on short-term outcomes after liver transplantation-A systematic review of the literature and expert panel recommendations

BACKGROUND

Liver transplantation (LT) is frequently complicated by coagulopathy associated with end-stage liver disease (ESLD), that is, often multifactorial.

OBJECTIVES

The objective of this systematic review was to identify evidence based intraoperative transfusion and coagulation management strategies that improve immediate and short-term outcomes after LT.

METHODS

PRISMA-guidelines and GRADE-approach were followed. Three subquestions were formulated. (Q); Q1: transfusion management; Q2: antifibrinolytic therapy; and Q3: coagulation monitoring.

RESULTS

Sixteen studies were included for Q1, six for Q2, and 10 for Q3. Q1: PRBC and platelet transfusions were associated with higher mortality. The use of prothrombin complex concentrate (PCC) and fibrinogen concentrate (FC) were not associated with reductions in intraoperative transfusion or increased thrombotic events. The use of cell salvage was not associated with hepatocellular carcinoma (HCC) recurrence or mortality. Cell salvage and transfusion education significantly decreased blood product transfusions. Q2: Epsilon-aminocaproic acid (EACA) and tranexamic acid (TXA) were not associated with decreased blood product transfusion, improvements in patient or graft survival, or increases in thrombotic events. Q3: Viscoelastic testing (VET) was associated with decreased allogeneic blood product transfusion compared to conventional coagulation tests (CCT) and is likely to be cost-effective. Coagulation management guided by VET may be associated with increases in FC and PCC use.

CONCLUSION

Q1: A specific blood product transfusion practice is not recommended (QOE; low | Recommendation; weak). Cell salvage and educational interventions are recommended (QOE: low | Grade of Recommendation: moderate). Q2: The routine use of antifibrinolytics is not recommended (QOE; low | Recommendation; weak). Q3: The use of VET is recommended (QOE; low-moderate | Recommendation; strong).

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.

A decline in functional status while awaiting liver transplantation is predictive of increased post-transplantation mortality

BACKGROUND

Functional status (FS) is dynamic and changes over time. We examined how changes in FS while awaiting liver transplantation influence post-transplant outcomes.

METHODS

Data on adult liver transplants performed in the United States during the MELD era were obtained through September 2020. Patient and graft survival were compared between groups with no change or improved FS, and those with worsening FS.

RESULTS

Of the 90,210 transplant recipients included in the analysis, 39,193 (43%) had worsening FS, which was associated with longer waiting-list time (187 vs. 329 days, p < 0.001) and worse patient survival after liver transplant (1858 vs. 1727 days, p < 0.001). A consistent and dose-dependent relationship was observed for each 10-point decrease in Karnofsky Performance Score and post-transplant survival. Multivariable regression analysis confirmed that a decline in FS was associated with worse patient survival (HR 1.15, p < 0.001). Similar findings were observed for graft survival.

CONCLUSION

A decline in FS on the waiting-list is associated with significantly greater post-liver transplant mortality in recipients. These results should be taken into consideration when allocating organs and determining transplant candidacy. Strategies to optimize FS prior to transplantation should be prioritized as even subtle decreases in FS are associated with inferior post-transplantation 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.

Multidrug-resistant infections in solid organ transplant recipients: a focus on risk factors, prevention and treatment strategies

Solid organ transplantation is the best therapeutic option for patients with end-stage organ disease and, according to the data from international registries, there has been a steady increase in numbers and results. However, post-transplant infections remain a fearsome complication with, in the last decade, an increasing incidence of episodes due to antibiotic-resistant bacteria and opportunistic agents. In this paper, we summarize the most relevant and updated knowledge concerning infections from multidrug-resistant germs in solid organ transplant recipients, focusing on risk factors, treatment and prevention strategies, and antimicrobial pharmacokinetics relevant to this particular population of patients.

Excellent outcomes with liver transplantation in hepatopulmonary syndrome across pre-transplant PaO2 spectrum

Background & Aims

Significantly worse survival has been reported in patients with hepatopulmonary syndrome (HPS) and partial pressure of arterial oxygen (PaO₂) <45 mmHg undergoing liver transplantation. Long-term pre- and post-transplant outcomes based on degree of hypoxaemia were re-examined.

Methods

A retrospective analysis of 1,152 HPS candidates listed with an approved HPS model for end-stage liver disease (MELD) exception was performed. A Fine and Gray competing risks model was utilised to evaluate pre-transplant outcomes for PaO₂ thresholds of <45, 45 to <60, and ≥60 mmHg. Post-transplant survival was analysed using the Kaplan-Meier method.

Results

Patients with a PaO₂ <45 mmHg were significantly more likely to undergo transplantation (hazard ratio [HR] 1.51; 95% CI 1.12-2.03), whereas patients with higher MELD scores had lower hazard of transplant (HR 0.80, 95% CI 0.67-0.95, p = 0.011) and higher hazard of pre-transplant death (HR 2.29, 95% CI 1.55-3.37, p <0.001). Post-transplantation, patients with a PaO₂ <45 mmHg had lower survival (p = 0.04) compared with patients with a PaO₂ ≥45 to <50 mmHg, with survival curves significantly different at 2.6 years (75% survival compared with 86%) and median survival of 11.5 and 14.1 years, respectively. Cardiac arrest was a more likely (p = 0.025) cause of death for these patients. Cardiac arrest incidence in patients who died with a PaO₂ >50 mmHg was 6.2%.

Conclusions

Patients with a PaO₂ <45 mmHg had a significantly higher rate of transplantation, and higher calculated MELD scores were associated with significantly higher pre-transplant mortality. Although post-transplant survival was lower in patients with a PaO₂ <45 mmHg, the median survival was 11.5 years, and survival curves only became significantly different at 2.6 years. This suggests that patients with HPS do benefit from transplantation up to 2-3 years post-transplant regardless of the severity of pre-transplant hypoxaemia.

Lay summary

A total of 1,152 patients with hepatopulmonary syndrome listed for liver transplant were analysed. Patients with a low PaO₂ <45 mmHg had a high likelihood of transplantation. If associated with advanced liver disease, the mortality risk was higher for patients with hepatopulmonary syndrome on the wait list. After liver transplantation, patients with a PaO₂ <45 mmHg had a lower survival, but this only became significant after 2.6 years, and the median survival was 11.5 years. This suggests that patients with hepatopulmonary syndrome do benefit from transplantation.

Hemodynamic Instability During Liver Transplantation in Patients With End-stage Liver Disease: A Consensus Document from ILTS, LICAGE, and SATA

Hemodynamic instability (HDI) during liver transplantation (LT) can be difficult to manage and increases postoperative morbidity and mortality. In addition to surgical causes of HDI, patient- and graft-related factors are also important. Nitric oxide-mediated vasodilatation is a common denominator associated with end-stage liver disease related to HDI. Despite intense investigation, optimal management strategies remain elusive. In this consensus article, experts from the International Liver Transplantation Society, the Liver Intensive Care Group of Europe, and the Society for the Advancement of Transplant Anesthesia performed a rigorous review of the most current literature regarding the epidemiology, causes, and management of HDI during LT. Special attention has been paid to unique LT-associated conditions including the causes and management of vasoplegic syndrome, cardiomyopathies, LT-related arrhythmias, right and left ventricular dysfunction, and the specifics of medical and fluid management in end-stage liver disease as well as problems specifically related to portal circulation. When possible, management recommendations are made.

Plasminogen activator inhibitor is significantly elevated in liver transplant recipients with decompensated NASH cirrhosis

Background

Non-alcoholic fatty liver disease is a prohaemostatic state with abnormal primary, secondary and tertiary haemostasis. Plasminogen activator inhibitor (PAI)-1 is the best-established marker for prohaemostasis in non-alcoholic fatty liver disease. While epidemiological studies demonstrate decompensated non-alcoholic steatohepatitis (NASH) cirrhosis patients have increased rates of venous thromboembolism, including portal vein thrombosis, mechanistic studies have focused exclusively on patients without or with compensated cirrhosis. We aimed to characterizecharacterise PAI-1 levels in decompensated NASH cirrhosis.

Methods

PAI-1 level was measured in consecutive adult liver transplant recipients immediately prior to liver transplantation. Multivariable models were constructed using linear regression to assess factors related to PAI-1 level.

Results

Forty-six subjects with mean age 57 (IQR 53–62) years and Model for Endstage Liver Disease (MELD) score of 34 (IQR 30–40) were enrolled. Baseline characteristics were similar between NASH (n=10) and non-NASH (n=36) subjects except for rates of diabetes and hyperlipidaemia. Mean PAI-1 level was greater in NASH (53.9, 95% CI 33.3 to 74.5 mg/mL) when compared with non-NASH (36.1, 95% CI 28.7 to 43.5), p=0.040. NASH remained independently predictive of PAI-1 level prior to transplant on adjusted multivariable modelling (β 40.13, 95% CI 14.41 to 65.86, p=0.003). Conclusions: PAI-1 level is significantly elevated in decompensated NASH cirrhosis independent of other pro-haemostatic factors. This may explain the greater rates of venous thromboembolism in decompensated NASH cirrhosis. Future study focusing on prevention of venous thromboembolism in this population is paramount to improve patient-oriented outcomes given the high morbidity and mortality of venous thromboembolism and the significant impact it has on transplant candidacy.

Fluid Management During Kidney Transplantation: A Consensus Statement of the Committee on Transplant Anesthesia of the American Society of Anesthesiologists

BACKGROUND

Intraoperative fluid management may affect the outcome after kidney transplantation. However, the amount and type of fluid administered, and monitoring techniques vary greatly between institutions and there are limited prospective randomized trials and meta-analyses to guide fluid management in kidney transplant recipients.

METHODS

Members of the American Society of Anesthesiologists (ASA) committee on transplantation reviewed the current literature on the amount and type of fluids (albumin, starches, 0.9% saline, and balanced crystalloid solutions) administered and the different monitors used to assess fluid status, resulting in this consensus statement with recommendations based on the best available evidence.

RESULTS

Review of the current literature suggests that starch solutions are associated with increased risk of renal injury in randomized trials and should be avoided in kidney donors and recipients. There is no evidence supporting the routine use of albumin solutions in kidney transplants. Balanced crystalloid solutions such as Lactated Ringer are associated with less acidosis and may lead to less hyperkalemia than 0.9% saline solutions. Central venous pressure is only weakly supported as a tool to assess fluid status.

CONCLUSIONS

These recommendations may be useful to anesthesiologists making fluid management decisions during kidney transplantation and facilitate future research on this topic.

Management of Patients With Non-alcoholic Steatohepatitis Undergoing Liver Transplantation: Considerations for the Anesthesiologist

Non-alcoholic fatty liver disease (NAFLD) currently affects more than 25% of the world population and is rising. NAFLD can progress to non-alcoholic steatohepatitis that is associated with hepatic inflammation and fibrosis and can result in cirrhosis with subsequent liver failure. Non-alcoholic steatohepatitis (NASH) has now emerged as one of the leading etiologies for a liver transplant among adults in the United States. Given the rising incidence of liver transplants in patients with NASH-related cirrhosis, it is essential for anesthesiologists to be familiar with this condition as well as with NASH-related comorbidities and perioperative complications. Not only is NASH linked to metabolic syndrome, but it also is independently associated with cardiovascular disease, renal and thyroid dysfunction, obstructive sleep apnea (OSA), and a hypercoagulable state. The association with these conditions can affect the perioperative outcome of these patients, particularly because of increased mortality from major adverse cardiovascular events and sepsis. In order to decrease the perioperative morbidity and mortality of patients with NASH undergoing a liver transplant, a multidisciplinary approach to their perioperative management is essential, along with careful preoperative evaluation and aggressive intraoperative and postoperative monitoring. The focus of this review article is to provide a comprehensive overview of challenges associated with liver transplants in patients with NASH and to provide suggestions for appropriate patient selection and perioperative management.

Improving intraoperative administration of surgical antimicrobial prophylaxis: a quality improvement report

Despite widespread adoption of the Surgical Care Improvement Programme, the incidence of surgical site infections (SSIs) remains high. It is possible that lapses in appropriate administration of antimicrobial prophylaxis may play a role. We noted significant discordance with national guidelines with regards to intraoperative antibiotic administration at our institution, leading to implementation of a quality improvement initiative using multidisciplinary education and reminder-based interventions to improve prescribing practices and increase compliance with national guidelines. We observed a significant improvement in adherence to all aspects of antibiotic administration guidelines as a result of such interventions. Targeted multidisciplinary interventions may help improve prescribing practices of surgical antimicrobial prophylaxis and provide an opportunity to potentially decrease the burden of SSI and the related morbidity and mortality.

Development of a Model to Predict Portal Vein Thrombosis in Liver Transplant Candidates: The Portal Vein Thrombosis Risk Index

Portal vein thrombosis (PVT) is associated with inferior pretransplantation and posttransplantation outcomes. We aimed to create a predictive model to risk stratify transplant candidates for PVT. Data on adult transplants in the United States during the Model for End-Stage Liver Disease (MELD) era through September 2016 were reviewed. We constructed and validated a scoring system composed of routine, readily available clinical information to predict the development of incident PVT at 12 months from transplantation listing. A total of 66,568 liver transplant candidates were dichotomized into 2 groups to construct (n = 34,751) and validate (n = 31,817) a scoring system. In general, the derivation and validation cohorts were clinically similar. Although nonalcoholic steatohepatitis was a significant predictor of incident PVT (hazard ratio, 1.29; 95% confidence interval, 1.08-1.54; P < 0.001), age, MELD score, and moderate-to-severe ascites were also associated with increased risk. African American race was associated with decreased risk. A scoring system (PVT risk index [RI]) of these 5 variables had an area under the curve of 0.71 and 0.70 in both derivation and validation cohorts, respectively. By applying the low cutoff score of 2.6, incident PVT could be accurately excluded (negative predictive value 94%). Using the high cutoff score of 4.6 (positive predictive value 85%), PVT could be diagnosed with high accuracy. The PVT-RI predicts which candidates awaiting lifesaving liver transplantation will and will not develop future PVT. Although this scoring system will require prospective validation, it provides a powerful new tool for the clinician when risk stratifying cirrhosis patients prior to liver transplantation for future PVT development.

Inherited thrombophilia and portal vein thrombosis in cirrhosis: A systematic review and meta-analysis

BACKGROUND

Portal vein thrombosis (PVT) is common in cirrhosis. PVT is associated with high morbidity and mortality. Individual reports suggest that PVT occurs more frequently in patients with cirrhosis and inherited thrombophilia. The relationship between cirrhosis, PVT development, and inherited thrombophilia was explored in this study. The aim of the study was to determine whether cirrhotic patients with nontumoral PVT have an increased rate of inherited thrombophilia.

METHODS

Studies were identified by searching electronic databases up to October 2017 with English language and human subject restrictions. Two independent reviewers screened citations and extracted data. Magnitude of effect was calculated to obtain aggregate estimates of effect size and 95% confidence intervals (CIs). Between-study variability and heterogeneity were assessed.

RESULTS

Of 2893 citations identified, 9 studies composed of 1929 subjects with cirrhosis were included. The overall prevalence of PVT was 6.5% (n = 125). Both prothrombin G20210A mutation (odds ratio [OR], 2.43; 95% CI, 1.07-5.53; P = 0.03) and factor V Leiden (FVL) (OR, 1.98; 95% CI, 1.06-3.68; P = 0.03) were significantly associated with PVT risk. Methyltetrahydrofolate reductase C677T mutation was not associated with increased PVT risk. No heterogeneity or publication bias was observed. One important study with opposite findings could not be included due to lack of primary data.

CONCLUSIONS

FVL and PTG20210A mutation were associated with increased PVT risk in patients with cirrhosis. This finding reframes the role of inherited thrombophilia in PVT development in patients with cirrhosis. Future prospective studies investigating screening for inherited thrombophilia in all cirrhosis patients with PVT seem warranted.

The "Ice Age" in Cardiac Surgery: Evolution of the "Siberian" Method of Brain Protection During Deep Hypothermic Perfusionless Circulatory Arrest

Deep hypothermic perfusionless circulatory arrest was the first practical neuroprotective technique used for open-heart surgery. It was refined at the Novosibirsk Medical Research Center in Siberia and was actively used from the mid-1950s until 2001.This review describes the development of this technique and its contribution to our understanding of the dynamic changes in human physiology during induced hypothermia for circulatory arrest without extracorporeal perfusion. Deep hypothermic perfusionless circulatory arrest was an important stepping stone in the development of modern approaches in neuroprotection and monitoring during cardiac surgery.

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.

Acute heart failure after Orthotopic liver transplantation: a case series from one center

Background

Patients undergoing liver transplantation (LT) can develop acute heart failure (HF) in the postoperative period despite having had a normal cardiac evaluation prior to surgery. End-stage liver disease is often associated with underlying cardiac dysfunction which, while not identified during preoperative testing, manifests itself during or immediately after surgery.

Case presentation

We describe three cases of non-ischemic acute HF developing shortly after LT in patients who had a normal preoperative cardiac evaluation. The challenges associated with both diagnosis and management of acute HF in the setting of a newly implanted graft will be discussed.

Conclusions

Diastolic dysfunction, QTc interval prolongation, and an increase in BNP may be predictive of postoperative HF. Current recommendations for preoperative cardiovascular evaluation of transplant candidates does not include studies examining these risk factors and should be revised. Further investigations are necessary to evaluate these findings.

Perioperative Anesthetic Management of Patients Having Liver Transplantation for Uncommon Conditions

This review focuses on the perioperative anesthetic management of patients having liver transplantation (LT) performed for several uncommon indications or in combination with rare pathology. Conditions discussed in the article include Alagille syndrome, hypertrophic cardiomyopathy, Gilbert's syndrome, porphyria, Wilson's disease, and Budd-Chiari syndrome. In comparison to other indications, LT in these settings is infrequent because of the low incidence of these pathologies. Most of these conditions (with the exception of Gilbert syndrome) are associated with a high probability of significant perioperative complications and increased mortality and morbidity. Experience in management of these unusual conditions is only gained over time. Developing clinical pathways for patients with these conditions should result in outcomes similar to LT performed for more common indications.

Liver graft preservation using perfluorocarbon improves the outcomes of simulated donation after cardiac death liver transplantation in rats

The outcomes of liver transplantation (LT) from donation after cardiac death (DCD) donors remain poor due to severe warm ischemia injury. Perfluorocarbon (PFC) is a novel compound with high oxygen carrying capacity. In the present study, a rat model simulating DCD LT was used, and the impact of improved graft oxygenation provided by PFC addition on liver ischemia/reperfusion injury (IRI) and survival after DCD LT was investigated. Orthotopic liver transplants were performed in male Lewis rats, using DCD liver grafts preserved with cold University of Wisconsin (UW) solution in the control group and preserved with cold oxygenated UW solution with addition of 20% PFC in the PFC group. For experiment I, in a 30-minute donor warm ischemia model, postoperative graft injury was analyzed at 3 and 6 hours after transplantation. For experiment II, in a 50-minute donor warm ischemia model, the postoperative survival was assessed. For experiment I, the levels of serum aspartate aminotransferase, alanine aminotransferase, hyaluronic acid, malondialdehyde, and several inflammatory cytokines were significantly lower in the PFC group. The hepatic expression levels of tumor necrosis factor α and interleukin 6 were significantly lower, and the expression level of heme oxygenase 1 was significantly higher in the PFC group. Histological analysis showed significantly less necrosis and apoptosis in the PFC group. Sinusoidal endothelial cells and microvilli of the bile canaliculi were well preserved in the PFC group. For experiment II, the postoperative survival rate was significantly improved in the PFC group. In conclusion, graft preservation with PFC attenuated liver IRI and improved postoperative survival. This graft preservation protocol might be a new therapeutic option to improve the outcomes of DCD LT. Liver Transplantation 23 1171-1185 2017 AASLD.

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.

Massive Fulminant Thrombosis During Liver Transplantation in a Patient With a Previously Unknown Antithrombin Pathway Mutation

We describe a case of fulminant intraoperative thrombosis during deceased donor liver transplantation. Despite significant medical bleeding, the patient suddenly developed diffuse thrombosis in all chambers of the heart and pulmonary vasculature resulting in intraoperative death. The patient's postmortem genetic analysis demonstrated a deleterious missense mutation in a coagulation pathway gene, SERPINC1, which codes for antithrombin III. The level of antithrombin III was not available to directly prove the causality of thrombosis, but our findings suggest that this mutation, in combination with antifibrinolytic administration in a hypercoagulable cirrhotic patient, might have contributed to the development of this catastrophic thrombotic event.

Hepatic resection is associated with reduced postoperative opioid requirement

Background and Aims:

Postoperative pain can significantly affect surgical outcomes. As opioid metabolism is liver-dependent, any reduction in hepatic volume can lead to increased opioid concentrations in the blood. The hypothesis of this retrospective study was that patients undergoing open hepatic resection would require less opioid for pain management than those undergoing open pancreaticoduodenectomy.

Material and Methods:

Data from 79 adult patients who underwent open liver resection and eighty patients who underwent open pancreaticoduodenectomy at our medical center between January 01, 2010 and June 30, 2013 were analyzed. All patients received both general and neuraxial anesthesia. Postoperatively, patients were managed with a combination of epidural and patient-controlled analgesia. Pain scores and amount of opioids administered (morphine equivalents) were compared. A multivariate lineal regression was performed to determine predictors of opioid requirement.

Results:

No significant differences in pain scores were found at any time point between groups. Significantly more opioid was administered to patients having pancreaticoduodenectomy than those having a hepatic resection at time points: Intraoperative (P = 0.006), first 48 h postoperatively (P = 0.001), and the entire length of stay (LOS) (P = 0.002). Statistical significance was confirmed after controlling for age, sex, body mass index, and American Society of Anesthesiologists physical status classification (adjusted P = 0.006). Total hospital LOS was significantly longer after pancreaticoduodenectomy (P = 0.03). A multivariate lineal regression demonstrated a lower opioid consumption in the hepatic resection group (P = 0.03), but there was no difference in opioid use based on the type of hepatic resection.

Conclusion:

Patients undergoing open hepatic resection had a significantly lower opioid requirement in comparison with patients undergoing open pancreaticoduodenectomy. A multicenter prospective evaluation should be performed to confirm these findings.

Autoimmune conditions are associated with perioperative thrombotic complications in liver transplant recipients: A UNOS database analysis

BACKGROUND

End stage liver disease (ESLD) is associated with significant thrombotic complications. In this study, we attempted to determine if patients with ESLD, due to oncologic or autoimmune diseases, are susceptible to thrombosis to a greater extent than patients with ESLD due to other causes.

METHODS

In this retrospective study, we analyzed the UNOS database to determine the incidence of thrombotic complications in orthotopic liver transplant (OLT) recipients with autoimmune and oncologic conditions. Between 2000 and 2012, 65,646 OLTs were performed. We found 4,247 cases of preoperative portal vein thrombosis (PVT) and 1,233 cases of postoperative vascular thrombosis (VT) leading to graft failure.

RESULTS

Statistical evaluation demonstrated that patients with either hepatocellular carcinoma (HCC) or autoimmune hepatitis (AIC) had a higher incidence of PVT (p = 0.05 and 0.03 respectively). Patients with primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC) and AIC had a higher incidence of postoperative VT associated with graft failure (p < 0.0001, p < 0.0001, p = 0.05 respectively). Patients with preoperative PVT had a higher incidence of postoperative VT (p < 0.0001). Multivariable logistic regression demonstrated that patients with AIC, and BMI ≥40, having had a transjugular intrahepatic portosystemic shunt, and those with diabetes mellitus were more likely to have preoperative PVT: odds ratio (OR)(1.36, 1.19, 1.78, 1.22 respectively). Patients with PSC, PBC, AIC, BMI ≤18, or with a preoperative PVT were more likely to have a postoperative VT: OR (1.93, 2.09, 1.64, 1.60, and 2.01, respectively).

CONCLUSION

Despite the limited number of variables available in the UNOS database potentially related to thrombotic complications, this analysis demonstrates a clear association between autoimmune causes of ESLD and perioperative thrombotic complications. Perioperative management of patients at risk should include strategies to reduce the potential for these complications.

The Resident Academic Project Program: A Structured Approach to Inspiring Academic Development During Residency Training

We report the successful implementation of structured resident academic projects in our Department of Anesthesiology at the Penn State Hershey Medical Center. Beginning with the graduating class of 2010, we adopted an expectation that each resident complete a project that results in a manuscript of publishable quality. Defining a clear timeline for all steps in the project and providing research education, as well as the necessary infrastructure and ongoing support, has helped grow the academic productivity of our anesthesia residents.

Successful Liver Transplant Complicated by Severe Portopulmonary Hypertension After an Initial Aborted Attempt: Case Report and Review of Treatment Options

Good right ventricular function and responsiveness to vasodilator therapy are the most important prerequisites for successful liver transplant in patients with portopulmonary hypertension. A patient with portopulmonary hypertension and good right ventricular function presented for deceased-donor liver transplant. Pulmonary arterial pressure was controlled with epoprostenol and sildenafil preoperatively. After anesthesia induction, pulmonary arterial pressure increased significantly and the procedure was aborted. Additional medical treatment included aggressive vasodilator therapy and the transplant was successfully performed 1 month later. During the procedure, elevations in pulmonary arterial pressure responded to a combination of inhaled nitric oxide, intravenous milrinone and nitroglycerin, and optimization of mechanical ventilation.

Myocardial perfusion imaging is an effective screening test for coronary artery disease in liver transplant candidates

A reliable screening test for coronary artery disease (CAD) in liver transplant (LT) candidates with end-stage liver disease is essential because a high percentage of perioperative mortality and morbidity is CAD-related. In this study, the effectiveness of myocardial perfusion imaging (MPI) for identification of significant CAD in LT candidates was evaluated. Records of 244 patients meeting criteria for MPI were evaluated: 74 met inclusion criteria; 40 had a positive MPI and cardiology follow-up; 27 had a negative MPI and underwent LT; and seven had a negative MPI and then had coronary angiography or a significant cardiac event. A selective MPI interpretation strategy was established where MPI-positive patients were divided into high, intermediate, and low CAD risk groups. The overall incidence of CAD in this study population was 5.1% and our strategy resulted in PPV 20%, NPV 94%, sensitivity 80%, and specificity 50% for categorizing CAD risk. When applied only to the subset of patients categorized as high CAD risk, the strategy was more effective, with PPV 67%, NPV 97%, sensitivity 80%, and specificity 94%. We determined that renal dysfunction was an independent predictive factor for CAD (p < 0.0001, odds ratio = 8.1), and grades of coronary occlusion correlated significantly with chronic renal dysfunction (p = 0.0079).

Effect of cold perfusion and perfluorocarbons on liver graft ischemia in a donation after cardiac death model

BACKGROUND

Effects of two perfluorocarbon (PFC) formulations (perfluorodecalin emulsion and perfluorodecalin liquid) on the quality of liver graft preservation, in a donation after cardiac death (DCD) rat model, were investigated. The significance of continuous graft perfusion during cold preservation was also explored.

MATERIALS AND METHODS

DCD model: 30 min after cardiopulmonary arrest was initiated, livers were excised and flushed with cold University of Wisconsin (UW) solution (± PFC) and preserved in the same solution for 8 h. The study groups were preserved as follows: group 1: no perfusion; group 2: perfusion with UW; group 3: PFC was administered before cardiac arrest and the liver was perfused with UW alone; and groups 4 and 5: perfused with UW + 1 of two PFCs. In a baseline group used only for comparison of gene expression, livers were quick-frozen after cardiac arrest. Microarrays were used to analyze liver messenger RNA transcripts. Histopathologic, immunohistochemical, and ADP/ATP ratio evaluations were performed to assess the quality of graft preservation.

RESULTS

Significant decreases in downregulation and increases in upregulation of hepatic genes (relative to baseline) were demonstrated in all perfusion groups. This trend was most pronounced in the PFC groups. Lower fat content and ADP/ATP ratio and a reduction in Caspase 3 activation were found in all perfusion groups.

CONCLUSION

Hypothermic perfusion of rat DCD liver grafts with oxygenated UW solution (± PFC) produced superior preservation compared with nonperfusion storage. The observed changes in expression of hepatic genes may represent a protective effect in the DCD model.

Peripartum anesthetic management of a parturient with inherited factor v deficiency

Inherited Factor V deficiency is a rare bleeding disorder. We describe the genetic analysis and anesthetic management of a parturient with severe Factor V deficiency who presented in spontaneous labor. Good hemostatic conditions were obtained with prophylactic fresh frozen plasma administration of 10 mL/kg. Detailed genetic analysis by next-generation sequencing identified several relevant mutations in the coding part of the Factor V (F5) gene in our patient, her parents, and the newborn.

Analysis of acute pain scores and skin conductance measurements in infants

BACKGROUND

Skin conductance (SC) has been previously used to measure acute post-operative pain in adults and older children (>1year old).We have investigated the ability of SC to predict the severity of post-operative pain scores in the exclusively infant population.

METHODS

Infants (ages 6-12months) scheduled for elective surgery were recruited for the study. Data for behavioral pain scores and SC values - frequency of electrodermal responses per second (EDR/s), peak and basal levels, were recorded in the post-anesthesia care unit (PACU). Blood samples were collected for genomic studies, including single nucleotide polymorphisms (SNP) in morphine opioid receptor (MOR) A118G and the catechol-O-methyltransferase (COMT) G1947A genes.

RESULTS

31 infants, mean age 8.9months (±1.9); mean weight 8.5kg (±1.1) were included in the final study analysis. With every 0.1 unit increase in peak values noted on SC, the odds of higher pain scores were found to be 5% greater (p=0.03). For predictability of moderate to severe pain, the area under the curve, sensitivity and specificity were 0.64, 90.9% and 51.4% respectively for peak values and 0.66, 54.5% and 79.4% respectively for EDR/s values. Genotyping performed in 16 out of 31 infants demonstrated that the carriers of MOR 118G allele had consistently higher basal SC values in the PACU.

CONCLUSION

Peak SC values may serve as indicators of unmitigated pain. Further studies are needed to fully investigate the effect of MOR A118G SNP on the post operative pain scores and SC values in the larger infant population in order to validate both the clinical significance of the skin conductance for routine pain assessment in infants and the observed genetic effect.

Association between plasma cyclic guanosine monophosphate levels and hemodynamic instability during liver transplantation

The activation of cyclic guanosine monophosphate (cGMP) production in patients with end-stage liver disease (ESLD) has been associated with hemodynamic instability during orthotopic liver transplantation (OLT). The aim of this prospective, observational study was to investigate the involvement of cGMP in the mediation of profound hypotension during liver graft reperfusion. An additional objective was to determine whether preoperative cGMP levels are associated with intraoperative hemodynamic instability. Forty-four consecutive patients undergoing OLT were included in the study. Blood samples for cGMP analysis were obtained from (1) the radial artery before the surgical incision; (2) the radial artery, portal vein, and flush blood during the anhepatic phase; and (3) the radial artery 20 minutes after liver graft reperfusion. On the basis of a statistical analysis, the patients were divided into 2 groups: group 1 (preoperative cGMP level ≥ 0.05 μmol/L) and group 2 (preoperative cGMP level < 0.05 μmol/L). We demonstrated a significant correlation between the preoperative levels of cGMP and the amount of catecholamine required to maintain hemodynamic stability during reperfusion (r = 0.52, P < 0.001), the length of the hospital stay (r = 0.38, P = 0.01), and the length of the intensive care unit (ICU) stay (r = 0.44, P = 0.004). We also demonstrated a significantly higher intraoperative catecholamine requirement (P < 0.001) and a prolonged postoperative ICU stay (P = 0.02) in group 1 patients versus group 2 patients. In conclusion, this study demonstrates increased baseline cGMP production in patients with ESLD, which is significantly associated with severe hypotension during OLT. We suggest that preoperative levels of cGMP correlate with hemodynamic instability during liver graft reperfusion.

Liver transplantation for hepatitis C from donation after cardiac death donors: an analysis of OPTN/UNOS data

Donation after cardiac death (DCD) liver transplantation is increasing largely because of a shortage of organs. However, there are almost no data that have specifically assessed the impact of using DCD livers for HCV patients. We retrospectively studied adult primary DCD liver transplantation (630 HCV, 1164 non-HCV) and 54 129 donation after brain death (DBD) liver transplantation between 2002 and 2009 using the UNOS/OPTN database. With donation after brain death (DBD) livers, HCV recipients had significantly inferior graft survival compared to non-HCV recipients (p < 0.0001). Contrary to DBD donors, DCD livers used in HCV patients showed no difference in graft survival compared to non-HCV patients (p = 0.5170). Cox models showed DCD livers and HCV disease had poorer graft survival (HR = 1.80 and 1.28, p < 0.0001, respectively). However, the hazard ratio of DCD and HCV interaction was 0.80 (p = 0.02) and these results suggest that DCD livers on HCV disease do not fare worse than DCD livers on non-HCV disease. The graft survival of recent years (2006-2009) was significantly better than that in former years (2002-2005) (p = 0.0482). In conclusion, DCD liver transplantation for HCV disease showed satisfactory outcomes. DCD liver transplantation can be valuable option for HCV related end-stage liver disease.